Schistosomiasis outbreak investigation, Empandeni Ward, Mangwe District, Matabeleland South Province, June 2012; a case control study

BACKGROUND: On 20(th) of June 2012, 31 pupils from Kwite primary school reported to the local clinic complaining of passing bloody urine. A study was conducted to identify factors, the etiology and risks of contracting the disease. METHODS: An unmatched 1:2 case control study was conducted at Kwite primary school. A case was defined as any child aged between seven to fifteen years, resident in Empandeni Ward for not less than two months, who had passed bloody urine with or without dysuria, fever, fatigue or lower abdominal pains from the 01/06/12 to 07/07/12. A control was a classmate of a case, staying in the same ward, who had not passed bloody urine. Controls were chosen by lottery method. A pretested questionnaire was administered to pupils and their caregivers. Environmental assessment was conducted; line lists, case notes, and district outbreak preparedness and response were reviewed using standard checklists. RESULTS: All the 42 cases, and 84 controls were enrolled into the study. The median age for cases and controls was 10 years (Q(1) = 9, Q(3) = 12) and 10 years (Q(1) = 8, Q(3) = 11), respectively. Swimming in Kwite dam [AOR = 9.02, 95% CI (2.29-35.53)] and bathing in the dam [AOR = 3.22, 95% CI (1.10-9.41)] were independent factors associated with contracting schistosomiasis. Schistosoma hematobium was isolated in 31 out of 100 urine specimens examined. Bulinus globosus snails were identified at Kwite dam. CONCLUSION: The outbreak was driven by human contact with S. hematobium infested Kwite dam water, while poor knowledge on prevention of schistosomiasis by the Kwite community was evident. As a result of this study, health education to pupils and the community, mass drug administration on school pupils and mollusciding at the dam were done. The provincial health team adopted as on-going activities, the inclusion of schistosomiasis prevention and control in malaria pre-elimination activities.