Explained | What is the Chandipura virus?

Chandipura virus outbreak in Gujarat, India, causes deaths in children; prevention includes vector control and early treatment.

On Wednesday, July 17, 2024, the National Institute of Virology (NIV) in Pune, confirmed the death of a four-year-old girl in Gujarat, as caused by the Chandipura virus. Meanwhile, the death toll of suspected cases of the virus has touched 15, and a total of 29 cases have been reported from almost a dozen districts. Of the 29 cases, 26 are from Gujarat, two from Rajasthan, and one case is from Madhya Pradesh. Of the 15 deaths, 13 are from the State while one each are from neighbouring Madhya Pradesh and Rajasthan.

Gujarat Health Minister Rushikesh Patel has said preventive measures have been launched in affected districts, over 50,000 people have been screened and all district and rural hospitals have been alerted to send samples of suspected cases to NIV. Officials expect the number of cases to surge in the next few days, even as more confirmations come in from NIV.

This is not the first outbreak of Chandipura virus in the country: there were outbreaks in 2003-04 in parts of central India including Maharashtra, Gujarat and Andhra Pradesh that caused the deaths of over 300 children. 

According to an article, ‘Chandipura virus: an emerging human pathogen?’published in The Lancet in 2004, the virus is a member of the Vesiculovirus genus of the family Rhabdoviridae. Incidentally this family also includes the rabies virus. The Chandipura virus, the paper states, was first isolated in 1965, from the blood of two adults with a febrile illness in a village in Nagpur, Maharashtra. The virus is reportedly named after the village it was isolated from. The other instance when the virus was isolated in human beings was in 1980, in Madhya Pradesh from a patient with acute encephalitis, the article says.

The virus is vector-borne, with the likely vector believed to be the female Phlebotomine sandfly, insects that are prevalent in the early monsoon period. A 2016 paper, ‘Changing clinical scenario in Chandipura virus infection’, published in The Indian Journal of Medical Research, also pointed to the role of Sergentomyia sandflies. It said several species of mosquitoes replicated and transmitted the virus experimentally, and among the different mosquito species studied, Aedes aegypti, (which also transmits dengue), was found to be highly susceptible and could transmit the virus more efficiently than others, under laboratory conditions. However it said no isolation of the virus from the mosquito had been reported as of then.

The Chandipura infection is an encephalitis-causing virus, which means the infection leads to an inflammation or swelling of the brain tissue. Another Lancet paper, ‘A large outbreak of acute encephalitis with high fatality rate in children in Andhra Pradesh, India, in 2003, associated with Chandipura virus’, said the typical clinical manifestations included:

The Chandipura virus has been found to mostly affect children under the age of 15, predominantly in rural locations. In the 2003 outbreak, the age of the affected children in Andhra Pradesh was between 9 months and 14 years. Most deaths occurred within 48 hours of admission to the hospital. In the current outbreak in Gujarat, all of the suspected deaths so far have been of children.