Health Professionals

Clinical Updates

7 May 2010

Rift Valley fever – human cases in South Africa - update

On 3 May 2010, a case of Rift Valley fever (RVF) was reported in a German tourist returning from South Africa [1,2].

The tourist, a 50 year old woman, travelled along the coast between Port Elizabeth in the Eastern Cape and Cape Town in the Western Cape, between 17 March and 8 April 2010. During her stay she visited rural areas and game reserves. The traveller became unwell with fever, headache and a rash on 7 April 2010 and RVF was confirmed on her return to Germany. She did not require hospitalisation. Her three travel companions have reported similar symptoms.

In February 2010, the first laboratory confirmed outbreak of RFV in animals was identified in Free State province. Cases have since been reported in several other provinces of South Africa [3]. A map of the RVF outbreak in animals is available on South Africa’s National Institute for Communicable Diseases website

As of 3 May 2010, a total of 172 human cases of RVF and 15 deaths have been reported in South Africa since the outbreak began in February 2010 [3].  The majority of cases have been reported in Free State, but cases have also occurred in Northern Cape, Eastern Cape, North West province and Western Cape [3]. Most of the cases have had direct contact with infected livestock.  


Rift Valley fever

RVF is a viral disease that primarily affects cattle, goats and sheep, but can also infect humans. RVF virus is a virus of the family Bunyaviridae [4]. Infection can cause severe disease in animals, leading to high rates of illness and death.

The virus is transmitted to humans through contact with body fluids or organs of infected animals, or following a bite from an infected mosquito (most commonly Aedes spp and Culex spp mosquitoes).

The majority of cases of RVF in humans are asymptomatic or mild consisting of a self-limiting, febrile illness. About one percent of patients will develop severe manifestations including meningoencephalitis or haemorrhagic complications.

Advice for travellers

The risk of RVF remains low for tourists. However, all travellers to South Africa are advised to take insect bite avoidance measures such as using insect repellents. This is particularly important for travellers visiting rural areas and game reserves. Travellers should not consume milk or meat from potentially infected animals. Those who may have contact with infected animals should ensure that appropriate personal protection measures are taken to prevent exposure to their blood and body fluids. There is no commercially available vaccine against RVF for humans.

Information on specific health risks for travellers to South African can be found on the NaTHNaC Country Information Pages.

References

1. Robert Koch Institute. Rift Valley fever infection imported from South Africa [in German]. Epidemiologisches Bulletin. 3 May 2010; No 17: 158-9. [Accessed 6 May 2010]. Available at: http://www.rki.de/cln_151/nn_1759378/DE/Content/Infekt/Epid

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2. World Health Organization. Rift Valley fever in South Africa – update. 4 May 2010. [Accessed 6 May 2010]. Available at: http://www.who.int/csr/don/2010_05_04a/en/index.html

3. National Institute for Communicable Diseases. Preliminary report on an outbreak of Rift Valley fever, South Africa, February to 3 May 2010. Communicable Disease Communiqué. May 2010, vol 9, No.5. [Accessed 6 May 2010]. Available at: http://www.nicd.ac.za/

4. World Health Organization. Rift Valley Fever fact sheet. Revised May 2010. [Accessed 6 May 2010]. Available at: http://www.who.int/mediacentre/factsheets/fs207/en/index.html

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