On September 28, 2017, the Taiwan Centers for Disease Control (Taiwan CDC) announced one indigenous dengue cluster of an over-50-year-old married couple occurred in northern Taiwan. They sought medical attention at a hospital after subsequently developing symptoms, including fever, muscle ache, joint pain and fatigue, and were hospitalized.，Infection with DEN-1 was confirmed in both cases on September 27. As of now, the 2 cases are still hospitalized for treatment and none of the contacts residing in the same household has experienced any suspected symptoms. To prevent the further spread of the disease, the local health authority has implemented various prevention measures, including cleaning of vector breeding sites, investigating the mosquito population density around the places the cases frequent, and providing the public with relevant health education.

Since the healthcare facilities in northern Taiwan have less experience with diagnosing dengue fever, the number of days between the symptom onset date and the date of reporting a case to the health authority can be prolonged, which can lead to delayed reporting of potential cases and elevating the risk of further transmission. Therefore, healthcare facilities are urged to heighten vigilance for suspected cases and report suspected cases to the competent health authority as soon as possible in order to facilitate the implementation of subsequent prevention measures that prevent the further spread of the disease. At the same time, the public is also urged to cooperate with disease prevention and control efforts such as epidemiological investigations in order to ensure their own health and wellbeing.

According to the surveillance data compiled by Taiwan CDC, during September 25 and 27, 2017, 2 new indigenous dengue cases, which constitute a family cluster, were confirmed. In addition, 5 new imported cases were confirmed. During the past one month, the majority of the imported cases acquired infection in Vietnam. As of September 27, 2017, a total of 234 imported cases, including 2 deaths, and 5 indigenous cases have been confirmed in Taiwan so far this year. Recently, the overall level of dengue activity in Southeast Asia, including Laos, Vietnam and Thailand, has been on the rise or above the epidemic threshold. Thus far, a cumulative total 125,000 cases have been confirmed in Vietnam, which is 40% more than that reported during the same period last year, and a cumulative total of 7,700 cases have been confirmed in Laos, which is higher than that reported during the same period last year.

According to the weather forecast made by the Central Weather Bureau (CWB), an approaching cold front this weekend will result in light showers in some parts of Taiwan.　　Taiwan CDC reminds that accumulation of standing rain water in containers facilitates the breeding of vector mosquitoes. Hence, Taiwan CDC urges the public to empty and clean any potential vector breeding sites such as containers that collect standing water in and around the home periodically in order to prevent dengue transmission. Travelers planning to visit areas affected by dengue fever are urged to take precautions against mosquito bites. If symptoms such as fever, headache, retroorbital pain, myalgia, arthralgia, and rash develop, please seek immediate medical attention and inform the doctor of recent travel history and activity to facilitate prompt diagnosis and case reporting. For more information, please visit the Taiwan CDC website at http://www.cdc.gov.tw or call the toll-free Communicable Disease Reporting and Consultation Hotline, 1922 (or 0800-001922).