Japanese encephalitis in Taiwan: 6 cases reported in 2025 to date
The Taiwan Centers for Disease Control announced recently five new confirmed cases of Japanese encephalitis have been reported in the country.
The latest cases, three men and two women aged between 40 and 60, are located in Nantun District, Taichung City, Huatan Township, Changhua County, Beigang Township, Yunlin County, Kanding Township, Pingtung County, and Gaoshu Township, Pingtung County.
The onset of the disease was between June 9 and June 23. The symptoms included fever, vomiting, stiff neck, impaired consciousness, headache, dizziness, etc. After medical treatment, they were diagnosed with Japanese encephalitis. All the cases are currently hospitalized, and none of their cohabitants have suspected symptoms.
According to the investigation by the health authorities, the residences of the five cases are near high-risk areas such as pig pens, rice fields, or pigeon houses. In order to reduce the risk of the epidemic, the health authorities have hung mosquito traps in high-risk areas around the residences of the cases, reminding local medical institutions to raise awareness of reporting and warnings, and at the same time strengthen public health education and prevention and control measures such as vaccination of children of appropriate age.
Monitoring data from the CDC shows that as of June 30 this year, there have been a total of 6 confirmed cases in Taiwan. The Japanese encephalitis epidemic season in Taiwan is from May to October each year, with the peak period from June to July. From 2021 to 2024, the number of confirmed cases in the country during the same period was 14, 7, 12 and 15 respectively. The majority of cases were in adults over 40 years old, but people of all ages are at risk of infection, and the public is reminded to be vigilant and not take it lightly.
Japanese encephalitis with Dr. Melvin Sanicas
The CDC stated that the Japanese encephalitis epidemic season is in Taiwan, and the three-spotted house mosquito, annular house mosquito and white-headed house mosquito are the main mosquito vectors in Taiwan, which often breed in rice fields, ponds and irrigation ditches. Most people infected with Japanese encephalitis have no obvious symptoms. A few may have headaches, fever or aseptic meningitis. In severe cases, there may be changes in consciousness, inability to distinguish people and places, general weakness, brain nerve damage, mild paralysis, and even coma or death. The mortality rate of Japanese encephalitis can reach 20-30%, and 30-50% of surviving cases have neurological or psychiatric sequelae. The CDC reminds the public to wear light-colored long-sleeved clothes and pants when they are near the aforementioned high-risk environments where mosquitoes are prone to breeding. Use mosquito repellents approved by government agencies containing DEET, Picaridin or IR3535 on exposed parts of the body to avoid infection by mosquito bites.
The CDC calls for the most effective way to prevent Japanese encephalitis to get vaccinated with Japanese encephalitis vaccines. The public should bring their children of appropriate age to local health centers or contracted hospitals for vaccination on time to avoid serious sequelae caused by infection. In addition, people who live or move around in high-risk environments such as pig pens and rice fields should implement anti-mosquito measures. Adults who feel they are at risk of infection can go to the tourism medicine clinic for evaluation and receive the Japanese encephalitis vaccine at their own expense.