Korea issues national Japanese encephalitis alert, advises bug spray

Social Affairs

Published: 26 Jul. 2024, 18:10

Korea issues national Japanese encephalitis alert, advises bug spray

Culex tritaeniorhynchuses [KOREA DISEASE CONTROL AND PREVENTION AGENCY]

Korea issued a nationwide alert for Japanese encephalitis virus (JEV) on Thursday, health authorities announced Friday.

The Korea Disease Control and Prevention Agency (KDCA) issued the warning after confirming on Wednesday that Culex tritaeniorhynchus mosquitoes made up 63.2 percent of the mosquito population in South Gyeongsang and 58.4 percent in South Jeolla.

Culex tritaeniorhynchus are small, dark-brown mosquitoes capable of carrying the virus and typically inhabit rice paddies, animal barns and puddles. They are most active at night and live throughout the nation.

JEV is classified as a Group 3 infectious disease, meaning it requires monitoring for potential outbreaks due to its intermittent nature. Most JEV infections result in mild symptoms, including mild fevers and headaches, while other cases may not present symptoms.

However, rare infections — approximately 1 in 250 cases — can result in severe clinical illness, including the rapid onset of high fever, disorientation, coma, seizures, spastic paralysis and ultimately death, according to the World Health Organization.

The fatality rate among symptomatic cases can be as high as 30 percent. Of those who survive, 30 to 50 percent may experience neurological complications.

Around 20 cases of JEV are reported annually in Korea, with the first typically appearing between August and September and some as late as November.

A total of 91 cases of JEV were reported from 2019 to 2023, with those aged 50 and older accounting for 87.9 percent, or 80 cases. Gyeonggi accounted for the most cases, followed by Seoul and Gangwon.

To reduce the risk of JEV, individuals are advised to wear light-colored, long-sleeved clothing at night, use mosquito repellents and avoid strong perfumes and cosmetics that may attract mosquitoes.

An effective vaccine is available, and the KDCA recommends that individuals born after 2011 who are eligible for national vaccination follow the standard immunization schedule to get the shot.

“Individuals should pay extra attention in avoiding mosquito bites, as the risk of encountering mosquitoes carrying JEV increases during the summer when outdoor activities are more frequent,” said Jee Young-mee, head of the KDCA. She encouraged those eligible for vaccination to adhere to the recommended immunization schedule.

BY WOO JI-WON [woo.jiwon@joongang.co.kr]