Explainer | Measles: a highly infectious disease previously brought under control but now appearing to be making a comeback in Hong Kong
- The number of cases of the disease reported in the city this year has already exceeded those for each of the last four years
Hong Kong as an international travel hub has often been exposed to potential health threats caused by communicable diseases. The recent measles outbreak has again highlighted the need for the government to step up measures to protect the public from infectious illnesses imported from abroad.
The rapid increase in measles cases reported in Hong Kong has aroused public concern about an infectious disease that has been brought under control in the city over the past two decades through high levels of vaccination. In 2016, the World Health Organisation (WHO) declared the city measles-free as local transmission of the disease had been eliminated for at least 36 months. But imported cases were still recorded.
What is measles and how contagious is it?
Measles is a highly infectious disease. People infected with measles will first have symptoms such as fever, cough and white spots inside the mouth, followed by a red blotchy skin rash, which usually spreads from face to the rest of the body, and can persist for up to three weeks. In severe cases, the lungs, gut and brain might be affected, leading to serious consequences or even death.
The virus of the disease lives in the nose and throat mucus of the infected person, and can be spread through coughing and sneezing. According to the United States Centres for Disease Control and Prevention, if a person carries the measles virus, up to 90 per cent of the people in the person’s immediate vicinity who are not immune will also be infected.
