Beware of contaminated food & water

by | November 12, 2012

Don’t let your holiday plans be ruined by getting Hepatitis A, get vaccinated.


Don't let your travel plans get ruined because of Hepatitis A.

Recent statistics show more people are travelling to high-risk areas associated with infectious diseases. Hepatitis A virus (HAV) is the most common travel-related disease infection, second only to travellers’ diarrhoea.

HAV is a viral infection that causes the liver to become enlarged, inflamed and tender. The virus is excreted in faeces and transmitted through contaminated food as well as water. A person is infectious for two to three weeks before he or she even experiences symptoms.

Singapore travellers, including the elderly, are encouraged to vaccinate themselves against HAV before going overseas to avoid affecting their holiday plans and bringing home an unwanted disease.


Pre-travel vaccination low

Singapore is located in a region highly endemic for HAV infection and yet pre-travel HAV vaccination remains low among Singaporean travellers as they are less aware of the need for pre-travel consultation and vaccination, according to a local study released in 2011 – “The Changing Epidemiological Patterns of Hepatitis A Infection in Singapore”. The study also found that nearly 60 percent of HAV cases seen in Singapore between 1999 and 2009 were imported (there was no breakdown in terms of age).

Over the last seven years, the number of imported cases stayed consistently above 50 percent. Of these cases, most were Singapore residents who contracted the disease from countries they visited in Southeast Asia and/or the Indian Sub-Continents including: Brunei, Indonesia, Malaysia, Myanmar, Philippines, Thailand, Vietnam, Bangladesh, India, Nepal, Pakistan, China, Hong Kong, Japan, North and South Korea, Syria, Taiwan and Uzbekistan.

Furthermore, in 1993, only 2.5 percent of the people tested below 25 years had the HAV antibody – which means that the majority of people in Singapore are not protected against HAV and are at risk of contracting the disease infection (no age breakdown was given here again). However the study does state that: “In developed countries with high standards of hygiene or sanitation, infection is uncommon in the young and it is usually acquired during travel to endemic areas. The age-specific prevalence of antibodies to HAV (anti-HAV) in developed countries therefore tends to be a sigmoid curve, with low prevalence among children and a high prevalence among the elderly.”

Dr Leong Hoe Nam, an infectious disease doctor at Raffles Hospital, said, “Many people are ignorant of the health risks of HAV; particularly for patients with chronic liver disease. Severe HAV infection in these individuals may lead to acute liver failure and, even death. For the vast majority of other patients, the illness is debilitating for weeks.”

The symptoms of HAV include jaundice, dark urine, fever, tiredness, loss of appetite, nausea and abdominal discomfort. There are more severe forms of the disease and the severity increases with age. Dr Leong advised: “Vaccination is highly recommended when travelling or living in areas where HAV is endemic. This will be in most parts of Asia, including our neighbouring countries in Southeast Asia.”


Link to shellfish

HAV is also linked to imported shellfish, particularly cockles. There have been three cockles-associated outbreaks in the past 20 years in Singapore.

Eating shellfish taken from sewage-contaminated water is a common means of contracting HAV. It can also be acquired by close contact with individuals infected with the virus, according to resources from the Health Promotion Board.

HAV has also been linked to uncooked vegetables, unclean water and cut fruits. Outbreaks of HAV have resulted from infected food handlers who failed to wash their hands after going to the toilet. There were also reported cases of contracting HAV from sexual contact and drug use with an infected person.

A Hepatitis A vaccination costs approximately S$100.

Beyond getting the vaccination against HAV (which costs approximately S$100), which is good for the long-term, always wash your hands after using the bathroom, or before preparing or eating food.


SIDEBOX: What is the difference between Hepatitis A and B?

If Hepatitis A virus can be acquired through contaminated food and water, what then is Hepatitis B? Hepatitis B virus (HBV) is transmitted through contact with blood or other body fluids (i.e. semen and vaginal fluid) of an infected person. In many developed countries, the majority of infections are transmitted through unprotected sexual contact and unsafe injections and transfusions. HBV is also a major infectious occupational hazard of health workers. HBV is the leading cause of liver cancer and can lead to complications like chronic hepatitis and liver cirrhosis.


(** PHOTO CREDIT: 3D illustration of world tour, Kolobsek, stock.xchng; Injection, forwardcom, stock.xchng)





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