The Korea Centers for Disease Control and Prevention issued an alert for Japanese Encephalitis (JE) on Friday, July 6th in response to mosquito surveillance results in South Jeolla Province confirming Culex tritaeniorhynchus, the main vector of JE.

Image/Robert Herriman
Image/Robert Herriman

Culex tritaeniorhynchus is a small, dark brown mosquito that is active at night and found mainly around puddles and in areas for farming and livestock.

Of all the mosquitoes collected in South Jeolla Province on July 3rd, a daily average of 962 mosquitos were Culex tritaeniorhynchus, accounting for 64.7% of the total samples collected.

Mosquitoes are collected twice every week as part of the JE surveillance system. An alert is issued when the daily average JE vector mosquito count is at least 500 and accounts for 50% or more of the total mosquitoes collected.

There is an effective vaccine for JE, and children should be vaccinated against the disease from as early as 12 months to 12 years of age, in accordance with the national immunization program.

Although vaccination against JE is not required for adults, it is recommended for individuals with weak or compromised immune systems who are at high risk of infection due to regular exposure to mosquitoes.

Within the past 10 years, JE surveillance data have shown an average of 20 JE cases per year, with 90% of reported cases aged 40 or over. As such, individuals in this age group should avoid mosquito bites to prevent infection.