Efficacy of integrated school based de-worming and prompt malaria treatment on helminths -Plasmodium falciparum co-infections: A 33 months follow up study
1 National Institute of Health Research, Box CY 573, Causeway Harare, Zimbabwe
2 College of Health Sciences, Department of Medical Microbiology, P.0 Box A178, Avondale, Harare, Zimbabwe
3 Johns Hopkins Bloomberg School of Public Health, Department of Molecular Microbiology and Immunology, Baltimore, Maryland, USA
4 University of Zimbabwe, Department of Biochemistry, P.O Box MP167, Mount Pleasant, Harare, Zimbabwe
5 Central Statistical Office, PO Box CY 342, Causeway, Harare, Zimbabwe
6 University of California, San Diego, Division of International Health & Cross Cultural Medicine, Department of Family and Preventive Medicine, San Diego, California USA
7 National Microbiology Reference Laboratory, P.O. Box ST749, Southerton, Zimbabwe
8 University of Edinburgh, Institute for Immunology and Infection Research, Edinburgh, UK
BMC International Health and Human Rights 2011, 11:9 doi:10.1186/1472-698X-11-9Published: 22 June 2011
The geographical congruency in distribution of helminths and Plasmodium falciparum makes polyparasitism a common phenomenon in Sub Saharan Africa. The devastating effects of helminths-Plasmodium co-infections on primary school health have raised global interest for integrated control. However little is known on the feasibility, timing and efficacy of integrated helminths-Plasmodium control strategies. A study was conducted in Zimbabwe to evaluate the efficacy of repeated combined school based antihelminthic and prompt malaria treatment.
A cohort of primary schoolchildren (5-17 years) received combined Praziquantel, albendazole treatment at baseline, and again during 6, 12 and 33 months follow up surveys and sustained prompt malaria treatment. Sustained prompt malaria treatment was carried out throughout the study period. Children's infection status with helminths, Plasmodium and helminths-Plasmodium co-infections was determined by parasitological examinations at baseline and at each treatment point. The prevalence of S. haematobium, S. mansoni, STH, malaria, helminths-Plasmodium co-infections and helminths infection intensities before and after treatment were analysed.
Longitudinal data showed that two rounds of combined Praziquantel and albendazole treatment for schistosomiasis and STHs at 6 monthly intervals and sustained prompt malaria treatment significantly reduced the overall prevalence of S. haematobium, S. mansoni, hookworms and P. falciparum infection in primary schoolchildren by 73.5%, 70.8%, 67.3% and 58.8% respectively (p < 0.001, p < 0.001, p < 0.001, p < 0.001 respectively). More importantly, the prevalence of STH + schistosomes, P. f + schistosomes, and P. f + STHs + schistosomes co-infections were reduced by 68.0%, 84.2%, and 90.7%, respectively. The absence of anti-helminthic treatment between the 12 mth and 33 mth follow-up surveys resulted in the sharp increase in STHs + schistosomes co-infection from 3.3% at 12 months follow up survey to 10.7%, slightly more than the baseline level (10.3%) while other co-infection combinations remained significantly low. The overall prevalence of heavy S. haematobium, S. mansoni and hookworms infection intensities were significantly reduced from: 17.9-22.4% to 2.6-5.1%, 1.6-3.3% to 0.0% and 0.0-0.7% to 0.0% respectively.
Biannual Integrated school based antihelminthic and sustained prompt malaria treatment has a potential to reduce the burden of helminths-plasmodium co-infections in primary school children. In areas of stable malaria transmission, active case finding is recommended to track and treat asymptomatic malaria cases as these may sustain transmission in the community.