Vaccinate against Rift Valley Fever

Although rain is a blessing for farmers, it can bring with it an increased risk of animal diseases.

Following the good rains that have recently fallen over parts of the country, the Department of Agriculture, Land Reform and Rural Development has warned that an increase in the number of mosquitoes that transmit Rift Valley Fever (RVF) can be expected.

RVF is a serious viral disease. Although it primarily affects animals, humans can also be infected. Signs to look for in animals include unexplained abortion and death,  especially in young cattle, sheep and goats.

A widespread RVF outbreak last occurred in South Africa in 2010-2011. According to the National Institute for Communicable Diseases, over 14 000 animal cases and 278 human cases were recorded, of which 25 were fatal.

People can get infected if they come into contact with blood and other body fluids from infected animals, or if they assist with abortions and handle infectious aborted material, like foetuses, placentas and placental fluids.

It is critical that any suspected cases be immediately reported to the nearest State Veterinarian.

Signs and symptoms in humans

The illness is mild in the vast majority of infected persons, with severe cases occurring in less than one percent of infected persons.

• The incubation period (interval from infection to onset of symptoms) for RVF varies from two to six days.
• Symptoms include sudden onset of flu-like fever and/or muscle pain, possible neck stiffness, sensitivity to light, loss of appetite and vomiting.
• Symptoms of RVF usually last from four to seven days, after which time the immune response becomes detectable and the virus gradually disappears from the blood.
• Severe RVF symptoms in humans include vision disturbances, intense headaches, loss of memory, hallucinations, confusion, disorientation, vertigo, convulsions, lethargy and coma and haemorrhagic fever.

Cattle, sheep and goats must be vaccinated against RVF, especially in areas that have recently received good rainfall.

Live vaccine can only be used on non-pregnant animals as it can cause abortions.  Dead/inactivated vaccine must be used on pregnant animals.

To enquire about disease control and how to keep your livestock healthy, contact Mariétta Bronkhorst at 012 319 7481 or email mariettaB@daff.gov.za.