Vaccin antirabique
Rabies is a serious viral disease affecting mammals, including humans. It is caused by a virus causing encephalitis. Zoonosis fairly common, it affects primarily carnivores. The symptoms are nervous and sometimes aggressive although there are also more primitive forms where the patient is particularly quiet. In Europe, rabies has been effectively eliminated in some countries by distributing baits vaccinating dispersed in nature.
Between 40,000 and 70,000 people die of rabies each year in countries of Africa and Asia where the disease is endemic.
Disease distribution
The disease has caused 55 000 deaths worldwide in 2004 according to a study commissioned by WHO, mostly in rural areas of Africa and Asia.
France
In France, the last case of rabies in humans, dating back to 1924 (fatal case in French Guiana in 2008), however, passengers may be contaminated abroad, in countries at risk, and return patients.The disease was considered extinct since the beginning of 2001, although:
Switzerland
Switzerland is recognized thoroughly checked for rabies since 1 January 1999. The onset of terrestrial case from wild animals is unlikely. However, if a bat or animal carrying imported is not excluded. Moreover, since that date, two cases have been reported: one case of infected bat was reported in 2002 in the canton of Geneva and the case of a dog imported from North Africa in 2003, Canton Vaud.
Germany
Germany could not get rid of some persistent pockets recently, particularly in the State of Hesse. This outbreak was the source of various episodic infections seen in other Land. Thus, Baden-Wurttemberg (December 2004), Rheiland Pfalz (January 2005) and of Kreiz Kussel (May 2005) revealed an increase of rabies westward. This ‘front’ progressing according to various estimates at a speed of 20km 60km per year.Other more recent estimates indicated a more rapid progression, and in all directions from the Land of Hesse. In each of Lands affected, Germany has undertaken campaigns of oral vaccination of foxes. In view of the absence of recorded cases in 2008 and 2009, Germany filed the application for declaration of ‘free’ state of rage, like its neighboring Austria. Since 1998 Germany has detected 642 animals infected with rabies, including 44 pet, 422 foxes and 115 bats. However, since 2001, only 8 domestic cases were confirmed. Five people died of rabies.
Description of virus
Rabies is caused by a virus of the family Rhabdoviridae and the genus Lyssavirus, which was identified in 1903 by Paul Remlinger. They are enveloped viruses, their genome is an RNA molecule of negative polarity of helical shape. As such, they are highly sensitive to physical and chemical agents for disinfection and therefore lower resistance in the external environment.
The rabies virus infects all mammals.He has a tropism nervous, especially the central nervous system, which explains the observed disorders.
Prevention and Treatment
Rabies Prevention
French as a global level, it is the eradication of rabies. In France, sylvatic rabies has been eradicated, it goes through the vaccination of pets and people potentially exposed to rabies (bat, veterinary ,…), and a monitoring plan for this disease national level.
Treatment of rabies
Rabies is a disease almost always fatal in humans so when it’s first signs. Cases of survival are quite exceptional, however, rabies vaccination performed between infection and the onset of signs is very effective. The vaccine was tested in 1885 by Louis Pasteur on Joseph Meister, a boy bitten by a rabid dog on the way to school Meissengott in Alsace. The dog’s owner, Theodore Vonne, had then shot the beast and then led the child to the doctor Weber Villé.
However in late 2004, in Wauwatosa, Wis., an experimental treatment has saved a young girl without vaccination American named Jeanna Giese, contaminated by a bat. Treatment, since known as the Milwaukee protocol, is to immerse the patient in a medically induced coma to slow the progression of the disease and to administer intensive medical treatment. Two other patients were able to be treated. In an article published in 2009, it was identified 25 attempts to apply this treatment (known as the Milwaukee Protocol) in its first version with a survival rate of 8% (2 out of 25), and 10 in its second version with 2 survivors, 20%. However, there is no animal model demonstrating the effectiveness of this method.
In areas where vampire bats are carriers of rabies is endemic (South America), it is recommended to protect against bites from bats during the night. Thus, travelers in the forest sleeping under a mosquito net even in the absence of mosquitoes.The screen should be positioned sufficiently large to make it impossible for a bat to bite the person through the net.
It is recommended not to handle bats found injured or approaching abnormally homes. Anyone bitten or scratched should immediately notify her doctor. The wound should be washed with soap and water.
Preventive treatment
A preventive vaccine against rabies exists. It is inoculated persons whose activity is a risk factor for infection. Veterinarians or people traveling to countries like India are examples. It preventive vaccine does not provide a curative vaccine.
Curative vaccination
It can prevent the disease if done before the first signs appear, that is to say during the incubation period, applying a curative vaccination. This idea due to Galtier was applied for the first time by Louis Pasteur in 1885.
Between when the virus enters the body (most commonly through bites, but sometimes also by licking a wound or scratch) and when the disease occurs, it usually takes between two and eight weeks leaving a reaction time. In fact, the incubation period depends on the dose of virus inoculated, the location of the bite (the closer it is an area rich in nerve endings, the sooner the disease is present) and the severity of the wound .
It has long been prepared vaccines against rabies from nervous tissue, but in 1991, the Treaty of GM Baer reserved the place of choice, first vaccines obtained by culture on embryos of ducks (PDEV ‘Purified duck embryo vaccine ‘) and the other three types of vaccines prepared on cell culture:
Action to be taken in respect of the dog biting
It is very important to know that a dog ‘biter’ infected with rabies can spread the virus before the onset of symptoms.It is therefore necessary to keep him under observation for at least fifteen days. Impounded, the dog must be fed and watered. If the dog is rabid, it will die within ten days after the first symptoms. Any dog which bites a person, even if no signs of rabies, should be placed under observation (three veterinary examinations within fifteen days after the bite). During this observation period, if the signs of the disease appear, the rapid evolution of the fatal character of evil can establish the diagnosis.
Do not sacrifice a dog ‘biting’ as it is often tempted to do so. This could prohibit whether it was rabid. If the biting dog is dead, you should contact the departmental (in France) veterinary services which will decide whether to perform laboratory analysis on the brain of the dog.
Indeed, the testing for the virus can not distinguish between antibodies from the virus, and antibodies due to the vaccine. In France, two tests are used in research of rabies virus:immunofluorescence and inoculation of cell cultures. Both techniques are used to see if the virus reaches the brain, but usually do not deny or confirm the contamination of the subject, the animal is generally sacrificed too early.
Since 1998, 9 cases were positive, but not the virus has been confirmed in animals euthanized contacts as a precaution, nor among those suites euthanized animal health measures applied in the case of suspected rabies cases.
Action to be taken in respect of the person bitten
When symptoms of rabies occur in humans it is too late to intervene: death is a near certainty, the only way out. Therefore it should follow the following recommendations:
When a person is bitten or very deeply, or in many parts of the body or face or head or neck, or fingers, it must undergo rabies treatment as soon as possible even if dog biting does not show signs of rabies and even though it has not been in contact with a rabid dog. The bitten person should wash the wound with soap and water then disinfect the wound with antiseptic and immediately consult a health center to be administered the serum anti-tetanus and rabies vaccine.
Accidents vaccine
Neurological accidents caused by rabies vaccine have been reported even in the time of Pasteur by Mr. Lutaud particular and later by Paul Remlinger, who spoke of ‘laboratory rabies’. Long remained unexplained, these accidents have been attributed to the presence of active virus in inactivated rabies vaccine imperfectly (and in Fortaleza, Brazil). Until the 1960s, the myelin is still present in the vaccine could also cause allergic encephalitis.
Transmission
An animal infected with rabies virus may begin to shed up to fifteen days before the first clinical symptoms. The virus is present in all secretions of the animal, including its feces. Given its fragility in the external environment, the entry of the virus in the body is done only through a break in the skin or oral mucous membranes and eyes.
Transmission in vitro can also be through aerosol through mucous membranes, that is, for example, what happens in the caves inhabited by rabid bats: we reported two cases of cavers who contracted rabies after been in contact with aerosols from rabid bat … More uncommon, transmission may also occur in a transmission corneal surgery.
In Europe, terrestrial non-flying vectors of rabies are foxes, wolves, badgers, deer, but also dog, cat, cow. In America, rabies is transmitted by raccoons or coyote.
Rabies is transmitted most often by biting but can also be transmitted by simply licking. After human infection, the virus enters (directly or indirectly) the peripheral nervous system. It then travels along nerves to the central nervous system. During this phase can not be easily detected by the immune system of the host, and vaccination may still confer immunity. Once the virus reaches the brain it rapidly causes encephalitis and symptoms appear. It can also infect the spinal cord, causing myelitis.
Animal rabies (symptoms in general)
In animals, symptoms depend on the species concerned. Typically, there is a generalized ataxia, the hyperesthesia, neck pain, hypersalivation marked and sometimes seizures of facial muscles (especially the masseter). In the case of carnivores, abnormally aggressive behavior is common but not systematic. In the first case the animal tries to bite any objects lying near his head, and do not give up after a bite.The bark of a rabid dog is specific (bitonal). We research and systematically exclude the first-line rage when a dog comes in consultation with nervous disorders. Classically, we describe that dogs bite an infected vampire bat virus (type desmodin frequently found in South America) are a form clinical paralytic and show no signs of aggression (eg a dog Cayenne in 2003) in this case, the carnivores are usually a dead epidemiological and do not transmit disease to humans.
The disease in vampire bats is not known with precision. In Guyana, rabies antibodies were detected in animals showing no symptoms and in whom the virus could not be identified.
Human Rabies
In humans, there are disorders of higher brain functions, anxiety, confusion, agitation with behavior disorders, hallucinations, insomnia, and possible delirium.The production of large quantities of saliva and tears with difficulty swallowing are typical of advanced stages. Specifically in humans is also expanding in advanced hydrophobicity: the sight of a liquid causes unreasonable fear, so that the contact causes unbearable burning sensations. Death, almost inevitable, occurs two to ten days after the first symptoms.
In one third of cases, the disease takes the form of an ascending paralysis resembling Guillain-Barre syndrome.
RABIES VACCINE
The vaccine is a suspension of inactivated and purified rabies virus obtained by cell culture on human diploid cells or fetal bovine kidney.
Immunity develops a month after the second injection of preventive vaccine and lasts for 1 year.
It preventive vaccine must be practiced among the people potentially exposed veterinarians, abattoir workers, sewer workers, gamekeepers, laboratory personnel.
It consists of two subcutaneous injections or intra-muscular at monthly intervals with booster 1 year later and then booster every 3 years.
In case of suspected exposure, should be performed 6 injections subcutaneously or intramuscularly 1st, 4th, 7th,
15 th, 30 th, 90 th day.
After the last injection must control the rate of rabies antibody (a rate of 0.5 IU / ml is considered protective).
if the rate is not sufficient requires further vaccination