On July 29, 2017, the Taiwan Centers for Disease Control (Taiwan CDC) announced this year’s third imported Zika case identified in Taiwan. The case is a 21-year-old Taiwanese male who resides in northern Taiwan. During June 1 and July 27, he traveled to Ho Chi Minh City, Vietnam alone to visit his relatives. On July 26, he subsequently developed symptoms, including fever and chills. On July 27, he returned to Taiwan with his relatives. When he arrived in Taiwan, he was identified with a fever by the quarantine officer at the fever screening station at the airport. The quarantine officer collected blood sample from the case and issued him notification to monitor his own health for the development of suspected symptoms. On July 29, infection with Zika virus was confirmed in the case. As of now, the case’s condition has improved. Currently, none of the family members residing in the same household and those that traveled with him have developed suspected symptoms. The local health authority has implemented various prevention measures and provided the case with relevant health education, including the “1+6 Principle”.

Since 2016, a total of 16 imported Zika cases have been identified in Taiwan and they respectively became infected in Thailand (4), Vietnam (4), Malaysia (2), Indonesia (1), Singapore (1), St. Lucia (1), St. Vincent and the Grenadines (1), Florida, the U.S. (1), and Angola (1).

Since 2015, 75 countries, areas and/or territories worldwide have reported local outbreaks of Zika virus infection. Among the countries, no new cases have recently been reported in Papua New Guinea and Cayman Islands and the previous transmission has been interrupted in both countries. Therefore, Taiwan CDC has lowered the travel notice level for Papua New Guinea to Level 1: Watch for Zika virus and removed the travel notice for Cayman Islands. Taiwan CDC has issued a travel notice of Level 2: Alert for Zika virus for 55 countries and territories with ongoing outbreaks or possible local transmission of Zika virus, including Singapore, Maldives and Vietnam. Moreover, 20 countries, including Indonesia, Thailand, Bangladesh, Cambodia, Laos, Malaysia, the Philippines and India, had previously reported Zika outbreaks. Although no Zika cases have been recently reported in those countries, no evidence has suggested that the local transmission of the virus has been interrupted. Hence, Taiwan CDC has issued a travel notice of Level 1: Watch for Zika virus for those countries. During the previous week, 3 new cases and 1 new Zika cluster area were reported in Singapore. Moreover, the cumulative number of Zika cases thus far confirmed in Singapore is 45 and there is currently one area with a Zika cluster in Singapore.

As outbreaks in neighboring Southeast Asian countries continue to persist and the vector mosquito season has arrived, the risk of imported and indigenous epidemic is elevated. Travelers returning to Taiwan from Zika-affected areas are urged to proactively contact the quarantine officer at the fever screening station at the airport when experiencing symptoms. If symptoms develop within two weeks of their return, please seek immediate medical attention and inform the physician of their travel history in order to facilitate diagnosis and treatment. Simultaneously, healthcare facilities are urged to heighten vigilance for suspected cases, inquire patients of their travel history when necessary, and report suspected cases to the competent health authority as required by the law in order to lower the risk of transmission.

Current scientific evidence has proved that Zika virus infection is usually mild in adults and suggested the occurrence of congenital microcephaly and even deaths in babies of mothers who were infected with Zika virus while pregnant. Therefore, pregnant women and women planning pregnancy are advised to postpone all unnecessary travels to Zika-affected areas. Travelers visiting Zika-affected areas are urged to take precautions against mosquito bites such as wearing light-colored clothing, long sleeves and long pants, applying officially approved mosquito repellent to exposed parts of the body, staying at accommodations installed with window screens, screen doors or air conditioners. In addition, travelers leaving Zika-affected areas are urged to follow the “1+6 Principle” to prevent Zika transmission. The “1+6 Principle” specifies that people who have recently traveled to Zika-affected areas should monitor their own health and take precautions against mosquito bites for at least 3 weeks, postpone blood donation for at least 1 month, and regardless whether they develop suspected Zika symptoms, they should practice safe sex for at least 6 months to prevent Zika transmission. Further, female travelers should postpone pregnancy for at least 6 months. 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).