Assessing Potential Intermediate Host Snails of Urogenital Schistosomiasis, Human Water Contact Behavior and Water Physico-chemical Characteristics in Alwero Dam Reservoir, Ethiopia

Abstract

Introduction: Urogenital schistosomiasis is one of public health problems in lowland areas of Ethiopia. The disease is caused by Schistosoma haematobium. Freshwater Bulinus snails are intermediate hosts for the parasite transmission. The aim of the study was to assess intermediate host snails of urogenital schistosomiasis, human water contact behavior and physico-chemical characteristics of Alwero Dam reservoir. Methods: Bulinus snails were sampled from 12 sites of Alwero Dam. Bulinus snails were collected, identified and examined for natural schistosome infections. A total of 206 people were interviewed to determine human water contact behavior. The water temperature, pH, dissolved oxygen, total dissolved solid, salinity and conductivity of the water were determined. Results: Of 1125 Bulinus snails collected, 72 (6.4%) were infected with echinostome cercariae but none of them were infected with schistosome cercariae. The abundance of Bulinus species did not show significant variation across seasons ( P = .61). Occurrence of Bulinus species was significantly higher in stony substratum than sandy substratum ( P = .01). Of the total 206 participants, 119 (57.8%) had water contact activities like washing clothes, bathing or swimming. Majority of respondents (70.0%) reported that they visited the dam reservoir once or twice a week, while 16.5% and 13.6% reported that they visited the dam 3 to 5 times a week and daily, respectively. Moreover, 72.3% of the respondents had reported they had history of urogenital schistosomiasis infection. The mean water temperature, pH, dissolved oxygen, total dissolved solid, electric conductivity, and salinity of the dam water was 28.6°C, 7.07, 5.75 mg/l, 90.0 ppm, 124.8 µS/cm, and 50.0 ppm, respectively. Conclusion: At Alwero Dam, Bulinus snails were highly abundant and the human water contact activities were frequent. Therefore, the community awareness creation should be made to reduce water contact with snail infested water to prevent risk of urogenital schistosomiasis infection.

Assessment of Urogenital Schistosomiasis Knowledge, Attitudes and Practices Among Abobo Communities in Gambella Regional State, Southwestern Ethiopia

“…30 Similarly, a previous study conducted near Alwero Dam reported that males tended to have more frequent contact with freshwater than females. 29 Age, occupation, and infection history were also factors that influenced participants knowledge, perception, and risky or safe practices in the research region, consistent with previous studies. 23 , 28 …”

“…Even though our data showed the community’s primary drinking water sources are public hand pumps, for other essential activities such as washing, bathing and recreational purposes such as swimming and playing, the community relies on dam/river water, as previously reported. 29 Additionally, a considerable number of participants frequently practice open-air urination and defecation, which could lead to the persistence of schistosomiasis in the area. Hence, it is imperative to develop integrated control strategies to break the transmission cycle effectively.…”

Effects of Land-Use and Environmental Factors on Snail Distribution and Trematode Infection in Ethiopia

“…The prevalence of cercarial infection was 33%, which is higher than the estimates in in Ethiopian rift valley regions, where the prevalence of infection was 30.5% [ 37 ]. This infection prevalence can be underestimated as the natural cercariae shedding method cannot detect snail prepatent infection rates [ 38 , 39 ]. Lymnea natalensis shed three types of cercariae and contributed to 61.4% of the total infection.…”

Seasonal and environmental dynamics of intra-urban freshwater habitats and their influence on the abundance of Bulinus snail host of Schistosoma haematobium in the Tiko endemic focus, Mount Cameroon region

“…Comparably, in the Tiko focus, the Bulinus snail species was abundant on rocky than sandy or muddy substratum habitat type. Rocky substratum habitat preference by Bulinus snails provide adhere to resist the water wave action thereby avoiding dislodgment [ 60 ]. The rocky biotope has other ecological advantages as it increases films of mud and fine salts that cover these rocks and favours aquatic plant growth which is used as a food source for snails [ 23 , 61 ].…”

“…Comparably, in the Tiko focus, the Bulinus snail species was abundant on rocky than sandy or muddy substratum habitat type. Rocky substratum habitat preference by Bulinus snails provide adhere to resist the water wave action thereby avoiding dislodgment [60]. The rocky biotope has other ecological…”