Hepatitis A is an infection of the liver and cases occur worldwide, although it is less common in Europe, North America, Australia and New Zealand. It is endemic in many low income countries. Around 1.5 million cases of hepatitis a occur each year.[1] It is spread through the faceal oral route, person to person spread or through eating and drinking contaminated food and water.Those working with human waste and sewage are also at occupational risk.
Signs and Symptoms
It has an incubation period of 2 - 6 weeks, but less than 10% of those infected develop symptomatic illness. Likelihood of symptomatic illness increases with age.Symptoms include mild fever, diarrhoea, nausea/vomiting and abdominal pain. Jaundice may follow and lasts up to 10 days. Recovery takes several weeks, but some patients are ill for longer. Complications can occur in those with pre - existing medical conditions or liver disease.There is no specific treatment for hepatitis a. Following infection life long immunity occurs.
Risk for Travellers
Risk of contracting hepatitis a in high income countries is low. Non- immune travellers are at risk of contracting the disease when visiting countries where risk of infection is high. The risk of acquiring hepatitis A in high-income countries is low. Non-immune travellers are at risk of contracting the disease during visits to countries of high or intermediate endemicity. Travellers to Africa, South East Asia, the Indian sub Continent and Latin America are at higher risk.In 2009, a total of 352 cases were reported in the UK, 61% of these where associated with travel. [2]. Although the incidence of hepatitis a infection amongst travellers is declining, it remains one of the most common vaccine preventable diseases amongst travellers. Risk is higher for those visiting friends and relatives abroad, long term travellers and those visiting countries where sanitation is poor.However, there have been cases occur in tourists staying in good quality accommodation. Many travellers think staying in a 5 star hotel puts them at lower risk, but because it can be transmitted person to person, staying in luxury accommodation in a high risk country still remains a risk.
Prevention
A every effective vaccine is available to prevent infection with
hepatitis a. Two doses are required to offer long term protection ( up to 30 years) One dose will offer protection for up to 1 year, the booster dose should be given 6 - 12 months after the first dose. Ideally you should have the vaccine at least 14 days before travel, but because hepatitis a has a long incubation period it can be given at the last minute and still offer good protection. The vaccine can be given to travellers aged 1 year and over.Contraindications to having the vaccine include: acute febrile illness, previous reaction to hepatitis a vaccine and egg allergy for those receiving the brand Epaxal vaccine. Side effects to the vaccine are usually mild but can include pain and redness at the injection site, less common are mild fever, tiredness, headaches and dizziness.
Food and water hygiene is equally important. You should:
- Drink and clean teeth with bottled or boiled water
- Avoid shellfish that may have come from contaminated water
- Avoid salads that may have been washed in contaminated water
- Avoid ice in drinks , unless you are sure it has been made with clean water
- Wash hands regularly or use an alcohol hand gel when washing facilities are not available
Read our previous blog post on
Typhoid, also a Food and Water borne illness.
References
