Tackling viral haemorrhagic fever in Africa
Authors: Chikwe Ihekweazu, Ibrahim Abubakar
Journal: The Lancet (2017)

Outbreaks of viral haemorrhagic fevers, such as the Ebola virus disease epidemic in west Africa, have caught the attention of the global health community because of perceived and real threats to local, national, and global health security and their economic impact.1Omoleke SA Mohammed I Saidu Y Ebola viral disease in west Africa: a threat to global health, economy and political stability.J Public Health Afr. 2016; 7: 534Crossref PubMed Scopus (45) Google Scholar Although viral haemorrhagic fever outbreaks primarily affect settings in which pathogens emerge from animal hosts, they also have the potential to spread worldwide. Consequently, models that accurately predict the emergence and spread of viruses that cause viral haemorrhagic fevers are needed. In The Lancet, David Pigott and colleagues2Pigott DM Deshpande A Letourneau I et al.Local, national, and regional viral haemorrhagic fever pandemic potential in Africa: a multistage analysis.Lancet. 2017; (published online Oct 11.)http://dx.doi.org/10.1016/S0140-6736(17)32092-5Summary Full Text Full Text PDF PubMed Scopus (57) Google Scholar use a combination of approaches to assess and understand the threat of viral haemorrhagic fevers across Africa by identifying locations that have the greatest potential for zoonotic spillover, regions that are susceptible to ongoing secondary transmission, and areas with the highest potential for local and global spread. A key strength of this study is the provision of subnational estimates of risks. The use of models to inform the distribution of resources to prevent or respond to outbreaks requires prospective validation. Gaps and bias in surveillance data on viral haemorrhagic fevers in human beings in most African settings3Tambo E Ugwu EC Ngogang JY Need of surveillance response systems to combat Ebola outbreaks and other emerging infectious diseases in African countries.Infect Dis Poverty. 2014; 3: 29Crossref PubMed Scopus (89) Google Scholar limit the ability to correctly predict zoonotic spillover. Pigott and colleagues predicted probable zoonotic transmission from animal hosts to human beings by combining geographical information on index cases of outbreaks and viral detection in animals and related this information to drivers in the environment to generate profiles that characterise where disease is likely to be found. In the absence of unbiased prospective surveillance, using similarities between environmental profiles to predict disease spread and which areas to focus surveillance should be used with appropriate caution. Nevertheless, this comprehensive assessment justifies investment in better surveillance and further animal–host surveys. Projects such as the US Agency for International Development's (USAID's) PREDICT programme4US Agency for International DevelopmentEmerging pandemic threats—the PREDICT project.https://www.usaid.gov/news-information/fact-sheets/emerging-pandemic-threats-programGoogle Scholar provide an opportunity to improve the quality of viral reservoir data, but these data must be combined with better local disease surveillance and human–animal interaction behavioural data. By contrast, the quality of data on human connectivity, especially for air travel, is more robust and predictions of subsequent spread after emergence are therefore likely to be accurate. In Pigott and colleagues' study,2Pigott DM Deshpande A Letourneau I et al.Local, national, and regional viral haemorrhagic fever pandemic potential in Africa: a multistage analysis.Lancet. 2017; (published online Oct 11.)http://dx.doi.org/10.1016/S0140-6736(17)32092-5Summary Full Text Full Text PDF PubMed Scopus (57) Google Scholar countries that have the greatest potential for spillover from animals reflect the original zoonotic niche of the viral haemorrhagic fevers examined, as expected. Analysis of outbreak receptivity, which relates to susceptibility to ongoing secondary transmission, showed that 90% of districts in the Central African Republic, Chad, Somalia, and South Sudan ranked in the top 90th percentile. These countries stand out for their political instability. Strikingly, estimating epidemic potential based on local and international connectivity showed that at-risk districts in Nigeria represented many of those with the highest potential for global spread of viral haemorrhagic fevers.2Pigott DM Deshpande A Letourneau I et al.Local, national, and regional viral haemorrhagic fever pandemic potential in Africa: a multistage analysis.Lancet. 2017; (published online Oct 11.)http://dx.doi.org/10.1016/S0140-6736(17)32092-5Summary Full Text Full Text PDF PubMed Scopus (57) Google Scholar Pigott and colleagues suggest that this work should inform investment at each stage of potential epidemic progression and propose areas in which they should be made. However, the authors did not mention where the investment will come from or which institutions should be the primary recipients. Sustainable action to prevent the emergence and spread of viral haemorrhagic fevers requires investment to include local sources and to strengthen national and local capacity. Science-led national public health institutes (NPHIs) are needed to use complex information to make informed decisions on preparedness and response. NPHIs can provide leadership in disease surveillance and outbreak investigations, reference laboratory services, including specialist diagnostic services for rare organisms, and advise their governments on development and evaluation of public health interventions. These institutes need scientists who are knowledgable in the local context. Many African countries already recognise the need to bring the requisite expertise together into one institute, which led to the establishment of several NPHIs.5International Association of National Public Health Institutes (IANPHI)African National Public Health InstitutesIANPHI members in Africa.http://ianphiafrica.org/members/Google Scholar Equally pertinent is the need for regional cooperation and resilience, which has led to new regional bodies such as the West African Regional Centre for Surveillance and Disease Control and the Africa Centres for Disease Control. These institutes are supported with modest resources compared with similar entities in high-income countries, despite the increased risk of major outbreaks from zoonotic and human sources. Not enough emphasis in the post-Ebola narrative has been placed on strengthening NPHIs to fulfil their global health security mandate. Instead, too much responsibility has been placed on WHO, which, despite improvements in technical expertise on emergency response,6WHOWHO's new Health Emergencies Programme.http://www.who.int/features/qa/health-emergencies-programme/en/Google Scholar does not have sufficient resources—should they be expected—to respond to all threats in a continent as vast as Africa, or the local presence to rapidly deal with emerging viral haemorrhagic fever threats. What if Guinea had a strong NPHI with the right expertise to respond to information on infectious disease risk and use this information to persuade its own government to act? An outbreak of the size and scale experienced might never have happened. Establishment of NPHIs provides the crucial national resources required to underpin the prevention, detection, and response to outbreaks of emerging infections. These organisations should be designed with relevant disciplines and expertise to ensure they are fit for purpose, such as technical, epidemiological, microbiological, research, and communication skills, and supported by adequate and stable financing.7Ihekweazu C Ncube F Schoub B et al.A north/south collaboration between two national public health institutes—a model for global health protection.J Public Health Policy. 2015; 36: 181-193Crossref PubMed Scopus (8) Google Scholar To build strong, science-based institutions takes time and effort; however, it is the only sustainable way that research can lead to the development of a robust global health response capacity to emerging infections including viral haemorrhagic fevers. Although Pigott and colleagues2Pigott DM Deshpande A Letourneau I et al.Local, national, and regional viral haemorrhagic fever pandemic potential in Africa: a multistage analysis.Lancet. 2017; (published online Oct 11.)http://dx.doi.org/10.1016/S0140-6736(17)32092-5Summary Full Text Full Text PDF PubMed Scopus (57) Google Scholar did not explore specific interventions, such as the ability to respond to outbreaks or the use of protective equipment with their model, future research using such models should investigate measures to mitigate spread. CI is the Chief Executive Officer of the Nigeria Centre for Disease Control and acting lead for the West Africa Regional Centre for Surveillance and Disease Control. IA and CI are investigators on the European & Developing Countries Clinical Trials Partnership-funded Pandora consortium and the UK Space Agency-funded scoping study to develop tools for predicting zoonotic infections. Local, national, and regional viral haemorrhagic fever pandemic potential in Africa: a multistage analysisOur analysis provides a unified assessment of potential epidemic trajectories, with the aim of allowing national and international agencies to pre-emptively evaluate needs and target resources. Within each country, our framework identifies at-risk subnational locations in which to improve surveillance, diagnostic capabilities, and health systems in parallel with the design of policies for optimal responses at each stage. In conjunction with pandemic preparedness activities, assessments such as ours can identify regions where needs and provisions do not align, and thus should be targeted for future strengthening and support. Full-Text PDF Open Access