A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

Date: Thu 5 Feb 2009
From: ProMED-mail
Source: News release Belgian Federal Agency for the Safety of the
Food Chain (FASFC; Dutch FAVV), [trans. Mod.AS, edited]

The FAVV has formally notified the EU on Tue 3 Feb 2009 that the
European reference laboratory in Pirbright identified on 15 Jan 2009
a new BT-serotype, namely BTV-11, in a sample from a cow from a herd
in East Flanders.
The cow was sampled in November 2008 as part of a
routine investigation. In a 1st analysis in CODA, the Belgian
Reference Laboratory, the possible presence of BTV was demonstrated.
It was not BTV-1, BTV-6 or BTV-8, the serotypes known to circulate in
our and neighboring countries. This finding was confirmed in
additional samples [apparently from the same animal. - Mod.AS], but
no final characterization of the virus could be effectively attained.
Eventually, the samples were forwarded in December 2008 to the
European reference laboratory, which reached the final conclusion
concerning BTV-11.

The analysis results and the inability to isolate the virus point out
that the infection of the cow took place during the 2008 season,
though probably at a considerable time before the date of the 1st
sampling in November 2008.

There are currently no indications that the virus would cause
clinical problems.

This finding has no immediate consequences. There is currently only
an isolated case
of infection involving one single animal. The tests
carried out in November 2008 and again during the last month [January
2009] in the said holding, as well as thousands of tests carried out
during the recent bluetongue season on samples from the entire
country, give no indication that BTV-11 could have been effectively
spread. Such virus circulation is an essential condition for the
official recognition of a bluetongue outbreak.

Communicated by:
Sabine Zentis
Castleview Pedigree English Longhorns
Gut Laach, Nideggen, Germany

[Though the applied tests are not specified in the news release, the
positive cow may have been discovered serologically; no isolate is
available. While from administrative, official, legal, and
bureaucratic aspects the detection of a single BTV-11 positive animal
does not give rise to prescribed official notification of a "new
strain of a listed disease," it deserves serious attention. The
infected animal is autochthon; the infection had taken place locally
during 2008. Such an infection could have been caused by several
theoretically possible modes, including the following:

1. Infected vectors (_Culicoides_).
2. Applied live attenuated BTV vaccine that includes BTV-11.
3. Injection of other biological(s) contaminated by BTV-11.

For details on the listed isolates of bluetongue virus type 11
(BTV-11) in the dsRNA virus collection at IAH Pirbright, see
The isolates are from Africa (RSA, Zimbabwe, Nigeria), USA and the
Caribbean (Dominican Republic).

BTV-11 is the 3rd BTV strain detected in the lowlands
(Netherlands/Belgium) since 2006 without their previous known
presence on European soil.
These include now BTV-8, BTV-6 and BTV-11.
A 4th, novel BTV strain ("Toggenburg") has been detected in
Switzerland in 2008. So far, none of the routes of their
introduction(s) have been elucidated
. - Mod.AS],75993