The epidemiology of schistosomiasis in Lango region Uganda 60 years after Schwetz 1951: Can schistosomiasis be eliminated through mass drug administration without other supportive control measures?

• Published in: Acta tropica Vol. 185; pp. 412 - 418
• Main Authors: Adriko, M., Tinkitina, B., Tukahebw, E.M., Standley, C.J., Stothard, J.R., Kabatereine, N.B.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2018
• Subjects: Intestinal schistosomiasis; Lango region; Uganda; Urinary schistosomiasis; Uganda; Intestinal schistosomiasis; Urinary schistosomiasis; Lango region
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2018.06.009

[Display omitted] •Lango region, the only known co-edndemic focus for Schistosomiasis in Uganda.•Epidemiological trends for Schistosomiasis since 1951–2011 determined through stool and urine examinations com bined with retrospective data review.•S.haematobium was low and confined to few putative foci with a reverse observation trend for S.mansoni.•Prevalence rates declined from 28.2% in 1951 to as low as 2.48% in 2011. Lango region is the only known endemic region for urinary and intestinal schistosomiasis in Uganda. Although there has been no significant improvement in sanitation and safe water supply in the region over years, the endemicity and prevalence of Schistosoma haematobium, in particular, have declined, perhaps due to yearly mass treatment campaigns implemented since 2003. We report the epidemiology of Urinary and Intestinal schistosomiasis in Lango since 1951–2011 determined through Microscopic examinations for S. mansoni and S. haematobium respectively. A retrospective data review from 195 to 2011 was done to establish the prevalence over the years in the region. We performed Poisson regression analysis to observe trends in epidemiology before and after control was initiated in 2002. In addition, malacological surveys were undertaken in 2007 to assess local transmission potential. Contrary to earlier records, S. haematobium was low and confined to a few putative foci, with declined in infections from 28.2% in 1951 to 2.48% by 2011. Although this decline can be attributed to control, this was already much lower in 1967 than 1951, long before control interventions began suggesting that environmental changes may have made the habitat less suitable for the transmission of S. haematobium. Compared to the historical records S. mansoni prevalence first increased up immediately before control interventions in 2003, significantly declined (p=<0.001) until 2007. However, in 2007 and 2011 declined insignificant, (p = 0.656). No snail has ever been isolated shedding S. haematobium cercariae but many Bulinus snail spp. were found shedding S. bovis cercariae. This suggests that a combination of environmental and mass treatment has had a significant impact on transmission in Lango region.