Hepatitis E – Are hunters particularly at risk??In connection with an increasing number of reported cases of hepatitis E in humans in Europe, domestic and wild pigs are repeatedly discussed as a virus reservoir and source of infection.
In many developing countries, hepatitis E is one of the most common liver diseases in humans, and here in the majority of cases infection with the hepatitis viruses occurs via contaminated drinking water and from person to person (poor kitchen hygiene, contamination with feces).
Hepatitis (plural: hepatitides) in general
A hepatitis is an inflammation of the liver, which can have various causes. Thus, among other things, viral infections, but also drugs, toxins and alcohol can lead to liver inflammation. In autoimmune hepatitis, the patient's own immune system attacks liver cells, resulting in liver inflammation. Treatment therefore depends on the cause.
Increased liver values in the blood can be a first indication of liver inflammation. Hepatitis is also known colloquially as jaundice. This is due to the most noticeable and most common symptom of liver inflammation: yellowing of the skin and eyeball.
Clinically, an acute hepatitis is distinguished from a chronic hepatitis. Chronic hepatitis occurs when the inflammation lasts longer than six months.
What are Viral Hepatitides?
Hepatitides A, B, C, D and E are classic viral hepatitides. These liver infections are caused by different types of "hepatitis viruses".
The only thing they have in common is their infected target tie, the liver, in which they cause liver inflammation. Hepatitis B and hepatitis C are usually chronic and the final stage of the disease is usually cirrhosis of the liver.
hepatitis A
Hepatitis A is caused by the hepatitis A virus. The infection is transmitted via contaminated drinking water. Food but also sexually transmitted. The incubation period (time from contact with the virus to the first symptoms of the disease) is 2 to 6 weeks. As a rule, the disease heals completely. There is no such thing as chronic hepatitis A.
Hepatitis B
Hepatitis B is caused by the hepatitis B virus. The virus is transmitted during blood or sexual contact. The incubation period is 30 to 180 days. It usually runs acutely, often without symptoms, but can also turn into a chronic infection.
Hepatitis C
Hepatitis C is caused by the hepatitis C virus. It very often goes unnoticed, but infected persons usually develop a chronic form of the disease.
Hepatitis D
Hepatitis D only occurs if hepatitis B infection is present at the same time.
The spread of hepatitis D has been underestimated to date. In Germany, the number of infected persons is currently estimated to be around 30.000, 15 to 20 million people worldwide are estimated to have hepatitis D.
Hepatitis E
Hepatitis E is particularly widespread in Southeast Asian, Central Asian and Indian regions. In our latitudes, it has so far occurred mainly as a travel infection (z.B. after contact with faeces or contaminated drinking water).
However, the number of hepatitis E cases in humans in Germany who have never been abroad has increased steadily in recent years in Germany, so that the source of the infection must be sought elsewhere. Infection of humans here probably occurs through contact with live animals, v.a. Domestic and wild boar, and products made from them.
Other potential routes of transmission include blood transfusions and organ transplants. Since 2002, there has been a reporting requirement under the Infection Protection Act.
Symptoms and course of hepatitis
Many hepatitis infections proceed without symptoms or with unspecific symptoms such as slightly elevated temperature, loss of appetite or pain on prere in the upper abdomen, so that the affected person does not even notice the disease. Patients often develop jaundice. In contrast to hepatitis A, the hepatitis B. Hepatitis C become chronic. The diseases often progress insidiously and are only discovered when they are already chronic and have destroyed the liver to the point of liver cirrhosis.
Hepatitis E – caution when handling wild boar?!
In recent years, there have been repeated reports in the press about an increase in human infections with the hepatitis E virus (HEV) in Germany. A significant proportion of infections have occurred in "risk areas" in South Asia, West Africa and Central America z.B. via drinking water contaminated with fecal matter.
However, a proportion of infections that should not be underestimated has occurred via direct contact with infected animals or via contaminated foodstuffs.
In addition to domestic pigs, v.a. Wild boar is a reservoir for this zoonotic pathogen.
Hepatitis E- an underestimated danger?
Physicians consider hepatitis E to be a clearly underestimated infectious disease that has long since ceased to be a "tropical disease". At least 17% of the population living in Germany has been infected with the hepatitis E virus (HEV), as antibody studies show. The detection of antibodies proves contact with the virus. The level in hunters is slightly higher compared to that of the "normal population".
Reports of HEV infections to the Robert Koch Institute have increased more than tenfold since 2000. It must be amed that there are over 100.000 infections per year, whereby the infected persons do not notice the infection, since no symptoms occur.
In immunosuppressed individuals, the disease can also take a severe chronic course.
Pathogen
Hepatitis E is caused by an infection with the hepatitis E virus (HEV).
In fact, hepatitis E was not identified as a distinct disease until 1980, when a putative hepatitis A epidemic in India was investigated more closely. It was discovered that a new type of virus, rather than hepatitis A viruses, is responsible for the outbreak of the disease. It has been named hepatitis E virus.
The domestic pig is the most important animal reservoir for virus type 3, which is mainly found in Germany and other industrialized countries. Wild boars also play a certain role. Other wild animals, z.B. Roe deer, red deer and elk are of secondary importance, but positive detections are also found here time and again. Other pathogen reservoirs are sheep, monkeys, rats and mice.
Infection route
While HEV infection in the tropics is usually transmitted through drinking water contaminated with feces, this route of transmission does not play a role in industrialized nations due to good drinking water hygiene. Instead, human infection here occurs through contact with live animals or food derived from them, z.B. inadequately cooked pork or beef. Wild boar meat or raw products thereof.
Filter-feeding organisms such as mussels can accumulate hepatitis E virus in the water and thus also serve as a source of infection. Human-to-human transmission is possible via smear infections.
At-risk groups include, in particular, hunters, forestry workers, pig farmers or slaughterhouse workers.
Clinical symptoms
The course of acute hepatitis E infection is similar to that of hepatitis A. Both diseases can hardly be distinguished from each other by their clinical symptoms. The incubation period is several weeks. In 99% of immunocompetent people, the disease runs its course "without abnormalities" and usually heals without consequences. If the infection progresses with symptoms, there is usually a spontaneous improvement and healing after about two to three weeks. In elderly persons, patients with chronic liver disease and pregnant women, severe courses with liver failure are observed, deaths occur. Chronic courses occur mainly in immunodeficiency (z. B. HIV infection) or immunosuppressed patients on. Chronic courses can also occur without major symptoms, but can lead to liver cirrhosis.
In the case of chronic infections, it must be amed that the virus is excreted as long as the infection persists.
In addition to non-specific symptoms such as fatigue, exhaustion, headache, loss of appetite, weight loss, muscle and joint complaints, a feeling of prere in the upper abdomen and fever, typical symptoms of liver dysfunction (jaundice, darkening of the urine, but discoloration of the stool) appear later on.
Therapy
A causal therapy directed against the virus is not available and is usually not necessary due to the usually mild course of the disease. Therefore, treatment of symptoms.
If liver failure occurs in a pregnant woman due to hepatitis E, liver transplantation is often the last therapeutic option.
A vaccine against hepatitis E (genotype 1) has been licensed in China since the beginning of 2012, but is not available for Europe.
In Germany, the disease is notifiable according to the Infection Protection Act (IfSG). Since the 1. 1. 2020, blood products in Germany must be tested for HEV contamination.
No reason to panic – recommendations for health protection
In order to protect against possible infection with hepatitis E viruses through wild boar hunting, it is urgently recommended that hunters, in particular, pay attention to the hygienic conditions when breaking open, cutting up and preparing products from pigs, wild boar and other game. Above all, the use of gloves is of great importance.
Venison, v.a. from wild boar as well as its offal should always be heated thoroughly before consumption (no more red meat juice leaks out); it is better to avoid eating the latter altogether, also in view of potential exposure to perfluorinated environmental chemicals ("PFCs"). Smoked and longer matured products carry a lower risk than z.B. Carpaccio of wild boar meat.
The Robert Koch Institute (RKI) advises especially when traveling to the "risk areas":
– to avoid unboiled tap water and ice made from it, – to refrain from eating raw or insufficiently heated food.
© Martin Weber; Hygiene should be observed when processing raw meat (symbol image).
Wrong: When breaking open wild animals, hunters should always wear rubber gloves. (Photo: © WiSiTiA/hh)
Hepatitis in dogs
Hepatitis contagiosa canis is a generalized viral infection with canine adenovirus -1 (CAV-1). The virus occurs worldwide, is resistant to the environment and survives for several weeks at room temperature.
H.c.c. – Hepatitis contagiosa canis – as the contagious viral liver inflammation in dogs is also called, is not transmissible to humans. Animal-to-animal transmission occurs via direct contact or through feces, urine, and saliva. The incubation period is 2-5 days. H.c.c. can have an acute or also a chronic form of progression. A truly reliable diagnosis can usually only be made on the dead animal. Infection occurs via the nasopharynx (oronasally). The virus is mainly transmitted through the ingestion of urine or urine-contaminated feed, or through the ingestion of food. Water. Subsequently, the virus multiplies in the tonsils. Gets into the regional lymph nodes. The virus then multiplies in the tonsils. Gets into the regional lymph nodes. A massive viral release into the blood, usually accompanied by fever, leads to colonization of the blood vessels and many organs (liver, kidneys and eyes). The virus multiplication that takes place there causes cell damage with more or less pronounced, corresponding clinical symptoms within a few days, such as fever, apathy, vomiting, diarrhea, thirst, refusal to eat, abdominal pain and jaundice. In addition, the destruction of the vessel walls can lead to bleeding and edema. An acute course often ends fatally for the dog. This is especially true for young, unvaccinated dogs. The more acute the course, the less favorable the prognosis.