1 February 2007

Rift Valley fever in Kenya and Somalia - update

Kenya

As of 30 January 2007, the Kenyan Ministry of Health have reported 411 suspected cases of Rift Valley fever (RVF), including 121 deaths [1]. Of these cases, 131 have been confirmed. The outbreak is now thought to be in decline, although cases continue to be reported. The most affected districts are Garissa and Ijara districts in North Eastern province with 175 and 125 cases respectively. Cases have also been reported in Wajir district in North Eastern province, Tana River, Kilifi, Malindi and Taita Taveta districts in Coast province, Isiolo district in Eastern province and Kirinyanga, Kajiado, Maragua and Thika districts in Central province [1].

The Kenyan Ministry of Health are coordinating a multidisciplinary team to respond to the outbreak. Enhanced surveillance is on-going with active case searching and information for health care workers [2]. There has been veterinary intervention, with over 8000 animals vaccinated so far [3], and bans on animal slaughter and movement controls put in place. Public health education, including the provision of mosquito nets, has been initiated and vector-spraying is being carried out [2].

Somalia

On 31 January 2007, the World Health Organization reported the presence of Rift Valley fever in Somalia. As of 30 January 2007, 100 suspected cases have been reported from the provinces of Gedo, Hiiraan, Lower Juba (Jubbada Hoose), Middle Juba (Jubbada Dhexe), Lower Shabele (Shabeellaha Hoose) and Middle Shabele (Shabellaha Dhexe). Of these cases there have been 48 deaths reported. Although only one case of RVF in Somalia has been confirmed, Médecins sans Frontières are now involved in the transport of samples to laboratories and therefore more confirmed cases are expected. The WHO country office has held training sessions in case detection and disease control for Somali medical officers, however, the deteriorating security situation in Somalia is hindering efforts [1].

Rift Valley Fever

RVF is caused by a virus of the family Bunyaviridae. It is primarily a zoonosis affecting domestic animals including cattle, goats, and sheep, and may cause substantial morbidity and mortality in the animals. The virus can be transmitted to humans following a bite from an infected mosquito (most commonly Aedes spp and Culex spp mosquitoes), or contact with body fluids or organs from an infected animal.  

The majority of cases of RVF are brief influenza-like illnesses; about 1% of patients will, however, develop more severe manifestations of meningoencephalitis or haemorrhagic fever.

Advice for travellers

Vigilant insect bite avoidance measures should be taken to avoid exposure to the mosquito vector. Those who may have contact with infected animals should ensure that appropriate measures are taken to prevent exposure to their blood and body fluids. There is no commercially available vaccine for humans.

References

1. World Health Organization. Rift Valley fever in Kenya and Somalia - Update 3, 31 January 2007. [Cited 1 February 2007]. Available at: http://www.who.int/csr/don/2007_01_31/en/index.html

2.  Ministry of Health, Kenya. Rift Valley fever - What you need to know about Rift Valley fever, 7 January 2007. [Cited 30 January 2007]. Available at: http://www.health.go.ke/

3. World Health Organization. Rift Valley fever in Kenya - Update 2, 15 January 2007. [Cited 30 January 2007]. Available at: http://www.who.int/csr/don/2007_01_15a/en/index.html

Links

World Health Organization. Rift Valley Fever fact sheet. Revised September 2000. [accessed 31 January 2007] Available at http://www.who.int/mediacentre/factsheets/fs207/en/index.html

Centers for Disease Control and Prevention. Rift Valley Fever. [accessed 31 January 2007]. Available at: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/rvf.htm