Published Date: 2010-12-19 21:00:04
Subject: PRO/AH/EDR> Rift Valley fever, livestock - Mauritania (02): OIE
Archive Number: 20101219.4478
RIFT VALLEY FEVER, LIVESTOCK - MAURITANIA (02): OIE
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A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: 16 Dec 2010
Source: OIE WAHID (World Animal Health Information Database) Disease
Information 2010; 23(49) [edited]
<http://www.oie.int/wahis/public.php?page=single_report&pop=1&reportid=10054>
Rift Valley fever, Mauritania
-----------------------------
Information received on 16 Dec 2010 from Dr Baba Doumbia, Directeur,
Directeur de l'Elevage, Ministere du developpement rural, Nouakchott,
Mauritania
Summary
Report type: Immediate notification
Start date 25 Oct 2010
Date of 1st confirmation of the event 15 Dec 2010
Report date 16 Dec 2010
Date submitted to OIE 16 Dec 2010
Reason for notification: Reoccurrence of a listed disease
Date of previous occurrence 2008
Manifestation of disease: Clinical disease
Causal agent: Phlebovirus
Nature of diagnosis: Laboratory (advanced)
This event pertains to a defined zone within the country
New outbreaks
Outbreak 1 Village of Meddah, Erdeime, Aoujeft, Aoujeft
Date of start of the outbreak 25 Oct 2010
Outbreak status: Continuing (or date resolved not provided)
Epidemiological unit: Village
Species Sheep / goats
Susceptible 300
Cases 64
Deaths 1
Destroyed 0
Slaughtered 0
Outbreak 2 Village of Tawaz, Agjatt, Atar, Atar
Date of start of the outbreak 10 Nov 2010
Outbreak status: Continuing (or date resolved not provided)
Epidemiological unit: Village
Species Camelidae
Susceptible 120
Cases 29
Deaths 20
Destroyed 12
Slaughtered 1
Outbreak 3 Village of Akjoujt, Tourarine, Akjoujt, Akjoujt
Date of start of the outbreak 11 Nov 2010
Outbreak status:Continuing (or date resolved not provided)
Epidemiological unit: Village
Species Sheep / goats
Susceptible 250
Cases 80
Deaths 0
Destroyed 0
Slaughtered 0
Total animals affected
Species Sheep / goats
Susceptible 550
Cases 144
Deaths 1
Destroyed 0
Slaughtered 0
Species Camelidae
Susceptible 120
Cases 29
Deaths 20
Destroyed 12
Slaughtered 1
Epidemiology - Source of the outbreak(s) or origin of infection.
Unknown or inconclusive. Vectors
Control measures - Measures applied: Control of arthropods;
Quarantine; Movement control inside the country; Dipping / Spraying;
* Modified stamping out; No vaccination; No treatment of affected animals
Measures to be applied - No other measures
Laboratory name and type: Agricultural Research Institute of Senegal
(ISRA) (Regional Reference Laboratory)
Species Camelidae
Test reverse transcription - polymerase chain reaction (RT-PCR)
Test date 15 Dec 2010
Result Positive
The event is continuing. Weekly follow-up reports will be submitted.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[One of the most under-utilized assets of ProMED-mail are its
Archives. When you examine the history of Rift Valley Fever in West
Africa through our archives, it is apparent that there is a cyclic
nature to the outbreaks in the western-most countries of West Africa
like Mauritania and Senegal -- just as RVF has a cyclic nature in East
Africa.
There were outbreaks in Mauritania in 2009 and 2010. This was preceded
by outbreaks in 2002 and 2003. Prior to that we have a series in
outbreaks in 1998 and 1999. But what is absolutely fascinating is one
of the earliest ProMED-mail posts in 1994 was concerning the emergence
of Rift Valley Fever in southern Mauritania and northern Senegal.
Scientist from The Pasteur Institute reported the following: 13
strains of Rift Valley Fever virus were isolated from _Aedes vexans_
and _Aedes ochraceus_ collected in October and November 1993 around
temporary ground pools in Northern Senegal. See the reference below
for details.
Another notable feature is that this cycle of outbreaks begs
verification that RVF occurrence can be predicted by climatic models.
RVF seems to be associated with above average rainfall and RVF
forecasting and climatic models can be useful in predicting outbreaks
as indicated on WHO fact sheet on RVF - see
<http://www.who.int/mediacentre/factsheets/fs207/en/>. The question
then arises as how well do climatic models predict this particular
series of outbreaks in Senegal and Mauritania and can they be useful
for further outbreaks? Another important question is how well
established is RVF in this region and when can we expect more outbreaks.
A summary of WHO information on climate models and RVF is given below:
Forecasting can predict climatic conditions that are frequently
associated with an increased risk of outbreaks, and may improve
disease control. In Africa, Saudi Arabia and Yemen RVF outbreaks are
closely associated with periods of above-average rainfall. The
response of vegetation to increased levels of rainfall can be easily
measured and monitored by Remote Sensing Satellite Imagery. In
addition RVF outbreaks in East Africa are closely associated with the
heavy rainfall that occurs during the warm phase of the El
Nino/Southern Oscillation (ENSO) phenomenon.
These findings have enabled the successful development of forecasting
models and early warning systems for RVF using satellite images and
weather/climate forecasting data. Early warning systems, such as
these, could be used to detect animal cases at an early stage of an
outbreak enabling authorities to implement measures to avert impending
epidemics.
Within the framework of the new International Health Regulations
(2005), the forecasting and early detection of RVF outbreaks, together
with a comprehensive assessment of the risk of diffusion to new areas,
are essential to enable effective and timely control measures
[livestock vaccination] to be implemented. - Mod.PC]
[The HealthMap/ProMED-mail interactive map of Mauritania can be
accessed at: <http://healthmap.org/r/0hQ0>. - Mod.JW]