Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa.

Elmar Saathoff,Jane D Kvalsvig,Chris C Appleton,Annette Olsen

doi:10.1186/1471-2334-4-27

Abstract

BackgroundGeohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN) established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province.MethodsGrade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection.ResultsThe hookworm prevalence in the study population (83.2%) was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively) were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR) of 78.8 and 96.4% and egg reduction rates (ERR) of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%). Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels.ConclusionHigh geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches.

Highlights

Geohelminth infection is a major health problem of children from rural areas of developing countries
The cure rates (CR) and egg reduction rates (ERR) as measured in most field studies including ours are notoriously unreliable and can only approximately indicate the true treatment success [25], the very low success rates that we found for the treatment of T. trichiura infection warrant attention
This study has shown that the high prevalence and intensity of geohelminth infection necessitate regular treatment of primary schoolchildren in the study area according to WHO criteria [6]

Summary

Introduction

Geohelminth infection is a major health problem of children from rural areas of developing countries. Children are the group with the highest prevalences and infection intensities and are very vulnerable to the effects of worm infection These include nutritional deficiencies [1,2] and impaired physical and mental development [3,4,5], resulting in additional insults to an already disadvantaged group. Who were absent or unable to produce a specimen during each of our repeated visits were not included in the analysis of the respective surveys due to lack of data. They were included for those parts of the study where they participated in order not to increase bias due to the likely difference in infection status between absentees and pupils who attended school [12].

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