Prevalence of zoonotic diseases in India: A caution for the vector/disease surveillance in 2020s

The South West Monsoon in present season in India is causing heavy rains inundating large stretches of human habitations as well as farm lands, sometimes for longer periods. At many places it caused floods also. Floods are often linked with leptospirosis and other vector borne disease outbreaks in several states of the country, particularly Kerala, Maharashtra, Gujarat, Orissa, Delhi and even other Northern states. Since leptospirosis is remained mostly undiagnosed, the debility caused by it to humans and farm animals also remained underestimated and ignored. Earlier, the Zoonosis division of National Centre for Disease Control, Ministry of Health and Family Welfare, Government of India issued guidelines for prevention and control of leptospirosis. It is also actively involved in other disease surveillance. However, it is to be further noted that several studies on serum samples of farm animals reported higher prevalence of leptospira infections related to heavy rains. In one study, blood samples collected from randomly selected animals from heavy rain-affected areas in Surat indicated Leptospira in 34 out of 184 blood samples, which was worst hit with floods. Leptospira pomona is reportedly caused abortions in last trimester in cattle and buffaloes at a prevalence of 4 to 20% as per the study. High seropositivity was recorded in Andhra Pradesh & Telangana during north east monsoon (28.29%) followed by south west monsoon (21.45%) and lowest in summer (7.26%). One can imagine the economic impact once this figure is attributed to the impact of leptospirosis among farm animal populations. Hence during this covid-19 pandemic period, it is essential to rule out co-morbid factors like malaria, dengue, leptospirosis, even plague etc. At the same time, present increasing populations at Indo-China border areas with marmots, a plague permanent rodent reservoir, chances exist for Yersinia pestis entering in border villages of India. Looking at this scenario, needful actions are needed in all vulnerable areas including urban local bodies on prevalence of leptospirosis and other zoonotic diseases (including Covid-19) to guide them in planning appropriate covid-19, rodent and other vector control measures using ecological principles.

Source: Author's experience