5. An Interdisciplinary Study of Leptospirosis Surveillance Systems in Three Regencies of East Java, Indonesia

In April–May of 2013, Sampang Regency (Madura Island), experienced extreme seasonal rains, and subsequent flooding, followed by dramatic peaks in reported leptospirosis. Local public health surveillance efforts responded to these events and an investigative regional report was launched by the Centre for Environmental Health Engineering and Disease Control, Sampang Regional Health Office. In light of this outbreak and targeted investigation, this study sought to combine existing surveillance data with descriptive household data to investigate leptospirosis incidence and its associated socio-environmental exposures in Sampang and two neighbouring regencies of Gresik and Surabaya in East Java, Indonesia. Leptospirosis has a complex and variable disease epidemiology. In order to identify environmental and social risk determinants of cases of leptospirosis, a total of 275 household questionnaires were administered across nine targeted sample sites in the regencies of Gresik, Sampang, and Surabaya, East Java, Indonesia. Univariate analysis and binomial logistic regression were used to analyze associations of independent predictor variables with suspected and probable case reporting.

Results revealed a history of leptospirosis in 30 respondents. Independent predictors that demonstrated significant association with reported leptospirosis were: living in flood prone areas, recent history of in-house flooding, living in close proximity to refuse deposits, occupational farming, and using alternative sources of water for domestic use (artesian wells, rivers and collected rain water). Household access to piped or canalized running water had a negative association with reported leptospirosis outcomes. The results of the binary logistic regression analysis produced a model with overall fit. Across the nine targeted sample sites, significant discrepancies in surveillance reporting were found between each of the five corresponding health clinics, as well as the three regencies of Gresik, Sampang, and Surabaya, indicating distinct surveillance systems and health responses. While increases in rainfall and flooding events have been well established as determinants, this study highlights two additional key factors attributable to changes in the distribution of leptospirosis: socio-sanitary deprivation, as well as a lack of integrated public health surveillance systems. This research reinforces the success of certain local and adaptive surveillance initiatives, and recommends the wider integration of disciplinary efforts and resources across communities, institutions and sectors for effective public health action.