On June 8, 2017, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s first case of Japanese encephalitis confirmed in Tainan City. The case is a 45-year-old foreign female who lives in Taiwan due to work. In the evening of May 30, she was rushed to the hospital and hospitalized for treatment after she developed splitting headache, fever and unconsciousness. 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 7. As of now, the case’s condition has improved, but she is still hospitalized for treatment.

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 (Danei District, Tainan City) and work area (Danei District, Tainan City). Occasionally, she visited Yujing District, Tainan City on her off days for grocery shopping. Within approximately 1 km distance of the case’s residence and work place, there is bird and pig farming. Hence, it was determined that she might have caught the infection around her residence. 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 8, 2017, 2 Japanese encephalitis cases have been confirmed in Taiwan, including 1 case in Kaohsiung City and 1 case in Tainan City. During 2012 and 2016, the total numbers of confirmed Japanese encephalitis cases respectively are 32, 16, 18, 30 and 23.

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. 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.

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).