The rabies virus

Rabies virus is one of the best known viruses. Fortunately, through active vaccination and eradication programs there have been registered only 3 cases of rabies in humans in the United States in 2006, although 45,000 people were exposed to the virus and required vaccinations and injections of antibodies. However, in other parts of the world, cases of infection with rabies virus are much more, and the number of deaths occurring, much higher. A person dies worldwide from rabies every 10 minutes.

The rabies virus, the etiologic agent of rabies, is part of the family Rhabdoviridae, genus Lyssavirus.

Morphology and structure

The virus has an elongated form, the characteristic of bullet or shell, with diameter of 70-80 nm and length of 120-240 nm. The shell comprises a double layer of fat. To the surface layer there are formations of glycoprotein (the G glycoprotein), and the M-protein is found within , being the major structural protein. Glycoprotein G is involved in attaching the virion to target cells, having an haemagglutinin activity as well. RNA genome has negative polarity.

Pathogenic

The source of rabies virus is represented both by wild animals (wolves, foxes, bats, rats) and domestic animals (dogs, cats). The disease is transmitted through bites from infected animals (intense salivary excretion of the virus). Once introduced through the skin or mucous membrane, the virus begins replicating in the striated muscles at the wound site. Incubation is variable (between 10 days and 1 year) depending on the location and severity of the infected wound . The virus can replicate in muscle cells for hours or weeks, or it can migrate immediately to the nervous system via unmyelinated sensory nerve endings at the inoculation site.

Because of the narrow viral tropism for the acetyl-choline receptors of the neuromuscular junction, the viral genome goes to the peripheral nerves of the entrance gate. After multiplication at this level, the infection goes toward the central nervous system, taking the path of the peripheral nerve, invading the brain. In the brain, the virus infects neurons in almost all brain regions, where it continues replication. The rabies virus attacks nervous tissue and appears to replicate almost exclusively in neuronal cells. After replication at this level, the rabies virus gets to invade other tissues, including the salivary glands, taste buds, hair follicles, kidney, skin, the adrenal glands, pancreas, tears, heart muscle, brown fat, nasal cavities, retina, and cornea. The rabies virus has never been detected in blood or blood cells.

Because of the central and peripheral nerve lesions can occur these symptoms: hyperexcitability, anxiety, pharyngeal spasm, convulsions, paralysis. Evolution is always lethal.


	The rabies virus Rabies virus is one of the best known viruses. Fortunately, through active vaccination and eradication programs there have been registered only 3 cases of rabies in humans in the United States in 2006, although 45,000 people were exposed to the virus and required vaccinations and injections of antibodies. However, in other parts of the world, cases of infection with rabies virus are much more, and the number of deaths occurring, much higher. A person dies worldwide from rabies every 10 minutes. The rabies virus, the etiologic agent of rabies, is part of the family Rhabdoviridae, genus Lyssavirus. Morphology and structure The virus has an elongated form, the characteristic of bullet or shell, with diameter of 70-80 nm and length of 120-240 nm. The shell comprises a double layer of fat. To the surface layer there are formations of glycoprotein (the G glycoprotein), and the M-protein is found within , being the major structural protein. Glycoprotein G is involved in attaching the virion to target cells, having an haemagglutinin activity as well. RNA genome has negative polarity. Pathogenic The source of rabies virus is represented both by wild animals (wolves, foxes, bats, rats) and domestic animals (dogs, cats). The disease is transmitted through bites from infected animals (intense salivary excretion of the virus). Once introduced through the skin or mucous membrane, the virus begins replicating in the striated muscles at the wound site. Incubation is variable (between 10 days and 1 year) depending on the location and severity of the infected wound . The virus can replicate in muscle cells for hours or weeks, or it can migrate immediately to the nervous system via unmyelinated sensory nerve endings at the inoculation site. Because of the narrow viral tropism for the acetyl-choline receptors of the neuromuscular junction, the viral genome goes to the peripheral nerves of the entrance gate. After multiplication at this level, the infection goes toward the central nervous system, taking the path of the peripheral nerve, invading the brain. In the brain, the virus infects neurons in almost all brain regions, where it continues replication. The rabies virus attacks nervous tissue and appears to replicate almost exclusively in neuronal cells. After replication at this level, the rabies virus gets to invade other tissues, including the salivary glands, taste buds, hair follicles, kidney, skin, the adrenal glands, pancreas, tears, heart muscle, brown fat, nasal cavities, retina, and cornea. The rabies virus has never been detected in blood or blood cells. Because of the central and peripheral nerve lesions can occur these symptoms: hyperexcitability, anxiety, pharyngeal spasm, convulsions, paralysis. Evolution is always lethal.	Rabies Rabies symptoms Rabies vaccine Rabies in humans Rabies treatment Signs of rabies Rabies side effects Rabies shot The rabies virus Rabies transmission Rabies Pictures Disclaimer and contact Sarcoidosis Lymphedema symptoms Gonorrhea symptoms Knee tendonitis Pulmonary embolism
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