Hepatitis E: transmission, symptoms, treatment, vaccine

 Hepatitis E causes inflammation of the liver. It is particularly common in countries with low levels of hygiene, but can also occur in industrialized countries. The disease is transmitted through food. Hepatitis E is most common in East and South Asia.

1. Definition of hepatitis E

Hepatitis E is a disease caused by a virus called HEV, affecting the liver. It was first described in 1955 during an epidemic in India. The disease can take different forms:

Acute hepatitis E takes an asymptomatic form in the majority of cases. Its symptomatic forms generally affect people aged between 15 and 35 in countries with low levels of hygiene, and people over 55 in industrialised countries, according to ANSES;

• chronic hepatitis E: it mainly concerns people with a deficient immune system;
• extra-hepatic manifestations: certain neurological or renal disorders are observed during hepatitis E infections in 15% of cases, according to ANSES.
• The World Health Organisation (WHO) estimates that there are 20 million HEV infections worldwide each year. It considers that, of these cases, 3.3 million are symptomatic. Hepatitis E is estimated to have caused 44,000 deaths in 2015, according to the WHO.

There are four genetic groups of hepatitis E in humans. Groups 1 and 2 are found exclusively in humans, while groups 3 and 4 are found in both humans and animals. Genotypes 1 and 2 originate in Asia and Africa. Genotype 3 exists in France and other industrialised countries. Finally, genotype 4 has been isolated in Southeast Asia.

Since 2002, there has been an increase in the number of hepatitis E cases in France. The National Reference Centre (CNR) considers that 200 to 300 cases appear in France each year. Nevertheless, the disease is present throughout the world.

2. Symptoms of hepatitis E

The disease has an incubation period of 2 to 10 weeks, with an average of 5 to 6 weeks. Infected persons shed the virus for 3 to 4 weeks after the onset of the disease.

Hepatitis E causes the following symptoms

• Moderate fever in the early phase of the disease, is associated with decreased appetite, nausea, and vomiting for several days. It can also cause abdominal pain, itching, skin rashes, and joint pain;
• jaundice causing yellowing of the skin and eyes, dark urine, and pale stools;
• Enlargement of the liver, and increased sensitivity.

In summary, hepatitis E causes flu-like symptoms, such as fever, headache, muscle and joint pain, fatigue, and abdominal pain. It can also cause digestive symptoms such as nausea, diarrhoea, loss of appetite, and pain in the liver area. Finally, it can cause skin symptoms, such as hives. In half of the cases, hepatitis E is asymptomatic. Symptoms persist for 1 to 6 weeks.

In some severe cases, hepatitis E can progress to severe liver failure, which can cause death. This form is particularly common in pregnant women, especially in the second or third trimester. According to the WHO, 20-25% of women who contract hepatitis E during their third trimester may die. Immunocompromised people can also develop a chronic form of hepatitis E.

3. Causes of hepatitis E

The cause of hepatitis E is a virus, which was identified in 1983. The virus is excreted in the faeces of infected people. It is mainly transmitted by drinking contaminated water. Thus, the causes of hepatitis E are linked to poor water sanitation conditions in countries where hygiene is poorly developed. In industrialised countries such as France, the mode of transmission is mainly through the consumption of animal products that can transmit the disease.

Hepatitis E is a highly contagious disease, which is transmitted mainly via the faecal-oral route. Hepatitis E is linked to the lack of effective sanitation facilities, which allows the virus excreted in faeces to enter the drinking water of others. It is therefore mainly the consumption of unsafe water that leads to the onset of the disease. It can also be through contaminated water products such as vegetables, fruit or shellfish.

However, there are other modes of transmission:

• transfusion of infected blood products;
• transmission from a pregnant woman to her child
• consumption of wild boar and deer meat and offal, especially the heart, spleen and lungs, which are often eaten almost raw;
• The consumption of pork liver products: dried or smoked liver sausages, liver dumplings, liver sausages and dry liver.

In the case of offal from deer or wild boar, or pork liver, contamination results from the ingestion of undercooked meat or products from infected animals.

4. Hepatitis E: when to seek medical attention?

It can be difficult to know when to seek medical advice if you have symptoms of hepatitis. It is not easy to recognise it. Most people are asymptomatic. The symptoms of hepatitis E are not specific and cannot be distinguished from other hepatitis.

It is advisable to consult a doctor if a patient has been travelling to an endemic country for less than two months and shows symptoms of hepatitis E. A gastroenterologist specialising in hepatology can be consulted if there is a suspicion of infection. The infection may be asymptomatic at first but may progress to a chronic form, so it is important to be diagnosed when in doubt.

5. Examination and diagnosis of hepatitis E

The clinical examination for hepatitis E does not distinguish it from other forms of hepatitis. However, this diagnosis becomes very likely in areas where the virus is circulating, especially where there is a risk of water contamination. To diagnose the disease by a blood test, IgM antibodies specifically directed against the virus are detected. Other tests such as RT-PCR can also detect the virus in blood or stool.

6. Treatments for hepatitis E

There is no cure for hepatitis E. In most cases, the disease heals spontaneously. It is advisable not to use acetaminophen, paracetamol or antiemetics. However, hospitalisation is recommended for pregnant women, and for fulminant hepatitis. Fulminant forms require emergency transplantation. Immunocompromised individuals receive ribavirin-based treatment for chronic hepatitis E. The evolution of the disease is favourable in 3 to 5 weeks. According to Hepatitis Info Service, the case fatality rate is 1 to 4% in adults. It is important to know that prevention is the best treatment to fight against hepatitis E, by respecting basic hygiene rules, whether in France or when travelling abroad.

7. How to prevent hepatitis E

In order to avoid contracting the disease, it is strongly recommended to adopt preventive measures. At the national level, the transmission of hepatitis can be reduced through the application of quality standards for water sanitation and the establishment of appropriate systems for the disposal of human faeces. At the individual level, the risk of infection can be reduced by practising good hygiene, and avoiding the consumption of water or ice of unknown origin. Hygiene measures to be implemented are essentially the following:

• Wash hands, surfaces and utensils after handling raw pork liver;
• Cook food sufficiently, especially risky food, such as figatelli (pork liver sausages), dry liver sausages, quenelle dough;
• Washing hands after leaving the toilet and before preparing meals;
• avoid drinking untreated water, for example from a well or river.

A vaccine has been developed in China, but it is not approved in other countries. People at risk should avoid eating raw pork liver products, and raw or undercooked wild boar or deer products. Thoroughly cooked products such as white ham, liver pâté, and pasteurised products are also at risk. People at risk are mainly pregnant women, immunocompromised people, people with liver disease, the elderly and children.

When travelling to the countries concerned, it is recommended to adopt the following measures

• Wash your hands often, especially before eating or drinking;
• Drink only bottled water. Or, if this is not possible, boil the water before drinking it;
• Use bottled water for brushing teeth;
• Avoid unpasteurised dairy products;
• Eat only well-cooked foods, and avoid seafood.

Your doctor or travel medicine specialist will be able to advise you on the spread of hepatitis E around the world, and the best ways to protect yourself.

Sources :

OMS, Anses, Hépatites info service, ministère des Solidarités et de la Santé