The Centre for Health Protection (CHP) of the Department of Health (DH) today (May 22) is investigating an imported measles case and reminded members of the public who are non-immune to measles to ensure that they have completed two doses of measles vaccination before travelling to reduce the risk of infection.

     The case involves a 29-year-old female who developed fever since May 14. She sought medical attention from a private doctor and attended the Accident and Emergency Department of Tuen Mun Hospital on May 14 and 15 respectively. She developed cough, runny nose and rash on May 16. She attended the Hong Kong Adventist Hospital - Tsuen Wan on May 18 and was admitted for treatment. Her clinical specimen was tested positive for the measles virus upon nucleic acid testing. She was discharged on May 19. 

     The case travelled to the Philippines during the incubation period (April 30 to May 6). As she did not have contact with measles patients in Hong Kong, the case was classified as an imported case.

    She had worked in three schools and a residential care home for the elderly (RCHE) during the communicable period. The CHP has maintained a close liaison with the schools and RCHE for follow-up on the contacts of the case. The CHP has reached 135 contacts in the abovementioned four institutions, no high risk persons have been identified and all were asymptomatic. The CHP assessed that they all have immunity against measles (completed two doses of measles vaccination or born before 1967). The CHP will continue to put the four institutions under medical surveillance and relevant management of the institutions was requested to report to the CHP if any persons develop measles symptoms for follow up.
   
     The CHP's investigation is ongoing.

     Recently, the number of measles cases in some overseas countries has been increasing. The outbreaks in North America (including the United States and Canada), Europe and neighbouring areas (including Vietnam, Cambodia and the Philippines) are ongoing due to the relatively low vaccination rate. Furthermore, an increasing number of measles cases have also been recorded in Japan and Australia this year. Overseas cases mainly affected people who were unvaccinated or had unknown vaccination status. This shows the importance of maintaining a high vaccination rate and herd immunity within the community.

     "The incubation period of measles (i.e. the time from infection to onset of illness) is seven to 21 days. Symptoms include fever, skin rash, cough, runny nose and red eyes. When such symptoms appear, people should wear surgical masks, stay home from work or school, avoid crowded places and contact with unvaccinated people, especially those with weak immune system, pregnant women and children under one year old. Those who suspected they are infected should consult their doctors as soon as possible and inform healthcare workers of their history of exposure to measles," the Controller of the CHP, Dr Edwin Tsui, said.

      "Under the Hong Kong Childhood Immunisation Programme, the overall immunisation coverage in Hong Kong has been maintained at a very high level through the immunisation services provided by the DH's Maternal and Child Health Centres and the School Immunisation Teams. As evidenced by the findings on vaccination coverage of primary school students and the territory-wide immunisation surveys conducted regularly by the DH, the two-dose measles vaccination coverage has remained consistently high, well above 95 per cent, and the local seroprevalence rates of measles virus antibodies reflect that most of the people in Hong Kong are immune to measles. However, Hong Kong, as a city with a high volume of international travel, still faces the potential risk of importation of measles virus and its further spread in the local community. Hence, a small number of people who have not completed measles vaccination (such as non-local born people including new immigrants, foreign domestic helpers, overseas employees and people coming to Hong Kong for further studies) are still at risk of being infected and spreading measles to other people who do not have immunity against measles, such as children under one year old who have not yet received the first dose of measles vaccine," he added.

     Dr Tsui also noted that people born before 1967 could be considered to have acquired immunity to measles through natural infection, as measles was endemic in many parts of the world and in Hong Kong at that time. People born in or after 1967 who have not yet completed the two doses of measles vaccination or whose measles vaccination history is unknown, to consult their family doctors as soon as possible to complete the vaccination and ensure adequate protection against measles. For those who plan to travel to measles-endemic areas, they should check their vaccination records and medical history as early as possible. If they have not been diagnosed with measles through laboratory tests and have never received two doses of measles vaccine or are not sure if they have received measles vaccine, they should consult a doctor at least two weeks prior to their trip for vaccination.

     Besides being vaccinated against measles, members of the public should take the following measures to prevent infection:
 

• Maintain good personal and environmental hygiene;
• Maintain good indoor ventilation;
• Keep hands clean and wash hands properly;
• Wash hands when they are dirtied by respiratory secretions, such as after sneezing;
• Cover the nose and mouth while sneezing or coughing and dispose of nasal and mouth discharge properly;
• Clean used toys and furniture properly; and
• Persons with measles should be kept out of school till four days from the appearance of a rash to prevent the spread of the infection to non-immune persons in school.

  
     For more information on measles, the public may visit the CHP's measles thematic page. Members of the public who are going to travel can visit the website of the DH's Travel Health Service for news of measles outbreaks outside Hong Kong.

Ends/Thursday, May 22, 2025
Issued at HKT 20:19

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