The rabies virus is approximately 180nm long and 75nm wide. The virus is a ribonucleoprotein which means it is composed of RNA encased in nucleoprotein. The rabies genome encodes 5 proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and polymerase (L).
Viral Specificity:
Once the rabies virus is introduced to the body it gradually makes its way to the brain by following the peripheral nerves. The length of time that the virus takes to reach the brain is the viruses incubation period. The incubation period is typically a few months in humans. when the rabies virus reaches the brain the more serious symptoms begin and at this point it may be too late for treatment. Studies show that once the virus reaches the brain the BBB(blood brain barrier) prevents anti viral cells produced by the body from entering the brain. As a result the cells are unable to reach the site of the rabies infection and stop them replicating.
Symptoms and progression of the disease:
The sypmtoms begin around 2 weeks after the infection. It may begin as flu-like symptoms but will eventually expand to slight or partial paralysis, cerebral dysfunction, anxiety,insomnia, confusion, aqitation, abnormal behavior, paranoia, terror, hallucinations, progressing to delirium. The production of large amounts of tears and saliva along with ability to speak or swallow are very common in later stages due to the fact that the throat and jaw are becoming slowly paralyzed. Humans infected with rabies often show panic when presented with liquids to drink, and cannot quench their thirst. Death is very common two-ten days after the first symptoms start. The few humans that have survived rabies without early treatment have all been left with severe brain injuries.
Common Methods of Transmission:
Rabies is most commonly transferred to humans by mammals that are carrying the virus. In direct contact it is transferred through the saliva of the infected animal often through punctured skin. In many cases the animal carrying the virus has been very aggresive and has attacked the human victum without being provoked. Transmission between humans is extremely rare and few cases have been documented.
Treatment and Prevention:
All human cases of rabies were fatal until a vaccine was developed in 1885 by Louis Pasteur and Émile Roux. Currently the most common rabies vaccines are made from infected human haploid cells and the less expensives options that have been recently discovered made from purified chicken embryo cells and purified vero cells. Thoroughly washing the wound as soon as possible with soap and water followed by the application of rubbing alchohol/iodine is also a very effective way of preventing the spread of the infection. Inorder to prevent rabies, be cautious of animals that are behaving abnormally agressive or are demonstrating any other symptoms that are common with infected animals.
Miscellaneous:
- The number of recorded deaths from rabies has dropped from one hundred or more annually in the early twentieth century, to 1–2 per year, mostly caused by bat bites.
- September 28 is World Rabies Day, which promotes information on, and prevention and elimination of the disease.
- Rabies is present in the animal populations of almost every country in the world, except in Australia and New Zealand.
Rabies Virus
Description of virus that causes the disease.
The rabies virus is approximately 180nm long and 75nm wide. The virus is a ribonucleoprotein which means it is composed of RNA encased in nucleoprotein. The rabies genome encodes 5 proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and polymerase (L).Viral Specificity:
Once the rabies virus is introduced to the body it gradually makes its way to the brain by following the peripheral nerves. The length of time that the virus takes to reach the brain is the viruses incubation period. The incubation period is typically a few months in humans. when the rabies virus reaches the brain the more serious symptoms begin and at this point it may be too late for treatment. Studies show that once the virus reaches the brain the BBB(blood brain barrier) prevents anti viral cells produced by the body from entering the brain. As a result the cells are unable to reach the site of the rabies infection and stop them replicating.Symptoms and progression of the disease:
The sypmtoms begin around 2 weeks after the infection. It may begin as flu-like symptoms but will eventually expand to slight or partial paralysis, cerebral dysfunction, anxiety,insomnia, confusion, aqitation, abnormal behavior, paranoia, terror, hallucinations, progressing to delirium. The production of large amounts of tears and saliva along with ability to speak or swallow are very common in later stages due to the fact that the throat and jaw are becoming slowly paralyzed. Humans infected with rabies often show panic when presented with liquids to drink, and cannot quench their thirst. Death is very common two-ten days after the first symptoms start. The few humans that have survived rabies without early treatment have all been left with severe brain injuries.Common Methods of Transmission:
Rabies is most commonly transferred to humans by mammals that are carrying the virus. In direct contact it is transferred through the saliva of the infected animal often through punctured skin. In many cases the animal carrying the virus has been very aggresive and has attacked the human victum without being provoked. Transmission between humans is extremely rare and few cases have been documented.Treatment and Prevention:
All human cases of rabies were fatal until a vaccine was developed in 1885 by Louis Pasteur and Émile Roux. Currently the most common rabies vaccines are made from infected human haploid cells and the less expensives options that have been recently discovered made from purified chicken embryo cells and purified vero cells. Thoroughly washing the wound as soon as possible with soap and water followed by the application of rubbing alchohol/iodine is also a very effective way of preventing the spread of the infection. Inorder to prevent rabies, be cautious of animals that are behaving abnormally agressive or are demonstrating any other symptoms that are common with infected animals.Miscellaneous:
- The number of recorded deaths from rabies has dropped from one hundred or more annually in the early twentieth century, to 1–2 per year, mostly caused by bat bites.- September 28 is World Rabies Day, which promotes information on, and prevention and elimination of the disease.
- Rabies is present in the animal populations of almost every country in the world, except in Australia and New Zealand.
Resources accessed:
http://www.health.gov.on.ca/english/public/program/pubhealth/rabies/qa/rabies_qa.html- Ministry of health and long term care(MOHLTC)
http://en.wikipedia.org/wiki/Rabies- wikipedia
http://www.cdc.gov/rabies/transmission/virus.html- Centers for disease control and prevention(CDC)
medhelp.org