The Centers for Disease Control (CDC) announced the first confirmed case of Japanese encephalitis in Chiayi City this year (2014). This is the third confirmed case within Taiwan this year. The patient is a 50-year-old man. On June 18, he fell on the road and was sent by passersby to the hospital for treatment. His symptoms at the time included fever, rash, disturbance of consciousness, neck stiffness, and cramps. After the hospital reported the case, the patient was tested and his illness confirmed. He remains unconscious and is being treated in intensive care. An investigation conducted by the Chiayi City Health Bureau has indicated that pig farmers are located approximately 1 km to 2 km and rice paddies are located 500 m from the location where the patient lives. The Health Bureau also hung lamps to trap mosquitoes in the neighborhood, strengthened education and public awareness for the neighboring households, and issued vaccine reminders for children of the appropriate age. Because confirmed cases of Japanese encephalitis persist and Taiwan is entering the epidemic period, the CDC calls on the people to increase their vigilance. Those with homes or activity locations near rice paddies, pig farmers, or pigeon keepers should pay particular attention to personal anti-mosquito measures to prevent infection. 


Historical data indicate the epidemic period for Japanese encephalitis is May to October of each year, with June and July being the peaks of the epidemic. Analysis of the environment surrounding the residences and activity locations of confirmed cases indicates that rice paddies, pig farms, and pigeon farms are the three riskiest environments. These environments are often breeding sites for vector mosquitoes. They are also areas where natural hosts (pigs) concentrate. People who live or engage in activity near these high-risk environments should pay particular attention to personal safeguards, including avoiding engaging in activity near breeding sites for vector mosquitoes at dusk and dawn as much as possible. If this cannot be avoided, light-colored and long-sleeved clothing should be worn and anti-mosquito agents approved by the Ministry of Health and Welfare should be applied to exposed areas on the body to avoid mosquito bites. 

No antivirals currently exist for the Japanese encephalitis virus. Only supportive therapy depending on patients’ conditions can be provided. Therefore, vaccination is globally recognized as the most effective preventive measure. Families with children of the appropriate age who have not completed their vaccinations should take their children to public health centers or designated medical institutions within their jurisdictions to complete the vaccinations, which prevent the infections that lead to serious complications. Those whose residences or workplaces are near piggeries, rice paddies, or other high-risk environments and perceive that they are in danger of infection can go to the medical centers described above and be vaccinated at their own expense. 

Those infected with Japanese encephalitis are often left with severe neurological or psychiatric sequelae, such as abnormal muscle tension, speech impairments, abnormal personalities, or mental deficiencies. The CDC calls on physicians to increase vigilance and strengthen suspected case reporting to help epidemic prevention units adopt preventive measures without delay and avoid the spread of the disease. For the latest epidemic information on Japanese encephalitis, please visit the CDC’s website (http://www.cdc.gov.tw) or call the toll-free domestic public outbreak reporting and care hotline at 1922 (or 0800-001922).