The Centre for Health Protection (CHP) of the Department of Health (DH) today (April 24) is investigating an imported measles case. Initial investigation revealed that the patient had no contact with any previously recorded local or imported cases in Hong Kong. Meanwhile, the CHP began providing free measles vaccinations today at the airport for eligible airport staff to strengthen herd immunity within the airport community, safeguard public health and prevent the spread of the virus. As of 6pm today, the CHP had administered measles vaccines to approximately 75 airport staff.
      
Details of imported measles case
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      The case involves a 31-year-old female with good past health. She has developed a fever and muscle aches since April 19, followed by a rash on April 22. She attended a private clinic on the same day and was referred to the Accident and Emergency Department of North Lantau Hospital. The CHP subsequently arranged for her admission to Princess Margaret Hospital for isolation and treatment. Her clinical specimen was tested positive for the measles virus upon nucleic acid testing. The patient remains hospitalised with mild symptoms and is in stable condition.
 
      The CHP's epidemiological investigation revealed that the patient travelled to Vietnam with family and friends during the incubation period (between April 9 and 12). Since there is currently a measles outbreak in Vietnam and the patient had no contact with anyone infected with measles in Hong Kong, the case is classified as imported.
 
     An initial investigation revealed that the patient was not born in Hong Kong, but according to the information she provided, she had received measles vaccines in her country of birth. She is a flight attendant but has no connection to the earlier airport cluster of cases. She had no contact with any aircraft maintenance personnel, and her workplace does not overlap with any of the airport cases. She did not go to work during her infectious period (i.e. since April 18) and had no contact with passengers or colleagues. She has one household contact, and travelled to Vietnam with 10 other relatives and friends. The CHP has contacted the private clinic the patient visited to identify close contacts and assess whether any high-risk individuals were involved. Currently, 27 individuals who stayed in the same clinic with the patient during the same time period were identified as close contacts. None of these individuals has any symptoms. The CHP will put them under medical surveillance and continue to investigate this imported case.
 
Measles vaccination booth at airport begins operation
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     Currently, measles outbreaks continue to occur worldwide. Given that airport staff frequently come into contact with large numbers of travellers and that a higher proportion of employees in the airport community are not born locally and may not have received the measles vaccine during childhood, the risk of measles transmission is relatively high. During the investigation into the recent cluster involving three airport backend support staff, the CHP found that approximately 30 per cent of the airport staff, especially those who were not born in Hong Kong, were unsure whether they had completed the two-dose measles vaccination series. In order to prevent another measles outbreak among airport staff, the CHP has set up a vaccination booth at the airport starting today to provide local airport staff with free measles vaccination. Under the coordination of the CHP and the Airport Authority Hong Kong, approximately 75 eligible airport staff received vaccinations in an orderly manner today.
 
     The CHP urged all airport staff, especially those non-locally born people, to review their vaccination records as soon as possible. The measles vaccination service targets Hong Kong airport staff who have not received two doses of the measles vaccine and have never had measles. If a Hong Kong airport employee has undergone a blood test confirming a positive reaction to measles antibodies (IgG), vaccination is not required.
 
     Taking into account the vaccinations administered last week by the CHP to contacts working at the airport who were linked to the aforementioned cluster of measles cases, a cumulative total of over 430 airport staff have now received measles vaccinations. So far, no secondary transmission among close contacts of the measles cluster has been detected. The CHP will continue to investigate and follow up on the abovementioned measles cluster, and conduct medical surveillance of close contacts.

     In 2019, Hong Kong International Airport experienced a measles outbreak involving airport staff. To control the outbreak at that time, the CHP arranged a one-off measles vaccination for airport staff to strengthen herd immunity within the airport community, safeguard public health and prevent the spread of the virus.
      
Non-airport staff should also review their vaccination records
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     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 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 people in Hong Kong are immune to measles.
 
     However, since measles outbreaks are currently occurring in many regions around the world, Hong Kong, as a city with a high volume of international travel, still faces the potential risk of importation of the measles virus and its further spread in the local community. A small number of people who have not completed a measles vaccination (such as non-locally 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 1 year old who have not yet received the first dose of the measles vaccine.
      
     In response to the global rise in measles cases and the risk of imported cases, the CHP sent a letter to all doctors in Hong Kong earlier, informing them of the latest situation regarding measles and urging them to remain vigilant and report any suspected cases. In addition to the airport industry mentioned above, the CHP has also sent a letter to foreign domestic helper agencies earlier, encouraging foreign domestic helpers to receive the measles vaccine to protect their health and prevent the spread of the virus in 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. If travellers returning from places with a high incidence or an outbreak of measles develop symptoms of measles (e.g. fever and rash), they should seek medical advice immediately and avoid contact with non-immune persons, especially pregnant women and infants under 1 year old. They should also report their symptoms and prior travel history to healthcare workers so that appropriate infection control measures can be implemented at the healthcare facilities to prevent any potential spread.
 
     The Hong Kong Childhood Immunisation Programme introduced a measles vaccine for the first time in 1967. Since then, the incidence of measles has gradually decreased. People born and raised in Hong Kong before 1967 can be considered to have acquired immunity to measles through natural infection, as measles was endemic in Hong Kong at that time. People born in Hong Kong in or after 1967 who have not yet completed the two doses of measles vaccination, or whose measles vaccination history is unknown, should consult their family doctors as soon as possible to complete the vaccination and ensure adequate protection against measles.

     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 until 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/Friday, April 24, 2026
Issued at HKT 20:10

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