Rift Valley Fever in Africa

Update:  May 16, 2007

The Public Health Agency of Canada (PHAC) is monitoring outbreaks of Rift Valley Fever in the countries of Kenya, Somalia, and the United Republic of Tanzania in Africa.  There are specific precautions that travellers can take to reduce their risk of contracting Rift Valley Fever – see 'Recommendations' below.

Kenya - From November 30, 2006 to March 12, 2007, a total of 684 cases including 155 deaths of RVF were reported in Kenya.  Cases were reported in:  North Eastern Province (333 cases), Rift Valley Province (183 cases), Coast Province (141), Central Province (14 cases), and Eastern Province (13 cases). Of the 684 reported cases, 234 (34%) were laboratory confirmed.

Somalia - From December 19, 2006 to February 2007, a total of 114 cases including 51 deaths of Rift Valley Fever were reported in the following regions of Somalia:  Lower Juba (73 cases), Gedo (26 cases), Hiran (7 cases), Middle Shabelle (4 cases),  Middle Juba (2 cases), and Lower Shabelle (1 case).  Of the 114 reported cases, 3 (3%) were laboratory confirmed.  During the outbreak response, the difficult security situation has continuously hampered surveillance and control activities in the affected areas.

United Republic of Tanzania - From January 13 to May 3, 2007, a total of 264 cases including 109 deaths of Rift Valley Fever (RVF) were reported in 10 of Tanzania's 21 regions.  The majority of cases were reported in: Dodoma (156 cases), Morogoro (50 cases), Singida (24 cases), and Arusha (12 cases).  Of the 264 cases, 154 (60%) were laboratory confirmed.  Only severe cases of RVF were detected through surveillance

Source: World Health Organization (WHO)

Rift Valley Fever

Rift Valley Fever (RVF) is a virus that primarily affects domestic animals including cattle, goats, and sheep. The virus can be transmitted to humans through the bite of an infected (day-time or night-time biting) mosquito and possibly other biting insects that have virus-contaminated mouthparts or through contact with blood or body fluids of infected animals. Exposure can occur through the slaughtering and handling of infected animals or through the preparation of meat or ingestion of raw milk from infected animals.

The virus exists in most countries of sub-Saharan Africa and in Madagascar; however, outbreaks have tended to occur more often in the eastern and southern areas of the continent. In 1997-98, a major outbreak occurred in Kenya and Somalia. In September 2000, outbreaks were reported in Saudi Arabia and Yemen; this was the first time RVF had been reported outside the African Continent.

Symptoms of RVF primarily range from no symptoms to a mild flu-like illness with the sudden onset of fever and most individuals recover within two days to one week following the onset of illness. While the majority of human cases are relatively mild, a small proportion of patients develop much more severe manifestations of the disease - including haemorrhagic fever, meningoencephalitis (swelling of the brain), or ocular diseases. Approximately 1% of human cases of RVF are fatal.

Recommendations for travellers

At this time, travellers to the affected regions in Kenya, Somalia, and the United Republic of Tanzania are at increased risk of infection with RVF.  There is no specific treatment for Rift Valley Fever, and no vaccine for humans, but travellers can take the following precautions to reduce their risk of infection:

Use personal insect protective measures to avoid insect bites. Comprehensive information on insect-bite avoidance is detailed in the Committee to Advise on Tropical Medicine and Travel's “Statement on Personal Protective Measures to Prevent Arthropod Bites”.

Avoid contact with domestic animals such as cows, goats and sheep and take the necessary precautions to avoid coming into contact with the blood, organs or body fluids of such animals.

Avoid ingesting raw (unpasteurized) milk and milk products.

As a reminder…

The Public Health Agency of Canada strongly recommends that Canadian travellers consult their personal physician or a travel clinic four to six weeks prior to international travel, regardless of destination, for an individual risk assessment to determine their individual health risks and their need for vaccination, preventative medication, and personal protective measures.

The Public Health Agency of Canada recommends, as well, that travellers who become sick or feel unwell on their return to Canada should seek a medical assessment with their personal physician. Travellers should inform their physician, without being asked, that they have been travelling or living outside of Canada, and where they have been.

Additional information

• World Health Organization - Rift Valley Fever
• World Health Organization - Flooding emergency in the Horn of Africa
• Foreign Affairs and International Trade Canada Travel Report on Kenya