Why Kerala Remains the Primary Reporter of Nipah Virus Cases

Kerala , the picturesque southern Indian state, finds itself grappling with another outbreak of the Nipah virus , a highly lethal zoonotic pathogen with mortality rates ranging from 40% to 70%. This marks the fourth Nipah virus outbreak in Kerala since the initial outbreak in 2018, which was the first in India . Despite efforts to contain the virus, six cases have been reported in the state so far this year, with two fatalities recorded.

The Nipah virus, originally identified in Malaysia 19 years ago, has been a recurring challenge for Kerala. The current outbreak in the state is attributed to the Bangladesh strain of the virus, which has a comparatively lower mortality rate of 9%, though it still poses a significant threat to public health.

One key question arises: why does Kerala consistently report Nipah virus cases when other Indian states remain largely unaffected? This phenomenon can be attributed to a combination of factors, including the endemic nature of the virus among fruit bats, the state's robust public health infrastructure, and a proactive approach to identifying and managing unusual fever cases.

Nipah virus is zoonotic, primarily spreading from fruit bats to humans. Kerala is home to numerous fruit bat colonies, and a 2019 study revealed that these bats carrying the virus were present in all 14 districts of Kerala, as well as in the Union Territory of Puducherry . This suggests that Nipah has become entrenched within the local fruit bat population, contributing to recurrent outbreaks.

The state's proactive stance on public health is another crucial factor. Kerala's healthcare infrastructure is well-equipped to investigate and diagnose cases of unknown fevers promptly. This capability, honed during the COVID-19 pandemic, has enabled the state to swiftly identify and respond to Nipah cases. While other states may not routinely send samples for Nipah virus testing, Kerala conducts such tests whenever unusual symptoms are observed.

An expert from Kerala stated, "Nipah virus infection and deaths may have occurred in different parts of India in people with undiagnosed fever anywhere in India except NIV Pune . While other states may not be routinely sending samples for Nipah virus testing, we test for Nipah whenever there are cases with unusual symptoms. That might be the real reason why Kerala is detecting Nipah cases."

Additionally, an ongoing nationwide survey has revealed that fruit bats, the primary carriers of the Nipah virus, have been identified in nine states across India. This indicates that the potential for Nipah outbreaks exists beyond Kerala's borders.

In conclusion, Kerala's recurrent battles with the Nipah virus can be attributed to the virus's endemic presence among fruit bats, the state's efficient public health infrastructure, and its proactive approach to identifying and managing infectious diseases. While Kerala continues to face this challenge, efforts to understand and combat the Nipah virus remain critical to prevent further outbreaks in the future.