rabies

Rabies: description

Rabies is a viral infection of the central nervous system. Other names for the disease are rage, Lyssa (Greek), Rabies (Latin / English) and Rage (French). The causative agents of the disease are lyssaviruses. The incubation period – that is, the time from infection to the onset of the disease – is generally three to eight weeks, but may be less than nine days in rare cases. Once the disease has broken out, it is almost always fatal. Immediately after infection, however, immunization may still prevent the onset of the disease.

Transmission by saliva

Rabies is almost always transmitted by infected animals. If an animal has become infected with the viruses, they initially multiply in the central nervous system and then scatter. Among other things, the viruses are expelled in bulk in saliva. The transmission to humans is usually due to the bite of an infected animal. However, infection is also possible through skin injury, or when infectious material such as saliva comes into direct contact with the mucosa.

Wild animals that have become infected with rabies often lose their fear of humans (for example, foxes). If a wild animal behaves unusually, you should therefore pay particular attention and go at a distance. Even those who find a lying on the floor bat and wants to help, should at least wear leather gloves. Anyone who is bitten anyway, must see a doctor immediately!

Germany is considered rabies free

Germany has been considered free from the classic wild rabies since 2008. This is achieved by the immunization of wild animals by feed baits, especially foxes. There were also regular rabies vaccines from pets. The last case of rabies in a wild animal – a fox – was registered in February 2006. Many other European countries such as Switzerland, France, Belgium, Luxembourg, the Scandinavian countries, the Czech Republic, Spain and Portugal, Great Britain and Ireland are officially “rabies-free”.

The last reservoirs of the pathogens in this country are bats. They carry a different form of Lyssaviruses than foxes, which are closely related to the fox. Doctors assume that bat rabies is as dangerous for humans as classic wild rabies.

Recent rabies cases among people in Germany

In 2005, a woman was removed from organs for transplantation, which had previously been infected with rabies in India. Of the total of six organ recipients, three died and died as a result of rabies. The recipients of the two corneas did not suffer, as did the recipient of the liver, who had previously been vaccinated against rabies.

Most recently, rabies was diagnosed in Germany in 2007 by a man who had become infected during a stay abroad in Morocco by a dog bite.

For people living in Germany today only an increased risk of infection exists when traveling to countries where rabies still occurs. However, a transmission of disease by bats in Germany can still not be ruled out.

Rabies: symptoms and disease course

The rabies incubation period (time from infection to the onset of the disease) is usually three to eight weeks. Occasionally, however, it can take several years. Rarely, the incubation period is shorter than nine days. The closer the portal of entry of the rabies virus is to the brain, the shorter the incubation period. Because the viruses move from the point of entry along the nerves towards the brain. Once they arrive there, it comes to the onset of the disease. It then runs deadly.

Three stages of rabies

Rabies occurs in humans in three stages:

prodromal: In the first stage of rabies, there are unspecific symptoms such as headache, nausea, vomiting, abdominal pain, diarrhea, usually also fever and possibly coughing. The bite tingles and itches. In the further course the patients become irritable and sensitive to light, noise and draft. The fever is constantly increasing.

Acute neurological phase (excitation stage): The so-called encephalitic form of a rabies infection manifests itself primarily in the brain. The patients develop a pronounced fear of water (hydrophobia). When swallowing, the pharyngeal muscles become cramped, causing patients to be afraid of swallowing. The patients even avoid swallowing their own saliva so that it flows out of their mouths. Already the sight of water or drops and noise trigger restlessness and convulsions. The state of mind of patients varies between aggression and depression.

The rarer paralytic form of rabies mainly affects the nerves of the spinal cord and the peripheral nerves. At this stage especially increasing paralysis occurs.

Coma (paralysis stage): In the last stage of rabies, the patient suffers from progressive signs of paralysis. The patient eventually falls into a coma and usually dies from respiratory paralysis. Once rabies breaks out, it ends fatally.

Rabies: causes and risk factors

The causative agent of rabies is the rabies virus (Lyssavirus). In industrialized countries, the virus is found mainly in forest animals; These transmit the rabies pathogen to pets and humans. In Africa, Asia and Latin America, however, dogs are the main vectors and responsible for most deaths from rabies worldwide.

The most common type of rabies transmission to humans are bites or scratch injuries from infected dogs, cats, foxes, raccoons, skunks, jackals and wolves, as well as insectivores (eg, hedgehogs) and vampire bats. Although cattle, horses, small game and other herbivores can become infected, they rarely occur as transmitters of rabies to humans.

Even with simple contact, for example, when stroking infected animals, you can be infected – but the risk of infection is very low here. Most viruses are in saliva. Especially if it comes in contact with mucous membranes or wounds, there is a very high risk of rabies infection.

Rabies is considered extinct in Germany. Suffering from bats, it still occurs. But since native species are not vampire bats, but mainly feed on insects, they do not attract humans. A risk of becoming infected is only in direct contact with the bats – or traveling to countries where there are still many rabies animals.

Rabies: investigations and diagnosis

The suspicion of rabies in humans is always given in every contact with a potentially infected animal – especially in biting and scratching wounds. A stronger suspicion arises when corresponding clinical symptoms already occur.

For a precise diagnosis, the genetic material – the RNA – of the rabies pathogen (Lyssavirus) is detected in the saliva, in the cornea of ​​the eye or in the brain fluid. However, it is not always possible to diagnose a rabies infection in this way. A safe, clear diagnosis of rabies is often possible only after the death of the person affected.

Rabies: Treatment

A rabies vaccination must be carried out on suspicion of contact with a rabid animal. In the case of an infection, it is the only chance of rescue.

After an animal bite or other contact with a potentially infected animal, you must rinse and clean the bite or contact points as quickly as possible with water, soap or detergent solution. You should also disinfect them with alcohol or iodine solutions.

Afterwards, after an animal bite, you must always consult a doctor who will administer the appropriate vaccine. Even with light scratches or after a conspicuous or wild animal has licked your skin, the rabies vaccination must be done as soon as possible.

The doctor administers ready-made antibodies (immunoglobulins) that fight the rabies virus in the body (passive immunization). In addition, the patient receives an active vaccine, which contains killed virus components and incites a self-protection of the body against the virus, thus stimulating the formation of specific antibodies against the virus.

If the first symptoms of rabies already appear, a vaccine or the administration of the antiserum is no longer effective. The treatment of rabies then consists exclusively in the relief of symptoms such as convulsions or respiratory paralysis. There are rarely more than seven days between the onset of the first rabies symptoms and the fatal outcome.

Rabies – vaccination

What you need to look out for when vaccinating against rabies, see the article Rabies – vaccination.

Rabies: What you can do yourself

Before traveling abroad, you should find out if rabies is occurring at your destination. If this is the case, a preventive rabies vaccine may be recommended. In particular, in regions outside the usual tourist centers is a subsequent passive vaccination sometimes not be raised quickly enough. Therefore, consult with a tropical health professional about how best to protect yourself.

Rabies is very contagious. Even a bite through clothing, a slight scratch or contact with contaminated saliva can cause a fatal infection.

Wild animals are usually shy. If an animal is unusually friendly, stay away from it.

After contact with a rabies-suspicious animal, you must thoroughly clean the affected skin with soap and water and, if possible, disinfect it. This also applies if you have touched an animal that may have died of rabies. In any case, see a doctor!

If you have found the carcass of a potentially rabies-infected animal, have it checked by a forester.

Rabies: Disease course and prognosis

If an infected person is not vaccinated against rabies, the prognosis depends on whether and how fast he then gets an active immune protection. Therefore, you must consult a doctor as soon as possible in case of contact with a potentially infected animal.

The earlier the subsequent vaccination with antibodies, the better the prognosis. If the virus has already lodged in the brain and the first symptoms of the disease appear, it can no longer help. As a rule, between the occurrence of the first symptoms of the rabies and death for a maximum of seven days. In that case, the patient dies of respiratory or cardiac palsy.