India’s Health Ministry said it has deployed National Response Teams to Gujarat and Rajasthan in response to a Chandipura virus outbreak.
The ministry said the expert teams will work with local health authorities on disease control, treatment of patients and stronger public-health protections.
At least 22 children were reported to have died in India in connection with the outbreak.
Gujarat has been described as the most affected state.
Gujarat Health Minister Praful Pansheriya said 184 blood samples had been tested and 35 were positive for Chandipura virus.
The World Health Organization says the virus is typically transmitted during the rainy season by sandflies, mosquitoes and other insect vectors.
The WHO says infection can cause encephalitis, or inflammation of the brain, particularly in children and may become severe rapidly.
Two deaths linked to the virus were also reported in Rajasthan last month.
Health authorities are increasing surveillance, early detection, vector-control work and public-awareness activities in affected areas.
Health experts advised prompt medical attention for children with fever, seizures or neurological symptoms.