[Life] Japanese Encephalitis Epidemic Peak, 3-Month-Old Infant Confirmed as Youngest Case in History

The Central Epidemic Command Center (CECC) announced today (16th) the second confirmed case of Japanese encephalitis this year, a female infant just over 3 months old in Hualien City, Hualien County. This is also the youngest case in the history of our country. July are the peak seasons for Japanese encephalitis in Taiwan. Epidemic prevention physician Lin Yong-ching reminds that less than 1% of infected individuals will develop symptoms, but if the symptoms are severe, the mortality rate can reach 20-30%. The public should be vigilant. The CECC announced on the 16th that a new case of Japanese encephalitis has been added domestically. It is a female infant just over 3 months old in Hualien City, Hualien County. She has not yet reached the age for Japanese encephalitis vaccination, has no history of domestic or international travel, and no congenital diseases. This is also the youngest case of Japanese encephalitis in the history of our country. The infant developed symptoms such as fever and drowsiness in late May. She sought medical attention at the emergency department and was hospitalized. During hospitalization, she continued to experience high fever and epileptic seizures. It was suspected to be acute disseminated encephalomyelitis. After reporting for Japanese encephalitis and testing positive, she has been hospitalized for nearly 3 weeks and is currently being treated in the intensive care unit. The infant has suspected mosquito bite marks. Her family members living with her have no similar symptoms. There are no pigsties, rice paddies, or other high-risk areas near the infant's residence. The source of infection is still under investigation, and the health authorities are continuing their epidemiological investigation. According to CECC statistics, there have been a total of 2 confirmed cases of Japanese encephalitis domestically this year, which is lower than the same period in 2023 and 2024. CECC spokesperson Tseng Shu-hui stated that Taiwan's Japanese encephalitis season is from May to October each year, with June and July being the peak months. Cases can occur in all counties and cities across Taiwan. Most cases are adults over 40 years old, but there is a risk of infection at all ages. The public is reminded to be vigilant. Lin Yong-ching, an epidemic prevention physician at the CECC, said that the mosquitoes that transmit Japanese encephalitis in Taiwan are mainly Culex tritaeniorhynchus, Culex annulus, and Culex bitaeniorhynchus. They often breed in rice paddies, ponds, and irrigation ditches, with peak biting times at dusk and dawn. Most people infected with Japanese encephalitis have no obvious symptoms. Those who develop symptoms will experience headaches and fever. Severe cases may lead to altered consciousness, inability to recognize people and places, general weakness, or even coma or death. He said: "(Original sound) Only less than 1% of infected individuals may develop clinical symptoms such as headache and fever. However, in a very small number of severe cases, there may be altered consciousness, general weakness, high fever, confusion, or even coma or death. If these severe symptoms occur, the mortality rate can be 20% to 30%. Even for survivors, there is a certain possibility of neurological sequelae." Lin Yong-ching emphasized that the most effective way to prevent Japanese encephalitis is to get vaccinated. The routine vaccination schedule for infants in our country is the first dose at 15 months of age, followed by the second dose 12 months later. He reminds the public to take their eligible children for vaccination on time to avoid serious sequelae from infection. In addition, individuals living or working near high-risk environments such as pigsties and rice paddies, as well as those planning to travel to endemic areas, can also consider getting vaccinated at their own expense.