There has been an increase in Hepatitis E (HEV) infections in Singapore, particularly among Chinese men aged 55 years and above, according to a study led by Singapore General Hospital.
The study noted that the incidence of HEV among residents in Singapore increased to 4.1 cases per 100,000 residents in 2016 from 1.7 cases in 2012. That’s about 1 in 25,000 residents, noted SGH in a statement on 9 October.
The study findings, which were published in Zoonoses Public Health journal in July 2019, showed that 75% of the 59 samples tested for the subtype of HEV showed that it was the same subtype detected in samples of raw pork liver.
The virus can be acquired from ingesting water that has been contaminated or eating raw and undercooked products of infected animals.
Dr Chan Kwai Peng, senior author of the study and Senior Consultant, Department of Microbiology at SGH said that while they cannot be certain if pig liver is the main contributor of HEV cases in Singapore, they observed that pig liver is found in many local dishes.
“As most people like it a little undercooked for its texture, this may put them at risk of hepatitis E infection,” said Dr Chan.
“The safest way of consuming food, including pork, is to cook it thoroughly,” he cautions.
HEV is a virus that infects the liver and symptoms include fever, lethargy (feeling tired), nausea and jaundice. However, most patients will show no symptoms.
While the infection usually doesn’t lead to long-term illness or liver damage and goes away on its own after a few weeks, it can be dangerous for pregnant women and people with weak immune systems, like transplant patients, or people with pre-existing chronic liver disease.
Globally, foodborne HEV infection is associated with pork meat or offal, game meat, and shellfish as animals like pigs, wild board and deers are reservoirs of HEV.
In their statement, SGH noted that the consumption of raw and undercooked pork products is the most common cause of HEV infect in Europe. In Hong Kong, the city’s Centre for Food Safety issued a report in December 2010 about eating undercooked pig livers for the same reason.
According to the World Health Organisation (WHO), there are an estimated 20 million HEV infections worldwide leading to about 3.3 million symptomatic cases of hepatitis E. WHO estimates there are approximately 44,000 deaths in 2015 caused by HEV.
According to statistics by the Ministry of Health in Singapore, there were 83 reported cases of acute Hepatitis E (foodborne/water sources) in 2016 compared to 76 in 2017. Last year in 2018, there were 53 cases.