ISSN 2756-3391
African Journal of Parasitology Research | Vol. 14, No. 8, August 2026 | pp. 549–556
DOI: 10.46882/AJPR/170542
Article Type: Full Length Research Paper
Title: Spatio-temporal expansion of Biomphalaria pfeifferi habitats and intestinal schistosomiasis transmission risks driven by climate shifts in the Ethiopian highlands
Names of Authors: Yared M. Alemu¹, Tewodros S. Kebede¹, Martha G. Wolde²
Authors’ Affiliations: ¹Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia. ²Department of Earth Sciences, College of Natural Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Abstract: Climatic variations are reshaping the altitudinal boundaries of vector-borne diseases in East Africa. This longitudinal investigation tracked the ecological expansion of the intermediate snail host Biomphalaria pfeifferi and corresponding Schistosoma mansoni transmission dynamics across historical low-risk highland zones (elevations 2100 to 2400 meters) in central Ethiopia. Systematic malacological sampling was conducted monthly at 45 water-contact sites alongside cross-sectional parasitological screening of 1840 school children. Results documented the establishment of stable Biomphalaria pfeifferi colonies at altitudes up to 2350 meters, driven by a 1.4 degrees Celsius increase in mean annual water temperatures over the last decade. The mean snail density at these elevated sites reached 34 snails per square meter, with a seasonal infection rate of 4.8 percent containing active Schistosoma mansoni cercariae. Concurrently, stool screening using double-smear Kato-Katz techniques revealed a rising intestinal schistosomiasis prevalence of 16.5 percent (n = 304) among children, with a geometric mean egg count of 142 eggs per gram of faeces. Spatial regression analysis coupled with satellite temperature data linked high transmission intensity with communal laundry zones located near expanding irrigation schemes (odds ratio = 4.12, 95 percent confidence interval [2.65 to 6.42]). These findings prove that climatic warming has enabled the upstream encroachment of intestinal schistosomiasis, necessitating the immediate extension of mass drug administration and snail control programs to previously non-endemic highland ecosystems.
Keywords: Schistosoma mansoni, Biomphalaria pfeifferi, Climate change, Altitude expansion, Highland malaria, Ethiopia
Manuscript Timeline: Received: 02 May 2026; Revised: 05 June 2026; Accepted: 12 July 2026; Published: 08 August 2026
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