South Korea issued a nationwide warning on Japanese encephalitis Sunday, urging the public to take precautionary measures including vaccination.

The Korea Centers for Disease Control and Prevention issued the warning in response to discovery of the culex tritaeniorhynchus, a species of mosquito that carries the virus, in South Jeolla Province and Jejudo Island.

The virus is the leading cause of vaccine-preventable encephalitis in Asia. Most human infections are asymptomatic or result in only mild symptoms such as fever and headache. However, a small proportion of infected patients develop inflammation of the brain with serious symptoms such as coma, tremors and convulsions. 

In order to prevent the mosquito-borne disease, the KCDC advised the public to wear long-sleeves, long pants and socks when going outdoors, starting from this month to October. As mosquitos may bite through thin clothing, the agency recommended treating clothes with repellent containing permethrin for extra protection.

The agency also urged all Korean households to avoid the accumulation of stagnant water at private properties, as many mosquitoes breed in standing water. Keeping drains free from blockages, putting used cans and bottles into covered dustbins, and changing water for plants at least once a week, leaving no water in the saucers underneath flower pots were all recommended.

Those with relatively weak immune systems, as well as all children aged 1-12, are strongly encouraged to get vaccinated against the disease.

By Claire Lee (dyc@heraldcorp.com)