What is Rift Valley Fever, what are the symptoms, can it be transmitted from animals to humans and does it cause birth defects?
The viral disease is most common in domesticated animals like cattle, sheep and goats but can infect humans
FIRST reported in livestock in Kenya's Rift Valley in 1931, Rift Valley Fever (RVF) is a viral disease that usually affects domesticated animals like cattle, buffalo, sheep, goats and camels.
But what does the disease do, where is it most common and can humans become infected with it? Here's everything you need to know.
What is Rift Valley Fever and what does it do?
RVF is a viral disease most commonly found in livestock.
It is a member of the Phlebovirus genus and causes a high fever and severe disease in infected animals.
The virus has an incubation period (the time it takes from infection to first signs and symptoms) of two to six days.
An animal infected with RVF would likely have severely deformed offspring, a case of a lamb being born severely deformed in South Africa prompted superstitious villagers to believe the bestial creature was sent by the devil.
As a result of such deformities, there is a massive economic impact when livestock get infected with the disease as farmers loose money due to deaths and abortions.
Outbreaks in livestock are called "epizootics", the most notable of which occurred in 1950-52 in Kenya - over 100,000 sheep died as a result.
Where is RVF most commonly found?
River Valley Fever is most commonly found in eastern and southern regions of Africa in areas where livestock are raised.
However, the virus does also exist in most of sub-Saharan Africa, including West Africa and Madagascar.
There have been no reported cases of RVF in the UK to date.
Can it be transmitted to humans?
River Valley Fever can effect humans as well as live stock.
The disease can be transmitted through exposure to the blood, bodily fluids or tissue of infected animals.
There is also a chance that a mosquito or other human-biting insect carrying the disease can infect a human.
You are at risk of contracting River Valley Fever if you are spending time in rural areas and sleeping outdoors at night in regions where outbreaks have occurred.
Vets, farmer, abattoir workers and others who work with animals in areas where the disease is, have a much higher risk of becoming infected.
Travellers also increase their chances of infection if they travel to areas that have recently experienced an outbreak.
To date there has been no reported human to human transmission of the disease.
What are the symptoms for humans suffering with Rift Valley Fever?
In it's early stages the disease presents with symptoms that are similar to that of a cold or mild flu.
The infected person is likely to experience a sudden onset of fever, muscle pain, joint pain and headaches.
Some develop neck stiffness, sensitivity to light, loss of appetite and vomiting, in the early diagnosing process these symptoms can often be confused with meningitis.
The symptoms usually last for about four to seven days, after which the immune systems response (sending anti-bodies to fight the virus) is visible in the blood.
Is there a cure for RVF?
Outbreaks in animals can be prevented through a continued programme of vaccinations, but treatment is often limited once they are infected.
Most human cases of River Valley Fever are mild and the immune system eradicates the disease from the system.
There is no one treatment for the infection, but the complications it can cause are treated.
A small number of humans can get a more severe form of the disease. The World Health Organisation say:
"This usually appears as 1 or more of 3 distinct syndromes: ocular (eye) disease (0.5–2% of patients), meningoencephalitis (less than 1% of patients) or haemorrhagic fever (less than 1% of patients)."
The most common complication with RVF in humans is inflammation of the retina (the part of the eye which connects the nerves and the brain), as a result severe cases of the virus can cause permanent loss of vision in one or both eyes.
The Centre for Disease Control and prevention estimates that one per cent of humans infected with RVF will die as a result of the disease.
The fatality rate in animals is a lot higher.
