Investigation of a Local Outbreak of Leptospirosis in an Urban Slum in Mumbai

Leptospirosis, caused by a spirochete of genus Leptospira, is considered the most widespread zoonosis in the world. It has a global distribution with a higher incidence in the tropics and subtropics. Leptospirosis is considered an “emerging” zoonosis due to increased contact between animals and humans and the resulting human encroachment into wildlife habitat. Most outbreaks of leptospirosis in India are reported from the coastal regions. Flooding and heavy rainfall have been associated with numerous outbreaks. The Study was planned to investigate the local outbreak of leptospirosis in the urban slum & to study the trend and demographic factors associated with the conrmed cases. During the period 01/10/2022 to 28/02/2023, 730 patients with fever were advised leptospirosis and other tests. Out of the 730 patients with fever for whom the fever prole panel was done, 98 (13.42%) came positive for leptospirosis by IgM ELISA test. Out of the 98 patients tested positive for leptospirosis, 35 were male and 63 were female. The mean age was found to be 26. The minimum age was found to be 1 year and the maximum age was 68 years. 3 of these 98 patients were coinfected with dengue as well and 33 of the 98 patients had positive titres on Widal test as well. Further investigation is needed to understand the mode of transmission of leptospirosis even in the dry season. Environmental samples need to be checked and studies need to be undertaken to understand the risk factors in the cases affected.