On June 19, 2017, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s first case of Japanese encephalitis confirmed in Pingtung County. The case is a 53-year-old female housewife. On May 25, she sought medical attention at a hospital after developing symptoms, including fever, fainting and consciousness disturbance. When her symptoms persisted, she was transferred to another hospital for further treatment. After the hospital reported her to the local health authority as a suspected Japanese encephalitis case and submitted her specimens for laboratory testing, infection with Japanese encephalitis was confirmed in the case on June 18.

According to the epidemiological investigation, the case had not recently traveled overseas, had not been vaccinated against Japanese encephalitis, and spent most of her time at home. Within approximately 2 km distance of the case’s residence, there is pigeon and poultry farming. Currently, none of the family members residing in the same household has experienced any symptoms. To prevent the further spread of the disease, the local health authority has set up mosquito lamps around the residence of the confirmed case and the places she frequents as an attempt to capture vector mosquitoes and reinforced health education among residents who live near the confirmed case as well as urged routine vaccination of age-appropriate children and at-risk individuals.

Thus far this year, as of June 19, 2017, 4 Japanese encephalitis cases have been confirmed in Taiwan, including 2 cases in Kaohsiung City, 1 case in Tainan City, and 1 case in Pingtung County. During 2012 and 2016, the total numbers of confirmed Japanese encephalitis cases respectively are 32, 16, 18, 30 and 23. All cities and counties have reported sporadic cases. As vaccination is the most effective way to prevent Japanese encephalitis, people who live near or work in close proximity to pig farms or rice paddy fields that increase their risk of Japanese encephalitis infection are recommended to visit one of the hospitals under the Ministry of Health and Welfare for self-paid vaccination. In addition, Taiwan CDC also urges parents and caretakers of age-appropriate children who have not received the vaccine to get vaccinated as soon as possible at their local health center or contracted healthcare facilities to prevent infection and severe complications.

According to Taiwan CDC’s surveillance data, transmission of Japanese encephalitis in Taiwan occurs annually between May and October and it usually peaks between June and July. The primary vector of Japanese encephalitis is a species of mosquito, Culex tritaeniorhynchus, which breeds in rice paddy fields, ponds, and irrigation canals. To prevent infection, avoid visiting vector-breeding sites such as pigpens at dawn and dusk when mosquitoes are most active. When needing to visit mosquito-prone places, people are advised to wear light-colored, long-sleeved shirts and long pants, and apply officially approved mosquito repellent to exposed body parts to prevent mosquito bites and lower the risk of contracting Japanese encephalitis. For more information, please visit the Taiwan CDC’s website at http://www.cdc.gov.tw or call the toll-free Communicable Disease Reporting and Care Hotline, 1922 (or 0800-001922).