Factors associated with urinary schistosomiasis in two peri-urban communities in south-western Nigeria

In Nigeria, there is only very limited epidemiological information on which the control of human urinary schistosomiasis could be based. In a cross-sectional study, therefore, the prevalences and intensities of, and risk factors for, human infection with Schistosoma haematobium infection were explored in two endemic peri-urban villages in the south-western state of Osun. The villagers' knowledge about the infection and demographic, socioeconomic and environmental variables were recorded using a structured questionnaire. Of the 1023 individuals who were investigated, 634 (62.0%) were found infected, with a mean (S. D.) overall intensity of 114.2 (327.7) eggs/10 ml urine. The subjects aged 10-14 years had both the highest prevalence (83.6%) and the highest mean (S. D.) intensity of infection [196.67 (411.7) eggs/10 ml urine]. Most (70.0%) of the subjects appeared to have no knowledge of the transmission of S. haematobium. The results of multivariate regression analysis indicated that infection and moderate-heavy infection (i.e. >50 eggs/10 ml urine) were both associated with: a low family income, of <U.S.$500/month [with adjusted odds ratios (aOR) of 3.72 and 3.35, respectively], the number of children aged 10-15 years living in the household (with aOR of 1.60 and 1.99, respectively), not living with biological parents (with aOR of 1.93 and 5.21, respectively), and living close to (i.e. within a 30-min walk of) the local river (with aOR of 1.38 and 1.61, respectively). Literacy of the family head was, however, a protective factor (with corresponding aOR of 0.28 and 0.30, respectively). Human urinary schistosomiasis appears to be highly endemic in peri-urban/rural Nigeria and closely associated with poverty. To reduce the transmission of S. haematobium in endemic communities, health education that is not only of high quality but also culturally sensitive is needed.