Browsing by Author "Kinung'hi, Safari"

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Schistosoma mansoni Infections, Undernutrition and Anaemia among Primary Schoolchildren in Two Onshore Villages in Rorya District, North-Western Tanzania
(Plos One, 2016-12-09) Munisi, David; Buza, Joram; Mpolya, Emmanuel; Kinung'hi, Safari
Background Undernutrition and anaemia remains to be a major public health problem in many developing countries, where they mostly affect children. Intestinal parasitic infections are known to affect both growth and haemoglobin levels. Much has been reported on the impact of geohelminths on anaemia and undernutrition, leaving that of Schistosoma mansoni not well studied. Therefore this study intended to determine the association between S.mansoni infections, anaemia and undernutrition among schoolchildren in Rorya district, Northwestern Tanzania. Methodology A cross-sectional study was carried among schoolchildren in two onshore villages namely Busanga and Kibuyi in Rorya district. Single stool specimens were collected from 513 randomly selected schoolchildren and processed for microscopic examination using the Kato- Katz method. Nutritional status was determined by anthropometry. Blood samples were also collected and examined for malaria parasites and haemoglobin levels using the Giemsa stain and HaemoCue methods, respectively. A pretested questionnaire was used to collect socio-demographic data and associated factors. Results The prevalence of S. mansoni infection and malaria was 84.02% and 9.16%, respectively. Other parasites found were Ascaris lumbricoides (1.36%) and Hookworm (1.36%). The prevalence of stunting and wasting was 38.21% and 14.42%, respectively. The prevalence of anaemia was 29.43%, whereby 0.58% had severe anaemia. S. mansoni infection was not found to be associated with undernutrition or anaemia (p>0.05). The risk of stunting and wasting increased with increasing age (p<0.001). Anaemia was associated with age, sex and village of residence (p<0.05). Conclusions S.mansoni, undernutrition and anaemia are highly prevalent in the study area. The observed rates of undernutrition and anaemia were seen not to be associated with S.mansoni infection suggesting possibly being a result of poor dietary nutrients. This study suggests that policy makers should consider Rorya district for inclusion into national schistosomiasis control and school feeding programmes.
Spatio-temporal variability in transmission risk of human schistosomes and animal trematodes in a seasonally desiccating East African landscape
(The Royal Society, 2024-01-10) Starkloff, Naima; Angelo, Teckla; Mahalila, Moses; Charles, Jenitha; Kinung'hi, Safari; Civitello, David
Different populations of hosts and parasites experience distinct seasonality in environmental factors, depending on local-scale biotic and abiotic factors. This can lead to highly heterogeneous disease outcomes across host ranges. Variable seasonality characterizes urogenital schistosomiasis, a neglected tropical disease caused by parasitic trematodes (Schistosoma haematobium). Their intermediate hosts are aquatic Bulinus snails that are highly adapted to extreme rainfall seasonality, undergoing prolonged dormancy yearly. While Bulinus snails have a remarkable capacity for rebounding following dormancy, we investigated the extent to which parasite survival within snails is diminished. We conducted an investigation of seasonal snail schistosome dynamics in 109 ponds of variable ephemerality in Tanzania from August 2021 to July 2022. First, we found that ponds have two synchronized peaks of schistosome infection prevalence and observed cercariae, though of lower magnitude in the fully desiccating than non-desiccating ponds. Second, we evaluated total yearly schistosome prevalence across an ephemerality gradient, finding ponds with intermediate ephemerality to have the highest infection rates. We also investigated dynamics of non-schistosome trematodes, which lacked synonymity with schistosome patterns. We found peak schistosome transmission risk at intermediate pond ephemerality, thus the impacts of anticipated increases in landscape desiccation could result in increases or decreases in transmission risk with global change.
Stocking African catfish in Lake Victoria provides effective biocontrol of snail vectors of Schistosoma mansoni
(PLoS Negl Trop Dis, 2025-09-15) Proud, Roland; Allan, Fiona; Whiston, Andrew; Kayanda, Robert; Kinung'hi, Safari; Angelo, Teckla; Sylivester, Yasinta D; Mrosso, Hillary D. J.; Kashindye, Benedicto B.; Elison, Mboni; Cox, Martin J.; Yang, Yang; Chamberlin, Andrew; Boyd, Ian; Civitello, David J.; De Leo, Giulio A.; Brierley, Andrew
In areas of high infection prevalence, effective control of schistosomiasis – one of the most important Neglected Tropical Diseases – requires supplementing medical treatment with interventions targeted at the environmental reservoir of disease. In addition to provision of clean water, reliable sanitation, and molluscicide use to control the obligate intermediate host snail, top-down biological control of parasite-competent snails has recently gained increasing interest in the scientific community. However, evidence that natural predators can effectively reduce snail abundance and, ultimately, transmission risk to vulnerable human populations remains limited. In this study, we used a Before-After-Control-Intervention (BACI) design implemented in seven lakeside areas, including three intervention areas and four control areas, on the southern shores of Lake Victoria (Tanzania) in 2019–2023. We tested whether the restoration of African catfish, Clarias gariepinus, a native species of commercial value, could reduce both the abundance of Biomphalaria snails (intermediate hosts of Schistosoma mansoni) and infection intensity in school age children (SAC). Where catfish were restored, mean site-level snail counts declined by 57% (95% CI: 29.4%, 74.3%). At primary schools located within each area, SAC infection intensity (mean parasite egg count in stool samples) also decreased significantly by 55% (95% CI: 26%, 73%). This study shows that natural predators of host snails have the potential for schistosomiasis control. Scaling up to a lake-wide approach will require systemic intervention, with snail host control contributing to a broader framework for schistosomiasis management.