Integrated Control of Malaria and Polyparasitism Clinical Trial
Official title:
Analysis on the Burden of Helminths-plasmodium Polyparasitism, Impact on Anaemia and Effects of Integrated School Based Parasite Control and Health Education in Zimbabwe
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
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.
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Observational Model: Cohort, Time Perspective: Prospective