Incidence of animal diseases and their current and future impacts on
crop-livestock systems in West Africa

John McDermott^1\*^, Didier Richard^2^ and Tom Randolph^1^

^1^ International Livestock Research Institute (ILRI), Nairobi, Kenya

^2^ Centre Internationalde Recherche--Developpement sur l'Elevage en
Zone Subhumide (CIRDES), Bobo-Dioulasso, Burkina Faso

\* corresponding authour

John McDermott

International Livestock Research Institute

P.O. Box 30709

Nairobi

Kenya

Tel: +254 2 630743 extension 4955

Fax: +254 2 631499

e-mail: j.mcdermott@cgiar.org

**Abstract**

*Animal diseases have a major impact on crop-livestock systems in West
Africa. The productivity of all crop-livestock systems is limited both
by the direct effects of overt disease and by strategies that are
adopted to mitigate disease risk. Epidemic diseases require substantial
expenditures to limit their spread, and so protect productivity, incomes
and market opportunities. Endemic diseases, either directly or
indirectly transmitted, decrease productivity, restrict production
opportunities and have substantial control costs. Zoonotic and
food-borne infections have important impacts on human health, livestock
productivity and market opportunities.*

*Current climatic, demographic and other socio-economic trends are
changing the patterns of livestock diseases in West Africa. This is
evidenced by changes in tsetse challenge and trypanosomosis risk at the
margins of its distribution. An increase in future demand for livestock
products will lead to a greater intensification of livestock production.
Four effects are likely: increased occurrence of new or emerging
diseases; an increase in diseases of intensification; persistence and
enhanced transmission of currently uncontrolled infectious diseases; and
a greater threat of food-borne infections and residues. The current
expansion of intensified livestock production and marketing in
peri-urban areas, particularly the expansion of short-cycle poultry and
small ruminant production will continue. In addition, increased demand
for milk in urban areas will lead to rapid expansion of formal and
informal milk markets. Particular attention will need to be paid to risk
assessment in these systems to protect food safety while ensuring market
access to the poor and vulnerable.*

*To adapt to these changing disease circumstances, animal health
services will need to be more accessible, affordable, acceptable and
sustainable. Currently animal health service delivery varies greatly
across countries in West Africa with a general overall decline in the
effectiveness of animal health services in recent years. Improving this
situation will require targeting public-sector activities to essential
public-good functions and allowing the private sector to play a greater
but more carefully evaluated role in service delivery. In improving
animal health service delivery, the public sector needs to be more
proactive in enhancing poverty alleviation. Livestock are particularly
important to poor people, as a way of securing assets, as providers of
marketable products and as a method for increasing productivity and
income to escape the poverty trap. Disease control efforts need to focus
on these poverty alleviation pathways. Livestock diseases pose a great
threat to efforts to enhance livelihoods in crop-livestock systems;
principally, through their many effects on crop and livestock production
and by regulations that can limit market opportunities. Overcoming these
losses and threats will require developing more responsive policies and
institutions and adapting disease control and food safety methods that
enhance their adoption and impact on farms, minimize consumer risk and
maximize market opportunities.*

**1. Animal diseases and their multiple impacts in crop-livestock
systems in West Africa**

Diseases can be classified in a variety of ways, based on their
causative agent, mode of transmission, impacts on humans, and many other
criteria. In terms of impact a number of factors will be important: the
number of species affected, the proportion of animals or size of
geographic area affected, the ability of the disease to spread, the
losses associated with the disease in both animals and humans, and the
availability, affordability and efficacy of measures to control it. In
Table 1, six major disease classes are proposed based on the main
patterns of occurrence (epidemic, endemic), level of disease impacts
(international, national, and farm), types of transmission (direct and
indirect) and importance in causing human disease (zoonotic and
food-borne). Examples of diseases that are common in West African
crop-livestock systems have been listed by category. In addition,
priority diseases for a subset of West African countries by species are
listed in Table 2 (CTA/CORAF, 1997).

Figure 1 highlights the multiple impacts of animal diseases in
crop-livestock systems. An important concept is that animal diseases can
have two major types of impacts, direct and indirect losses associated
with disease occurrence (clinical and sub-clinical) and losses
associated with strategies used to cope with disease risk. This latter
aspect is not widely appreciated, but can be extremely important for
some diseases, most notably trypanosomosis in West Africa, in which the
threat of disease severely limits crop-livestock management options and
opportunities in many areas. The direct and indirect losses associated
with animal disease occurrence can be briefly summarized as:

-   **Loss of livestock productivity**: these are the well-known impacts
    of mortality, production losses and decrease in work capacity.

-   **Treatment costs**: these costs are often substantial for farmers
    both because of input market inefficiencies and their lack of
    information on what are the best treatments and whether the drugs
    and other products they buy are efficacious

-   **Loss of farm productivity**: this is an important loss in many
    crop-livestock systems in West Africa, particularly, in mixed
    systems including cotton, rice, groundnuts and other crops requiring
    animal traction and manure as intermediate inputs.

-   **Human disease**: zoonotic diseases transmitted from animals to
    humans are particularly important in some crop-livestock systems. In
    West Africa, brucellosis is considered by most to be important
    throughout the region with other zoonoses such as bovine
    tuberculosis, anthrax and Rift Valley Fever being of importance in
    specific regions. Food-borne infections such as complex parasites
    (Cysticercosis, Echinococcosis) and pathogenic coliforms are also
    important in certain systems.

-   **Other impairments of human welfare**: these include direct and
    indirect effects on food security, human nutrition and cognitive
    development plus important socio-cultural impacts.

-   **Reduction in market opportunities**: animal diseases can limit
    farmers' ability to market their animals and animal products. Local
    market impacts are often most important but limitation on regional
    and international trade also occur.

Even if no disease occurs on a farm at a particular time, the threat of
disease can have profound impacts. As an extreme example, high tsetse
challenge and trypansosmosis risk may cause farmers to abandon certain
areas or particular crop-livestock strategies requiring draught oxen
(for example in Sissili, Burkina Faso; M. Kamuanga, ILRI, personal
communication). More commonly, it limits the number of cattle. On
average 50% less cattle are kept in ecologically similar tsetse-infested
versus tsetse-free areas (Kristjanson et al., 1999). Trypanosomosis risk
also affects the choice of livestock species and breeds (tolerant versus
susceptible cattle breeds), grazing and other management practices
(Wacher et al., 1994) and the necessity of implementing expensive
disease control packages. All these risk management strategies have
negative impacts on livestock production potential and household income
and constrain options for natural resource use. Potential disease risk
can also impact on market opportunities. For example, the circulation of
Rift Valley Fever virus without disease in Mali has led to international
regulations limiting Malian livestock exports

To better illustrate, the impacts of animal diseases in crop-livestock
systems in West Africa, we consider three examples.

***Example 1.1: Trypanosomosis in sub-humid crop-livestock systems with
draught cattle***

Historically, livestock production in sub-humid zones of West Africa has
been limited; mainly, to cattle migrating from semi-arid and arid zones
in search of grazing and water during the dry season (Schuetterle and
Coulibaly, 1998; Tano et al., 1999). During the colonial and
post-colonial period, cash crop production expanded in sub-humid areas
based on their high agricultural potential. However, labour limitations
prevented expansion of this sector. From the 1970s, draught oxen were
actively encouraged and numbers increased rapidly (Itty, 1992). Draught
power use is now well established in the sub-humid zone, for cotton,
groundnut and rice production. Trypanosomosis is the major disease
constraint to draught cattle in these sub-humid crop-livestock systems
(e.g. Starkey, 1990). In addition to its main effects on directly
decreasing livestock productivity, it has other multiple impacts
summarized in Table 2.

***Example 1.2: Impacts of disease in systems with small ruminants***

Small ruminant production is extremely important in all main
crop-livestock production systems of West Africa from arid to humid.
Small ruminants provide food, income, assets and are important in social
transactions. Faugère et al. (1991) have estimated production and health
indices across the range of production systems in Senegal. Two important
general trends were that, mortality was greater in goats than sheep,
particularly, during the first year of life and that the importance of
different diseases varied greatly by production system. In drier areas,
the control of respiratory diseases such as enzootic pneumonia, had
greater impact while in more humid zones, controlling helminth
infections was found to be 4-5 times more beneficial (Tillard et al.,
1992). Trypanosomes can also be important in sub-humid and humid zones
(Osaer et al., 1999). Peste des petits ruminants (PPR) occurs and is
considered important across all eco-climatic zones of West Africa in
both sheep and goats (Table 2). In general, PPR occurs endemically
(enzootic pneumonia) in semi-arid systems and epidemically (PPR
outbreaks) in sub-humid and humid zones (Lefèvre and Diallo, 1990). In
Cameroon, PPR vaccination was associated with benefit : cost ratios of 3
to 4.2 in sheep and 2.3 to 3.3 in goats (Awa et al., 2000). In
intensifying systems with small ruminants, enzootic pneumonia, foot
problems, external and internal parasites, nutritional constraints and
reproductive disorders (Domenech et al., 1994) can all be important
depending on the type of management and level of inputs.

***Example 1.3: The importance of disease in village poultry systems***

The numerical contribution of village (or family) poultry production to
overall poultry production averages approximately 70% across the region
and is estimated to be 94% in Nigeria, including 83% of the 82 million
chickens (Sonaiya et al., 1999). In West Africa, chickens are
universally important, overshadowed by guinea fowl in some countries
(e.g. Burkina Faso where disease constraints were investigated by Bessin
et al., 1998). Ducks are also important in a number of systems (Sonaiya
et al., 1999). Poultry provide multiple benefits to smallholders, as
food, for social functions, to accumulate assets (including moving up
the livestock ladder by saving for a goat or sheep and later for a cow),
and as cash for school fees, health care, and a wide variety of small
emergencies.

There is general agreement and much evidence that the control of
Newcastle Disease has great benefits on village poultry production
usually reducing chick mortality by 50% (see Alders and Spradbrow
(2001)). In some circumstances other infectious diseases, such as
Gumboro and Fowl Pox are also a critical constraint. In West Africa,
these diseases plus coccidiosis, and helminthosis are considered
important in most countries (CTA/CORAF, 1997). In section 5, the control
of Newcastle Disease for poor livestock keepers is discussed further,
particularly from whether disease control alone or packaged with other
inputs is most beneficial.

**2. Current and Future trends in crop-livestock systems and their
likely effects on disease incidence and impacts at production system and
farm level**

It is clear that disease patterns in crop-livestock systems will change
profoundly in West Africa, if only based on current population trends
and likely climate-change trends. Kristjanson et al. (2001), in this
conference, outline the major impacts; particularly, the impacts of a
drier climate in semi-arid and sub-humid zones and an increasing human
population density throughout the region. These underlying human
population and climate change trends are likely to influence both the
distribution of animals, animal diseases and the impacts of these
diseases in different crop-livestock and livestock-only systems. One
obvious change due to increasing human population and a drier climate in
West Africa is a reduction in tsetse numbers and distribution in
semi-arid and sub-humid zones (McDermott et al., 2001). The effects of
increasing human population and their activities on trypanosomosis have
been most pronounced in Nigeria, and include expanding settlements and
roads, expanding cultivation and increased cattle numbers, conversion of
natural habitats to farmland, and decline in wildlife numbers, thus,
changing trypansomosis transmission to a largely livestock-only cycle
(Bourn et al., 2001).

Beyond these more obvious changes in diseases, such as trypanosomosis,
that are closely linked to natural habitats (Ford, 1971), other disease
trends can be foreseen, based on current trends in West Africa and on
trends in intensifying systems in other areas of both the developing and
developed world. The intensification of livestock systems in many areas
of the developing world, faster than those in any other agricultural
sub-sector (Delgado et al., 1999), will have many implications for
future disease types, occurrence and impacts. We predict four main
animal disease trends that will be very important in West Africa and in
most of the developing world. The first is the greater possibility of
the emergence of new diseases; the second is for an increase in
livestock diseases associated with more intensive husbandry systems, now
largely confined to developed countries; the third is the persistence
and enhanced transmission of classic infectious diseases because of
increased livestock densities and movement; and the fourth is the
greater threat of food-borne infections and intoxications and with them
the problem of food-borne drug and other chemical residues and
antibiotic-resistant organisms.

Diseases in humans have been closely linked with those of their
livestock over the millennia. Many diseases organisms that are only
transmitted within human populations at present had their origins in
livestock populations (e.g measles from rinderpest in cattle; smallpox
from pox viruses of ruminants; and flu from influenza infections of
pigs) and human populations which had developed without livestock were
highly susceptible to their introduction by livestock-owning peoples
(e.g. smallpox introduced by the Spanish to the New World) (Diamond,
1997). Such ecological co-evolution, with disease outbreaks when
ecological barriers were first breached has been an important feature of
disease occurrence throughout history (Burnet and White, 1971). In
recent years, we have seen the emergence of important human and/or
animal diseases, such as Nipah infections in pigs and humans in
south-East Asia, Ebola in Central Africa, bovine spongiform
encephalopathy linked to new variant Creutzfeld-Jakob disease in the
United Kingdom and acquired immune deficiency (AIDS) in humans world
wide. These provide striking evidence that increased human and animal
population densities, changing animal husbandry and feeding technologies
and the greater movements of humans and animals can lead to changes in
ecological circumstances that will lead to the emergence of "new" micro-
and macro-parasitic diseases. Better understanding and predicting when
new diseases may emerge will be an important (and fascinating!) task for
epidemiologists.

More predictable are increases in livestock diseases associated with
intensifying livestock production systems. Delgado et al. (1999) predict
that most of the project increase in livestock productivity will occur
in the developing world, largely in peri-urban and more intensive
crop-livestock systems. No doubt disease problems associated with
husbandry stress such as neonatal diarrhea and pneumonia, nutritional
imbalances and production diseases such as mastitis and food problems
will become a greater and greater feature of intensive crop-livestock
systems in West Africa in the future. Some of these diseases may also be
associated with pollutants, such as pneumonia associated with noxious
gases released from manure.

The other relatively predictable disease trend is that many of the
classic infectious diseases, epidemic, endemic and zoonotic, will
persist and spread in developing countries due to a combination of
increased livestock densities and movements and poor disease control
infrastructure. Increasing reports of African Swine Fever outbreaks in
Nigeria and other West African countries is but one example (Ega, 2000).
Zoonotic diseases such as brucellosis and cysticercosis will also become
an increasing threat if targeted activities to control them in high-risk
populations are not undertaken. These diseases are likely to have
greatest impact among poor farmers and consumers but will occasionally
spillover to richer populations as well.

Of even greater importance is the expected increase the transmission and
impacts of food-borne infections and intoxications. This trend is very
evident in the industrialized livestock systems in many developed and
some developing countries ([add a reference]{.mark}). However, because
of poor surveillance and diagnostic facilities, their impact on
consumers, farmers and traders of livestock products are likely to be
great and poorly controlled. Currently, poor consumers face greater risk
from specific and relatively easily controllable food-borne infections
such as anthrax and hydatid disease, because they are forced to accept
disease risks because of their poverty. Parallel (black) markets of
poorer quality livestock products exist in many countries. On top of
these risks, the new and less controllable food-borne diseases risks,
evidenced in industrialized livestock systems such as infections with
*Salmonella spp*., *Camplyobacter spp*. and enterotoxigenic coliforms,
will increase (see Section 3 for further details).

**3. Trends in the marketing of livestock and livestock products and
their impact animal diseases and public health**

Regional trade in livestock has been a tradition in West Africa. For
generations, cattle have been trekked long distances, often over several
months, from Sahelian zones to be sold in coastal zones. More locally in
most West African countries, small ruminants are moved from rural to
urban areas for fattening and selling, especially during religious
feasts. While such traditional trade in livestock is likely to continue,
demographic and global marketing trends are likely to drastically change
future marketing of livestock and livestock products in the region.

Delgado et al. (1999 and 2001) have noted some key trends in markets in
livestock and livestock products in developing countries. These include:
a rapid increase in demand for meat and milk in urban areas of the
developing world, especially marked in countries with increasing
incomes; a decline in grazing systems supplying large urban markets with
an increase supply from "industrial" non-ruminant (poultry and pig)
livestock production systems; and more concentration and vertical
integration of industrial systems, including feeds, supply of genetic
stock, animal health services, etc. Evidence of the development of
peri-urban systems for poultry production can be seen around major West
African cities such as Dakar.

The continued expansion of such industrial livestock production systems
will have a number of effects. Clearly management will need to be
fine-tuned so that potential nutritional and disease constraints of such
large, intensively managed and fast-growing populations are overcome. On
the production side, some initial efforts will meet with errors but in
general, expertise will be developed. One major effect on public health,
already observed in industrial livestock production and food systems in
developed countries, will be the increased transmission of infectious
agents such as *Salmonella spp*., *Camplylobacter spp*. and
enterotoxigenic coliforms (e.g. *E. coli* O157). These infections will
almost certainly be compounded by increasing levels of antibiotic
resistance and chemical residues. For poor consumers, this will be a
serious problem, as they will confront many of the multiple antibiotic
resistant infections seen in western countries but without the benefit
of newer generation antibiotic treatments. The challenge will be to
develop appropriate risk assessment and surveillance systems that strike
a balance between appropriate consumer health protection and
cost-effective and equitable marketing systems for livestock and
livestock products (see Section 5 for further discussion).

The industrialization and intensification of milk production and
marketing systems is likely to be less dramatic. Evidence from Kenya and
other countries throughout the developing world (Omore et al., 2000) has
shown that small-scale farmers and traders have maintained a surprising
market share of rural and urban fresh milk markets. Informal milk
markets are also important in a number of West African countries, for
example Ghana ([ref]{.mark}) and Mali ([ref]{.mark}). A challenge has
been to balance the need for processes and regulations to protect
consumer health (such as the risks associated with selling unpasteurized
milk) with the economic, equity, and employment benefits associated with
an informal and less regulated milk marketing system. The scale of
trading and distance traveled is an important indicator of risk. For
local trade of a few hundred litres in smallholder systems of Kenya,
milk quality is reasonable and infectious disease risk minimal (Omore et
al., 2000). However, as systems intensify and grow, longer distance
transportation of greater volumes of milk will almost certainly be
associated with poorer milk quality and greater risks from milk-borne
diseases such as brucellosis, tuberculosis, salmonellosis, etc.

**4. Trends in the delivery of animal health services** **and key
considerations in improving the future performance of delivery systems**

Historically, animal health services were developed to contain the major
epidemic diseases, such as rinderpest (ILCA, 1979). As the threat of
diseases was brought largely under control, state animal health services
continued to expand, extending their mandates from control of epidemic
diseases to include control of endemic and zoonotic diseases at district
and farm levels. State veterinary services absorbed most of the
available trained manpower in their extension of farm level control
measures and crowded out private-sector provision.

However, the fiscal crises experienced by African countries as early as
the 1970s led to a decline in expenditures on and provision of public
services. At the same time, there was a growing acceptance of the
paradigm that the private sector could provide many types of disease
control services more efficiently and effectively than the public sector
(de Haan and Bekure, 1991; Umali-Deininger et al., 1992; Leonard, 1993;
Holden, 1999). As a result, there was a massive decline in public-sector
services with the hope that the private sector and livestock keepers
would find ways of filling the gap (Schillhorn van Veen and de Haan,
1995). Both the shift from public to private provision and the
implementation of policies and structures to support private provision
have been undertaken by most West African countries but to varying
degrees and with varying levels of commitment. The general consensus is
that the provision and effectiveness of animal health services has
worsened rather than improved in recent years (Holden, 1999; McLeod and
Wilsmore, 2001; Schillhorn van Veen and de Haan, 1995). The key
challenges in improving the situation are: (1) how to support the
private-sector to play an effective role in providing services, (2) what
key public goods should be provided and how can this best be done
(public, private or mixed delivery) and (3) how the provision of animal
health services to poor, vulnerable and marginal livestock keepers can
be ensured.

There are a number of important components of animal health services. A
simplified animal health delivery system for livestock keepers is
illustrated in Figure 2. Specific animal health goods and services
required in such systems include: clinical services, parasite and vector
control, vaccination for epidemic and endemic diseases, quality control
of drugs and vaccines, disease surveillance and animal movement control,
veterinary public health, and adaptive research providing information
and policy (McDermott et al., 1999).

Holden (1999) has reviewed the economic framework for assessing public
and private roles in the delivery and financing of animal health
services. Two key features for determining public sector priorities for
delivery and finance of animal health services are the excludability and
rivalry of the service (see Figure 3). Essentially, high excludability
occurs when those that pay for a service can exclusively capture its
benefits (low externalities) while high rivalry occurs when the
consumption of a service by one user precludes it use by others. Private
provision is most appropriate for goods and services with high rivalry
and excludability and public provision for those that have low rivalry
and excludability. However, many animal health services are neither
purely public or private (see Figure 3). Based on her assessment of the
economic characteristics of different animal health services, Holden
(1999) proposed roles (Table 4) and financing sources for different
types of animal health services. Clearly, individual countries will
establish different mixes of private and public animal health service
provision depending on their national policy orientation, animal disease
situation, infrastructure, trade situation and other factors. However,
most countries are likely to focus public resources on epidemic disease
control; food safety; product quality control; information,
certification and registration issues; and monitoring of private
contractors providing public services. Rinderpest control by the state
veterinary services with donor aid, has proven modestly beneficial in
economic terms (roughly 1.5 : 1) (Tambi et al., 1999). To lower delivery
costs, we think it likely that many countries will contract the
provision of public services such as epidemic disease control to private
suppliers. How these contracts are managed, monitored and evaluated will
remain the key public concern. Another issue that governments and
livestock producers need to resolve is how to equitably finance animal
health services. Payment for clinical services, drugs and vaccines is
now commonplace for livestock keepers throughout Africa; but many public
services such as epidemic disease control and food safety surveillance
can and should be financed by livestock producers as a function of how
they benefit. For example, the control of epidemic diseases that
provides an export market with higher prices for some livestock
producers should be paid for by the producers who benefit.

Within West Africa, there are major differences in how animal health
services are delivered in different countries. Some countries have tried
to retain a larger role for public veterinary services while others have
moved more quickly towards privatization. As an example, Côte d'Ivoire,
Ghana, Mali and Senegal have privatized drug importation and
distribution while Benin and Burkina Faso have retained government
control over these activities. Not surprisingly, drug availability and
use is significantly higher in those countries that have privatized
(Holden, 1999). Also, not surprisingly, drugs readily move across
national boundaries from countries where they are available to those
where they are not. Ouedraogo (1999) has documented the flow of
trypanocides and other animal health products from Mali into western
Burkina Faso. Given that drugs (and other services) will flow between
countries and that common problems of drug resistance (McDermott et al.,
1999) and drug quality control (Geerts and Holmes, 1998) for
trypanocides and other products exist, regional animal health product
and service delivery policies and regulations need to be developed and
implemented.

While the national and local context as well as the technical and
economic characteristics of the disease and its control will be
influential in determining disease control strategies and how they are
delivered, a number of opportunities exist for improving the delivery of
animal health services to enhance their adoption and impact. These
include:

-   **Better products:** for example thermostable and cheap vaccines for
    Newcastle Disease (Spradbrow and Copland, 1996; Alders, 2001; Bell
    2001).

-   **Better information:** farmers lack information on appropriate use
    of common drugs, drug resistance and information on the quality of
    drugs. This lack of information seriously undermines their ability
    to control disease effectively.

-   **Better services:** Kleeman (1999) has proposed a toolkit for
    assessing service delivery. In general, the private-sector has been
    best able to serve clients in market-oriented crop-livestock systems
    with good infrastructure. More marginal pastoral and agro-pastoral
    systems will require different options such as community-based
    animal health workers.

-   **Better institutions and policies:** We see three main issues that
    need to be improved upon in West Africa. The first is to consider,
    using the economic theory described above, the roles and
    contributions of the public and private sectors. The second is to
    improve methods for assessing the performance of private-sector
    contractors and public-sector agencies in disease control using the
    New Institutional Economics and other methods. The third is to
    consider strategies for regional coordination in trade, disease
    control regulation, and product quality control.

As farmers are key clients of animal health delivery systems,
understanding their demand is crucial to developing better systems.
Animal health information on the incidence and impact of different
diseases is one component of demand. How livestock keepers respond to
the disease risk they face depends on the role of livestock in the
household economy, their perception and understanding of the disease and
its control, their resources and the costs and benefits of control
options relative to other household priorities. Participatory techniques
can play a useful role in understanding farmer perceptions,
understanding of diseases and their control, and the perceived demand
for services (see Catley, 1999 for their use in pastoralist systems). In
addition, marketing techniques such as willingness-to-pay (Ahuja et al.,
2000), contingent valuation (Echessah et al., 1997) and conjoint
analysis (Randolph and Ndung'u, 2000) will help service providers to
better understand their livestock-keeping clients.

Assessing and improving delivery systems will be essential for all
stakeholders. McLeod and Wilesmore (2001) have begun developing an
approach to assessment based on the following four criteria:

-   Accessibility, referring to the willingness of providers to supply
    disease control and time taken to find a service provider or product
    when needed;

-   Affordability, the actual cost as well as ability and willingness of
    livestock keepers to pay;

-   Acceptability, the form and manner in which the product or service
    is presented; and

-   Sustainability, both financial and institutional.

These criteria capture a number of the elements discussed above. The
challenge will be to identify indicators and methods that can
practically, effectively and affordably be used by different players to
assess and improve the performance of delivery systems.

**5. Animal diseases and the poor -- options for disease control to
accelerate poverty alleviation programmes**

Rural poverty is an important problem in West Africa. Of the total rural
population of approximately 221 million, 90 million or 41% are
considered poor (\< USD 2 per day). Table 5 describes the number of poor
people in each of the main livestock production systems in West Africa.
The importance of livestock to the poor in rural areas throughout the
developing world has been effectively argued by Livestock in Development
(1995).

In a recent report, Perry et al. (2001), have highlighted the importance
of animal diseases to the poor. The poor are more prone to animal and
zoonotic diseases because of their closer contact to their livestock and
inability to cope with the risk of animal diseases. At a recent seminar
in Sikasso, Mali (April 2001) veterinary experts from a number of West
African countries were asked to rank the livestock species important to
the poor in the main livestock production systems of West Africa and for
those species to rank the diseases that had greatest impact on poor
livestock keepers. The impacts were largely weighted based on the
on-farm impacts but national level impacts were also considered. A
separate ranking of zoonotic diseases was also conducted. The rank of
the major animal diseases of importance to the poor, by system and
species, are listed in Table 6. Zoonotic diseases that were not also
ranked as important animal diseases are listed at the end of the ranking
list.

While it is important to highlight the impact of animal diseases on the
poor, an even more important issue is what might be done to improve the
situation. An analytic framework for assessing the impacts of research
and development impacts for the poor is the sustainable livelihoods (SL)
approach (Carney, 1998; DfID, 2000). Central to the SL approach is the
improvement of capital -- human, financial, natural, social and physical
(see Figure 4). Within the SL context, Perry et al. (2001) considered
three impacts of controlling animal diseases that could directly improve
the livelihoods of the poor. These were:

-   secure the current assets (human, financial, and social) of poor
    people who keep livestock, and who consume livestock products,
    market livestock and livestock products, and work as wage labourers
    with livestock, by reducing the risks they experience through animal
    and zoonotic diseases;

-   enhance the market opportunities of the poor by controlling the
    diseases that affect the movement and marketing of livestock and
    animal products, primarily locally, but also regionally and
    internationally; and

-   reduce the constraints experienced by the poor to livestock-based
    pathways out of poverty through intensification (improved
    productivity and performance efficiency through the use of inputs).

Three research pathways were proposed by which animal disease control
for poor people could be improved. These were:

-   transferring knowledge and available tools;

-   making existing technologies more effective and appropriate for the
    poor; and

-   developing new disease control tools by capitalising on new
    developments in science.

Table 7 illustrates animal disease control research options for each
category of research pathway cross-classified by poverty impact (Perry
et al., 2001). In prioritizing research options, the fundamental
criteria will be potential impact and probability of success. One
obvious example of a research opportunity that can be achieved in the
short-term and will have considerable impact is the control of Newcastle
Disease using thermostable eye-drop or feed-delivered vaccines.
Newcastle Disease is the critical disease constraint to poor livestock
keepers (Sonaiya et al., 1999) in all crop-livestock production systems
in West Africa. The principle effect of Newcastle Disease is in killing
the poultry assets of the poor. The thermostable vaccines that have been
developed (Spradbrow and Copland, 1996) have proved very successful in
south-East Asia, but methods for their delivery and adoption need to be
adapted for West African conditions (see Alders and Spradbrow (2001) for
a discussion of Newcastle Disease Vaccine delivery in Southern Africa).

**6. The way forward -- policy options, institutional arrangements and
research needs for enhancing sustainable animal production and animal
disease control programmes**

Given the trends in disease occurrence and their impacts described
above, West African countries face a number of challenges, threats and
opportunities in enhancing sustainable animal disease control within
their national development plans. How might these future trends be best
addressed by different stakeholders in the region?

The fundamental opportunity is that consumption of animal and animal
products will grow rapidly (on the order of 2.5 -- 4% per annum in
sub-Saharan Africa for different meat and milk products over the next 20
years) (Delgado et al., 2001). This will provide market opportunities,
mainly in local markets, but also regionally and internationally.
Sanitary and phytosanitary regulations will play an important part in
determining access to these markets, but the promise of the
international community is that the regulatory system will be more
transparent and linked to quantitative disease risks than the present
system. The other main opportunity is to build on the initial successes
of innovative livestock and crop-livestock production-to-consumption
systems in a number of countries; for example, the development of
efficient commercial poultry production units around Dakar ([reference
-- Cardenal ?)]{.mark} and the much greater production efficiencies
gained by small-scale crop-livestock farmers in a number of countries
([reference).]{.mark} Important in this are the growing opportunities
for public-private synergies in enhancing input and output markets
including animal disease control and food safety systems.

However, there are serious threats that could limit the realization of
these opportunities. Assuming political and socio-economic stability and
improving general infrastructure, both nationally and regionally, we see
the major future threat to livestock market opportunities being posed by
animal diseases and regulations to control them. Complying with
internationally agreed upon sanitary and phyto-sanitary agreements may
be difficult and prevent market access to many. The threat of market
exclusion will be greatest for poor countries, poor livestock keepers
and poor traders. A second and related threat is that the public sector
will not have the technical capacity to adapt and respond to its new
obligations in animal disease control, food safety, or the research
capacity to enhance livestock health and production under evolving
systems.

Thus, the challenge will be to ensure that countries in West Africa, and
particularly their poor livestock keepers, traders and consumers have
open access to markets that are both efficient and safe and that they
have the capacity to respond to these market opportunities. There are a
number of components to this challenge that we will address
specifically.

***(1) Development of institutional capacity and linkages***

The capacity, confidence and performance of public-sector institutions
in contributing to animal disease control and food safety systems have
all been severely compromised. Public policy makers and institutions
need to decide on what their fundamental domain of required activities
is, concentrate on building their capacity in these activities and
support the role for a better participation, often with public-sector
supervision, of the private sector in animal disease control and food
safety assurance. For a number of key public-sector functions, such as
training, epidemic disease control, and the quality assurance of
veterinary products, collaboration between countries in the region is
and will be essential and must be enhanced.

***(2) Developing veterinary technical capacity***

Many of the future trends in animal disease control that we predict for
West Africa have already commenced in some developed and developing
countries. Based on their experiences, there is an increasing array of
methods and tools, from epidemiology, economics, risk assessment,
diagnosis and food safety surveillance, that can be obtained and adapted
by West African countries. However, this will not be a simple borrowing
exercise, as all of the methods and most of the tools will have to be
adapted to local situations. There are two challenges. The first is to
build the necessary technical capacity through training. The second is
to establish systems that allow the expertise developed to effectively
contribute to animal disease control and food safety assurance.

***(3) Enhancing animal and human health in intensifying crop-livestock
systems***

Enhancing the impact of animal disease control within intensifying
crop-livestock systems will require a global approach integrating
policy, systems analysis and impact assessment, and many technical
disciplines. There are a number of key issues to be addressed, varying
by market access and production system. The first is to improve the
efficiency of input and output markets, particularly by developing and
adapting methods and tools for adding value to the products from
small-scale farms (for example methods to preserve milk) and by
enhancing information flows. Lack of information is a particular problem
in many agro-pastoral systems in West Africa, where farmers have poor
knowledge of animal diseases and the efficacy and availability of
control options. A second key issue is to better understand and adapt to
changing disease dynamics resulting from intensification, including the
emergence of new animal and zoonotic diseases and changes in food safety
risks. Thirdly, the environmental consequences of changes and
interventions in intensifying crop-livestock systems need to be
monitored and evaluated over time. This is of critical importance for
resource-poor farmers who often rely on common natural resources for
their livelihoods.

As noted by many others (for example Kristjanson et al. 2001), increases
in human populations, changes in climate and many other global and local
influences will greatly affect West African crop-livestock systems.
Currently, the occurrence of animal diseases has a great impact in these
systems and the needs for disease control far exceed available
capacities. We expect that without better coordinated and more
efficacious control strategies, many current disease problems will
further worsen and new animal and human disease threats will emerge or
occur more frequently. If the great opportunities of livestock to
enhance the livelihoods of farmers, traders and consumers in West Africa
are to be realized, the threat of animal diseases to improving
production, securing assets and maintaining market access must be met.

**References**

Ahuja V, George P S, Ray S, McConnell K E, Kurup M P G, Gandhi V,
Umali-Deininger D and de Haan C. 2000. *Agricultural services and the
poor: case of livestock health and breeding services in India*. Indian
Institute of Management, Ahmedabad; The World Bank, Washington DC, and
The Swiss Agency of Development and Cooperation, Bern, Switzerland. 148
pp.

Awa D N, Njoya A and Ngo Tama A C. 2000. Economics of prophylaxis
against peste des petits ruminants and gastrointestinal helminthosis in
small ruminants in north Cameroon. *Tropical Animal Health and
Production* 32:391-403.

Alders R G and Spradbrow P B (eds). 2001. *SADC planning workshop on
Newcastle Disease control in village chickens*. ACIAR (Australian Centre
for International Agricultural Research) Proceeding No. 103, Canberra,
158pp.

Bourn D, Reid R, Rogers D, Snow W and Wint W. 2001. *Environmental
changes and the autonomous control of tsetse and trypanosomosis in
sub-Saharan Africa -- case histories from Ethiopia, the Gambia, Kenya,
Nigeria and Zimbabwe*. Environmental Research Group, Oxford, UK, 248 pp.

Burnet M and White D 1971. *Natural History of Infectious Diseases*,
2^nd^ ed. Cambridge University Press.

Carney, D. (Ed.) (1998). *Sustainable Rural Livelihoods: What
contribution can we make?* DFID, London.

Catley A. 1999. *The Herd Instinct -- Children and livestock in the Horn
of Africa*. Save the Children, London UK.

[CTA/CORAF 1997]{.mark}

de Hann C and Bekure S. 1991 *Animal health services in sub-Saharan
Africa: initial experiences and new approaches.* Technical Paper No.
134. World Bank, Washington DC, 49 pp.

Delgado C, Rosegrant M, Steinfeld H, Ehui S and Courbois C. 1999.
*Livestock to 2020: The next food revolution.* Food Agriculture and the
Environment Dicussion Paper 28. IFPRI (International Food Policy
Research Institute), Washington DC, 72pp.

Delagado C, Rosegrant M and Meijer S. 2001. *Livestock to 2020: the
revolution continues.* Paper presented at the International Agricultural
Trade Research Consortium (IATRC), Auckland New Zealand, 18-19 January,
2001, in press, 38pp.

DfID (Department for International Development, UK), 2000. *Sustainable
livelihood guidance sheets.* (livelihoods@dfid.gov.uk).

Diamond J. 1997. Guns, Germs and Steel -- a short history of everybody
for the last 13,000 years. Vintage -- Random House, London, UK, 480 pp.

[Domenech J. et al. 1994. *La pathologie des petits ruminants en
Côte-D'Ivoire* -- LANAVET, Bingerville, Côte-d'Ivoire, 170 pp.]{.mark}

Echessah P N, Swallow B M, Kamara D W and Curry J J. 1997. Willingness
to contribute labor and money to tsetse control: application of
contingent valuation in Busia District, Kenya. *World Development*
25:239-253.

Ega L A. 2000. Report on the socio-economic impact analysis of African
Swine Fever in Nigeria. FAO, Rome, 24 pp.

Ekboir J M. 1999. The role of the public sector in the development and
implementation of animal health policies. *Preventive Veterinary
Medicine* 40:101-115.

FAO (Food and Agriculture Organization). 2001. *Fostering the policy
dialogue in support of improved animal health and veterinary public
health as an entry point for poverty reduction and sustainable
livelihoods for livestock farmers.* FAO, Rome, 67pp.

Faugère O, Faugère B and Moulin C H. 1991. *Enquêtes par suivi
individuel du cheptel. II. Exemples de résultats obtenus au Sénégal.*
Fiche MCD, CIRAD-EMVT, Paris, Maisons-Alfort, No 4, 8 pp.

Ford J. 1971. *The role of trypanosomiases in African ecology: a study
of the tsetse fly problem.* Clarendon Press, Oxford UK, 582 pp.

Geerts S and Holmes P H. 1998. *Drug management and parasite resistance
in bovine trypanosomiasis in Africa.* PAAT Technical and Scientific
Series, No. 1, FAO, Rome, 31 pp.

Holden S. 1999. The economics of the delivery of veterinary services.
R*evue Scientifique et Technique Office International des Epizooties*
18:425-439.

ILCA (International Livestock Centre for Africa). 1979. *Towards an
economic assessment of veterinary inputs in tropical Africa.* ILCA
Working Document 1, Addis Ababa. 63 pp.

Itty P. 1992. *Economics for village cattle production in tsetse
affected areas of Africa* (PhD thesis). Hartung-Gorre Verlag, Konstanz,
316 pp.

Kleeman G. (ed). 1999. *Service management in livestock development:
concepts and elements.* Deutsche Gesellschaft für Technische
Zusammenarbeit (GTZ) GmbH: Wiesbaden, 430 pp.

Kristjanson, P.M., B.M. Swallow, G.J. Rowlands, R.L. Kruska and P.N. de
Leeuw (1999). Measuring the costs of African animal trypanosomiasis, the
potential benefits of control and returns to research. *Agricultural
Systems* 59:79-98.

Kristjanson P, Thornton P K, Williams T, Tarawali S, Neizen J, Larbi A,
Kruska R L and Reid R. 2001. Mapping livestock systems and changes to
2050: implications for West Africa. [Proceedings of this conference in
press.]{.mark}

Lefèvre, P.C., Diallo, A., 1990. Peste des petits ruminants. R*evue
Scientifique et Technique Office International des Epizooties* 9:
935-981.

Leonard D K. 1993. Structural reform of the veterinary profession in
Africa and the New Institutional Economics. *Development and Change*
24:227-267.

Livestock in Development (LID). 1999. *Livestock on Poverty-Focused
Development.* Livestock in Development, Crewkerne, UK, 95pp.

Ly C. 2000. Management and impact of auxiliaries on pastoral production
and veterinary services delivery in Senegal. In. Leonard D K (ed).
*Africa's Changing Market for Health and Veterinary Services -- the New
Institutional Issues.* MacMillan, London, 224-259.

McDermott J J, Randolph T F and Staal S J. 1999. The economics of
optimal health and productivity in smallholder livestock systems in
developing countries. R*evue Scientifique et Technique Office
International des Epizooties* 18:399-419.

McDermott J J, Sidibe I, Bauer B, Diarra B, Clausen P H, Woitag T,
Ouedraogo D, Kamuanga M, Peregrine A S, Eisler M C and Mehlitz D. 2000.
Field studies on the development and impact of drug resistant animal
trypansomes in market-oriented production systems in the southern
Guinean zone of West Africa. *ICPTV Newsletter* 2, 18-21.

McDermott J J and Coleman P G. 2001. Comparing apples and oranges --
model-based assessment of different tsetse-transmitted trypanosomosis
control strategies. *International Journal of Parasitology* 31:603-609.

McDermott J J**,** Kristjanson P M, Kruska R L, Reid R S, Robinson T P,
Coleman P G, Jones P G and Thornton P K. 2001. Effects of climate, human
population and socio-economic changes on tsetse-transmitted
trypanosomiasis to 2050. In Seed R and Black S (eds). *World Class
Parasites -- Vol. 1. The African Trypanosomes.* Kluwer, Boston, in
press.

McLeod A and Wilsemore A. 2001 The delivery of animal health services to
the poor: a review. Appendix 9. In: Perry B D, Randolph T F, McDermott J
J, Sones K R and Thornton P K. 2001. Investing in Animal Health Research
to Alleviate Poverty. ILRI (International Livestock Research Institute),
Nairobi, Kenya, 125 pp (plus appendices).

Omore A O, McDermott J J, Staal S, Arimi S M, Kang\'ethe E K and Ouma E
A. 2000. Analysis of public health risks from consumption of informally
marketed milk in sub-Saharan African countries. In: Proceedings of the
9^th^ International Symposium on Veterinary Epidemiology and Economics,
Breckenridge Colorado, 7-11 August 2000, Paper 502 (electronic
proceedings).

Osaer S, Goossens B, Kora S, Gaye M and Darboe L. 1999. Health and
productivity of traditionally managed Djallonke sheep and West African
dwarf goats under high and moderate trypanosomosis risk. *Veterinary
Parasitology* 82:101-119.

Ouedraogo D. 1999. *Acteurs et fonctionnement du marché des intrants
veterinaries dans la province du Kénédougou*. Document de Travail, No.
2, CIRDES/ILRI, Bobo Dioulasso, Burkina Faso, 26 pp.

Perry B D, McDermott J J and Randolph T F. 2001. Can epidemiology and
economics make a meaningful contribution to national animal-disease
control? *Preventive Veterinary Medicine* 48:231-260.

Perry B D, Randolph T F, McDermott J J, Sones K R and Thornton P K.
2001. *Investing in animal health research to alleviate poverty.* ILRI
(International Livestock Research Institute), Nairobi, Kenya, 125 pp
(plus appendices).

Perry B D, McDermott J J and Randolph T F. 2001. The control of
infectious diseases: making appropriate decisions in different
epidemiological and socio-economic circumstances. In: Coetzer J A W and
Thomson G R (eds) *Infectious Diseases of Livestock*, Oxford, Oxford UK,
in press.

Randolph T and Ndung'u L. 2000. Gender and transaction cost: a conjoint
analysis of choice of livestock health service among smallholder dairy
farmers in Kenya. Background paper for a poster presented at the XXIVth
Congress of the IAAE, Berlin, 18-24 August 2000, ILRI (International
Livestock Research Institute), Nairobi. 23 pp.

Schillhorn van Veen T W and de Haan C. 1995. Trends in the organization
and financing of livestock and animal health services. *Preventive
Veterinary Medicine* 25:225-240.

Schuetterle A and Coulibaly M. 1988. The socio-economic aspects of
livestock production in villages in northern Côte d'Ivoire. In:
*Livestock Production in tsetse affected areas of Africa*. In:
Proceedings of a meeting, 23-27 November, 1987, ILCA (International
Livestock Centre for Africa) / ILRAD (International Laboratory for
Research in Animal Diseases), Nairobi, 389-398.

Sonaiya E B, Branckaert R D S and Gueye E F. 1991. Research and
development options for family poultry. In: Gueye EF (ed). First
INFPD/.FAO Electronic Conference on family poultry, FAO, Rome, 20 pp.

Spradbrow P B and Copland J W. 1996. Production of thermostable
Newcastle Disease virus in developing countries. *Preventive Veterinary
Medicine* 29:157-159.

Starkey P H. 1990. Animal traction for agricultural development in West
Africa: production, impact, profitability and constaints. In: Starkey P
H and Faye A (eds). *Animal traction for Agricultural Development*.
Technical Centre for Agricultural and Rural Cooperation (CTA),
Wageningen, the Netherlands, 90- 114.

Swallow B M. 2000. *Impacts of trypanosomiasis on African agriculture.*
PAAT Technical and Scientific Series, No. 2, FAO, Rome, 52 pp.

[Tacher G (2000). ....]{.mark}

Tambi E N, Maina O W, Mukhebi A W and Randolph T F. 1999. Economic
impact assessment of rinderpest control in Africa. *Revue Scientifique
et Technique Office International des Epizooties* 18: 458-477.

Tano K, Kamuanga M, Faminow M D, Swallow B, d'Ieteren G D M. 1999.
*Adoption and demand for trypanotolerant cattle in the sub-humid zone of
West Africa.* ILRI/CIRDES Working Paper. 29pp.

Tillard E., Faugère O and Faugère B. 1992. Evaluation
technico-économique de prophylaxies chez les petits ruminants au Sénégal
: régionalisation des interventions de protection sanitaire. In:
*Production et santé animales tropicales - L\'élevage, facteur essentiel
d\'une agriculture durable*. VIIe Conférence internationale des
institutions de médecine vétérinaire tropicale, Yamoussokro, Sept 1992,
DSE, Bonn and CIRAD-EMVT, Maisons-Alfort, 519- 528.

Umali-Deininger D, Feder G and de Haan C. 1992. *The balance between
public and private sector activities in the delivery of livestock
services*. Discussion Paper No. 163, World Bank, Washington DC, 114 pp.

Wacher T J, Milligan P M, Rawlings P and Snow W F. 1994. Spatial factors
in the assessment of trypanosomosis challenge. B.D. Perry and J.W.
Hansen (eds). *Modelling vector-borne and parasitic diseases*. ILRAD
(International Laboratory for Research in Animal Diseases and FAO (Food
and Agriculture Organization), Nairobi, 119-130.

> **Table 1. Classification of infectious diseases based on their
> transmission, types of impacts and levels of impacts (modified from
> Perry et al., 2001a).**

+---------------+-----------+----------------+-------+----------------+
| **Category of | **Example | **Major        | **L   | **Impact       |
| infectious    | d         | impacts**      | evels | indicators**   |
| disease**     | iseases** |                | of    |                |
|               |           | **(rank varies | impa  |                |
|               |           | by production  | cts** |                |
|               |           | system)**      |       |                |
+---------------+-----------+----------------+-------+----------------+
| 1.  Epidemic, | Ri        | 1.  Costs to   | Inte  | Incidence of   |
|     directly  | nderpest, |     minimize   | rnati | disease        |
|               | Foot and  |     epidemic   | onal, |                |
|   transmitted | Mouth     |     risk       | Regi  | Control costs  |
|               | Disease,  |                | onal, |                |
| international | African   | 2.  Production | Nati  |                |
|               | Swine     |     losses in  | onal, |                |
|    importance | Fever     |                | Local |                |
|     (OIE list |           |    susceptible | Area, |                |
|     A)        |           |     animals if | F     |                |
|               |           |     epidemic   | armer |                |
|               |           |                |       |                |
|               |           | 3.             |       |                |
|               |           |   Restrictions |       |                |
|               |           |     to trade   |       |                |
+---------------+-----------+----------------+-------+----------------+
| 2.  Ende      | Hae       | 1.  Production | Nati  | Disease        |
| mic/sporadic, | morrhagic |     losses     | onal, | occurrence     |
|     directly  | se        |                | Local |                |
|               | pticemia, | 2.  Control    | Area, | Production     |
|  transmitted, | Dermat    |     costs      | F     | losses         |
|     farm and  | ophilosis |                | armer |                |
|     national  |           | 3.             |       | Control costs  |
|               |           |   Restrictions |       |                |
|    importance |           |     to trade   |       |                |
|     (OIE list |           |                |       |                |
|     B)        |           | 4.  Production |       |                |
|               |           |                |       |                |
|               |           |  opportunities |       |                |
|               |           |     lost       |       |                |
+---------------+-----------+----------------+-------+----------------+
| 3.  Ende      | Ba        | 1.  Production | Nati  | Disease        |
| mic/sporadic, | besiosis, |     losses     | onal, | occurrence     |
|               | Co        |                | Local |                |
|    indirectly | wdriosis, | 2.  Production | Area, | Vector         |
|               | Thei      |                | F     | abundance      |
|   transmitted | leriosis, |  opportunities | armer |                |
|     (usually  | African   |     lost       |       | Production     |
|     v         | Animal    |                |       | losses         |
| ector-borne), | Trypa     | 3.             |       |                |
|     farm and  | nosomosis |   Restrictions |       | Control costs  |
|     national  |           |     to trade   |       |                |
|               |           |                |       |                |
|    importance |           | 4.  Control    |       |                |
|     (OIE list |           |     costs      |       |                |
|     B)        |           |                |       |                |
+---------------+-----------+----------------+-------+----------------+
| 5.  Ende      | Mastitis  | 1.  Production | F     | Disease        |
| mic/sporadic, | (Staph    |     losses     | armer | occurrence     |
|     directly  | ylococcus |                | (Nati |                |
|               | aureus),  | 2.  Production | onal, | Production     |
|  transmitted, | Pneumonia |                | Local | losses         |
|     mainly    | (Pasteur  |  opportunities | Area  |                |
|     farm      | ellosis), |     lost       | less  | Control costs  |
|               | Foot Rot  |                | impor |                |
|    importance |           | 3.  Control    | tant) |                |
|     (OIE      |           |     costs      |       |                |
|     other     |           |                |       |                |
|     diseases) |           |                |       |                |
+---------------+-----------+----------------+-------+----------------+
| 6.  Zoonotic  | Bru       | 1.  Impacts on | Nati  | Disease        |
|     diseases  | cellosis, |     human      | onal, | occurrence --  |
|               | Tube      |     health     | Local | animals and    |
|   transmitted | rculosis, |                | Area, | humans         |
|     directly  | some      | 2.  Production | F     |                |
|     or        | types of  |     losses     | armer | Production     |
|               | Gambiense |                |       | losses in      |
|    indirectly | sleeping  | 3.  Control    |       | animals        |
|     from      | sickness  |     costs      |       |                |
|     animals   | (?)       |                |       | Burden of      |
|     to        |           |                |       | disease        |
|     humans.   |           |                |       | (DALYs) in     |
|     Human     |           |                |       | humans         |
|     risk      |           |                |       |                |
|     important |           |                |       | Control costs  |
|     factor in |           |                |       |                |
|     animal    |           |                |       |                |
|     disease   |           |                |       |                |
|     control.  |           |                |       |                |
+---------------+-----------+----------------+-------+----------------+
| 7             | E.coli    | 1.  Impacts on | L     | Burden of      |
| .  Food-borne | O157      |     human      | ocal, | disease        |
|               | in        |     health     | Area, | (DALYs) in     |
|    infections | fections; |                | Nat   | humans         |
|     and       | Salmo     | 2.  Costs of   | ional |                |
|               | nellosis; |     food       |       | Control costs  |
| intoxications | Camplyoba |     quality    |       |                |
|               | cteriosis |     control    |       |                |
|               |           |     systems    |       |                |
+---------------+-----------+----------------+-------+----------------+

**Table 2. Main disease priorities in humid and sub-humid zones in some
West Africa countries (CTA/CORAF, 1997).**

+------+--------------+----------+----------+------------+-----------+
| **C  | **Bovine**   | *        | **C      | *          | **        |
| ount |              | *Ovine** | aprine** | *Porcine** | Poultry** |
| ry** |              |          |          |            |           |
+------+--------------+----------+----------+------------+-----------+
| **   | ##           | PPR      | PPR      | African    | Newcastle |
| Côte | ####### CBPP |          |          | Swine      | Disease   |
| d'   |              | Sheep    | GI       | Fever      |           |
| Ivoi | Foot and     | Pox      | Para     |            | Gumboro   |
| re** | Mouth        |          | sitism\* | Pneumonia  |           |
|      | Disease      | Orf      |          |            | Co        |
|      |              |          |          |            | ccidiosis |
|      | Tr           | Mange    |          |            |           |
|      | ypanosomosis |          |          |            | Fowl Pox  |
|      |              | Foot Rot |          |            |           |
|      | Brucellosis  |          |          |            | GI        |
|      |              |          |          |            | par       |
|      | Der          |          |          |            | asitism\* |
|      | matophilosis |          |          |            |           |
+------+--------------+----------+----------+------------+-----------+
| *    | Rinderpest   | PPR      | PPR      | Kidney     | Newcastle |
| *Gha |              |          |          | worm       | Disease   |
| na** | CBPP         | P        | P        |            |           |
|      |              | neumonia | neumonia | Round worm |           |
|      | Anthrax      |          |          |            |           |
|      |              | Endopar  | Endopar  |            |           |
|      | Blackleg     | asites\* | asites\* |            |           |
|      |              |          |          |            |           |
|      | End          | Ectopar  | Ectopar  |            |           |
|      | oparasites\* | asites\* | asites\* |            |           |
+------+--------------+----------+----------+------------+-----------+
| **   | CBPP         | PPR      | PPR      | Endopa     | Newcastle |
| Guin |              |          |          | rasitism\* | Disease   |
| ée** | Anthrax      | Para     | Para     |            |           |
|      |              | sitism\* | sitism\* | Ectopa     | Fowl Pox  |
|      | Haemorrhagic |          |          | rasitism\* |           |
|      | Septicemia   | Pasteu   | Mange    |            | Gumboro   |
|      |              | relloses |          | Pneumonia  |           |
|      | Rabies       |          | Blackleg |            | Par       |
|      |              | Mange    |          |            | asitism\* |
|      | Tr           |          |          |            |           |
|      | ypanosomosis | Anthrax  |          |            |           |
+------+--------------+----------+----------+------------+-----------+
| **N  | CBPP, FMD    | Helmi    | PPR      | Hel        | Newcastle |
| iger |              | nthiasis |          | minthiasis | Disease   |
| ia** | Black        |          | Helmi    |            |           |
|      | quarter      | Tick     | nthiasis | Mange      | Gumboro   |
|      |              | borne    |          |            |           |
|      | Rinderpest   | diseases | Ti       | Pneumonia  | Go        |
|      |              |          | ck-Borne |            | ccidiosis |
|      | H            |          | diseases |            |           |
|      | elminthiasis |          |          |            | Helm      |
|      |              |          |          |            | inthiasis |
+------+--------------+----------+----------+------------+-----------+
| ##   | CBPP, FMD    | PPR      | PPR      | Cys        | Newcastle |
| Togo |              |          |          | ticercosis | Disease   |
|      | Anthrax      | Anthrax  | Anthrax  |            |           |
|      | (north)      | (north)  | (north)  | GI         | Fowl Pox  |
|      |              |          |          | Pa         |           |
|      | Brucellosis  | Trypan   | Trypan   | rasitism\* | GI        |
|      |              | osomosis | osomosis |            | par       |
|      | Tr           |          |          |            | asitism\* |
|      | ypanosomosis | GI       | GI       |            |           |
|      |              | para     | para     |            |           |
|      |              | sitism\* | sitism\* |            |           |
+------+--------------+----------+----------+------------+-----------+

\* parasitism was not consistently defined; we assume parasitism is a
general term including ecto- (external) and endo- (internal) parasitism.
GI parasitism is a component of endo-parasitism. Additionally, specific
parasitoses were mentioned (e.g. mange, helminthiasis)

Table 3. Multiple impacts of trypanosomosis in crop-livestock systems in
sub-humid West Africa (from FAO, 2001 with data largely compiled by
Swallow, 2000).

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

**Direct impacts on livestock productivity**

-   reduced calving rates (1-12% tolerant; 11-20% susceptible)

-   increased calf mortality (0-10% tolerant; 10-20% susceptible)

-   small ruminants (lambing/kidding rates decreased 4-28% / 37%)

-   decreased milk production (cow: 10-26% tolerant; land-area: - 83%)

-   decreased animal offtake (herd: 5-31%; land-area: - 97%)

-   drug use (SSA -- US\$ 35 million; estimated at 1.3 doses per head in
    sub-humid West Africa (McDermott and Coleman, 2001)

**Impacts on livestock risk management**

-   decreased cattle numbers (arid -- 14%; subhumid -- 27%; humid --
    77%)

-   grazing changes (Wacher et al., 1994; Basset, 1993)

**Impacts on agricultural and other products**

-   decreased draught efficiency (40%)

-   increased crop production (+25-45% per unit land; +140-143% per unit
    labour

-   decrease in agricultural GDP in effect countries from 5-10%

**Effects on natural resource use**

-   change in migration/settlement patterns (variable effects)

-   limited to moderate changes in biodiversity associated with tsetse
    control

**Impacts on Human Welfare**

-   loss of income and assets related to impacts above

-   livestock reservoir of sleeping sickness, some importance in West
    Africa (more important in East Africa and of only limited importance
    in Central Africa)

**Table 4. Public and private sector roles in the delivery of animal
health services (modified from Holden, 1999).**

**Private Sector Public, sub-contracted to Private Public Sector**

Clinical services Food safety inspection Planning service delivery

Endemic disease prevention and control Drug quality control Epidemic
disease control

Sales of drugs and vaccines Public-good extension Food hygiene

Some extension functions Public-good research Quality control of
veterinary products

Some research functions Control of epidemic diseases Legislation --
design and enforcement

Vaccine production Control of zoonotic diseases Managing and monitoring
performance

> of subcontractors

Diagnostic services

Information, certification, registration

Dip tanks

**Table 5: Poverty rates by livestock production system in West Africa**

+------------+---------------+---------+---------+---------+---------+
| **System** | **Human       | *       | **      | **Poor  | #       |
|            | Population**  | *Poor** | Poverty | Li      | # Share |
|            |               |         | Rate**  | vestock |         |
|            |               |         |         | Ke      |         |
|            |               |         |         | epers** |         |
+------------+---------------+---------+---------+---------+---------+
| LGA        | 8,095,611     | 4,      | 51.8%   | 3,      | 39.4%   |
|            |               | 191,610 |         | 185,623 |         |
+------------+---------------+---------+---------+---------+---------+
| LGH        | 6,064,280     | 2,      | 43.4%   | 1,      | 33.0%   |
|            |               | 629,573 |         | 998,476 |         |
+------------+---------------+---------+---------+---------+---------+
| LGT        | 6,501         | 2,264   | 34.8%   | 1,721   | 26.5%   |
+------------+---------------+---------+---------+---------+---------+
| # Pastoral | *             | **6,82  | **      | **5,18  | **      |
|            | *14,166,392** | 3,447** | 48.2%** | 5,820** | 36.6%** |
+------------+---------------+---------+---------+---------+---------+
| MRA        | 85,181,782    | 37,     | 43.6%   | 25,     | 29.7%   |
|            |               | 173,778 |         | 278,169 |         |
+------------+---------------+---------+---------+---------+---------+
| MRH        | 118,572,952   | 46,     | 38.9%   | 31,     | 26.4%   |
|            |               | 087,432 |         | 339,454 |         |
+------------+---------------+---------+---------+---------+---------+
| MRT        | 1,491,115     | 488,000 | 32.7%   | 331,840 | 22.3%   |
+------------+---------------+---------+---------+---------+---------+
| # Agr      | **            | **83,74 | **      | **56,94 | **      |
| o-pastoral | 205,245,849** | 9,211** | 40.8%** | 9,463** | 27.7%** |
+------------+---------------+---------+---------+---------+---------+
| LL         | 1,450,284     | 627,678 | 43.3%   | 163,196 | 11.3%   |
+------------+---------------+---------+---------+---------+---------+
| #          | **1,450,284** | **62    | **      | **16    | **      |
| Peri-urban |               | 7,678** | 43.3%** | 3,196** | 11.3%** |
+------------+---------------+---------+---------+---------+---------+
| Total      | 220,862,524   | 91,     | 41.3%   |         | 0.0%    |
| Rural      |               | 200,336 |         |         |         |
+------------+---------------+---------+---------+---------+---------+
| Non        | 35,072,616    | 14,     | 41.4%   |         | 0.0%    |
| -livestock |               | 509,304 |         |         |         |
+------------+---------------+---------+---------+---------+---------+
| **Total**  | **            | *       | **      | **62,29 | **      |
|            | 476,797,665** | *105,70 | 22.2%** | 8,480** | 13.1%** |
|            |               | 9,640** |         |         |         |
+------------+---------------+---------+---------+---------+---------+

Numbers of poor based on World Bank rural poverty rates.

Includes: Benin, Burkina Faso, Cameroon, Chad, Cote d\'Ivoire,
Equatorial Guinea, Gambia, Ghana, Guinea, Liberia, Mali, Mauritania,
Niger, Nigeria, Senegal, Sierra Leone, Togo

Livestock systems based on Seré and Steinfeld, 1996: LGA=Livestock
grassland arid; LGH=Livestock grassland humid, LGT=Livestock grassland
temperate; MRA= Mixed Rainfed Arid, MRH=Mixed Rainfed Humid; MRT=Mixed
Rainfed Temperate; LL=Livestock landless

Table 6. Main agricultural systems with livestock in West Africa --
livestock species of importance to the poor and their disease
constraints (from a DfID-sponsored ILRI workshop held in Sikasso, Mali,
April 25, 2001 -- see Perry et al., 2001 for further details)

+-------------+-------------------+------------------------------------+
| Cro         | Rank of Species   | Disease Constraints                |
| p-Livestock |                   |                                    |
|             | Important to the  |                                    |
| Production  | Poor              |                                    |
| System      |                   |                                    |
+-------------+-------------------+------------------------------------+
| Pastoralist | 1\. Small         | > Small ruminants: Anthrax,        |
| (arid and   | ruminants (goats  | > Enzootic pneumonia, Pox,         |
| semi-arid)  | more important    | > Helminthosis, Peste des Petits   |
|             | than sheep)       | > Ruminants (PPR), Tryps,          |
| Often with  |                   | > Heartwater, Liver Fluke,         |
| some        | 2\. Donkeys       | > Contagious Caprine               |
| subsistence |                   | > Pleuropneumonia (CCPP), Foot     |
| crops       | 3\. Camels        | > problems, Rift Valley Fever      |
|             |                   | > (RVF), Brucellosis               |
|             | 4\. Cattle        | >                                  |
|             |                   | > Donkeys: Helminthosis; Wounds;   |
|             | 5\. Poultry       | > Tryps                            |
|             |                   | >                                  |
|             |                   | > Camels: Tryps, Mange, Helminths, |
|             |                   | > Anthrax, Camel Pox               |
|             |                   | >                                  |
|             |                   | > Cattle: Tryps, CBPP, Anthrax,    |
|             |                   | > Dermatophilosis, Blackleg,       |
|             |                   | > Haemorrhagic Septicemia,         |
|             |                   | > Helminths, Brucellosis, FMD,     |
|             |                   | > Botulism, Ecto-parasites,        |
|             |                   | > Babesiosis, Anaplasmosis,        |
|             |                   | > Heartwater, RVF, TB; Botulism    |
|             |                   | >                                  |
|             |                   | > Poultry: Newcastle, Helminths,   |
|             |                   | > Ectoparasites                    |
+-------------+-------------------+------------------------------------+
| Agro-       | Done globally for | > Small ruminants: Helminths,      |
| pastoralist | all agro-pastoral | > Anthrax, Respiratory complexes,  |
|             | systems in the    | > Sheep & Goat Pox, Heartwater,    |
| (sub-humid  | region.           | > Liver fluke, PPR, Tryps, CCPP,   |
| and humid)  |                   | > Foot problems, Ecto-parasites,   |
|             | 1\. Small         | > Brucellosis, RVF                 |
| -Cat        | ruminants         | >                                  |
| tle-keeping |                   | > Donkeys: Helminthosis, Wounds,   |
| cultures    | 1\. Poultry       | > Tryps                            |
|             | (chickens, guinea | >                                  |
| -Traction   | fowl)             | > Cattle: Tryps, Anthrax,          |
|             |                   | > Dermatophilosis, Helminths,      |
| -           | 3\. Cattle        | > Ectoparasites, Blackleg,         |
| Cattle-less |                   | > Haemorrhagic Septicemia,         |
| systems     | 4\. Donkeys       | > Brucellosis, FMD, CBPP,          |
|             |                   | > Babesiosis, Anaplasmosis,        |
|             | 5\. Pigs          | > Heartwater, Liver fluke, Lumpy   |
|             |                   | > skin disease, Bovine             |
|             | 6\. Horses        | > tuberculosis, RVF                |
|             |                   | >                                  |
|             |                   | > Pigs: African Swine Fever,       |
|             |                   | > Helminths, Ectoparasites         |
|             |                   | >                                  |
|             |                   | > Poultry: Newcastle, Helminths,   |
|             |                   | > Ectoparasites                    |
+-------------+-------------------+------------------------------------+
| Smallholder | 1\. Poultry       | > Small ruminants: Helminths,      |
| peri-urban, |                   | > Anthrax, Enzootic pneumonia,     |
| Landless    | 2\. Small         | > Pox, Heartwater, Liver fluke,    |
|             | ruminants         | > PPR, Tryps, CCPP, Foot problems, |
|             |                   | > RVF, Brucellosis                 |
|             | 3\. Pigs          | >                                  |
|             |                   | > Donkeys: Helminthosis, Wounds,   |
|             | 4\. Cattle        | > Tryps                            |
|             |                   | >                                  |
|             | 5\. Donkeys       | > Cattle: Tryps, Ectoparasites,    |
|             |                   | > CBPP, FMD, Anthrax,              |
|             | 6\. Rabbits, Cane | > Dermatophilosis, Helminths,      |
|             | rats              | > Blackleg, Haemorrhagic           |
|             |                   | > Septicemia, Heartwater, Lumpy    |
|             | Landless not done | > skin disease, Brucellosis,       |
|             | as a separate     | > Babesiosis, Anaplasmosis, Liver  |
|             | category (donkeys | > fluke, Bovine tuberculosis       |
|             | are very          | >                                  |
|             | important in      | > Pigs: African Swine Fever,       |
|             | Sahelian areas    | > Helminths, Ectoparasites         |
|             | for landless      | >                                  |
|             | people).          | > Poultry: Newcastle, Helminths,   |
|             |                   | > Ectoparasites                    |
+-------------+-------------------+------------------------------------+

**Table 7. Research and development strategies and their contribution to
poverty alleviation (adapted from Perry et al. 2001 in press)**

+-----------------+------------------+-----------------+--------------+
| Research and    | Contributions to |                 |              |
| development     | poverty          |                 |              |
| categories      | alleviation      |                 |              |
+-----------------+------------------+-----------------+--------------+
|                 | *Securing        | *Reducing       | *Improving   |
|                 | assets*          | constraints to  | market       |
|                 |                  | i               | op           |
|                 |                  | ntensification* | portunities* |
+-----------------+------------------+-----------------+--------------+
| *Transferring   | -   Neo-natal    | -   Hygiene     | -   Hygiene  |
| knowledge and   |     mortality    |     issues for  |     issues   |
| available       |                  |     the         |     for the  |
| tools*          | -   Reproductive |     prevention  |              |
|                 |     disorders    |     of mastitis |   prevention |
|                 |                  |                 |     of       |
|                 | -   Nutritional  | -   Heat        |     c        |
|                 |     deficiencies |     detection   | ysticercosis |
|                 |     / imbalances |     in cows     |              |
|                 |                  |                 |              |
|                 |                  | -   Integrated  |              |
|                 |                  |     control of  |              |
|                 |                  |                 |              |
|                 |                  |    haemonchosis |              |
+-----------------+------------------+-----------------+--------------+
| *Improved       | -   Development  | -   Development | -   Testing  |
| tools, better   |     of a more    |     and         |     of       |
| strategies,     |     efficacious  |     evaluation  |     vaccine  |
| better          |     HS vaccine   |     of          |     for      |
| delivered*      |                  |     integrated  |              |
|                 | -   Testing and  |     control     | *Cysticercus |
|                 |     evaluation   |     measures    |              |
|                 |     of new PPR   |     for         |  cellulosae* |
|                 |     vaccine      |                 |              |
|                 |                  |  trypanosomosis | -   Improved |
|                 | -   Evaluation   |                 |     FMD      |
|                 |     of strategic | -   Development |     vaccines |
|                 |     therapy and  |     of          |              |
|                 |     management   |     strategies  | -   FMD      |
|                 |     strategy for |     to manage   |     control  |
|                 |     the          |     resistance  |     strategy |
|                 |     prevention   |     to          |     & policy |
|                 |     of *Toxocora |                 |              |
|                 |     vitulorum*   |   anthelmintics |  development |
|                 |                  |                 |              |
|                 | -   Newcastle    |                 | -   Improved |
|                 |     disease      |                 |     vaccines |
|                 |     vaccine      |                 |     for      |
|                 |     delivery     |                 |              |
|                 |     strategies   |                 |  brucellosis |
|                 |                  |                 |              |
|                 |                  |                 | -   Impact   |
|                 |                  |                 |              |
|                 |                  |                 |   assessment |
|                 |                  |                 |     and      |
|                 |                  |                 |              |
|                 |                  |                 | epidemiology |
|                 |                  |                 |     of       |
|                 |                  |                 |     bovine   |
|                 |                  |                 |     TB       |
|                 |                  |                 |              |
|                 |                  |                 | -   Spatial  |
|                 |                  |                 |              |
|                 |                  |                 |    targeting |
|                 |                  |                 |     of       |
|                 |                  |                 |     anthrax  |
|                 |                  |                 |     control  |
|                 |                  |                 |     to poor  |
+-----------------+------------------+-----------------+--------------+
|                 | Delivery and     |                 |              |
|                 | adoption of      |                 |              |
|                 | animal health    |                 |              |
|                 | services and     |                 |              |
|                 | technologies     |                 |              |
|                 | issues           |                 |              |
+-----------------+------------------+-----------------+--------------+
| *New tools and  | -   Development  | -   New vaccine | -            |
| approaches*     |     of a vaccine |     development |   Diagnostic |
|                 |     for RVF in   |     for East    |     for B.   |
|                 |     humans       |     Coast       |              |
|                 |                  |     fever,      |   melitensis |
|                 | -   Oral         |     heartwater, |              |
|                 |     recombinant  |                 | -   Vaccines |
|                 |     and marker   |   anaplasmosis, |     for CBPP |
|                 |     vaccines for |     babesiosis, |     & CCPP   |
|                 |     PPR          |                 |              |
|                 |                  | dermatophilosis |              |
|                 | -   Vaccines for |                 |              |
|                 |     sheep & goat | -   New         |              |
|                 |     pox          |                 |              |
|                 |                  |    therapeutics |              |
|                 | -   Diagnostics  |     for         |              |
|                 |     and vaccines |                 |              |
|                 |     for          |  trypanosomosis |              |
|                 |                  |                 |              |
|                 | fascioliasis[^1] |                 |              |
|                 |                  |                 |              |
|                 | -   Vaccines for |                 |              |
|                 |     African      |                 |              |
|                 |     Swine fever  |                 |              |
+-----------------+------------------+-----------------+--------------+

**Figure 1, The multiple impacts of animal diseases.**

**(from Perry et al., 2001- in press -- modified from Swallow, 2000)**

**Figure 2 -- A generic animal health delivery systems (modified from
Perry et al., 2002 -- in press).**

![](media/image1.wmf)

**Figure 3. Characterisation of disease control based on rivalry and
excludability (from Holden, 1999).**

+------+---+----------------------------+----------------------------+
|      |   | #### Excludability         |                            |
+------+---+----------------------------+----------------------------+
|      |   | **Low**                    | **High**                   |
+------+---+----------------------------+----------------------------+
| >    | # | ## Public goods            | > **Toll goods**           |
|  **R | # |                            |                            |
| ival | # | -   Epidemic or zoonotic   | -   vaccine production     |
| ry** |   |     disease control        |                            |
| >    | L |     (including             | -   diagnostic services    |
| > *  | o |     surveillance, movement |                            |
| *(or | w |     control, quarantine    | -   veterinary clinics     |
| > su |   |     services)              |                            |
| btra |   |                            | -   dips                   |
| ctab |   | -   Some extension         |                            |
| ilit |   |                            |                            |
| y)** |   | -   Some research          |                            |
|      |   |                            |                            |
|      |   | -   Control of food-borne  |                            |
|      |   |     diseases               |                            |
|      |   |                            |                            |
|      |   | -   Drug quality control   |                            |
+------+---+----------------------------+----------------------------+
|      | # | **Common pool goods**      | **Private goods**          |
|      | # |                            |                            |
|      | # | -   Tsetse control on      | -   Endemic disease        |
|      |   |     communal land using    |     prevention and control |
|      | H |     traps, targets or      |                            |
|      | i |     aerial spraying        | -   Sales of drugs and     |
|      | g |                            |     vaccines               |
|      | h |                            |                            |
|      |   |                            | -   Some extension         |
|      |   |                            |                            |
|      |   |                            | -   Some research          |
+------+---+----------------------------+----------------------------+
| Defi |   |                            |                            |
| niti |   |                            |                            |
| ons: |   |                            |                            |
|      |   |                            |                            |
| **   |   |                            |                            |
| Excl |   |                            |                            |
| udab |   |                            |                            |
| ilit |   |                            |                            |
| y**: |   |                            |                            |
| the  |   |                            |                            |
| abi  |   |                            |                            |
| lity |   |                            |                            |
| of   |   |                            |                            |
| the  |   |                            |                            |
| user |   |                            |                            |
| to   |   |                            |                            |
| exc  |   |                            |                            |
| lude |   |                            |                            |
| ot   |   |                            |                            |
| hers |   |                            |                            |
| who  |   |                            |                            |
| have |   |                            |                            |
| not  |   |                            |                            |
| paid |   |                            |                            |
| from |   |                            |                            |
| be   |   |                            |                            |
| nefi |   |                            |                            |
| ting |   |                            |                            |
| from |   |                            |                            |
| the  |   |                            |                            |
| us   |   |                            |                            |
| er's |   |                            |                            |
| in   |   |                            |                            |
| vest |   |                            |                            |
| ment |   |                            |                            |
| in a |   |                            |                            |
| good |   |                            |                            |
| or   |   |                            |                            |
| serv |   |                            |                            |
| ice. |   |                            |                            |
|      |   |                            |                            |
| **Ri |   |                            |                            |
| valr |   |                            |                            |
| y**: |   |                            |                            |
| con  |   |                            |                            |
| sump |   |                            |                            |
| tion |   |                            |                            |
| of a |   |                            |                            |
| good |   |                            |                            |
| or   |   |                            |                            |
| ser  |   |                            |                            |
| vice |   |                            |                            |
| by   |   |                            |                            |
| one  |   |                            |                            |
| user |   |                            |                            |
| p    |   |                            |                            |
| recl |   |                            |                            |
| udes |   |                            |                            |
| its  |   |                            |                            |
| use  |   |                            |                            |
| by   |   |                            |                            |
| o    |   |                            |                            |
| ther |   |                            |                            |
| us   |   |                            |                            |
| ers. |   |                            |                            |
+------+---+----------------------------+----------------------------+

**Figure 4. Sustainable livelihoods framework (source: DfID, 2000)**

[^1]: Control measures for fascioliasis will also be important in
    enhancing market opportunities