The National Centre for Disease Control has issued high alert across the country after an outbreak of the Nipah virus (NiV) infection in Kerala. The virus has claimed around 10 lives in the southern state over the past two weeks
What is the Nipah virus infection?
The infection causes severe diseases in both animals and humans. The natural hosts of the virus are fruit bats. The virus has also been isolated from environmental samples of bat urine and partially eaten fruit in Malaysia. Due to the migratory habit of the locally abundant fruit bats in South Asia, Nipah outbreaks occur more in this region. Transmission of Nipah virus to humans may occur after direct contact with infected bats, infected pigs or from other people infected with the virus.
Is this the first reported Nipah virus outbreak?
No. Previous outbreaks have been reported in India, Bangladesh, Thailand, Cambodia, the Philippines, Laos and Malaysia. NiV was first identified during an outbreak of disease in Kampung Sungai Nipah, Malaysia, in 1998. On this occasion, pigs were the intermediate hosts. However, in subsequent Nipah virus outbreaks, there were no intermediate hosts. In Bangladesh in 2004, humans were infected with Nipah virus after consuming date palm sap that had been contaminated by infected fruit bats.
Who are the major carriers of the virus?
Bats shed the virus in their excrement and secretions, but they are symptomless carriers. NiV is highly contagious among pigs and is spread by coughing.
What are the symptoms of the infection? How is it treated?
NiV infection in humans has a range of effects, from asymptomatic infection to acute respiratory distress syndrome and fatal encephalitis. The primary treatment is intensive supportive care. Treatment is focused on managing fever and the neurological symptoms. Ribavirin may alleviate the symptoms of nausea, vomiting, and convulsions.
How can it be prevented?
As options for treatment are limited, the focus should be on prevention. Strategies include preventing farm animals from eating fruit contaminated by bats and avoiding consumption of contaminated date palm sap. Healthcare workers caring for patients should put in place standard precautions including washing hands. Wearing a gown, mask, cap and gloves is also recommended.