Novel and Re-emerging Zoonotic Viral Diseases in India during Last Two Decades: An Overview

Zoonotic diseases or zoonosis is an infectious disease caused by the transmission of pathogens from animals to humans. Depending on the pathogens, these diseases can be bacterial, viral, or parasitic and the route of transmission of the pathogens can be via reservoirs including birds, bats, pigs, and mosquitoes, eventually infecting humans. Spread among humans arises primarily through person-person contact and fomites, causing major outbreaks (epidemics and pandemics). Some of the major zoonotic outbreaks include plague, influenza, West Nile fever, brucellosis, and rabies. This review focuses on zoonotic viral outbreaks in India over the past 20 years highlighting the spread and severity of the disease, measures to control the infection and prevention, treatment and management of the infectious diseases. New or emerging and re-emerging viral diseases such as coronavirus, Japanese encephalitis, dengue and chikungunya are discussed. These outbreaks have been reported to cause high morbidity and mortality, in addition, pose a major risk to the health security, safety, and economy of the country. Insufficient knowledge of emerging diseases is a major challenge for producing effective anti-viral drugs and vaccines. Understanding the etiology and spread of the disease is essential for preventive measures and the development of efficient treatment strategies.