On July 7, 2017, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s first case of Japanese encephalitis confirmed in Taoyuan City. The case is a 71-year-old female. On June 20, she sought medical attention after developing fever, fatigue, neck stiffness and cognitive degradation. On July 6, infection with Japanese encephalitis was confirmed in the case. As of now, the case has been gradually improving and is still hospitalized. Currently, none of her family members residing in the same household has experienced any symptoms. As it is the Japanese encephalitis season now, thus far this year, a cumulative total of 11 cases have been confirmed in Taiwan. The public is once again urged to heighten vigilance for the disease, take precautions against mosquito bites and receive vaccination against Japanese encephalitis in order to lower the risk of infection.
 

According to the epidemiological investigation, the case’s related vaccination history is unknown. The case’s primary areas of daily activities include places around her residence and work place. During the incubation period, the case visited Tainan City, Kaohsiung City and Pingtung County. On the other hand, although there are no pig and pigeon farms and rice paddy fields around her house, there are creeks nearby. The possible source of infection is still being investigated. 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 July 7, 2017, 11 Japanese encephalitis cases have been confirmed in Taiwan, including 3 cases in Kaohsiung City, 2 cases in Pingtung County, 2 cases in Changhua County, 1 case in Tainan City, 1 case in New Taipei City, 1 case in Chiayi County, and 1 case in Taoyuan City. During the same period in the recent 5 years, the number of Japanese encephalitis cases confirmed varies between 9 and 26. 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.

Most infected individuals experience no symptoms. A few cases experience headache, fever and acute aseptic meningitis. Severe cases may experience acute encephalitis, psychological or neurological sequelae, and even death.　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.

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).