Rift Valley Fever – Causes, Symptoms, Treatment, Prevention

What is Rift Valley Fever?

Rift Valley Fever (RVF) is a viral infection that can be transmitted from animals to humans. A 2010 Rift Valley Fever outbreak in South Africa has triggered concern about an epidemic similar to the 2009 H1N1 swine flu scare. This infection, however, is a low grade condition and death is not common, occurring in less than 2% of patients infected with RVF. South Africa has experienced a previous outbreak in the mid 70s but the current RVF cases are receiving widespread media  attention and contributing to unnecessary public fears.

Causes of Rift Valley Fever

The Rift Valley Fever virus belongs to the Bunyaviridae family of viruses and usually affects livestock like cattle, sheep and goats. Infected animals often experience stillbirths or miscarriages and the infections are usually fatal in young animals. The virus is transmitted among livestock by mosquitos and while human transmission via this route is possible, it is not common.

Humans are infected when they come in contact with animal tissue and this is predominantly seen in people involved with animal husbandry (animal birth/delivery). Any person involved with animal slaughter is also at risk of contracting RVF. Eating the infected meat, especially if it is inadequately cooked, or drinking unpasteurized milk from an infected animal can also result in the spread of RVF from animals to humans.

Symptoms of Rift Valley Fever

The signs and symptoms of RVF is similar to those of the seasonal flu (influenza). Fever is by far the most common symptom and the following may also be present :

• Headaches.
• Malaise or fatigue.
• Body aches and joint pains.
• Lack of appetite.

RVF often presents with eye symptoms and an infected person may complain of poor or blurred vision. This should not be confused with conjunctivitis (pink eye) since RVF affects the retina and not the conjunctiva.

Other severe symptoms may include bleeding (haemorrhagic fever – vomiting of blood, blood in the stool or bleeding from the skin), encephalitis, meningitis, and/or jaundice (yellow discolouration of the skin and conjunctiva). RVF can be fatal but this more often occurs in immunocompromised patients like in cases of HIV/AIDS and those with poorly managed chronic conditions.

Treatment of RVF

There is not specific treatment for RVF and antivirals may not be effective. Always speak to your doctor about supportive treatment while your body recovers from the infection. Bed rest, plenty of fluids and a healthy diet is important but if the symptoms are persisting and the condition worsening, emergency medical treatment may be necessary.

The flu-like signs and symptoms usually persist for 4 to 7 days but the eye symptoms can present for up to 3 months. Blood tests to confirm Rift Valley Fever is not routinely conducted but it is available if necessary.

Prevention, Vaccination and Quarantine

There is no RVF vaccine available and it is unlikely that mass vaccination will be necessary due to the low mortality rate. Quarantine is also not necessary as there has been no cases of human to human transmission of Rift Valley Fever The best methods to prevent RVF is to :

• Practice good hygiene especially if you handle livestock or raw meat.
• Avoid eating meat from sick animals or animals that have died from unknown causes.
• Do not drink unpasteurized milk and be cautious of milk products from unknown suppliers.