Worm Infestation and Child Health in Zimbabwe
Condition: Integrated Control of Malaria and Polyparasitism
MeSH terms: Malaria
Study type: Observational

Summary: 
      The main objective of the project was to determine the effect of integrated school based
      deworming and health education on prevalence and morbidity due to co-infection infection with
      schistosomiasis, STHs and malaria among primary school age children living in rural and
      farming areas in Zimbabwe

      There is need for regular school based de-worming and health education programs for the
      helminths-Plasmodium co-infections in primary schoolchildren living in rural and commercial
      farming areas in Zimbabwe
    

Detailed description: 
      Schistosomiasis is one of the major communicable diseases of public health and socio-economic
      importance in the developing world. More than 600 million people are at risk of infection
      with schistosomiasis, 207 million are infected and 120 million are suffering from severe
      morbidity due to schistosomiasis. Soil transmitted helminths (hookworms, Trichuris trichura
      and Ascaris lumbricoides) infect more than 2 billion people with children being the most at
      risk age group. Common clinical outcomes of soil transmitted helminths (STHs) include
      anaemia, impaired physical development, cognition and malnutrition area especially in primary
      school children. Global estimates indicate 243 million cases of malaria worldwide of which
      (85%) were reported in African region only. It accounted for an estimated 863 000 deaths in
      2008, of which 89% occurred in the Africa alone.

      The high prevalence of schistosomiasis, STHs and malaria and the striking similarity of the
      conditions that favour their survival, reproduction and transmission that include poverty,
      lack of preventive measures, health care, safe water and sanitary facilities, and the
      similarity in temperatures conditions, make polyparasitism from these parasites a "norm that
      an exception" in tropical and sub-tropical areas. Separate studies have shown endemicity of
      schistosomiasis, STHs and malaria in Zimbabwe and all these studies have demonstrated high
      prevalence of schistosomiasis, STHs and malaria among primary schoolchildren. Though only
      single parasite were investigated in separate studies, results from previous studies indicate
      geographic overlap of helminths and Plasmodium and thus polyparasitism especially in primary
      schoolchildren. However data is scarce on extend of polyparasitism with schistosomiasis, STHs
      and Plasmodium malaria in Zimbabwe and else where. Delineation of areas co-endemic for
      helminthiasis and malaria and the knowledge of the proportion of the population with
      co-infections is a first step in allocating limited public health resources for integrated
      control programmes. Using parasitological methods this study sought to determine the
      distribution of polyparasitism in primary schoolchildren living in rural and commercial
      farming areas in Zimbabwe.

      Prevalence of anaemia among children under 5 years of age in Zimbabwe is 58% (range
      55.4%-63.1%) and it is 38% (range 30.7%-47.5%) for women. However the prevalence of anaemia
      in primary school age children (5-15 years) is not reported. Neither is there a report on the
      etiology of anaemia in this age group. Data is also lacking on the contribution of STHs,
      schistosomiasis and Plasmodium falciparum on the reported anaemia prevalence in Zimbabwe
      although they are major contributors to this disease. There is also a paucity of evidence on
      the impact of polyparasitism with helminths and Plasmodium on anaemia especially among the
      most susceptible primary schoolchildren in the developing world including Zimbabwe. These
      gaps derail policy decisions on appropriate integrated control strategies that should be
      based on scientific evidence from field studies. The impact of polyparasitism on anaemia
      among primary schoolchildren living in the commercial farming area was determined in this
      study.

      The growing interest for the global control of polyparasitism by combining different
      interventions is economically considered cost effective and the global attention is focused
      on this strategy. However a number of operational research questions including the choice of
      different integrated control strategies, timing of treatment cycles, feasibility of
      implementation and impact on prevalence of polyparasitism, and anaemia requires evaluation
      before rolling out large scale control programmes. A longitudinal study was conducted to
      investigate the impact of combined regular school based treatment and delayed treatment of
      parasitic diseases on polyparasitism and anaemia.

      Zimbabwe is among WHO member states that have placed control of schistosomiasis, malaria and
      STHs high on the agenda. Wide spread use of Praziquantel will be inevitable. However whilst
      global use of Praziquantel is scaling up, there is also a growing concern in the use of this
      single drug for treatment of a disease affecting more than 200 million people especially in
      the wake of low cure rates reported in Senegal and Egypt. Consequently recommendations for
      continued monitoring for Praziquantel resistance under the pressure of wide spread use of the
      drug have been made. Current data is lacking on the efficacy of Praziquantel in treatment of
      schistosomiasis in Zimbabwean population. Praziquantel drug efficacy was determined in this
      study in order to advice health managers on the implications of mass drug administration that
      is pending as Zimbabwe prepares from mass treatment using the school based approach.

      The World Health Organization recommends that any large scale control programme should be
      preceded by a baseline survey in order to monitor and evaluate control strategies during and
      after implementation. For the control of helminthiasis, conducting the baseline survey in
      grade three children (8-10years) is recommended since they harbour the highest prevalence and
      intensity of infection in the community and can be followed up to at least two years to
      monitor and evaluate effectiveness of any control strategy implemented. Thus the prevalence
      of helminths in this age group can be used as an index for assessing community prevalence.
      However data on Knowledge attitudes and practice (KAP) of grade three children in relation to
      schistosomiasis, STHs and malaria is lacking. The impact of school health education on
      behaviour modification of the school children towards prevention of helminthiasis and malaria
      in Zimbabwe is also scarce. A follow up KAP study was conducted in grade three children
      before and after school based health education integrated with treatment.
    

Intervention name(s): Health education intervention
Intervention type(s): Behavioral
Intervention description(s): Health education was conducted in two ways. (1) Teachers were taught how to use the flip chart that contained health education material about parasites. The lessons were done during free periods as this intervention had not been formally fitted into the school syllabus. (2) The research team provided health education to school children. Focus group discussions were conducted by the research team with school children all assembled outside their classes. Health education leaflets were distributed to all school children at the school. Children were asked to share the health information with their friends and families.
Other intervention name(s): Knowledge Attitude and Practice intervention
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Primary school going children living in rural and commercial farming areas
      
Keywords: health education; Polyparasitism; school based deworming program; integrated control of parasites