Browsing by Author "Kabatereine, Narcis B"

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Cytokine Production in Whole Blood Cultures from a Fishing Community in an Area of High Endemicity for Schistosoma mansoni in Uganda: the Differential Effect of Parasite Worm and Egg Antigens
(American Society for Microbiology, 2003-03) Jones, Frances M; Kimani, Gachuhi; Mwatha, Joseph K; Kamau, Timothy; Kazibwe, Francis; Kemijumbi, Jovanice; Kabatereine, Narcis B; Booth, Mark; Kariuki, Henry C.; Ouma, John H.; Vennervald, Birgitte J; Dunne, David W.; Oseph, Sarah J
The human host is continuously exposed to the egg and the adult worm developmental stages of Schistosoma mansoni during chronic infections with the parasite. To assess the cytokine responses induced by these different costimulating stages and how they are influenced by host age and infection intensity, whole blood samples from a cross-sectional cohort of 226 members of a Ugandan fishing community who had been resident in an area with high transmission of S. mansoni for the previous 10 years or from birth were stimulated with S. mansoni egg antigen (SEA) or worm antigen (SWA). SWA-specific gamma interferon (IFN-_) production increased with age, and the levels of SWA- and SEA-specific interleukin 3 (IL-3) were weakly correlated with schistosome infection intensity. The production of most cytokines was little affected by age or infection intensity but was either SEA or SWA specific. One hundred thirty-two members of the cohort coproduced IL-5 and IL-13 specifically in response to SWA, whereas only 15 produced these cytokines, and at much lower levels, in response to SEA. IL-10, IL-4, and IFN-_ were also produced in response to SWA, whereas the response to SEA consisted almost exclusively of IL-10. Our results suggest that, in contrast to what has been described for the murine model of S. mansoni and during acute human infections, chronic intense exposure to and infection with S. mansoni in this cohort resulted in very low levels of response to SEA in vitro in the presence of a vigorousand mixed Th1-Th2 response to SWA.
Epidemiology and geography of Schistosoma mansoni in Uganda: implications for planning control
(Blackwell Publishing Ltd, 2004-03) Kabatereine, Narcis B; Brooker, Simon; Tukahebwa, Edridah M; Kazibwe, Francis; Onapa, Ambrose W
Intestinal schistosomiasis caused by infection with Schistosoma mansoni is a widespread public health problem in Uganda. Although long known to be endemic, its current distribution within the country equires updating of parasitological data to help guide planned control. We report such data collected between 1998 and 2002 from 201 schools and 68 communities across Uganda. In accordance with epidemiological expectation, prevalence and intensity increased with age, peaking at 10–20 years and thereafter declined moderately with age, whereas intensity declined more rapidly with age, and the prevalence of infection in a school was non-linearly related to the mean intensity of infection. We used geographical information systems to map the distribution of infection and to overlay parasitological data with interpolated environmental surfaces. The derived maps indicate both a widespread occurrence of infection and a marked variability in infection prevalence, with prevalence typically highest near the lakeshore and along large rivers. No transmission occurred at altitudes >1400 m or where total annual rainfall was <900 mm; limits which can help estimate the population at risk of schistosomiasis. The results are discussed in reference to the ecology of infection and provide an epidemiological framework for the design and implementation of control efforts underway in Uganda.