What do I need to know about Rift Valley fever?
Rift Valley fever is a disease caused by a virus. It is a zoonotic disease, which is a disease that passes between animals and people.
Rift Valley fever infects animals, most commonly cows and sheep, but can also infect people.
It is most common in South Africa, East and West Africa, the Arabian Peninsula, and Egypt.
In people, the virus is usually mild but rarely it is severe and even fatal.
How do people get Rift Valley fever?
Mosquitoes carry the virus. Livestock, including cows and sheep, get the virus through bites from infected mosquitoes.
People get Rift Valley fever mainly from contact with infected animals. For example, by handling infected meat, blood, or milk. People can also get infected from:
Eating or drinking raw or undercooked animal products
An infected mosquito's bite
Farmers, slaughterhouse workers, and veterinarians are at increased risk because of their contact with animals. People in areas where Rift Valley fever regularly occurs or during an outbreak are more at risk.
Rift Valley fever is not known to spread from person to person.
How does Rift Valley fever affect people’s health?
Some people never get symptoms from a Rift Valley fever infection.
In people who do have symptoms, the symptoms start 2 to 6 days after they get infected. Symptoms can be mild or severe. For most people, Rift Valley fever is mild. But Rift Valley fever is deadly in people who develop bleeding.
Mild symptoms include:
Fever
Headache
Muscle pain
Joint pain
Severe symptoms include:
Eye problems, including blurry vision or even blindness
Swelling in the brain
Pregnancy loss (also called miscarriage or spontaneous abortion)
Bleeding (for example, vomiting blood, having blood in stool, bleeding from gums and nose)
How is Rift Valley fever treated?
Most people with Rift Valley fever have mild symptoms that go away in 2 to 7 days without treatment. Medications (ibuprofen or acetaminophen) can help reduce fever and muscle and joint pain. Most people with Rift Valley fever have mild symptoms that go away in 2 to 7 days without treatment. Medications (ibuprofen or acetaminophen) can help reduce fever and muscle and joint pain.
People with severe symptoms may need to go to the hospital for fluids and pain medication.
How does Rift Valley fever affect animals' health?
Rift Valley fever can be very severe in animals, specifically young lambs and calves. Young infected animals may:
Have fever
Act tired
Stay still
The disease is generally less severe in adult sheep and cattle.
Adult female animals who are pregnant and infected often lose the pregnancy. Many livestock animals losing a pregnancy often occurs in an area before any infection in a person is reported.
Other animals including camels, horses, pigs, cats, and dogs can become infected but generally only have mild symptoms and survive.
Birds and reptiles do not appear to get Rift Valley fever.
Does Rift Valley fever cause a risk to food safety or supply?
Rift Valley fever poses a significant risk to both food safety and food supply, especially in regions where the virus is spreading.
How is a Rift Valley prevented in animals?
Vaccinating animals is the only effective way to protect livestock from Rift Valley fever.
After an outbreak has started, efforts to slow down the spread of the virus among animals are generally not effective.
How can you protect yourself from Rift Valley fever?
People in areas with Rift Valley fever should:
Avoid contact with infected animals, including their blood and meat.
If working with animals, wear gloves, boots, long sleeves, and a face shield.
Thoroughly cook all animal products, including meat, milk, and blood, before eating or drinking them.
Avoid mosquito bites by using mosquito nets, insect repellents, or long-sleeved shirts and pants.
Where can I learn more about Rift Valley fever?
Centers for Disease Control and Prevention (CDC): Rift Valley fever
World Health Organization (WHO): Rift Valley fever
