What is rabies?
Rabies is a disease transmitted from animals to humans, which is caused by a virus. There are two clinical manifestations of rabies – frantic and paralytic.
Frantic rabies is most common form of human rabies.
Early symptoms can include fever and tingling at the site of exposure.
These symptoms are followed by one or more of the following symptoms:
violent movements,
uncontrolled excitement,
fear of water,
an inability to move parts of the body,
confusion, and
loss of consciousness.
Once symptoms appear, the result is nearly always death.
The time period between contracting the disease and the start of symptoms is usually one to three months; however, this time period can vary from less than one week to more than one year.
The time is dependent on the distance the virus must travel to reach the central nervous system.
It is caused by lyssaviruses, including rabies virus and Australian bat lyssavirus.
It spreads when an infected animal scratches or bites another animal or human.
Saliva from an infected animal can also transmit rabies if the saliva comes into contact with the eyes, mouth, or nose.
What should not be done with an animal bite wound?
Avoid:
●Applying irritants to the wound such as chilli
powder, plant juices, acids or alkalis.
●Covering the wound with dressings or bandages.
How does rabies develop in humans?
After entering the human body, the rabies virus progresses from the innermost layer of tissue below the human skin (called subcutaneous tissue), or from muscle, into peripheral nerves (i.e. the nerves in the body which are outside the brain or spinal cord).
The virus migrates along nerves to the spinal cord and brain at an estimated speed of 12–24 mm a day.
The infected person exhibits behavioural changes and clinical signs when the virus reaches the brain. The incubation period ranges from a few days to several months, and can be as long as 1 year.
Globally, dogs are the most common animal involved.
More than 99% of rabies cases in countries where dogs commonly have the disease are caused by dog bites.
In the Americas, bat bites are the most common source of rabies infections in humans, and less than 5% of cases are from dogs.
Rodents are very rarely infected by it.
The virus travels to the brain by following the peripheral nerves. The disease can only be diagnosed after the start of symptoms.
Animal control and vaccination programs have decreased the risk of the virus from dogs in a number of regions of the world.
Immunizing people before they are exposed is recommended for those who are at high risk.
The high-risk group includes people who work with bats or who spend prolonged periods in areas of the world where it is common.
In people who have been exposed to rabies, the rabies vaccine and sometimes rabies immunoglobulin are effective in preventing the disease if the person receives the treatment before the start of rabies symptoms.
Washing bites and scratches for 15 minutes with soap and water, povidone iodine, or detergent may reduce the number of viral particles and may be somewhat effective at preventing transmission.
Only five people have survived a rabies infection after showing symptoms, and this was with extensive treatment known as the Milwaukee protocol.