“Although the vaccination coverage remains very high and the risk of a large-scale local outbreak is considered to be low, Hong Kong has been constantly facing the risk of measles virus importation and the potential risk of further spread in the local community,” the centre said.
Dr Wilson Lam says travellers should be careful overseas after a resurgence in measles worldwide. Photo: Handout
Health officials said two of the patients, all city residents, had received two doses of the measles, mumps and rubella (MMR) vaccine and one was not yet due for inoculation against the disease.

They added all the cases displayed typical symptoms such as rash, fever, cough and irritation and inflammation of the mucous membrane inside the nose.

Only three measles cases were reported for the whole of last year and 2022, and one in 2021.

“It is possible for some people who are non-immune to get infected and transmit the measles virus to susceptible people, as illustrated by the measles outbreak at Hong Kong International Airport in 2019,” the centre said.

The airport was among the hotspots for a measles outbreak between March and May that year.

Thirty cases were detected over the period and authorities provided measles vaccination to airport workers to prevent further spread of the disease. More than 8,500 workers got the jabs.

Better to be safe than sorry on Hong Kong Covid and flu front

A total of 91 infections were reported in 2019, compared with 15 in 2018 and four in 2017.

The centre said Europe, Central Asia and Southeast Asia had witnessed a drop in measles vaccination coverage over the Covid-19 pandemic, resulting in more than 58,000 cases in the last year.

It added similar trends had been observed in the Philippines and Malaysia, where measles is still endemic.

The centre highlighted a statement from the World Health Organization (WHO) which said measles cases around the world had risen by about 79 per cent year on year in 2023, with 168 countries reporting more than 300,000 infections.

The WHO also reported in January that measles infections had soared in Europe last year to 58,114 cases, a nearly 62-fold increase over 2022.

Measles, one of the most contagious diseases, has the potential to spread rapidly if vaccination levels fall.

The disease typically resolves itself within 10 days, but it can lead to severe complications such as blindness, seizures, meningitis or even death in some cases.

What is behind uptick in infectious diseases among children in Hong Kong?

Dr Wilson Lam, vice-president of the Hong Kong Society for Infectious Diseases, said the city’s measles vaccination level exceeded 90 per cent, and the injection was effective in preventing infection and reducing the severity of symptoms.

But he warned some countries, including popular destinations such as Japan, did not have the same levels of vaccination as Hong Kong.

Lam added travellers, especially people with weakened immunity such as pregnant women, should be careful when they visited countries with lower vaccination rates.

“We should be paying attention, but not be too worried, and it is important to consult doctors if symptoms are present,” Lam said.

The centre said vaccination was the best protection against measles and it was essential to maintain a high level of immunity in Hong Kong to prevent the spread of the disease.

The authorities urged doctors to advise pregnant women, women planning for pregnancy, and those with children less than one year old who had not yet had the first dose of the MMR vaccine not to travel to regions with measles outbreaks.