Immune System Modulation and Viral Persistence in Bats: Understanding Viral Spillover

Subudhi, Sonu; Rapin, Noreen; Misra, Vikram

Over the past few years, numerous viruses have been detected in bats and these viruses seldom cause any overt disease (with the exception of Tacaribe virus and rabies virus) [1, 16, 37] . Detection of virus and absence of disease have led researchers to suggest that bats are likely the reservoirs of these viruses. Asymptomatic infections have been observed in bats for human pathogens such as henipaviruses (Nipah and Hendra viruses), coronaviruses (Middle Eastern Respiratory Syndrome coronavirus (MERS-CoV)), and filoviruses (Marburg virus and ebolaviruses) [38] [39] [40] . For a species to be a viral reservoir, the virus needs to persist in the population. Two probable ways in which this can happen are (1) virus infection and clearing from infected individuals is an ongoing process and introduction of naïve individuals maintains the virus in the population and (2) individuals infected with the virus are able to maintain the virus in the form of a persistent infection. Although either or both of these possibilities may influence the bat-virus relationship, there is considerable evidence for the maintenance of some viruses in bat populations by continued, low-level persistence.