The holiday season is fast approaching, and some people are already slowly starting to plan a trip to warm countries, such as the Mediterranean basin. Holidays are also a time of more frequent use of mass catering facilities, which is also associated with an increased risk of foodborne infections.
Apart from classic food poisoning, which most often takes effect shortly after infection, there is a risk of infection with viruses that cause hepatitis.
The hepatotropic viruses (i.e. viruses causing infection of liver cells = hepatocytes) transmitted by the faecal-oral route include: hepatitis A virus and hepatitis E virus.
Hepatitis A = hepatitis A
An acute infectious disease that is widespread worldwide and presents itself as self-limiting inflammation of the liver parenchyma. The disease is caused by a virus belonging to the Picornaviridae family, the reservoir of which is man. The virus is excreted in large amounts with the faeces from the sick person. These viruses are highly infectious and highly resistant to external factors such as low and high temperatures, and detergents.
Hepatitis A accounts for almost 40% of all diagnosed hepatitis and the highest risk of the disease is observed in the poorest countries. Due to high overcrowding and poor sanitary and hygienic conditions, especially the lack of access to clean water, in these countries mainly children suffer from viral hepatitis. However, in countries with a higher social status, infections are more common among adults. Periodically (every 10-20 years) outbreaks of hepatitis A are observed in these countries, which results from the loss of immunity to the virus in the population.
People with an increased risk of developing hepatitis A include:
- Tourists traveling to countries with high rates of hepatitis A – reported collective cases of people on cruise ships on the Nile
- Children attending nurseries or kindergartens
- Nursing home residents
- Soldiers on foreign missions
- People who are in close contact with the sick person
- Homosexuals
The most common sources of the virus are contaminated water and inadequately heat treated food. In the Mediterranean countries, raw fish and seafood are very common sources. Infection can also occur as a result of sexual contact, especially anal.
Stages of the disease:
- incubation period – the first symptoms may appear 2 to 6 weeks after infection
- the pre-emptive period – malaise, joint and muscle pains, low-grade fever or low fever, loss of appetite, nausea and vomiting; this period may vary from 3 to 10 days
- acute period (disease proper) – symptoms result from hepatitis: pain in the right hypochondrium, jaundice, dark urine (the color of dark beer), stool discoloration; possible enlargement of the liver and spleen; in blood tests: significant elevation of liver enzymes, especially alanine aminotransferase (ALT) and elevated bilirubin levels; the acute phase may last from a few to several weeks
- recovery period
Hepatitis A can take the form of:
- asymptomatic – very common in children under 10 years of age
- symptomatic, but without jaundice – in older children and adolescents
- classic as described above – for most adults
- fulminant – manifested by liver failure with the risk of hepatic coma and with the risk of death – this form is observed in the elderly (over 50 years of age with accompanying liver diseases);
Hepatitis A ends with full recovery, and the person develops permanent immunity after contracting the disease. This hepatitis does not become chronic and is not virus carrier.
The diagnosis of the disease is based on the detection of specific IgM antibodies (anti-HAV) in the blood serum, which indicate the acute phase of the disease. The presence of IgG antibodies proves a history of hepatitis A; these antibodies last for life.
Treatment of hepatitis A is only symptomatic and consists in limiting physical exertion, an easily digestible diet and an absolute ban on alcohol consumption for six months and a significant reduction up to a year, as well as a significant reduction in the use of drugs that burden the liver. No antiviral drugs are used. Only in the fulminant form of hepatitis A, liver transplantation may be necessary.
It is possible to prevent hepatitis A through preventive vaccinations. There are two types of vaccines available in Poland: vaccines containing only inactivated hepatitis A viruses and combined vaccines – towards hepatitis A and hepatitis B.
Vaccinations are recommended for: tourists traveling to countries with high and intermediate risk of hepatitis A, people with chronic liver diseases and haemophilia, preschool and school children, people working in the production of food and waste removal, people around the sick person and people taking risky sexual contacts (mainly homosexual).
It is very important to carry out tests for the presence of anti-HAV antibodies in the IgG class before vaccination – the possibility of having asymptomatic hepatitis A in childhood.
The vaccination schedule is 2 doses of the vaccine – the second dose 6-12 months after the first one. Long-term immunity exists after full vaccination. In travelers, the first dose of the vaccine should be administered at least 2-4 weeks before the planned departure.
Hepatitis E = hepatitis E
This disease is an exotic disease for us, because it does not occur in Poland, Europe or the Americas. Recognized cases of hepatitis E concern people traveling to endemic regions, i.e. to the countries of Central and Southeast Asia. The disease is caused by a virus belonging to the Caliciviridae family and is transmitted through the ingestion. The main source is contaminated water, and the reservoir of viruses is man, although animal reservoirs (pigs, sheep, cattle) are also not excluded. Illnesses are observed mainly during the rainy season and immediately after its end, and the most infections concern people between 15 and 45 years of age.
The course of the disease is similar to that of hepatitis A, with slight differences, such as:
- the incubation period lasts on average 40 days (from 2 to 9 weeks)
- in the teasing period, gastric symptoms are more severe and the patient may have a high fever
- asymptomatic forms are rarely observed; the disease is most often associated with severe jaundice accompanied by itching of the skin (a symptom of cholestasis in the liver)
- the disease is very dangerous for pregnant women, especially in the third trimester – it takes the form of fulminant or hyperacute hepatitis with a mortality of approx. 25%
In most cases, hepatitis E fully recovers and no transition to chronic hepatitis is observed. The prognosis is only poor in pregnant women and in young children co-infected with hepatitis E and hepatitis A. Diagnosis is based on the detection of positive IgM (anti-HEV) antibodies in the serum.
Treatment is reduced to symptomatic treatment. There is no specific prophylaxis with a vaccine.
When going on vacation, remember that a plate full of tasty food may hide an unwanted additive, so follow the basic rules of hygiene and possibly protect yourself in advance by vaccination.
Nice impressions and healthy returns.