Infectious Diseases

28 September 2017

95% of human rabies deaths occur in Asia and Africa

Symptoms might not be present at first, but human rabies is almost always fatal. On World Rabies Day we take a closer look.

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Rabies is a fatal viral encephalitis (brain inflammation) that occurs in wild and domesticated mammals. This virus may also occur in humans.

Rabies is transmitted to humans through the bite saliva or scratches from of an infected cat or dog – domesticated or wild.

The South African National Travel Health Network (SaNTHNet) reports that rabies is present on all continents except Antarctica, and that 95% of human deaths from rabies is Asia and Africa.

Dogs are the main carrier and transmitter of the rabies virus. They are also the source of infection in around 50 000 annual human rabies deaths in Asia and Africa according to SaNTHNet.

Know the signs

The gestation period of rabies in humans is around one to three months but may vary from one week to one year.

SaNTHNet lists the symptoms of rabies as follows;

Initial symptoms:

  • Fever
  • Pain or unusual tingling, pricking or burning sensation (paraethesia) at the wound site

Progressed symptoms:

  • Virus spreads through the central nervous system (CNS)
  • Fatal brain inflammation of the spinal cord and brain occurs

Types of rabies

Two types of rabies may develop after the progressed symptoms of the virus.

Furious rabies encompasses bouts of hyperactivity, excited behaviour, hydrophobia (extreme or irrational fear of water), and sometimes aerophobia (extreme or irrational fear of flying). The person will most likely die of cardiac arrest after a few days.

The second type of rabies, paralytic rabies, accounts for around 30% of the total reported cases of rabies in humans.

This type of rabies often lives longer in the human body and only gradually brings about death.

The muscles of the infected person will gradually become paralysed from the wound site. The patient will slowly go into a coma, and eventual death.

Who is at risk?

Poor and vulnerable populations are at great risk for contracting rabies. According to the SaNTHNet rabies occurs mainly in remote and rural communities who do not have access to treatment and preventative measures such as vaccinations.

Exposure to rabid dogs still account for over 90% of worldwide human exposures to the rabies virus according to the Centers for Disease Control and Prevention (CDC).

Treatment

The rabies virus can often be removed at the side of the infection by physical or chemical means, according to SaNTHNet. Local treatment is important for all bites and scratches. Post-exposure prophylaxis (PEP) is recommended, depending on the type of contact with the infected animal.

But once the symptoms of rabies are present, it is nearly always deadly.

The rabies vaccine can prevent rabies. It is made from the killed rabies virus and is given to people who are at high risk.

CDC recommends that if you have been exposed to the rabies virus, you should be vaccinated as soon as possible regardless of any other illnesses that are present.

Image credit: iStock