Prevalence, Morbidity, And Response To Treatment Of Schistosoma Mansoni In A Rural Primary School Population

Abstract

All the children in Lietune Primary School,Machakos District, Kenya were examined in a study to determine the prevalence and intensity of Schistosoma mansoni infection and correlated with morbidity as determined by standard medical examination. The individuals were 357 with a male : female ratio of 1.2 : 1 and ages ranged from 4 to 19 years. Schistosoma mansoni infection was diagnosed by quantitative egg counts from a modified Kato thick smears of stool. An overall prevalence of 74% was found. With respect to intensity, 21.6% were uninfected, 43.7% had light, 22.4% moderate and 9.3% heavy infections. Peak intensity occured in males at ages 11 to 13 and in females at 17 years and above. Hepatomegaly occurred more frequently in the heavily infected.Splenomegaly was noted in only 2% of the population.Malaria parasites did not feature much but many intenstinal parasites were noted. A sample of 130 children from the school was chosen on the basis of their consistent egg counts in two stool smears and 98.5% were infected with Schistosoma mansoni : light infection 56.9%, moderate 28.5%, heavy 13.1% and uninfected 1.5%. A clinical examination was carried out and 31.5% were found to have enlarged livers. The children were then treated with Oxamniquine at a dose of 30 mg per kg. body weight, in two divided doses administered orally six hours apart under supervision. Three months later their stools were re-examined and 68.5% were uninfected, 27.7% had light, 3.1 moderate and 0.8% heavy infections. Physical examination then revealed a prevalence of hepatomegaly of only 4.6%.