Measles transmission at an international airport — Taiwan, March–April 2018

•We investigated the transmission of measles in Taiwan from an international traveler.•Transmissions occurred in airport, flight, office, and hospital settings.•Secondary and tertiary cases were largely cabin crew, airport staff, and passengers.•An international airport can be a hotspot for measles transmission. During March–April 2018, an infectious measles index case traveling from Thailand led to two successive generations of measles transmission in Taiwan, with 21 cases confirmed. The median patient age was 30.5 years (range 22–47 years); six (27%) had documented receipt of one (n=3) or more (n=3) previous measles-containing vaccine doses at age ≥12 months. Epidemiological investigation and sequence analysis found that most (n=16, 76%) measles transmissions had occurred in airport and flight settings; secondary and tertiary cases included cabin crew (n=7), airport staff (n=2), and passengers who had been at the same airport or on the same flight (n=7). This investigation serves as a reminder that an international airport can be a hotspot for measles transmission. International travelers, airline cabin crew, and airport employees are recommended to check their vaccination status and ensure that they are fully vaccinated against measles. Furthermore, it is recommended that airline and airport employers have an occupational health vaccination program in place to ensure appropriate pre-employment assessment of measles immunity and vaccination.