15 October 2008

Arenavirus infection in South Africa and Zambia

Four people have recently been diagnosed with an arenavirus infection in Zambia and South Africa. The index case became ill in Zambia, and other cases are epidemiologically linked [1].

The index case was a woman working for a safari tour company and resident in Lusaka, Zambia [2]. On 12 September 2008 she was medically evacuated to a hospital in Johannesburg, South Africa for a severe febrile illness. She died on 14 September.

The second case was a paramedic who accompanied the woman during her evacuation to South Africa. On 27 September he was admitted to the same hospital in Johannesburg, where he died on 2 October. The third case was a South African nurse who cared for the index case in hospital and who became ill, and died on 5 October.  The fourth case is a nurse at the Johannesburg hospital who has become ill after caring for an earlier case and is currently undergoing antiviral treatment. No additional cases have been identified and contacts of cases in South Africa and Zambia are being traced.

Clinical symptoms common to all cases include a prodrome lasting about a week of fever, headache, diarrhoea, and myalgia, followed by acute illness with high fever, rash, deterioration and hepatic failure [2, 3]. 

The results of preliminary tests suggest that the causative agent of the disease is a virus from the Arenaviridae family [1]. Further analysis is being undertaken by both the National Institute for Communicable Diseases in South Africa and the Centers for Diseases Control and Prevention in the United States, to characterise the virus more fully. The World Health Organization and its partners are supporting the Ministries of Health in both Zambia and South Africa with the investigation of the outbreak.

Arenaviruses

Arenaviridae are one of several virus families that can cause viral haemorrhagic fever (VHF). Notable viruses causing VHF are Ebola and Marburg, of the Filoviridae family, and Congo Crimean Haemorrhagic Fever virus of the Bunyaviridae family. Arenaviruses are zoonotic and cause chronic infection in rodents. Humans can become infected from exposure to excretions of infected rodents such as urine. Arenaviruses can also be transmitted between humans through direct contact with blood, urine and other bodily secretions.

Advice for travellers

Investigations and contact tracing is continuing, but there have been no new cases identified in either South Africa or Zambia since 5 October 2008. Arenavirus infections in tourists are rare. Only six cases of Lassa fever, another arenavirus seen in West Africa, have been imported into the United Kingdom since 1976. These cases were in high risk individuals such as those working in the medical or aid sectors [4].

There are no travel restrictions to South Africa or Zambia, and no special measures are required from travellers arriving from either country.

Travellers should avoid contact with rodents and must use extensive personal protection measures if working in a healthcare setting (see links below).

Information on the general health risks for travellers to South Africa and Zambia can be found on the NaTHNaC Country Information Pages.

NaTHNaC will continue to monitor the situation and post further updates as appropriate.

  

References

1. World Health Organization. New virus from Arenaviridae family in South Africa and Zambia – update. 13 October 2008. [Accessed 14 October 2008]. Available at http://www.who.int/csr/don/2008_10_13/en/index.html

2. World Health Organization. Unknown disease in South Africa and Zambia. 10 October 2008. [Accessed 14 October 2008]. Available at http://www.who.int/csr/don/2008_10_10/en/index.html

3. National Institute for Communicable Diseases. Outbreak of acute disease, ex-Zambia. Communicable Disease Comuniqué. October 2008. 7:1, 2008. [Accessed 15 October 2008]. Available at http://www.nicd.ac.za/pubs/communique/2008/NICDSpecial

CommOct_alert01.pdf

4. Health Protection Agency. Lassa fever information sheet. Online resource. Available at http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/

HPAweb_C/1195733761194?p=1191942149574

Links

NaTHNaC Country Information Page for South Africa

NaTHNaC Country Information Page for Zambia

Health Protection Agency information on viral haemorrhagic fever

UK guidance on the management and control of haemorrhagic fevers has been written by the Advisory Committee on Dangerous Pathogens

Guidance for healthcare workers who will be working with VHF patients in African healthcare settings, has been written by the US Centers for Disease Control and Prevention (CDC) in conjunction with the World Health Organization