This disease is named for the Rift Valley in Kenya where it was discovered
ame
Rift Valley fever
Transmission
- A severe mosquito-borne disease that primarily affects animals but can also infect humans
- The virus is most commonly found in animals such as camels, goats, cattle, sheep, and buffalo
- Humans get infected in three ways:
- Bites from infected mosquitoes
- Exposure to the body fluids, blood, or tissues of infected animals. This is common when people are involved in caring for animals (veterinary services) or animal slaughter
- Ingesting unpasteurized or uncooked milk from infected animals
- Person-to-person transmission has never been recorded
Geography
Sub-Saharan Africa, Yemen, and Saudi Arabia
Incubation Period
2 – 6 days after infection
Signs and Symptoms
Most people infected do not have any symptoms, or have mild symptoms lasting 2 – 7 days including:
- Fever
- Headache
- Neck stiffness
- Joint pain
- Muscle pain
- Vomiting
- Loss of appetite
- Sensitivity to light
8 – 10% of those infected develop more severe syndromes:
- Ocular: Eye diseases with symptoms such as eye lesions and blurred/decreased vision
- About 50% of patients with these symptoms will have permanent vision loss, but death is rare with this form of the disease
- Encephalitis: Brain inflammation which can lead to headaches, coma, seizures, loss of memory, hallucinations, confusion, disorientation, vertigo, convulsions, lethargy, and in rare cases persistent neurological deficits
- Death with this form of the disease is also rare
- Hemorrhagic fever: Symptoms include vomiting blood, passing blood in the feces, rash/bleeding in the skin, bleeding from the nose or gums
- Occurs in less than 1% of patients but has a 50% fatality rate
Diagnosis
Laboratory testing of blood samples
Treatment
- There is no vaccine or specific treatment
- Most patients receive supportive therapy for their symptoms
Prognosis
- Typically, patients recover within two days to one week after onset of illness
- 1 – 10% of patients may have permanent blindness
Prevention: What Can You Do?
- Animals can be vaccinated against Rift Valley fever
- Humans should avoid unnecessary, close contact with animals and their body parts and should always make sure to reduce the chances for mosquito bites (wear light colored, long clothing; use mosquito repellent; sleep under mosquito nets, etc.)
Rift Valley Fever In the News
- Rift Valley Fever outbreak kills 21 in western Niger
- Outbreak: Rift Valley Fever reported in Niger, Mali
Sources:
https://www.cdc.gov/vhf/rvf/
http://www.who.int/mediacentre/factsheets/fs207/en/
