News

Rabies, one of the world’s oldest, most lethal diseases

Know as much as possible about this deadly affliction

Wednesday, September 25 2013

Rabies has been around for over 3 000 years, making it one of the oldest known infectious diseases. Yet, according to the World Health Organization, this viral disease is still responsible for more than 55 000 human deaths each year. Put differently, one person dies every 10 minutes as a result of rabies.

Closer to home, a communiqué by the National Institute of Communicable Diseases (NICD) stated that seven laboratory-confirmed and two probable cases of rabies in humans have been reported so far this year, compared to ten cases in 2012.

Dr Pete Vincent of Netcare Travel Clinics and Medicross Tokai Family Medical and Dental Centre says people should know as much as possible about this disease. He points out that while rabies cases were reported in all provinces, it is more prevalent in KwaZulu-Natal, Limpopo and the Eastern Cape. Figures published by the NICD for the last decade (2003 to 2013), list 51 human rabies cases in KwaZulu-Natal, 40 in Limpopo, 31 in the Eastern Cape, six in Mpumalanga, four in the Free State, two in the North West and one in the Northern Cape.

Dr Vincent added that it is generally believed that rabies is more widespread than assumed, as the condition tends to go unreported in rural and poorer communities where it is less likely to be recognised. While rabies cases are unusual in suburban areas, they do occur. Most deaths occur in developing countries in Africa and Asia with some 44% of all rabies deaths occurring in Africa.

Rabies is transmitted by infected animals. In South Africa the main hosts are dogs, yellow mongeese, black-backed jackals and bat-eared foxes. The virus is spread through the saliva of these animals, either when they bite, or when their saliva comes into contact with an open wound or the eyes, nose or mouth of an individual through licking. The rabies virus is introduced into the muscle and nerve ending-rich tissues from where it penetrates the nerve cells, reproduces and spreads to the spinal cord and brain.

Depending on the distance of the bite site from the brain, it can take weeks or even months before symptoms appear. In untreated patients replication of the virus in the brain causes hydrophobia, (difficulty in swallowing and panic when presented with liquids to drink, resulting in an inability to quench thirst), hallucinations, aggressive behaviour and paralysis in patients that can ultimately lead to coma and death. The virus also spreads to the salivary glands, skin, corneas, nasal and intestinal mucosa and other organs, including the kidneys.

Dr Vincent notes that animals infected with rabies often undergo behavioural changes. For example, a wild animal may suddenly lose his fear of humans while a docile house animal could become aggressive. This goes hand-in-hand with severe salivation, jaw paralysis, uncoordinated movements and abnormal sounds. Sometimes infected animals may also foam at the mouth. It is advisable to stay away from stray dogs or any animal displaying aggressive tendencies or strange behaviour. Vaccinating domestic animals against the disease and keeping vaccinations up-to-date are imperative, as this will prevent pets from becoming infected if bitten by a rabid animal.

Dr Vincent points out that a rabies vaccine is available which is only recommended for travellers who have a strong possibility of coming into contact with rabid dogs or animals such as bats, which are quite commonly infected. Travelling to certain countries in Africa and Asia poses a higher risk and it is therefore important to check with your travel clinic whether you should have a rabies vaccination before your trip. The vaccine is also recommended for individuals who work in high-risk occupations, such as veterinarians, animal handlers and game park rangers.

There was a time when an individual who was infected with rabies faced certain death, but today the disease can be treated with post-exposure prophylaxis. However, it is vital that an infected person seek medical attention as soon as possible. If post-exposure prophylaxis is not taken soon after infection, the person may still develop the illness and may well die from it.

“More education about rabies, particularly in rural and poorer areas where it tends to be more common, is urgently needed. Education will assist people in identifying animals carrying the disease and staying away from them. It would also help to ensure that anyone who has been exposed to a rabid animal knows that it is essential to seek medical treatment promptly,” concludes Dr Vincent.

 

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Issued by: Martina Nicholson Associates (MNA) on behalf of Netcare Travel Clinics and Medicross
Contact: Martina Nicholson, Graeme Swinney or Sarah Beswick
Telephone: (011) 469 3016
Email: [email protected], [email protected] or [email protected]