Schistosoma mansoni in infants (aged < 3 years) along the Ugandan shoreline of Lake Victoria.

Abstract

In two complementary epidemiological surveys of villages on the Ugandan shoreline of Lake Victoria, the putative occurrence of intestinal schistosomiasis in the local infants (children aged < 3 years) was investigated. When, during the first survey, 136 mother-and-infant pairs from a total of 12 villages were studied, only 7% of the infants but 45% of the mothers were found to be egg-patent for Schistosoma mansoni infection. The use of dipstick tests for urine-circulating cathodic antigen indicated, however, a much higher prevalence, of approximately 40%, among the infants. In the second survey, urine samples and multiple, not single, stool samples were collected from another 19 mother-and-infant pairs in two of the 12 study villages (Bugoto and Bwondha), and a standardized questionnaire was implemented. The prevalence of egg-patent infection was then found to be markedly higher in the study infants from Bugoto (86%) than in those from Bwondha (25%). A greater level of mother-and-infant water contact, a higher abundance of (infected) Biomphalaria choanomphala, and an unusual lakeshore topology may explain why S. mansoni infection was so much more common in the Bugoto subjects than in the Bwondha. All but one of the infants studied in the second survey were found to be anaemic (with <110 g haemoglobin/litre). Taken together, these children were less likely to be found infected with hookworm (16%), Hymenolepis nana (11%) or Trichuris trichiura (5%) than with S. mansoni (47%). Infection with the parasites causing intestinal schistosomiasis can be common among the infants living in these lakeshore villages. Although the immediate and later-life clinical impacts of such infection have yet to be elucidated, such infants would probably benefit from regular de-worming. Mothers should be strongly encouraged to visit the nearest health-services clinic, with their infants, for any necessary anthelmintic treatment.