On May 21, 2018, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s first Japanese encephalitis case confirmed in an over 50-year-old male who resides in Pingtung County. On May 14, 2018, the case began to develop symptoms, including lethargy, headache and fever. Subsequently, he sought medical attention at a hospital. On May 17, when his symptoms persisted and he began to develop personality change, he was transferred to another hospital for further treatment and reported to the competent health authority as a suspected case. On May 21, infection with Japanese encephalitis was confirmed in the case. As of now, the case is still hospitalized for treatment.
According to the epidemiological investigation, the case’s vaccination history is unknown and the case had not recently traveled. He works in agriculture and animal husbandry. The case’s primary areas of daily activities include places around his residence and workplace. There is a pigpen around his workplace. Hence, it is determined the case could have acquired his infection around his workplace. To prevent the further spread of the disease, the local health authorities have set up mosquito lamps around the residence of the confirmed case and the places he frequented 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.
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. Thus far this year, as May 21, 2018, a total of 1 Japanese encephalitis case has been confirmed in Taiwan. During 2013 and 2017, the number of Japanese encephalitis cases confirmed respectively was 16, 18, 30, 23 and 25. All cities and counties have reported sporadic cases and people of all age are at risk of contracting the disease. The majority of the confirmed cases are adults aged 40 and above. Hence, the public is advised to heighten vigilance for the disease.
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 children who aged 15 months and above and 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.
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 https://www.cdc.gov.tw or call the toll-free Communicable Disease Reporting and Care Hotline, 1922 (or 0800-001922).