Published Date: 2010-12-02 19:00:05
Subject: PRO/AH/EDR> Rift Valley fever, livestock, human - Mauritania
Archive Number: 20101202.4332
RIFT VALLEY FEVER, LIVESTOCK, HUMAN - MAURITANIA
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Thu 2 Dec 2010
Source: Romandie, Agence France-Press report [in French, trans.
An outbreak of Rift Valley [fever] has erupted in the Mauritanian
town of Aoujeft (North), causing loss of life amongst people and
cattle, Mauritanian officials said Thursday [2 Dec 2010]. The
Independent press, quoting from official sources, speaks of 17 deaths.
"Cases of fever Rift Valley [fever] have caused losses of (human)
lives and of livestock," stated the Mauritanian News Agency (l'Agence
mauritanienne d'information, AMI), without specifying the total.
According to local independent media, the epidemic has already killed
17 people, and the sick were sent to hospitals including those in Nouakchott.
The Minister of Health and Interior visiting the region has given
strict instructions to the population of the Adrar (the region where
Aoujeft is situated) that they must refrain, in response to these
[Rift Valley] fever cases, from consuming locally produced meat and
milk, says AMI. These restrictions on meat and milk, 2 essential
commodities in the diet of the people, must last at least until the
investigation is finished and the results of laboratory tests
conducted since Thursday [2 Dec 2010] by veterinary specialists on
infected animals are confirmed says AMI.
Rift Valley fever is a disease that primarily affects animals but can
also infect humans. The infection can cause severe disease in both
animals and humans. The deaths and abortions in cattle infected with
the disease also result in substantial economic losses.
There is no specific treatment, and no human vaccine is available
against the disease, which is transmitted by mosquitoes and affects
mainly young men in contact with infected cattle.
Rift Valley fever bears the name of the region of Kenya where it was
identified in 1931. The disease has hit Kenya, Somalia and Tanzania
in the years 1967/68, and the last major outbreak was reported in
2000 in Yemen and Saudi Arabia [and Mauritania in 2003; see
ProMED-mail archive references below].
HealthMap Alerts via
[Mortality on this scale is unusual for local outbreaks of Rift
Valley fever. The text of this press report suggests that a precise
diagnosis has still to be confirmed. Further information is awaited.
Rift Valley fever (RVF) is a viral zoonosis that primarily affects
animals but also has the capacity to infect humans. Infection can
cause severe disease in both animals and humans. The disease also
results in significant economic losses due to death and abortion
among RVF-infected livestock.
RVF virus is a member of the _Phlebovirus_ genus, one of the 5 genera
in the family _Bunyaviridae_. The virus was 1st identified in 1931
during an investigation into an epidemic among sheep on a farm in the
Rift Valley of Kenya. Since then, outbreaks have been reported in
sub-Saharan and North Africa [Mauritania]. In 1997-98, a major
outbreak occurred in Kenya, Somalia and Tanzania, and in September
2000, RVF cases were confirmed in Saudi Arabia and Yemen, marking the
1st reported occurrence of the disease outside the African continent.
The vast majority of human infections result from direct or indirect
contact with the blood or organs of infected animals. The virus can
be transmitted to humans through the handling of animal tissue during
slaughtering or butchering, assisting with animal births, conducting
veterinary procedures, or from the disposal of carcasses or fetuses.
Certain occupational groups such as herders, farmers, slaughterhouse
workers and veterinarians are, therefore, at higher risk of
infection. The virus infects humans through inoculation, for example
via a wound from an infected knife or through contact with broken
skin, or through inhalation of aerosols produced during the slaughter
of infected animals.
There is some evidence that humans may also become infected with RVF
by ingesting the unpasteurized or uncooked milk of infected animals.
Human infections have also resulted from the bites of infected
mosquitoes, most commonly the _Aedes_ mosquito. Transmission of RVF
virus by hematophagous (blood-feeding) flies is also possible. To
date, no human-to-human transmission of RVF has been documented, and
no transmission of RVF to health care workers has been reported when
standard infection control precautions have been put in place. There
has been no evidence of outbreaks of RVF in urban areas.
While most human cases are relatively mild, a small percentage of
patients develop a much more severe form of the disease. This usually
appears as one or more of 3 distinct syndromes: ocular (eye) disease
(0.5-2 percent of patients), meningoencephalitis (less than one
percent) or haemorrhagic fever (less than one percent).
The total case fatality rate has varied widely between different
epidemics but, overall, has been less than one percent in those
documented. Most fatalities occur in patients who develop the
haemorrhagic icterus form.
More detailed information can be obtained from the WHO website at:
The HealthMap/ProMED-mail interactive map of Mauritania can be
accessed at: <http://healthmap.org/r/0hQ0>. - Mod.CP]