Joint Meeting on Leptospirosis Sep 2024
Leptospirosis poses a significant public health threat, with over 1 million reported cases and more than 50,000 fatalities annually. It has emerged as a growing concern in urban settings of developing and tropical countries, particularly affecting residents of deprived areas such as slums.
This work aims to develop and evaluate an innovative tool designed to identify, characterise, and georeference sanitation, storm drainage, and waste management risk factors within urban areas with high leptospirosis burdens. The tool was implemented and evaluated in four slums in Salvador, Brazil: two intervention areas with planned sewerage works by the state government, and two control areas with similar environmental, socioeconomic, and exposure characteristics but without planned sewerage works. Environmental engineering data were collected through detailed identification, characterisation, and georeferencing using a high-precision Global Navigation Satellite System (GNSS) receiver. Simultaneously, serological exposure to Leptospira of 1,086 residents was evaluated through a microagglutination test. The association between risk factors and human Leptospira exposure was analysed.
A total of 1,215 environmental engineering components were mapped, including those in densely populated areas. Around 80% of storm drainage components were deemed problematic, and only 19% were considered adequate. Approximately 45% of sewage system components exhibited issues, including open sewers, and waste dumping in streets surrounding households where positive leptospirosis cases were identified. Concurrently, serological results revealed 94 positive cases (8.66%) out of 1,086 tests conducted.
Capturing the proximity of features such as improper sewerage and storm drainage components, open sewer points, and waste dumping to households presents great potential for leptospirosis prevention. This ranges from understanding the fate of Leptospira in the environment to indicating more targeted investments to tackle leptospirosis transmission in slums. Therefore, this comprehensive approach enables identifying potential sources of leptospirosis contamination.