CHP investigates outbreak of measles infection

     The Centre for Health Protection (CHP) of the Department of Health (DH) is today (May 13) investigating an outbreak of measles infection affecting three workers at a shop in Tsim Sha Tsui.

     As at 4pm today, three cases were recorded. The first case involves a 30-year-old man with good past health who developed fever since May 7 and rash since May 10. He attended the Accident and Emergency Department at Kwong Wah Hospital (KWH) on May 11 and was admitted to Princess Margaret Hospital for treatment on May 12. A laboratory test of his respiratory specimen was positive for the measles virus. He has been in a stable condition and reported to have received measles vaccination. He had no travel history during the incubation period and had travelled to Japan during the communicable period.

​     The second case involves a 25-year-old woman with good past health who developed fever and rash since May 11. She attended the Accident and Emergency Department at KWH on May 11 and was admitted to Tuen Mun Hospital for treatment today. A laboratory test of her respiratory specimen was positive for the measles virus. She has been in a stable condition and reported to have received measles vaccination. She had no travel history during the incubation period and had travelled to Shenzhen during the communicable period.
 
     The third case involves another 25-year-old woman with good past health who developed fever since May 8 and rash since May 10. She attended the Accident and Emergency Department at Tseung Kwan O Hospital on May 11 and was admitted for treatment. A laboratory test of her respiratory specimen was positive for the measles virus. She has been in a stable condition and reported to have received measles vaccination. She had travelled to Macao during the incubation period and had no travel history during the communicable period.

     According to all patients, they did not have contact with measles patients during the incubation period. Their home contacts have remained asymptomatic so far and have been put under medical surveillance.

      Upon notification of the cases, the CHP immediately commenced epidemiological investigations and conducted relevant contact tracing. Investigations are ongoing. The public places the patients visited during the communicable period are listed in the appendix.

     "To prevent possible spread of infection, measles mop-up vaccination has been given today to workers of the shop and measles-related health advice has also been provided. The mop-up vaccination will continue tomorrow," a spokesman for the DH said.
 
     The spokesman said, "Those who might have had contact with the patients during the period of communicability are urged to observe if they have developed measles-related symptoms, and to seek medical treatment immediately if such symptoms appear. They should also report their symptoms and prior travel history to the healthcare workers so that appropriate infection control measures can be implemented at the healthcare facilities to prevent any potential spread."
      
     The spokesman explained that measles is a highly infectious disease caused by the measles virus. It can be transmitted by airborne droplets spread or direct contact with nasal or throat secretions of infected persons, and, less commonly, by articles soiled with nose and throat secretions. A patient can pass the disease to other persons from four days before to four days after the appearance of skin rash.

     "The incubation period (the period from infection to appearance of illness) of measles ranges from seven days to 21 days. Symptoms of measles include fever, skin rash, cough, runny nose and red eyes. If symptoms arise, members of the public should wear surgical masks, stop going to work or school and avoid going to crowded places. They should also avoid contact with non-immune persons, especially persons with weakened immunity, pregnant women and children aged below 1. Those suspected to have been infected are advised to seek medical attention as early as possible and reveal relevant contact history of measles to healthcare professionals," the spokesman advised.
     
     Separately, regarding measles control measures implemented at Hong Kong International Airport (HKIA), measles vaccination service at the airport vaccination station will be continued from tomorrow (May 14) to May 17. Measles vaccination will be provided to airport staff who:

(1) Were born in or after 1967, and have not received two doses of measles vaccination, and have not been infected with measles before; or

(2) Have laboratory evidence of testing not positive against measles antibody (IgG).

     The vaccination quota for the measles vaccination station at the airport remains at 600 doses daily. The venue and operation hours of the airport vaccination station are as follows: