Rabies is a viral infection caused by lyssaviruses.
Rabies presents itself in the form of flu like symptoms in the beginning. The incubation period is around 2-12 weeks. Later the symptoms seen are increased sensation at the site of bite, excitability, muscle spasms, restlessness, excitability, slight or partial paralysis, pain at the site of bite, numbness and tingling, convulsions, insomnia, agitation, low-grade fever, confusion, paranoia, hallucinations, terror, abnormal behaviour that progresses towards delirium.
Drooling is also seen as the saliva production is highly increased. Any attempt to drink or even the intention of drinking can lead to very painful spasms of the muscles in throat and larynx. Death is the final outcome in 2-10 days, once the symptoms start showing. The chances of survival are negligible even if proper intensive care is given .
If possible, the animal that bit patient should be captured and delivered to a veterinarian for investigation of rabies . Skin biopsy from the nape of neck can be done to detect rabies antigen by direct fluorescent antibody, even corneal epithelia can be used for this purpose. Nuchal skin biopsy is a very reliable test for rabies infection in the first week.
The diagnosis can also be made using saliva, cerebrospinal fluid and brain tissue for viral cultures and polymerase chain reaction (PCR) assay but brain tissue can be obtained on postmortem and is the most reliable finding. Detection of viral RNA from saliva using PCR assay and viral antigen from brain biopsy specimens yields 100% specificity.
Blood examination may show elevated WBCs with 6-8% atypical monocytes.
Electroencephalography (EEG) findings include encephalopathic changes.
The nucleic acid sequence ̶based amplification (NASBA) technique on saliva and CSF can be used for rapid diagnosis as early as 2 days after symptom onset. Serum rapid fluorescent focus inhibition test (RFFIT) titer results are positive in 50% of rabies cases.
Clean the wound thoroughly with soap and water, and explore it carefully to remove any foreign body if present. Usually stitches are not taken so as to allow the drainage of wound fluids, avoid infection and heal the wound by secondary intention  . Prophylactic treatment using antibiotics should be considered  .
It is recommended that any person who is not vaccinated previously against rabies should receive one dose of human rabies immunoglobulin (HRIG) followed by rabies vaccine. The dose for HRIG is 20 IU/kg for both adults and children. Give maximum dose at the site of injury and the remaining should be given as deep intramuscular injection away from the site of injury. HRIG can be given up to 7 days after the exposure to the virus, if it is not available immediately  . Post-exposure prophylaxis dose of vaccine is 1 ml intramuscular in the deltoid or in the upper outer thigh in infants.
The first dose of rabies vaccine is given as soon as possible after exposure, and later on the other doses are given on the 3, 7 and 14 day after the first. In case of an immunocompromised patient an additional dose is given on the 28 day after the first. Patients who have taken pre-exposure vaccination previously do not need the immunoglobulin, only the post exposure vaccinations on days 0 and 2.
Intramuscular vaccination should be given into the deltoid, and not gluteal area, as it is associated with vaccination failure due to injection into fat rather than muscle.
Once the patient starts developing the symptoms of rabies, they have to be transferred to an intensive cardiopulmonary supportive care for treatment. Rabies vaccination or giving HRIG at this point is of no use. Even if the patient is given treatment, the symptoms of rabies are almost invariably fatal.
Rabies can be prevented if vaccine is given immediately after the bite. Post exposure prophylaxis (PEP) is very successful in preventing the disease if given promptly i.e. within 6 days of infection. If the vaccine is not given then the infection becomes fatal once the person starts showing neurological symptoms.
Death from respiratory failure occurs within 7 days once the symptoms start. There have been only a very few cases of survival from a rabies infection in the world till date.
Rabies is caused due to lyssa virus family including rabies virus and Australian bat virus. The rabies virus spreads through the saliva of the infected animals to another animal or a person by the means of biting. In very few cases, rabies has spread when the infected saliva gets into an open wound or the mucous membranes. This happens if an infected animal licks an open cut on the skin.
In rare cases, human to human transmission has also taken place due to organ transplant from an infected donor. It has occurred with corneal and other organ transplants   . Animals that can transmit rabies are cows, ferrets goats, horses, beavers, cats and dogs   , coyotes, foxes, monkeys, raccoons , skunks, woodchucks and bats .
Rabies causes around 26,000 to 55,000 deaths across the world per year  and more than 95% of them occur in Asia and Africa. In biggest part of Europe and Australia it is seen only in bats. Lot of small island nations are free from rabies entirely.
Rabies develops in the following pattern:
Incubation period: The infected person remains asymptomatic in this period. The average duration of incubation is 20-90 days. Due to a prolonged incubation period, patients do not remember the exact incident of exposure. The rabies virus is separated from the immune system during this time, and no antibody response is seen.
Prodromal period: In the period of 2-10 days, the virus enters the central nervous system (CNS). Patient starts developing nonspecific signs and symptoms like paresthesia, pain or severe itching at the site of injury, fever, insomnia, malaise, depression, agitation, headaches, pharyngitis etc.
Acute neurologic period: The patient develops objective signs of CNS disease during this period of 2-7 days. Symptoms include muscle fasciculations, focal or generalized convulsions and priapism. Sometimes patients die immediately or can progress towards paralysis, which presents only in the bitten limb at first but later becomes diffuse.
Rabies can be prevented by decreasing the chances of coming in contact with a rabid animal.
Also getting the treatment as soon as possible following the exposure will help in preventing rabies.
Rabies is a lethal viral infection that causes inflammation of the brain in humans and is almost fatal once the person starts showing the signs and symptoms of rabies. The time span between contracting the disease and beginning of the symptoms is generally one to three months, but it can vary from few days to a year.
Rabies is a viral infection that is mainly transmitted from animals to the human beings. The common mode of transmission is being bitten by the animal suffering from rabies. Hence it is always advisable to get your pets vaccinated regularly and also you get yourself vaccinated to prevent it if you are in close contact of animals.
Once the symptoms of rabies start developing it is almost impossible to cure it, the patient finally succumbs to death after few days. Therefore it is suggested that whenever in case you are bitten by any stray animal better get vaccinated for rabies because their is no point of taking chances and also finding that whether that particular animal is suffering from rabies or no is difficult. Prevention is better than cure is the most apt motto in case of rabies.