Rat density and related factors in leptospirosis among waste workers in India: An evaluation

Background: Rats are the main source of Leptospira contamination in tropical 
nations like India, where leptospirosis is a serious health risk. There aren't many 
previous studies that evaluated rat density in Leptospirosis endemic areas using 
the Bi-index. In order to track rat density and related variables in urban 
Leptospirosis endemic areas, this study will use the Bi-index.
Methods: Based on leptospirosis data from the Primary Health Centre, Mylapore, 
four endemic areas of Chennai City were chosen as study sites. Over the course 
of three days, live traps were set up in one case house and 39–49 nearby homes 
within a 100-meter radius. Rats that had been trapped were gathered in order to 
identify the species, assess their morphometrics, compute their rat indices, and 
calculate the Bi-index. Meanwhile, environmental parameters were observed.
Results: People, aged 23–75, working in private employment made up 76.2% of 
the participants. With the Bi, diversity, dominance, and evenness indices of 0.02-
0.32, 0.94-1.09, 0.36-0.44, and 0.79-0.96, respectively, the range of trap success 
was 2.5–26.5%. Rattus norvegicus, Rattus tanezumi, and Mus musculus were 
among the trapped species, with percentages of 61.3%, 34.1%, and 4.7%, 
respectively. Rats were linked to a number of factors, including being close to the 
stagnant Cooum River, regular flooding, water entering homes during floods, open 
trash cans, and trash cans surrounding homes. 
Conclusion: There was a correlation between Chennai City's rat density 
(dominated by R. norvegicus), water drainage, and waste management. 
Consequently, it is advised to conduct additional research to identify Leptospira 
bacterial infection in rodents.