Hepatitis A ‘outbreak’ prompts Hong Kong health authorities to roll out free vaccines across the city
Thirteen cases of the virus were detected between September 2015 and January 2017
A spike in the number of reported hepatitis A cases among Hong Kong men who engage in sexual relations with other HIV-positive men has prompted health authorities to offer free vaccinations to “high-risk” individuals.
Ten cases of the virus were reported to the Integrated Treatment Centre between August last year and last month, according to Dr Wong Ka-hing, controller of the Centre of Health Protection. A further three cases were identified after the authority traced records back to September 2015.
The findings marked a significant increase from just zero to two detected cases among men per year between 2006 and 2015.
“Our epidemiological investigations so far have not identified a common food or water source among these cases,” Wong said.
“With reference from overseas experience, our epidemiological and laboratory investigations coupled with their clinical presentations suggest that male person-to-person sexual transmission may have accounted for this hepatitis A outbreak.”
According to Wong, laboratory information revealed four of the 13 cases were identical to one genetically distinguishable group within genotype 1A, and another eight cases to another group also within genotype 1A.
“Because the virus [within each of the two groups] is identical, there is a possibility that the infection is related,” Wong said.
Wong said men who have sex with men have a higher risk of acquiring the virus due to their sexual practices.
He said hepatitis A is transmitted primarily through the faecal-oral route – that is when a susceptible person contacts or ingests objects, food or water that has been contaminated with the faeces of an infected person. It can also be transmitted through sexual contact not limited to anal-oral contact.
To control the outbreak, the centre will from Friday provide free vaccinations to men who are patients of the Integrated Treatment Centre, Aids Clinical Service of Queen Elizabeth Hospital, Infectious Disease Special Medical Clinic of Princess Margaret Hospital, Wan Chai Male Social Hygiene Clinic and Yau Ma Tei Male Social Hygiene Clinic. Up to 1,800 men are expected to benefit.
A single dose of the vaccine – to be taken in two jabs over six months – has a lifetime protection efficacy rate of 80 to 100 per cent. That figure is lower for HIV positive patients, at 70 to 80 per cent.
According to the World Health Organisation, symptoms of hepatitis A include fever, loss of appetite, diarrhoea, nausea, dark-coloured urine and jaundice. Not everyone will experience all symptoms.