Published Date: 2005-12-21 23:50:00
Subject: PRO/AH/EDR> Avian influenza - Eurasia (106): Denmark, wild birds, surveillance
Archive Number: 20051221.3650
AVIAN INFLUENZA - EURASIA (106): DENMARK, WILD BIRDS, SURVEILLANCE
A ProMED-mail post
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Date: Wed 21 Dec 2005
From: Kurt Jensen Handberg <email@example.com>
We hope that the following information on avian influenza virus (AIV)
surveillance in Denmark will contribute to make the overview for AIV in
Europe more complete.
Due to increasing international interest and concern on the spread of avian
influenza (AI), the occurrence of AI virus (AIV) in certain species of
migratory water birds was monitored in Denmark during 2003 and 2004.
Similar surveillance is in progress in 2005 as well. The surveillance has
been carried out as a collaborative study by the Danish Food and Veterinary
The Danish Institute for Food and Veterinary Research (DFVF)
and the National Environmental Research Institute (DMU)
Fecal samples from freshly deposited droppings were collected by DMU and
examined at the DFVF. The samples were tested in pools of 5 by virus
isolation in SPF chicken embryos and by RT-PCR applied directly to the samples.
In 2003, 579 pools, representing approximately 2895 birds, from 13
different species of birds were tested. 15 AIV isolates of the following
subtypes were obtained: H1N1, H3N2, H3N6, H3N8, H4H6, H6N5, H6N8, H10N7.
All isolates were from dabbling ducks, i.e. mallard (_Anas platyrhynchos_),
widgeon (_Anas Penelope_), and teal (_Anas crecca_).
34 pools were positive by RT-PCR (pan-influenza A RT-PCR)(Ref 1). Of these,
4 contained H5 specific HA gene segments, and 2 contained H7 specific HA
gene segments, as revealed by H5 and H7 specific RT-PCR. Sequencing of the
PCR products at the HA cleavage site indicated that the H5 (PQKETR*GLF) and
H7 (PEIPKGR*GLF) HA gene segments were derived from low pathogenic AIV.
In 2004, 600 pools, representing approximately 3000 birds, and 65 samples
from individual birds were tested by similar procedures as in 2003. In
2004, samples from mallard, widgeon, teal and pintail (_Anas acuta_) were
collected. 14 AIV isolates were obtained. The subtypes were H2N3, H3N2,
H3N8, H5N2, H6N2, H8N1 and H8N4. The amino acid sequence (PQKETR*GLF) at
the HA cleavage site of the H5N2 isolates indicated viruses of low
131 samples were positive when tested by RT-PCR (pan-influenza A PCR)(Ref
1). Of these, 13 contained H5 HA gene segments, but none contained H7 HA
gene segments. Again, sequencing of the HA cleavage site of the H5 HA genes
indicated that they were derived from viruses of low patogenicity (PQKETR*GLF).
(1) Munch, M., Nielsen, L. E., Handberg, K. J. & Jorgensen, P. H. (2001).
Detection and subtyping (H5 and H7) of avian type A influenza virus by
reverse transcription-PCR and PCR-ELISA. Archives of Virology 146: 87-97.
Poul H. Jorgensen, Avian Virology
Senior Scientist, DVM, PhD
Kurt J. Handberg, Avian Virology
Senior Scientist, MSc, PhD
Department of Poultry, Fish and Fur Animals
Danish Institute for Food and Veterinary Research
2, Hangoevej, DK-8200 Aarhus N
[We are grateful to Drs. Jorgensen and Handberg for this firsthand
information reflecting exemplary ongoing efforts. Results of the 2005
surveillance are anticipated with interest.
The importance of surveillance in wild birds worldwide has been highlighted
in previous postings, in particular to assess the role of migrating birds
in the spread of the H5N1 HPAI virus, and to detect its possible
introduction into receptive, susceptible regions at the earliest stages. It
is of particular interest to know whether sampled birds are sedentary or
migratory. If the latter is the case, their origin and flyway are of
significance. To obtain such data, active involvement of ornithologists is
required. A recent example was the swan, ringed in Hungary, which was found
dead in Croatia and tested positive for the H5N1 strain (see
20051106.3251). - Mod.AS]
[Elsevier on-line reference:
Avian influenza: perfect storm now gathering? Lancet, March 2005,