scholarly journals Variation in water contact behaviour and risk of Schistosoma mansoni (re)infection among Ugandan school-aged children in an area with persistent high endemicity

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Suzan C. M. Trienekens ◽  
Christina L. Faust ◽  
Fred Besigye ◽  
Lucy Pickering ◽  
Edridah M. Tukahebwa ◽  
...  

Abstract Background Annual mass drug administration with praziquantel has reduced schistosomiasis transmission in some highly endemic areas, but areas with persistent high endemicity have been identified across sub-Saharan Africa, including Uganda. In these areas many children are rapidly reinfected post treatment, while some children remain uninfected or have low-intensity infections. The aim of this mixed-methods study was to better understand variation in water contact locations, behaviours and infection risk in school-aged children within an area with persistent high endemicity to inform additional control efforts. Methods Data were collected in Bugoto, Mayuge District, Uganda. Two risk groups were identified from a longitudinal cohort, and eight children with no/low-intensity infections and eight children with reinfections were recruited. Individual structured day-long observations with a focus on water contact were conducted over two periods in 2018. In all identified water contact sites, four snail surveys were conducted quarterly over 1 year. All observed Biomphalaria snails were collected, counted and monitored in the laboratory for Schistosoma mansoni cercarial shedding for 3 weeks. Results Children came into contact with water for a range of purposes, either directly at the water sources or by coming into contact with water collected previously. Although some water contact practices were similar between the risk groups, only children with reinfection were observed fetching water for commercial purposes and swimming in water sources; this latter group of children also came into contact with water at a larger variety and number of sites compared to children with no/low-intensity infection. Households with children with no/low-intensity infections collected rainwater more often. Water contact was observed at 10 sites throughout the study, and a total of 9457 Biomphalaria snails were collected from these sites over four sampling periods. Four lake sites had a significantly higher Biomphalaria choanomphala abundance, and reinfected children came into contact with water at these sites more often than children with no/low-intensity infections. While only six snails shed cercariae, four were from sites only contacted by reinfected children. Conclusions Children with reinfection have more high-risk water contact behaviours and accessed water sites with higher B. choanomphala abundance, demonstrating that specific water contact behaviours interact with environmental features to explain variation in risk within areas with persistent high endemicity. Targeted behaviour change, vector control and safe water supplies could reduce reinfection in school-aged children in these settings. Graphical Abstract

2015 ◽  
Vol 5 (4) ◽  
pp. 553-564 ◽  
Author(s):  
Lydia Osei ◽  
Jonathan Amoyaw ◽  
Godfred Odei Boateng ◽  
Sheila Boamah ◽  
Isaac Luginaah

According to the United Nations, the world has met the Millennium Development Goal target of halving the proportion of people without access to safe drinking water. However, global figures mask massive disparities between regions and countries, and within countries. For instance, only 64% of the people in sub-Saharan Africa have access to improved water sources. Over 40% of all people globally who lack access to drinking water live in sub-Saharan Africa. Rwanda is used as a case in point in this study. Despite the abundance of water resources in the country, access to improved water sources is limited. Using the Rwandan Demographic and Health Surveys (2000–2010), we examined regional disparities in access to improved water sources. Results from logistic regression models show that overall, access to improved water has declined between 2000 and 2010; except in the western region, where access to water marginally improved. Educated individuals, wealthier and urban dwellers were more likely to have access to improved water sources over time compared to their uneducated, poor and rural counterparts. The persistence of regional disparities in access to improved water over time suggests the need for policy to address insufficient investments in water infrastructure in Rwanda.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gertrude Kyere-Davies ◽  
Christian Agyare ◽  
Yaw Duah Boakye ◽  
Brian M. Suzuki ◽  
Conor R. Caffrey

Schistosomiasis is a disease caused by a flatworm parasite that infects people in tropical and subtropical regions of Sub-Saharan Africa, South America, China, and Southeast Asia. The reliance on just one drug for current treatment emphasizes the need for new chemotherapeutic strategies. The aim of this study was to determine the phenotypic effects of extracts and fractions of leaf and stem bark of Erythrophleum ivorense (family Euphorbiaceae), a tree that grows in tropical parts of Africa, on two developmental stages of Schistosoma mansoni, namely, postinfective larvae (schistosomula or somules) and adults. Methanol leaf and stem bark extracts of E. ivorense were successively fractionated with acetone, petroleum ether, ethyl acetate, and methanol. These fractions were then incubated with somules at 0.3125 to 100 μg/mL and with adults at 1.25 μg/mL. The acetone fractions of both the methanol leaf and bark of E. ivorense were most active against the somules whereas the petroleum ether fractions showed least activity. For adult parasites, the acetone fraction of methanol bark extract also elicited phenotypic changes. The data arising provide the first step in the discovery of new treatments for an endemic infectious disease using locally sourced African medicinal plants.


2004 ◽  
Vol 9 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Jeffrey Bethony ◽  
Jeff T. Williams ◽  
Simon Brooker ◽  
Andrea Gazzinelli ◽  
Maria F. Gazzinelli ◽  
...  

Parasitology ◽  
2010 ◽  
Vol 137 (13) ◽  
pp. 1937-1949 ◽  
Author(s):  
C. J. STANDLEY ◽  
N. B. KABATEREINE ◽  
C. N. LANGE ◽  
N. J. S. LWAMBO ◽  
J. R. STOTHARD

SUMMARYIntestinal schistosomiasis continues to be a major public health problem in sub-Saharan Africa, and is endemic in communities around Lake Victoria. Interest is growing in the molecular evolution and population genetic structure of Schistosoma mansoni and we describe a detailed analysis of the molecular epidemiology and phylogeography of S. mansoni from Lake Victoria. In total, 388 cytochrome oxidase 1 (COI) sequences were obtained from 25 sites along the Ugandan, Tanzanian and Kenyan shorelines of Lake Victoria, and 122 unique barcodes were identified; 9 corresponded to previously discovered barcodes from Lakes Victoria and Albert. A subset of the data, composed of COI sequences from miracidia from 10 individual children, was used for population genetics analyses; these results were corroborated by microsatellite analysis of 4 isolates of lab-passaged adult worms. Overall, 12 barcodes were found to be shared across all 3 countries, whereas the majority occurred singly and were locally restricted. The population genetics analyses were in agreement in revealing high diversity at the level of the human host and negligible population structuring by location. The lack of correlation between genetic distance and geographical distance in these data may be attributed to the confounding influence of high intra-individual diversity as well as human migration between communities.


2020 ◽  
Author(s):  
Babatunde A. Olusola ◽  
David O. Olaleye ◽  
Georgina N. Odaibo

AbstractAbout 37.9 million persons are infected with HIV globally resulting in 770,000 deaths. Over 50% of this infection and deaths occur in Sub-Saharan Africa with countries like Nigeria greatly affected. The country also has one of the highest rate of new infections globally. Diverse HIV-1 subtypes have been identified in the country. Febrile persons and blood donors pose a great transmission risk in the country especially during the early stages of infection. HIV-1 rapid kits are routinely used for diagnosis among the general population and high risk groups. However, there is limited information on the usefulness of HIV rapid kits for early detection especially in areas where diverse HIV-1 subtypes circulate. In this study, the prevalence of early HIV-1 infection as well as circulating HIV-1 subtypes among febrile persons and blood donors were determined. Furthermore, the sensitivity of a widely used HIV-1 rapid antibody kit was compared with those of Antigen/Antibody ELISA based methods. Participants were recruited from selected hospitals in Ibadan and Saki, Nigeria. The prevalence of early HIV infection among 1028 febrile persons (Ibadan: 2.22%; Saki: 1.36%) and blood donors (5.07%) studied were significantly different (P<0.03674). CRF02_AG was the predominant subtype detected with more diverse HIV-1 subtypes observed among febrile persons compared to blood donors. About 1.2% of the samples detected on Antibody based ELISA methods were undetectable on the HIV-1 rapid antibody kit. Genetic diversity of HIV-1 strains among infected individuals in Oyo State, Nigeria is still relatively high. This diversity is likely impacting on diagnosis.


2021 ◽  
Author(s):  
Ella V. Rodwell ◽  
Nicolas Wenner ◽  
Caisey V. Pulford ◽  
Yueyi Cai ◽  
Arthur Bowers-Barnard ◽  
...  

AbstractIn recent years, novel lineages of invasive non-typhoidalSalmonella(iNTS) serovars Typhimurium and Enteritidis have been identified in patients with bloodstream infection in sub-Saharan Africa. Here, we isolated and characterised 32 phages capable of infectingS. Typhimurium andS. Enteritidis, from water sources in Malawi and the UK. The phages were classified in three major phylogenetic clusters that were geographically distributed. In terms of host range, Cluster 1 phages were able to infect all bacterial hosts tested, whereas Clusters 2 and 3 had a more restricted profile. Cluster 3 contained two sub-clusters, and 3.b contained the most novel isolates. This study represents the first exploration of the potential for phages to target the lineages ofSalmonellathat are responsible for bloodstream infections in sub-Saharan Africa.


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