TAIPEI (TVBS News) — Health officials in Chiayi County (嘉義縣), a rural agricultural region in southwestern Taiwan, confirmed Tuesday (June 17) the year's first case of Japanese encephalitis, a potentially fatal mosquito-borne disease that threatens communities across East Asia annually. A middle-aged man who developed fever symptoms on June 7 received his diagnosis two days later and remains hospitalized while receiving treatment. The Chiayi County Health Bureau (嘉義縣衛生局) has responded by launching an aggressive public awareness campaign, warning residents that the region has entered the disease's peak transmission period, which typically stretches from May through October.
The patient, who works in the animal husbandry industry, resides in an environment considered highly conducive to disease transmission, surrounded by pigeon coops, pig farming operations, and extensive rice paddies — all known breeding grounds for the Culex mosquitoes that transmit the virus. Medical records indicate he had never received the Japanese encephalitis vaccine despite his occupational risk factors. County health authorities have deployed mosquito surveillance traps throughout the vicinity of his home and neighboring livestock facilities while simultaneously urging workers at nearby pig farms to seek preventive consultations and vaccination services at the specialized travel medicine clinic of Chang Gung Memorial Hospital (嘉義長庚醫院), one of Taiwan's largest healthcare networks.
Chao Wen-hua (趙紋華), who directs the county health bureau, issued public guidance recommending residents limit exposure to high-risk environments during dawn and dusk hours when mosquito activity intensifies, and consistently apply EPA-approved repellents containing active ingredients such as DEET, picaridin, or IR3535. During a public health briefing, Chao emphasized that vaccination remains the gold standard for prevention, particularly pointing to Taiwan's routine childhood immunization program that includes Japanese encephalitis vaccines. Health officials cautioned that while approximately 99% of infections produce mild or no symptoms, the rare severe cases can progress rapidly to neurological complications including disorientation, muscle weakness, coma, and potentially death.
Public health officials strongly recommend that adults who believe they face elevated exposure risks — particularly those working in agricultural settings or residing near mosquito breeding grounds — consult with specialists at travel medicine clinics to determine their vaccination needs, though these preventive immunizations are not covered by Taiwan's national health insurance and require out-of-pocket payment. The Chiayi County Health Bureau has mobilized environmental health teams to conduct mosquito population monitoring and targeted insecticide applications in affected communities, while simultaneously coordinating with agricultural authorities to implement enhanced biosecurity measures at pig farms identified as potential virus reservoirs within the region. ◼