Understanding Rabies

Dr Sarangthem Zeshmarani *

Helping & caring man's best friend : Anti-rabies vaccination drive at CCpur on 20 Jan 2015 :: Pix - Jayananda Angom

Rabies is a neglected zoonotic disease ( a disease that is transmitted from animals to humans) caused by the rabies of the genus Lyssavirus within the family Rhabdoviridae. Domestic dogs are the most common reservoir of the virus with more than 95% of human death caused by dog mediated virus. Dog mediated human rabies disproportionately affects poor rural communities particularly children with the majority (80%) of human death occurring in rural areas where awareness and access to appropriate post exposure prophylaxis is limited or non existence.

All warm blooded animals can get rabies. The rabies virus can infect any mammals but infection is most common among dogs, cat, cows, horses, bats, mongooses, monkey. Most people get rabies from being bitten by a rabid animal. The virus is transmitted in the saliva of rabid animals and generally enters the body via infiltration of virus laden saliva from a rabid animal into a wound (e.g scratches) or by direct exposure of mucosal surfaces to saliva from an infected animals (e.g bites). The virus cannot infiltrate intact skin.

SYMPTOMS

The problem with rabies is that symptoms do not usually occur immediately, but vaccinations must be taken within 48 hours (and an absolute maximum of a week) to prevent rabies from occurring after a dog bite. The symptoms (if post-exposure treatment is not taken promptly and correctly) usually manifest within one to three months, though there have been cases of symptoms occurring within a week, and after six years.

The time lag between the bite and symptoms happens because the rabies virus must reach the central nervous system before the occurrence of symptoms. Additionally, it is thought that the distance of the place of bite from the brain and spinal cord also determines the period of onset of symptoms.

Once the virus reach the brain, it further replicates, resulting in presentation of clinical signs from the patient. There are two clinical manifestation of rabies

Furious Rabies

Symptoms of rabies in animals may include any one or more of the following signs:
o Excitability
o Vicious behavior or attack
o Agitation
o Restlessness
o Change in te tone of dog's bark
o Uncharacteristic aggression
o Fearlessness
o Excessive salivation so called frothing at the mouth
o Aversion to the mouth
o Inability to swallow or drink (the animal may appear to be choking on a foreign object. This is a dangerous trap for humans who in trying to help the animal, may expose themselves to in fection without knowing it
o Dilated pupils
o Coordination or gait irregularities
o Paralysis
o Convulsion

And eventually death, almost within 10 days.

Dumb rabies

Some rabid animals do not exhibit typical rabid symptoms. This is generally referred to as Dumb rabies. These animals may display othe symptoms of general illiness which may include
o An avoidance of contact with humans or other animals
o Lethargy
o Loss of appetite
And eventually death

Are these symptoms characteristic of Rabies only

Unfortunately the answer is NO. extreme pain, fear or confussion can make an animal aggressive. Profuse salivation and the inability to swallow may result from an obstruction in the throat, foreign bodies in the teeth, or the ingestion of irritating or toxic substances. Howling could be due to hunger,fear, pain. But in any case, such animals should be approached with caution as in their pain may attack

THINGS TO DO IF BITTEN /SCRATCH

So what can be done to prevent rabies if you have been bitten by a stray dog?

According to the National Guidelines on Rabies Prophylaxis (of the Government of India):

Clean the wound immediately and thoroughly and liberal amounts of soap and water to remove saliva from the area.
If the wound is not bleeding profusely allow the wound to bleed as this will help to clean it.
If the wound is bleeding profusely apply pressure with fingers or hands or apply apressure bandage.
The wound should not be sutured as this is thought to increase the risk of the virus entering nerves.
Once the wound has been thoroughly cleansed, apply locally povidone iodine 1% or 70%alcohol.
Do not apply chilli powder, turmeric powder oil or any other home remedy to the wound.

Next, it is necessary to visit a clinic which provides anti-rabies vaccination as soon as possible. The doctor usually checks the area of the bite and decides treatment based on it known as Post-Exposure Prophylaxis (PEP).

The treatment usually involves administration of anti-rabies vaccine on days 0, 3, 7, 14 and 28. Rabies Immunoglobulin (RIG) is also administered. The treatment is given both intra-dermal and intra-muscular. A tetanus shot and a course of antibiotics may also be recommended.

What should I do if I see a possible Rabid Dog?
o Do not approach or provoke the animal
o Do not throw sticksnor stones at it
o Disperse gathering crowds to reduce stress on the dog and reduce risks
o Call the appropriate authority: the local animal control agency, Police department, animal welfare organization, Veterinary Service or public health authority
o Try to maintain a visual contact of the dog until the responsible authority arrives, but do not put yourself in jeopardy by doing this.

CONTROL OF RABIES

o Keep vaccinations upto date for your own pets. This requirement is important not only to keep your pets from getting rabies but also to provide a barrier of protection to you, in case your animal is bitten by a rabid animal.

o Keep your pets under supervision with their movement restricted

o Do not let them wander the streets unsupervised

o Do not let them come into contact with unfamiliar unvaccinated animals

o If you see any animal acting strangely notify the local health or animal authorities. Do not try to catch the animals yourself . However 'Barking a lot', 'looking odd','sniffing other dogs', or 'looking threatening' should not necessarily be interpreted as strange or unusual behavior.

CONCLUSION

September 28th is celebrated as World Rabies Day. It has been recognized as such by the United nations and marked every year since 2007. The campgain is coordinated by the global Alliance for Rabies control. The day has benn choosed as the World Rabies Day because it is the death anniversary of Louis Pasteur who developed the first rabies vaccine.

"PREVENTION IS BETTER THAN CURE" so each and every person should vaccinate their animals before exposing the disease.