Rabies Lyssavirus - Everything You Need To Know
We are sure you’ve all heard of Rabies and chances are that your parents have, at least once in your lifetime, warned you against petting or feeding a stray dog, worried that it might be rabid. They aren’t entirely paranoid. However, proper knowledge on this condition and its prevention goes a long way in ensuring your safety as well your pets’. Rabies is a term that is well recognised as a serious condition by almost all Indian households, yet it is shocking to see how little of this fatal disease we all understand. In this post, we hope to cover everything you need to know about rabies.
So what is Rabies?
Unlike what many of us assume, rabies is more than just suffering from a painful bite. It is a zoonotic disease, which essentially means that it is transmitted between different species of mammals. It affects the Central Nervous System (CNS) and is almost always fatal to animals and humans alike, unless the required treatment is administered right after exposure. It is caused by the Rabies virus from the family of Lyssavirus, where Lyssa literally means ‘rage’ in Greek and is aptly named so, keeping in mind its symptoms. It is fairly curable, but if and only if it is treated properly and immediately, well before it reaches the CNS, after which characteristic symptoms start to appear.
How is it transmitted?
The most common mode of transmission of rabies is through the saliva of an infected animal. When an infected animal, say a rabid dog, bites an individual or another animal, the virus from the dog’s saliva enters the host system through the bite wound and goes on to proliferate and infect the new host. There have been reported cases of the disease being transmitted when a rabid animal licks or scratches over open wounds on the host, although these are very less in number. Transmission can also technically occur when saliva from the infected animal enters a host’s mucous membranes such as eyes or nose. Person to person transmission is extremely rare and has not been reported well. In any case of suspected exposure, it is recommended to visit the doctor right away.
Okay, give me the works.
Gear up, we are getting down to the nitty gritty of it. Once a rabid animal bites a human, the virus from the saliva of the animal enters the host’s body through bite punctures and starts multiplying at the site of the wound. Rabies is a neurotropic virus, which means it has an affinity towards nerve tissue where it can thrive more efficiently. Once inside the host, it starts replicating in minimal numbers, so as to survive without alerting the host’s immune system of its presence. This way, it slowly sneaks its way from the nerve tissues through the spinal cord and into the brain by crossing the blood-brain barrier (BBB).
Once inside the brain they multiply very quickly without any threat, as the virus neutralizing antibodies that the immune system produces are stopped by the BBB from entering the brain. So much for antibodies being the heroes. At this stage, the virus extends into the salivary glands and into the host’s saliva, eager and ready for its next victim. Very convenient, isn’t it? Hereon, it is full steam ahead for the rage virus, which loosely translates to mayhem for the host as the virus attacks the protein in the neural cells, causing symptoms like agitation, hallucination, hydrophobia and even paralysis before invariably causing death, unless treated immediately. This is also the reason why the distance of the bite from the head of the host is considered crucial for effective treatment, as it is directly proportional to the time it takes for the first of symptoms to appear. This period is also called the incubation period, which is normally 3 to 12 weeks but can also last as little as 5 days or extend to as long as 2 or more years.
The farther the wound is from the brain, the longer the virus takes to reach it, where it flourishes before infecting the rest of the organs, which means the available time for effective treatment is relatively longer. The stage where the virus successfully infects other organs is when the immune system is finally tipped off and in its defence, it does start fighting with all its might, but sadly by then, it is too late and there is little that the warriors can do to help the host recover. Noticeable symptoms in both animals and humans depend and sometimes overlap based on the type of rabies they develop.
Wait, there are types? Tell me more.
There are two types of rabies:
Furious or Encephalitic rabies - This type of rabies occurs in 80% of reported cases and normally brings about very violent or aggressive behavior in animals and humans.
Paralytic or ‘dumb’ rabies - This is the less common type where the infected animal or human succumbs to organ failure through predominant symptoms of paralysis and acute limb failure.
What are some symptoms common to humans and animals?
Acute behavioural changes such as increased agitation and irritability
Excess salivation
Lethargy
Paralysis
Aversion to water or hydrophobia
Unusual sensitivity to light and temperature changes in the environment
Symptoms observed specifically in humans
Early flu-like symptoms during and after the incubation period, including but not limited to fever, headache, sore throat and cough, nausea/vomiting, anxiety and discomfort at the site of the wound
Dilation of pupils
Seizures
Hallucinations
Confusion
Hyperventilation and difficulty breathing
Diagnosis
Usually, waiting for a diagnosis of rabies is highly discouraged, as by the time symptoms appear, it may be too late to save the animal or the individual. If you suspect exposure to the virus by any means, immediate treatment is imperative. Confirmatory diagnosis may be carried out in animals post-mortem.
Preventative Care
Rabies is one hundred percent a preventable disease and some mindful practices can save us from experiencing and losing to the horror that it is.
Stray dogs are the most common source of rabies for human infections in India and ensuring that dogs, both strays and pets are vaccinated timely is the most cost-effective way of preventing the disease from infecting dogs and thus, humans too.
Preventative human vaccine (same as the one used post exposure) is available and if you are a person who regularly interacts with stray animals for any reason, it is highly recommended that you are administered this beforehand.
Awareness campaigns help in enlightening the public about the pain and tragedy associated with contracting this deadly virus and educating people on how to safely interact with stray animals minimises risks of possible bites and scratches.
I was bitten by an animal, am I at risk of contracting rabies?
You really don’t want to be waiting to know if the animal that bit you was rabid or not, since that means you lose precious time that could be spent saving your - yes, you guessed it right - life!
If any animal bites you or any of your pets, it is highly imperative that you do the following in a very timely manner.
Wash the site of the bite immediately with soap and water for at least 15 minutes. If you or your pets are by any chance exposed to the virus through the bite, doing this can reduce the risk of infection by killing the load of virus at the entry site.
Visit your doctor right away to receive Post-exposure prophylaxis - the immediate treatment available after rabies exposure. Post-exposure prophylaxis usually entails administration of a course of potent rabies vaccine, followed by multiple courses of the rabies immunoglobulin (RIG) to strengthen your immune system to fight off the virus.
Ninety-five percent of rabies cases in India are caused by infected stray dogs and hence rabies prevention is truly a community effort where people should come together to ensure that their pet animals as well as their neighborhood dogs are vaccinated. At The Pawsome People Project, we routinely schedule vaccination drives to address rabies cases region-wise across the city. Join our Anti-Rabies Team today and play a key role in keeping your community residents, animals and humans alike, safe from rabies.