The Centre for Health Protection (CHP) of the Department of Health today (April 10) announced that the number of new hepatitis A cases has decreased since last month's announcement of a cluster of hepatitis A infections involving men who have sex with men (MSM) and the provision of two doses of hepatitis A vaccine for MSM.
 
     "Given the relatively long incubation period of hepatitis A infection, the transmission chain within a specific group may persist for several months to a year. To control the transmission chain, the CHP will continue to provide two doses of hepatitis A vaccine free of charge to MSM to safeguard public health. The CHP has launched an online booking platform today to help MSM with Hong Kong residency to book hepatitis A vaccinations at designated locations," the Controller of the CHP, Dr Edwin Tsui, said.
 
Latest data on hepatitis A infection
------------------------------------------
 
     The CHP recorded seven and eight cases of hepatitis A infection in February and March respectively, which are fewer than in January (15 cases). The CHP's epidemiological investigations showed that all eight cases recorded in March involved males, aged between 28 and 61. Two of them self-identified as MSM. The residential locations and restaurants patronised by these eight cases did not overlap with those of previous cases. Genetic analysis by the CHP revealed that the virus in three of the new hepatitis A cases harboured an identical genetic sequence to that of the cluster previously reported to be associated with MSM. As of March 31, this cluster involved a total of 27 cases (25 men and two women). Due to the long incubation period of hepatitis A, the CHP will continue to closely monitor the situation and take appropriate follow-up measures to interrupt the hepatitis A transmission chain within this group.
  
Hepatitis A vaccination
--------------------------
 
     "In light of the infection cluster among a specific group during the past six months, the CHP has offered an appointment service since March 12 to provide MSM with two doses of hepatitis A vaccine free of charge with the aim of controlling the transmission chain. In less than a month, over 60 people have made appointments for vaccination. The CHP urged MSM to book their vaccination as soon as possible through the newly launched online booking platform in order to protect their personal health," Dr Tsui said.
 
     Hepatitis A virus is primarily transmitted through the ingestion of contaminated food or water, or contaminated hands before eating. The virus can also be transmitted through high-risk sexual contact. The incubation period of hepatitis A is usually 14 to 28 days, though it can last up to 50 days. Due to the long incubation period, symptoms such as fever, malaise, abdominal discomfort, loss of appetite, nausea, diarrhoea and jaundice may not appear until one to two months after infection.
 
     Scientific literature indicates that, apart from foodborne transmission, hepatitis A outbreaks have occurred among MSM populations in many regions worldwide in the past. Due to the long incubation period, outbreaks transmitted through person-to-person contact tend to persist longer. Between 2015 and 2017, Hong Kong also experienced hepatitis A transmission chains involving MSM, which were successfully interrupted by vaccinating the affected groups at risk. According to the Scientific Committee on Vaccine Preventable Diseases under the CHP, individuals in high-risk groups (including MSM) should consult their doctors about receiving hepatitis A vaccination to protect their personal health.
 
     Dr Tsui said that the CHP will continue to monitor and investigate hepatitis A infection cases, and cautiously consider the epidemiological situation and transmission risks when determining the duration of the ad hoc vaccination service, in order to provide comprehensive protection for public health. He also reminded doctors to remain vigilant about hepatitis A cases and to provide relevant recommendations on hepatitis A vaccination to high-risk groups.
 
     The CHP will continue, through its Red Ribbon Centre and in collaboration with non-governmental organisations, to raise awareness and provide education on hepatitis A prevention to MSM, and to encourage them to receive timely vaccinations.
 
     For more information on hepatitis A, please visit the CHP's website.

Ends/Friday, April 10, 2026
Issued at HKT 15:30

NNNN