Rabies is a viral disease that nearly always occurs due to transmission by an animal bite carrying the infection. Anyone who receives a bite in a geographical area where rabies occurs should seek immediate treatment. For treatment to succeed, it must take place before symptoms appear.
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What is the causative agent of rabies?
Nov 29, 2021 · Rabies is a dangerous virus that causes brain inflammation in humans and other mammals. Animals carrying the infection can spread rabies to humans through bites and scratches. Without treatment,...
What is the mode of transmission of rabies?
Rabies is a viral disease that spreads through the bite of an infected animal. Symptoms include fever, headaches, and weakness. Learn about the rabies vaccine and treatment.
What is rabies?
Jun 11, 2019 · Español (Spanish) minus. Related Pages. Rabies virus is transmitted through direct contact (such as through broken skin or mucous membranes in the eyes, nose, or mouth) with saliva or brain/nervous system tissue from an infected animal. People usually get rabies from the bite of a rabid animal. It is also possible, but rare, for people to get rabies from non …
What is the pathophysiology of rabies?
One of the most unique symptoms of rabies infection is a tingling or twitching sensation in the area around the animal bite. After the virus leaves the local bite area, it travels up a nearby nerve to the brain and can cause such symptoms as: Pain. Fatigue. Headaches. Fever. Muscle spasms. Irritability. Excessive movements.
What is the M protein in rabies?
The glycoprotein forms approximately 400 trimeric spikes which are tightly arranged on the surface of the virus. The M protein is associated both with the envelope and the RNP and may be the central protein of rhabdovirus assembly. The basic structure and composition of rabies virus is depicted in the longitudinal diagram below.
How many proteins are in the rabies genome?
Rhabdoviruses are approximately 180 nm long and 75 nm wide. The rabies genome encodes five proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and polymerase (L). All rhabdoviruses have two major structural components: a helical ribonucleoprotein core (RNP) and a surrounding envelope. In the RNP, genomic RNA is tightly encased by the nucleoprotein. Two other viral proteins, the phospoprotein and the large protein (L-protein or polymerase) are associated with the RNP.
What is rabies in mammals?
What is Rabies? Rabies is a preventable viral disease most often transmitted through the bite of a rabid animal. The rabies virus infects the central nervous system of mammals, ultimately causing disease in the brain and death. The vast majority of rabies cases reported to the Centers for Disease Control and Prevention ...
What is the rabid virus?
Rabies virus belongs to the order Mononegavirales, viruses with a nonsegmented, negative-stranded RNA genomes. Within this group, viruses with a distinct “bullet” shape are classified in the Rhabdoviridae family, which includes at least three genera of animal viruses, Lyssavirus, Ephemerovirus, and Vesiculovirus. The genus Lyssavirus includes rabies virus, Lagos bat, Mokola virus, Duvenhage virus, European bat virus 1 & 2 and Australian bat virus.
What is the process of fusion of the rabies virus envelope to the host cell membrane?
The fusion of the rabies virus envelope to the host cell membrane (adsorption) initiates the infection process. The interaction of the G protein and specific cell surface receptors may be involved.
What is the first step in viral replication?
The first step in viral replication is synthesis of full-length copies (postive strands) of the viral genome. When the switch to replication occurs, RNA transcription becomes “non-stop” and stop codons are ignored.
What is the L gene?
A viral-encoded polymerase (L gene) transcribes the genomic strand of rabies RNA into leader RNA and five capped and polyadenylated mRNAs, which are translated into proteins. Translation, which involves the synthesis of the N, P, M, G and L proteins, occurs on free ribosomes in the cytoplasm.
Incubation
Incubation is the time before symptoms appear. It usually lasts from 2–3 months and varies from 1 week to 1 year, depending on where the virus entered the body and the number of viral particles involved. The closer the bite is to the brain, the sooner the effects are likely to appear.
Coma and death
A person may enter a coma, and most people then die within 3 days. During the coma stage, even with supportive therapy, virtually no person survives rabies.
Why does rabies cause a fear of water?
People used to call rabies hydrophobia because it appears to cause a fear of water. The reason is that the infection causes intense spasms in the throat when a person tries to swallow. Even the thought of swallowing water can cause spasms, making it appear that the individual is afraid of water.
Rabies vaccine
Doctors do not offer the rabies vaccine routinely. Instead, they reserve it for those at high risk of rabies exposure, such as laboratory staff working with the virus that causes the disease, veterinarians, and people likely to receive animal bites. These individuals may receive regular vaccinations.
Individual precautions
Individuals should follow some safety rules to reduce the chance of contracting rabies.
How do rabies animals transmit the virus?
Rabid animals transmit the virus via a bite or saliva exposure. Early signs and symptoms of rabies mimic those of a viral flu-like infection. People should start post-exposure prophylaxis (PEP) treatment as soon as they suspect an exposure. In the U.S., two to three people die from rabies each year.
How to diagnose rabies in humans?
In humans, health care professionals diagnose rabies by testing saliva, blood samples, spinal fluid, and skin samples. Multiple tests may be necessary.
How does rabies spread?
Rabies is a viral illness spread via the saliva of an infected animal by the rabies virus (genus Lyssavirus ). Rabies exposure occurs usually through biting a human or another infected animal. Transmission can also occur through saliva touching an open wound or touching mucous membranes.
How long does it take for rabies to spread?
After a rabid animal bites someone, the virus is deposited in the muscle and subcutaneous tissue. For most of the incubation period (which is usually one to three months), the virus stays close to the exposure site. The virus then travels via peripheral nerves to the brain and from there, again via peripheral nerves, to nearly all parts of the body.
How do you know if you have rabies?
The disease can then take two forms: 1 With paralytic rabies (approximately 20% of cases), the patient's muscles slowly become paralyzed (usually starting at the site of the bite). This is the less common form and ends in coma and death. 2 With furious rabies (about 80% of cases), the patient exhibits the classic symptoms of rabies, such as#N#anxiety and confusion (The patient is often overly active.);#N#encephalitis, causing hallucinations, confusion, and coma;#N#hypersalivation;#N#hydrophobia (fear and avoidance of water);#N#aerophobia (fear of fresh air);#N#difficulty swallowing.
What are the early symptoms of rabies?
The early symptoms of rabies are very generalized and include weakness, fever, and headaches. Without a history of a potential exposure to a rabid animal, these symptoms would not raise the suspicion of rabies as they are very similar to the common flu or other viral syndromes.
What animals have rabies?
In the United States, the saliva of rabid bats, coyotes, foxes, raccoons, and skunks most often transmits rabies. In the developing world, stray dogs are the most likely animal to transmit rabies. The virus has also been found in cows, cats, ferrets, and horses.
How is rabies transmitted?
Rabies virus is transmitted through direct contact (such as through broken skin or mucous membranes in the eyes, nose, or mouth) with saliva or brain/nervous system tissue from an infected animal. People usually get rabies from the bite of a rabid animal.
When does rabies become noninfectious?
Rabies virus becomes noninfectious when it dries out and when it is exposed to sunlight. Different environmental conditions affect the rate at which the virus becomes inactive, but in general, if the material containing the virus is dry, the virus can be considered noninfectious.
Can you get rabies from a rabid animal?
People usually get rabies from the bite of a rabid animal. It is also possible, but rare, for people to get rabies from non-bite exposures, which can include scratches, abrasions, or open wounds that are exposed to saliva or other potentially infectious material from a rabid animal.
Is rabies exposure a risk?
Casual contact, such as touching a person with rabies or contact with non-infectious fluid or tissue (urine, blood, feces), is not associated with risk for infection. Contact with someone who is receiving rabies vaccination does not constitute rabies exposure, does not pose a risk for infection, and does not require postexposure prophylaxis.
Can rabies be transmitted through organ procurement?
Bite and non-bite exposures from an infected person could theoretically transmit rabies, but no such cases have been documented.
Can you inhale rabies?
Inhalation of aerosolized rabies virus is one potential non-bite route of exposure, but except for laboratory workers, most people won’t encounter an aerosol of rabies virus. Rabies transmission through corneal and solid organ transplants have been recorded, but they are also very rare.
How long does it take for rabies to show up?
Symptoms can appear as soon as a few days after being bitten by an infected animal. However, in most cases, symptoms may not appear until weeks or months later. One of the most unique symptoms of rabies infection is a tingling or twitching sensation in the area around the animal bite.
How many days after first rabies shot?
If the decision is made to begin the rabies vaccine shots and you have never been vaccinated against rabies: You should get 5 doses of the rabies vaccine – first dose immediately, then additional doses 3, 7, 14, and 28 days after the first dose.
How does rabies get transmitted?
The virus is transmitted to humans through the infected animal's saliva. Very rare cases occur when infected saliva gets into someone’s eyes or mouth or into an open wound.
What are the factors that determine a rabies shot?
These include: The circumstances of the bite (whether the bite provoked or unprovoked). The type of animal (wild or domestic; species of animal).
How to keep a dog from getting rabies?
Make sure your pets are up-to-date with their rabies vaccines. Consider keeping them indoors so that they are less likely to be bitten by other animals that may be infected with rabies.
What does it feel like to be bit by a rabies?
One of the most unique symptoms of rabies infection is a tingling or twitching sensation in the area around the animal bite. After the virus leaves the local bite area, it travels up a nearby nerve to the brain and can cause such symptoms as:
What to do if you have rabies?
If you have been bitten by an animal or exposed to rabies, call your doctor and go to a nearby emergency room immediately. Once there, the doctor will clean the wound thoroughly and give a tetanus shot if you are not up-to-date with your tetanus immunization.
How many days before travel do you get rabies shots?
In the United States, preexposure vaccination consists of a series of 3 intramuscular injections given on days 0, 7, and 21 or 28 in the deltoid with human diploid cell rabies vaccine (HDCV) or purified chick embryo cell (PCEC) vaccine ( Table 4-17 ). Travelers should receive all 3 preexposure immunizations before travel. If 3 doses of rabies vaccine cannot be completed before travel, the traveler should not start the series, as few data exist to guide PEP after a partial immunization series.
What are the symptoms of rabies after a booster shot?
Travelers should be advised that they may experience local reactions after vaccination such as pain, erythema, swelling, or itching at the injection site, or mild systemic reactions such as headache, nausea, abdominal pain, muscle aches, and dizziness. Approximately 6% of people receiving booster vaccinations with HDCV may experience systemic hypersensitivity reactions characterized by urticaria, pruritus, and malaise. The likelihood of these reactions may be less with PCEC. Once initiated, rabies PEP should not be interrupted or discontinued because of local or mild systemic reactions to rabies vaccine. If an adverse event occurs with one of the vaccine types, consider switching to the alternative vaccine for the remainder of the series.
How to prevent rabies in travelers?
Rabies in travelers is best prevented by having a comprehensive strategy. This consists of 1) education about risks and the need to avoid bites from mammals, especially high-risk rabies reservoir species; 2) consultation with travel health professionals to determine if preexposure vaccination is recommended; 3) knowing how to prevent rabies after a bite; and 4) knowing how to obtain postexposure prophylaxis (PEP). The last may involve urgent importation of rabies biologics or travel to where PEP is available. A list of pretravel considerations in regards to rabies precautions can be found at www.cdc.gov/travel.
What to use to clean rabies bites?
Any animal bite or scratch should be thoroughly cleaned with copious amounts of soap and water, povidone iodine, or other substances with virucidal activity. All travelers should be informed that immediately cleaning bite wounds as soon as possible substantially reduces the risk of rabies virus infection, especially when followed by timely administration of PEP. For unvaccinated patients, wounds that might require suturing should have the suturing delayed for a few days. If suturing is necessary to control bleeding or for functional or cosmetic reasons, rabies immune globulin (RIG) should be injected into all wounded tissues before suturing. The use of local anesthetic is not contraindicated in wound management.
How does rabies spread?
Rabies virus is neurotropic and gains access to the peripheral nervous system by being taken up at a nerve synapse at the site of the bite. The virus travels through peripheral nerves to the central nervous system, where most viral replication occurs, before traveling back out through the peripheral nervous system. After reaching the salivary glands, virus can be secreted allowing the transmission cycle to repeat. Exposure of rabies virus to highly innervated tissue may increase the risk of successful infection. Exposure of rabies virus to anatomic sites nearer the central nervous system may reduce the incubation period. In addition to saliva, rabies virus may also be found in nervous tissues (central and peripheral) and tears. Infection from nonbite exposures, such as organ transplantation from infected humans, does occur. However, human-to-human transmission does not generally occur otherwise.
Why are children at higher risk for rabies?
Children are at higher risk for rabies exposure and subsequent illness because of their inquisitive nature and inability to read behavioral cues from dogs and other animals. The smaller stature of children makes them more likely to experience severe bites to high-risk areas, such as the face and head. Also contributing to the higher risk is their attraction to animals and the possibility that they may not report an exposure.
Does preexposure prevent rabies?
Preexposure vaccination does not eliminate the need for additional medical attention after a rabies exposure, but it simplifies PEP. Preexposure vaccination may also provide some protection when an exposure to rabies virus is unrecognized or PEP might be delayed. Travelers who have completed a 3-dose preexposure rabies immunization series or have received full PEP are considered previously vaccinated and do not require routine boosters. Routine testing for rabies virus-neutralizing antibody is not recommended for international travelers who are not otherwise in the frequent or continuous risk categories ( Table 4-16 ).
What is the importance of education on dog bite prevention?
Education on dog behaviour and bite prevention for both children and adults is an essential extension of a rabies vaccination programme and can decrease both the incidence of human rabies and the financial burden of treating dog bites.
How long does it take for rabies to die?
Death occurs after a few days due to cardio-respiratory arrest. Paralytic rabies accounts for about 20% of the total number of human cases.
What is the paralytic form of rabies?
Paralytic rabies accounts for about 20% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralysed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.
What is PEP in rabies?
Post-exposure prophylaxis (PEP) is the immediate treatment of a bite victim after rabies exposure. This prevents virus entry into the central nervous system, which results in imminent death. PEP consists of: Extensive washing and local treatment of the bite wound or scratch as soon as possible after a suspected exposure;
How much does rabies cost?
Globally rabies causes an estimated cost of US$ 8.6 billion per year. 40% of people bitten by suspect rabid animals are children under 15 years of age. Immediate, thorough wound washing with soap and water after contact with a suspect rabid animal is crucial and can save lives.
How many people get rabies shots every year?
Every year, more than 29 million people worldwide receive a post-bite vaccination. This is estimated to prevent hundreds of thousands of rabies deaths annually. Globally, the economic burden of dog-mediated rabies is estimated at US$ 8.6 billion per year.
Why is rabies surveillance important?
Monitoring of rabies programmes and disease surveillance are needed to measure impact and for increasing awareness and advocacy.
What is the causative agent of rabies?
The causative agent is rabies virus (RV), a negative-stranded RNA virus of the rhabdovirus family. RV pathogenesis, like that of other viruses, is a multigenic trait. Recent findings indicate that in addition to the RV …. Rabies is a central nervous system (CNS) disease that is almost invariably fatal. The causative agent is rabies virus (RV), ...
What is the neuroinvasiveness of RV?
A key factor in the neuroinvasion of RV is transsynaptic neuron al spread.
Which protein is responsible for retrograde transport of the virus?
While the ability of RV to spread from the post-synaptic site to the pre-synaptic site is mediated by the RV G protein, the RV P protein might be an important determinant of retrograde transport of the virus within axons.
Is rabies a CNS disease?
Rabies is a central nervous system (CNS) disease that is almost invariably fatal. The causative agent is rabies virus (RV), a negative-stranded RNA virus of the rhabdovirus family. RV pathogenesis, like that of other viruses, is a multigenic trait. Recent findings indicate that in addition to the RV G protein viral elements ...