A case-control study of epidemiological factors associated with leptospirosis in South Gujarat region

Background: The current study was planned to identify the epidemiological factors associated with leptospirosis in South Gujarat region using neighborhood controls. Methods: A total of 100 cases of leptospirosis occurred in South Gujarat region during the year 2012 were selected using simple random sampling. Three neighbors of the selected cases formed the controls (n = 300). A pretested structured questionnaire was used for data collection and data were analyzed using Epi Info 2007. Results: There was significant association of illiteracy (odds ratio [OR] =1.82, 95% confidence interval [CI] =1.14-2.89), working in waterlogged fields during the reference season (OR = 4.6, 95% CI = 1.6-17.9), swimming/bathing in canals, open air defecation practices, storage of cow dung in or surrounding house, residence in the house made up of cow dung walls, households with access of food to rodents, injuries over hands/foot during the endemic season (OR = 3, 95% CI = 1.8-4.8), and history of skin disease during the endemic season (OR = 4.2, 95% CI = 2-8.5), with leptospirosis. Only 10% of individuals had gumboots for protection. A total of 83 (83%) cases and 240 (80%) controls had taken oral doxycycline chemoprophylaxis (P > 0.05). Cases had taken chemoprophylaxis for a median 4 weeks (range: 1-8) while controls had taken the same for median 8 weeks (range = 1-8) (P < 0.002). Conclusions: Although the commonly established factors appear to be associated with leptospirosis, the role of host factors seems to play a more important role in determining susceptibility to leptospirosis in exposed individuals.