CHP investigates cluster of hepatitis A infection involving men who have sex with men

CHP investigates cluster of hepatitis A infection involving men who have sex with men 
Cluster information
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     “Through routine surveillance, epidemiological investigations and genetic analysis, the CHP recorded 24 cases of hepatitis A infection where the virus detected harboured an identical genetic sequence, over the past six months (from September 2025 to February 2026), involving 22 males and two females. Epidemiological investigations revealed no overlap in their residences or restaurants patronised by the patients. They were aged between 18 and 55. At least 14 of them identified themselves as MSM, accounting for over 60 per cent. The CHP cannot rule out the possibility of an epidemiological link between the infection sources of this cluster and male-male sexual contact,” the Controller of the CHP, Dr Edwin Tsui, said.

Hepatitis A vaccination
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     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.      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 vaccination.

     For more information on hepatitis A, please visit the CHP’s websiteIssued at HKT 18:12