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Making Sense of ... Hepatitis A

formerly known as infectious hepatitis

FAQ

What is hepatitis A?

Hepatitis A is an acute infectious disease of the liver, caused by the hepatovirus hepatitis A virus

Where is hepatitis A usually found?

Hepatitis A is found around the world; it is endemic in most developing countries, particularly is areas with hygiene and water supply problems. It is also associated with seafood and food preparation

How common is hepatitis A?

Hepatitis A occurs in at least 1.5 million people per year, probably many times that figure, as under-reporting is common, and many cases are undiagnosed. Most of these people live in developing countries, but Hepatitis A also occurs in the developed world; at least 150,000 cases per year in the USA, for example.

How is hepatitis A transmitted?

Hepatitis A is a food borne virus, most commonly spread by poor hygiene in food preparation, with the virus passed on by an infected person - or someone who has had indirect contact with an infected person, who excretes in the virus in faeces. But the virus can survive on the skin or other surface for three to four hours, making food preparation a very easy route: not only the food, but utensils used in preparing or serving food. Contaminated shellfish is a common source of infection.

Can hepatitis A be spread from person-to-person?

Hepatitis A can be spread by person-to-person contact, such as oral kissing or anal sex; and shared intraveneous equipment is probably a convenient route.

Who is most at risk from hepatitis A?

Those at risk include:

Recent travellers to endemic countries
Young children who attend day care
Contacts of a person with hepatitis A
Certain occupations
Receipt of clotting factor concentrates (in some countries)
Men who have sex with men
Illicit drug users

Statistically, people from developed countries who travel to developing countries are at highest risk of acquiring hepatitis A. The risk is present even in urban areas of such countries, where the food supply chain is not secure, and water may be contaminated.

What are the symptoms of hepatitis A?

Hepatitis A is an acute but self-limiting disease. there is an incubation period of about 30 days (but this can vary from 15 - 50 days). Early symptoms include fever, severe malaise, anorexia, vomiting, abdominal discomfort, followed by a persistent fatigue, which can be disabling.

Hepaptitis A is associated with jaundice, which sets in as the initial symptoms begin to subside. Jaundice is characterized by yellowing of the skin, eyes and mucous membranes - caused by excretion being obstructed in the liver and therefore released into the blood. Urine will also turnappear dark and concentrated with bile, while faeces are typically clay-colored from lack of bile.

In general, the acute illness lasts from about day to three weeks; then most patients begin to feel better as the liver settles down and blood chemistry starts to get back to normal. The severity of illness tends to increase with age.

What are the long term effects of hepatitis A?

It is not unusual for blood chemistry to remain abnormal for several months, delaying full recovery for up to a year. Most patients, however, recover completely within 3 - 6 months of the onset of symptoms.

Relapse can occur with Hepatitis A, usually within three months of the initial illness - and it is more common in children than adults.

The vast majority of people will fully recover from Hepatitis A, which does not lead to chronic hepatitis.

What is the mortality rate for hepatitis A?

The mortality rate is about 2 in 1000; usually people weakened by co-existing illness, older people or the very young.

How is hepatitis A diagnosed?

initailly, hepatitis is usually diagnosed by the characteristic clinical picture; confirmation of the type will depend on laboratory tests.

The presence of IgM anti-HAV in the blood confirms the diagnosis of acute hepatitis A infection. Once infected and recovered, the antibodies to the virus will provide protection from future re-infection. Following infection, the HAV blood test will always be positive.

Is there a treatment for hepatitis A?

There is no specific treatment for hepatitis A. Patients are treated symptomatically; for example, antihistamines for the unbearble itching that may accompany jaundice. A small number of patients will go on to acute liver failure, and need multisystem support - but this is rare.

Is there a way to prevent infection?

Hepatitis A risks can be reduced by lifestyle choices, careful travelling and hygiene - especially with food and food preparation. There is evidence that a key factor in limiting the duration of outbreaks is rapid intervention, plus the need to reconise that communities where significant numbers may return to visit their country of oriign will significantly inmpact on control measures1.

What is the hepatitis A vaccine?

There are four vaccines against HAV; all are safe and effective, with long-lasting protection. None are licensed for children less than one year of age.

What is the protocol for hepatitis A vaccination?

A single dose of vaccine will provide short-term protection, but manufacturers recommend two doses to ensure long-term protection. After two or more doses of hepatitis A vaccine, 99%–100% of recipients can expect protection for at least 8 - 20 years; possibly for life.

Who should get vaccinated against hepatitis A?

In regions where the disease is endemic at a low level, vaccination is indicated for individuals with increased risk of contracting the infection, such as travellers to higher risk areas.

However, WHO currently does not recommend mass vaccination in countries where the disease is endemic at a high level. In these countries, almost everyone is infected in childhood with the virus, without symptoms, and this effectively prevent the disease being a problem for adolescents and adults. In these countries, large-scale vaccination programmes are not recommended.

In countries of intermediate endemicity, where adult infection is an issue, and where hepatitis A is a significant public health issue, childhood vaccination may be considered in parallel with health education and improved sanitation.

Are there adverse reactions to the hepatitis A vaccine?

The are well tolerated and no serious adverse events have been statistically linked to their use, after many millions of adminisartions.

Hepatitis A vaccine may be safely administered with many other vaccines.

Contraindications include a known allergy to vaccine components.

Can hepatitis A be controlled environmentally?

In low-incidence areas, the most effective control is simple hygiene and common sense, coupled with the appropriate use of vaccine. In higher-incidence areas, hygiene must be combined with education and the development of safer water supplies and food preparation systems; mass vaccination may be considered.

In highly-endemic areas, where the vast majority of the population is infected in childhood, environmental control is not a realistic target until basic poverty is better managed, and the water and food supplies can be secured.

Is there legal protection for workers and others?

There's plenty of precedent for legal action against food services where people have contracted hepatitis A; civil action for pain ansd suffering - and possibly loss of earnings involved, plus criminal action relating to negligence, health and safety and / or food hygiene laws.

What can be learned from history?

While infectious hepatitis is known to have existed for many hundrds of years (if not forever!), it was not until the second half of the 20th century that the disease has been recognised as having several distinct for, courses and management needs.

Question asked about "infectious types of hepatic jaundice" started to show results in 1963; and hepatitis A virus (HAV) was eventually isolated by Purcell as recently as 1973.