Urogenital Schistosomiasis in Dam-Adjacent Communities, Kano State, Nigeria

Background

Urogenital schistosomiasis remains a major neglected tropical disease in rural communities, particularly in reservoir-adjacent settings where sustained human-water contact facilitates persistent transmission. Despite ongoing control efforts, communities located around reservoirs may experience persistent transmission partly due to socioeconomic water exposure and presence of infected intermediate host snails in aquatic habitats. This study assessed the prevalence, intensity, and epidemiological correlates of Schistosoma haematobium infection in reservoir-adjacent communities in Kano State, Nigeria to better understand local transmission.

Methods

A community-based cross-sectional study was conducted among 447 consenting participants from six communities located around three water reservoirs in Kano State.

Sociodemographic characteristics, water-contact behaviour, sanitation practices, treatment-seeking behaviour, and knowledge related to urogenital schistosomiasis were obtained using interviewer-administered questionnaires. Urine samples collected between 10:00 and 14:00 were examined using microscopy following centrifugation/sedimentation. Schistosoma haematobium isolates were characterised by molecular methods, using PCR and Sanger dideoxy sequencing. Bulinus snails were collected from the reservoirs by handpicking and scooping methods. Nucleotide sequences were analysed using NCBI BLAST to confirm species identity.

Epidemiological data on Schistosoma haematobium infection were analysed using chi-square tests and univariate and multivariate logistic regression analyses to assess associations with explanatory variables.

Results

The overall prevalence of S. haematobium infection was 34.23% (153/447), indicating moderate endemicity. Molecular study confirmed the occurrence of pure S. haematobium .

Community-specific prevalence ranged from 32.35% to 37.84%. Heavy-intensity infection (>50 eggs/10 mL urine) occurred in 17.65% of infected participants. Infection was most common among children and adolescents and was higher in males than females, although the sex difference was not statistically significant. Water-contact behaviour was the strongest correlate of infection: participants reporting water contact had a markedly higher prevalence than those without such exposure (39.12% vs 3.28%; OR = 18.96, 95% CI: 4.56-78.73). Fetching water (aOR = 2.57; 95% CI = 1.53-4.34; p < 0.001) and Swimming (aOR = 2.37; 95% CI = 1.42 - 3.94; p = 0.001) were the specific activities most strongly associated with higher odds of S. haematobium infection. Age (aOR = 0.91; 95% CI = 0.87 - 0.95; p < 0.001) significantly reduced the odds of infection. In terms of gender, female participants had significantly lower odds of infection compared with males (aOR = 0.52; 0.29 0.92; p = 0.03). Knowledge of transmission was poor, with only a small proportion of participants correctly identifying contact with contaminated water as the cause of infection. A rare ectopic detection of S. mansoni eggs in urine was also observed. Presence of S. haematobium -infected Bulinus intermediate hosts in the water reservoirs was reported.

Conclusions

Urogenital schistosomiasis remains actively transmitted in reservoir-adjacent communities in Kano State, with infection strongly associated with frequent human-water contact and poor disease knowledge. These findings support the need for integrated control strategies combining praziquantel-based preventive chemotherapy, targeted health education, improved water and sanitation, and behaviour-focused interventions to reduce reinfection and interrupt transmission.

Author summary

Urogenital schistosomiasis is a neglected tropical disease that continues to affect rural communities in Nigeria, especially those living near water reservoirs where people frequently come into contact with unsafe water. This study investigated how common the infection is and the factors that contribute to its spread in communities around reservoirs in Kano State. We found that about one in three people was infected, indicating that the disease is still actively transmitted. Molecular analysis of S. haematobium isolates confirmed species identity. Infection was more common among children and adolescents and was strongly linked to activities such as swimming and fetching water from contaminated sources. Many participants had limited knowledge of how the disease is transmitted, which may contribute to continued exposure and reinfection. The presence of infected snail hosts in the reservoirs further supports ongoing transmission in these communities. These findings highlight the need for improved control measures, including regular treatment with praziquantel, better access to safe water and sanitation, and increased community education to reduce risky water-contact behaviour and interrupt disease transmission.