Changes in Morbidity, Physical Fitness, and Perceived Quality of Life among Schoolchildren following Four Years of Different Mass Drug Administration Strategies against Schistosoma mansoni Infection in Mwanza Region, Northwestern Tanzania.

Annette Olsen,Pascal Magnussen,Godfrey Kaatano,Safari Kinung’Hi

doi:10.4269/ajtmh.19-0428

Abstract

.Schistosoma mansoni infection negatively impacts children’s physical health and may influence general well-being. Schistosomiasis control programs aim at reducing morbidity through mass drug administration (MDA). This study aimed to compare morbidity markers between two cohorts of Tanzanian schoolchildren with initial high prevalence of S. mansoni infection. One cohort (N = 254 at baseline) received annual MDA for 4 years using community-wide treatment (CWT). The second cohort (N = 318 at baseline) received school-based treatment (SBT) every other year for 4 years. At year 5, the CWT cohort and the SBT cohort were reduced to 153 and 221 children, respectively. The characteristics of the 198 children lost to follow-up did not differ at baseline from those who were examined in year 5. Schistosoma mansoni infection, hemoglobin (Hb) and anemia, physical fitness, and perceived quality of life were investigated at baseline, year 3, and year 5, whereas liver and spleen pathology (ultrasound) were investigated only at baseline and year 5. Cohorts were compared using two-way mixed-model analysis of variance (ANOVA). Both treatment regimens significantly decreased individual-level mean intensity of S. mansoni infection, anemia, and hepatomegaly, and increased Hb levels after 5 years. Hepatomegaly was the only parameter affected by the treatment regimen as the CWT approach reduced the percentage of individuals with hepatomegaly significantly more than the SBT approach. Both treatment regimens led to reduced physical fitness at year 5 compared with baseline. The modest impact of the two control strategies are probably due to initial low intensity of infection, ensuring low level of schistosomiasis-related morbidity.

Highlights

Schistosomiasis is one of the neglected tropical diseases and a major public health problem, especially in sub-Saharan Africa.[1,2] Of the 252 million estimated cases of schistosomiasis, more than 90% occur in sub-Saharan Africa.[3]
Schistosoma mansoni infection, hemoglobin (Hb) and anemia, physical fitness, and perceived quality of life were investigated at baseline, year 3, and year 5, whereas liver and spleen pathology were investigated only at baseline and year 5
In Tanzania, both intestinal and urogenital schistosomiases are endemic, but along the shores of Lake Victoria, the intestinal form caused by Schistosoma mansoni is the most common

Summary

Introduction

Schistosomiasis is one of the neglected tropical diseases and a major public health problem, especially in sub-Saharan Africa.[1,2] Of the 252 million estimated cases of schistosomiasis, more than 90% occur in sub-Saharan Africa.[3]. In Tanzania, both intestinal and urogenital schistosomiases are endemic, but along the shores of Lake Victoria, the intestinal form caused by Schistosoma mansoni is the most common. The infection occurs in adolescents and adults in these communities, it is especially prevalent in school-aged children.[4,5]. The clinical consequences of S. mansoni infections result from tissue damage and blood loss caused by eggs trapped in host tissues. The immunologic reaction to the eggs causes granuloma formation in the intestine and liver, leading to liver enlargement in advanced cases. This is frequently associated with portal hypertension and may result in enlargement of the spleen. In children, lead to marked nonspecific symptoms such as anemia, malnutrition, impaired growth, impaired mental development, and general body weakness.[1]

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