In Sudan, schistosomiasis remains a life-threatening public health problem with an estimation of more than eight million people at risk of infection. Thus, Sudanese government prioritised collecting data on the burden of NTDs, particularly schistosomiasis. In response; many epidemiological studies were conducted in central and east Sudan (10, 11), with relatively few, if any, such studies being conducted in Darfur area.
Therefore, this study was conducted to estimate the prevalence and intensity of S. haematobium infection in selected populations from the city of Tulus, South Darofur State. The study revealed that the percentage of infected people with S. haematobium infection based on urine filtration method was 62% (62/100). The high observed prevalence of urinary schistosomiasis (62%) was relatively in agreement with the study conducted by Deribe et al. (2011) in the same state whose reported a rate of 56% of infection among the respondents (12). Similarly, remarkably high prevalence (80.6%) was also reported in Gereida Camp, South Darfur (13).
The high prevalence could be attributed to the high exposure and dependence of the people in the area on open water sources for drinking and household purposes (12, 14). The adaptation of intermediate host (Bulinus truncates) to pools and slow-flowing waters in South Darfur area reflect consideration of these water bodies to be potential transmission sites for the disease (15). In addition, the fact that these small ponds in entire area are used for fishing, bathing, and swimming increase the risk of getting the infection.
In contrast, the present study showed very much higher prevalence of S. haematobium compared to that obtained from nationwide survey (5.2%), even though, South Darfur States was the second most endemic area with a prevalence of 13.91% in that survey (9). Moreover, many other finding across the country reported lower findings when the S. haematobium diagnostic stages were screened particularly among children (11, 16, 17). Such as that of Hajissa et al. (2018) in Um‑Asher Area, Khartoum State; Sulieman et al. (2017) in Alsaial Alsagair Village, River Nile State, and Abou-Zeid et al. (2013) in Southern Kordofan State (8, 18, 19).
Worldwide, similar observation of high Egg positive rate was also made in Senegal (57.6%) (1), while in many other country the rates were slightly lower such as those reported from Nigeria (48%), Gabon (45%), Malawi (10.4%) (4, 6, 20). This variation could be due to study period, target population, environmental condition, sample size variations and the method of laboratory diagnosis.
With regard to the intensity of the infection, majority of the S. haematobium infections (82%, 51/62) were of intense infection (≥ 50 eggs/10 ml urine). This finding agrees with previous reports (1, 4) where the intensity was classified as high. However, light infection intensity was also reported (21). The variation between areas could be explained by the frequency of people contact with contaminated water bodies, burden of the adult worms hosted as well as the differences in environmental setting and culture. As a consequence of the high prevalence with heavy S. haematobium infection haematuria was observed in the current study, and there was a positive correlation between the haematuria and intensity of eggs (P. value = .000), this result is in line with result of Ismail et al.,2014 (22) [16]. Indeed the observed hematuria could be attributed to the heavy egg intensity reported among the study participants
In conclusion: the very high prevalence of S. haematobium infection observed in the study area, indicate that the city of Tulus is endemic for urinary schistosomiasis, with a high intensity of infection. Therefore, integrated control program and prevention measures need to be implemented in the study area.