A four-year-old boy was hospitalised last week in Hà Nội due to Japanese encephalitis (JE). He was suffering from a high fever and seizures. — Photo hanoimoi.vn

Last year’s first case of JE was discovered in June with the virus being most active between May and August. The virus is commonly spread though mosquito bites with symptoms include fever, headache, vomiting and difficulty moving.

Doctor Trần Minh Điển, deputy director of the Vietnam National Children's Hospital, said JE was difficult to detect early as it showed similar symptoms to other infectious diseases. It could, however, develop rapidly, in some extreme cases within 24 hours.

JE has been known to have a high mortality rate among young children and often leaves devastating effects.

The city’s health department advised parents to vaccinate their children at the earliest date possible and to keep houses and surrounding areas clean to prevent mosquitoes from breeding.  VNS