Published Date: 2009-10-09 19:00:03
Subject: PRO/AH> African swine fever - Russia (08): transmission
Archive Number: 20091009.3505
AFRICAN SWINE FEVER - RUSSIA (08): TRANSMISSION
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A ProMED-mail post
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International Society for Infectious Diseases
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Date: Fri 9 Oct 2009
From: Mary Louise Penrith
<marylouise@sentechsa.com>
Spread of African swine fever
Re: African swine fever - Russia (07): (Dagestan, Rostov)
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The way African swine fever (ASF) is spread according to the report
[item 1, Republic of Dagestan] definitely needs to be corrected.
There is no evidence whatsoever of spread with migratory birds. I
believe this is a confusion with HPAI. 'Ectoparasites' is also far
too broad. Argasid ticks of the genus Ornithodoros are capable of
maintaining and transmitting the virus and are natural host and
vector. A number of arthropods that suck the blood of pigs have been
examined and only one other arthropod, the stable fly _Stomoxys
calcitrans_, has proven capable of mechanical transmission for a
period of 24-48 hours. I consider this to be important because pig
farmers should be advised to observe strict biosecurity to prevent
their herds from being infected. This is feasible, but would be less
so if the virus could come in with birds and a wide range of ectoparasites.
When properly applied, confining pigs and limiting access to the pig
herd, change of footwear for those who must come in, and not feeding
anything that could contain the remains of pigs works wonders in
keeping farms free of ASF even during an outbreak.
--
Mary-Louise Penrith
Extraordinary Professor
Department of Veterinary Tropical Diseases
Faculty of Veterinary Science
University of Pretoria
South Africa
<marylouise@sentechsa.com>
[Prof Penrith's comment on the (in)accuracy in the newswire of the
Russian RIA news agency, concerning the involvement of migratory
birds in the transmission of African swine fever (ASF), is correct.
Detailed background information on ASF can be found in several past
ProMED-mail postings, such as 20070608.1860, 20080522.1692,
20080726.2278 as well as at
<http://www.cfsph.iastate.edu/Factsheets/pdfs/african_swine_fever.pdf>
(go to "transmission"). - Mod.AS]