Rift Valley Fever (RVF) is a mosquito-borne disease. It is an acute condition that affects domestic ruminants (cattle, sheep, camels, and buffalo). Humans can also contract this illness. RVF is caused by a phlebovirus pathogen called Rift Valley Fever virus (RVFV). Animals that contract RVF suffer from abortive storms in pregnant females and high death rates in young animals. It impacts the economy due to severe production casualties.
The Occurrence
RVF outbreaks usually happen after flooding and heavy rainfall. These events create suitable breeding areas for female mosquitoes (Anopheles, Aedes, and Culex). Large numbers of infected eggs hatch simultaneously. This event triggers rapid viral infection among the mentioned livestock.
Humans contract the infection through mosquito bites. They can also get it by assisting with births and slaughtering livestock. Studies show that most RVF infections are mild. Yet, some individuals can develop severe versions of the disease. Some cases may also result in death.
These explosive RVF events can disrupt regional and local trade. They can also impact smallholders and pastoralists. Market closure can also happen. That is why anticipation and early treatment are imperative in preventing outbreaks.
Basic Facts
The following are basic facts about RVF:
- Animal vaccination can prevent outbreaks in livestock.
- RVF affects animals and humans.
- RVF is a viral disease.
- RVF’s incubation period is from two to six days.
- Humans can contract the disease through mosquito bites.
- There are no recorded transmissions among humans.
- Contact with infected animal organs and blood is the usual cause of illness in humans.
The Human Symptoms
RVF will incubate for about two to six days in your body. After this period, the symptoms will start to manifest. Headaches, flu-like fever, and joint and muscle pains begin to occur. Some infected individuals may develop vomiting, light sensitivity, a stiff neck, and loss of appetite. The early stages of RVF may be mistaken for meningitis.
The symptoms often last four to seven days. Then, your immune system responds. Antibodies appear and fight off the virus. The infection disappears from your blood. The following symptoms are evident in some patients who develop a severe form of RVF:
Hemorrhagic fever
This form occurs in fewer than 1% of patients. It appears two to four days after the symptoms begin. Severe liver dysfunction is the primary evidence. The patient will then experience bleeding from the gums or nose, purpuric rashes, blood in the feces, vomiting blood, and menorrhagia in females. Death often follows three to six days after the first appearance of symptoms.
Ocular
This form occurs in 0.5% to 2% of RVF patients. Mild symptoms occur. The retinal lesions appear about one to three weeks after the primary symptoms. A decrease or blurred vision is often telling. It may take 10 to 12 weeks for this RVF form to resolve itself. If the lesions affect the macula, 50% of the affected patients usually experience permanent vision loss.
Meningoencephalitis
Less than 1% of RVF patients experience this form. Its onset happens one to four weeks after the first RVF symptoms appear. Patients usually experience hallucinations, vertigo, memory loss, severe headache, coma, lethargy, and convulsions. Neurological complications may occur at least two months later. There is a low death rate in this RVF form. But it is common for severe neurological deficits to occur in patients.
Reducing the Risks
The following are ways to reduce the risk of contracting RVF:
- Do not consume raw animal tissue, blood, or milk
- Practice safe slaughtering and animal husbandry practices
- Always practice personal protection by wearing gloves and performing proper handwashing
- Use larvicidal techniques on mosquito breeding areas
- Use repellents and treated mosquito nets
- Stay inside during peak biting times of the day
- Wear light-colored clothing
Rift Valley Fever is usually mild in most cases. But some infected individuals can develop severe symptoms. The situation can then turn fatal. As always, prevention is the most ideal way to stay healthy. Protect yourself and your loved ones from this illness, which can come from mosquito bites, too.
