On June 18, 2013, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s second confirmed case of Japanese encephalitis in Taiwan. The case is a 17-year-old male student who received four doses of Japanese encephalitis vaccine in 2003 and resides in Xinyuan Village, Pingtung County. On May 31, he developed symptoms, including fever, headache and nausea. On June 1, he was hospitalized and Japanese encephalitis was confirmed in the case. On June 8, the case was fully recovered and discharged. The three people who reside in the same household with the case have not developed any suspected symptoms. There are several pig farms and rice paddy fields around the case’s residence. The health authority has set up mosquito lamps at pig farms as an attempt to capture vector mosquitoes and reinforced promotion of vector control and prevention to prevent the further spread of the disease. Taiwan CDC reminds the public that the Japanese encephalitis season is upon us and the weather is getting hot and humid, which favors growth of vector mosquitoes. Hence, Taiwan CDC once again urges the public to take precautions against mosquitoes bites and avoid visiting vector-breeding sites such as pigpens or other animal farms in order to prevent Japanese encephalitis.  

As of June 17, 2013, a total of two cases of Japanese encephalitis have been confirmed in Taiwan this year. One case is still currently hospitalized for treatment and the other case has recovered and been discharged. 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. Prior to implementing the Japanese encephalitis vaccine policy, the number of confirmed cases of Japanese encephalitis in a year was once as high as 273 and the number of deaths associated with Japanese encephalitis was once as high as 206. Since implementing the Japanese encephalitis vaccine policy in 1968, the number of Japanese encephalitis cases confirmed in a year has declined drastically. On average, about 20 to 30 cases of Japanese encephalitis occur in Taiwan each year and the number of deaths is about 0 to 2. Most cases experience mild symptoms. Nevertheless, severe cases may experience sequelae such as personality changes, learning disability, speech difficulties, mental retardation and even death.

A 2-dose regimen for routine childhood Japanese encephalitis vaccination is recommended for all toddlers aged 15 months and the 2 doses should be given two weeks apart. A booster dose should be given one year after the 2-dose primary vaccination. A second booster should be administered when the child attends first grade at elementary school. Japanese encephalitis vaccination is available at all local health centers. Parents are urged to make sure their children receive the vaccine timely. If adults wish to receive the vaccine, they can visit any of the hospitals under the Department of Health or other designated hospitals for self-pay vaccination. One dose of the vaccine costs between NT$150 to NT$500.

As Japanese encephalitis cases continue to occur and we have entered the Japanese encephalitis season, Taiwan CDC reminds the public to avoid mosquito bites by limiting visits to vector-prone areas such as pig and other animal farms especially at dawn and dusk when mosquitoes are most active. If, however, visits to vector-prone areas are unavoidable, please wear light-colored clothing, long sleeves and long pants and apply officially approved mosquito repellent to exposed parts of the body to prevent mosquito bites and lower the risk of infection. Physicians are advised to be vigilant for and notify any suspected cases to the health authority immediately to facilitate implementation of subsequent measures that prevent further spread of the disease.    For more information on Japanese encephalitis, please call the toll-free Communicable Disease Reporting and Care Hotline, 1922, or 0800-001922 if calling from a cell phone, or visit the Taiwan CDC’s website at http://www.cdc.gov.tw.