In a follow-up on the hepatitis A cluster in Hong Kong, the Centre for Health Protection (CHP) reports a decrease in cases since February.
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 men who have sex with men (MSM).
As of March 31, this cluster involved a total of 27 cases (25 men and two women).
“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,”according to Controller of the CHP, Dr Edwin Tsui.
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.
Hepatitis A and the Hep A vaccine
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.
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