Epidemiology and morbidity of Schistosoma mansoni infection in a fishing community along Lake Albert in Uganda

Abstract

Schistosoma mansoni infection, associated morbidity and symptoms were studied in Piida fishing community at Butiaba, along Lake Albert, Uganda, from November 1996 to January 1997. The study revealed that S. mansoni is highly endemic with an overall prevalence of 72%, a mean intensity of 419.4 eggs per gram (epg) faeces (geometric mean for positives only), with 37.8% of males and 33.0% of females excreting over 1000 epg. Prevalence and intensity peaked in the 10-14 year old age group and decreased with increasing age. Females were less heavily infected than males. Differences were also shown between tribes. Diarrhoea and abdominal pain were commonly reported in Piida. However, no clear-cut correlation between intensity of S. mansoni infection and these conditions could be demonstrated, indicating that retrospective questionnaires concerning S. mansoni related-symptomatology are of limited value. Organomegaly, as assessed by ultrasonography, was frequent and hepatomegaly was associated with heavy S. mansoni infection. No correlation was demonstrated between splenomegaly and infection. This study emphasizes that schistosomiasis mansoni is a major public health problem in Piida fishing community and presumably also in many similar fishing communities. These observations call for immediate intervention and can help in planning long-term strategies for sustainable morbidity control.

Assessment of Ultrasound Morbidity Indicators of Schistosomiasis in the Context of Large-Scale Programs Illustrated With Experiences From Malian Children

“…Likewise, in the case of hepatomegaly, we were unable to distinguish clear associations, which may have been due to the fact that these observed morbidities were likely to have been multifactorial, with S. mansoni infection being only one of a number of potential causes. 57 There are often many factors (genetic and possibly most importantly malaria, which is transmitted throughout the year in Mali 58 ) other than S. mansoni that can cause liver enlargement, and their role and interaction with S. mansoni infection also requires further clarification.…”

“…7 Ultrasonography is currently the diagnostic tool of choice for detecting pathologic conditions associated with schistosomiasis, such as dilatation of the renal pelvis, bladder wall lesions, liver fibrosis and enlargement, and dilatation of the portal vein. 8,9 For detection of infection with S. haematobium, ultrasonography is an established method for detecting urinary tract pathologic effects not only in the hospital setting, [10][11][12][13] but also in field-based studies, 14 with the advantage of being non-invasive, relatively simple to perform, well accepted by communities, and providing a direct image of the pathologic changes. 15 Additionally, ultrasonography provides sensitive and precise measurements of S. mansoni-associated pathologic changes 16,17 In the attempt to objectively define and categorize the pathologic changes associated with schistosomiasis and to standardize the different scoring systems used in the past in different disease-endemic areas, 18,19 successive ultra-sound consensus meetings were held in Niamey, Niger in 1996 and Belo Horizonte, Brazil in 1997.…”

High Schistosoma mansoni Disease Burden in a Rural District of Western Zambia

“…Variations in infection prevalence in male and female participants are mostly attributed to differences in exposure habits, which are usually occupation-based. 22 For instance, in our study communities, women have more contact hours with these Schistosomainfested water bodies carrying out domestic chores, such as washing, than men, because access to a clean water supply and good sanitation is limited in most households. However, findings from a recent study in Uganda 23 showed that men were more likely to be infected with S. mansoni than their female counterparts, because they have more water contact hours with infested water during their fishing activities.…”

“…Similar trends in the intensity of infection have been documented in other S. mansoni-endemic areas. 22,23 Differences in parasite distribution among the different age groups have been attributed to behavioral changes and acquisition of immunity to infection in the older age groups. 24,25 Although it is true that immunity to Schistosoma infection develops over time and in line with increasing age, the trend may not be so for behavioral change as a factor for infection reduction among adults living in S. mansoni-endemic areas.…”

A comparative study of Multiple versus Single infection doses of <i>Schistosoma haematobium</i> in Golden hamsters (<i>Mesocricetus auratus</i>)

“…Factors that determine the level of morbidity in an exposed population include: the degree and length of exposure [4], intensity of infection, coinfection [5] and ability to modulate those reactions [4]. Low infection rates over prolonged periods of time characterize schistosome infections of people living in endemic areas.…”