EFSA-paper , HPAI H5N8 entry and spread in Europe

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no authors given

32 pages .pdf

link: http://www.efsa.europa.eu/en/efsajournal/doc/3941.pdf



SCIENTIFIC REPORT OF EFSA
Highly pathogenic avian influenza A subtype H5N81
European Food Safety Authority2, 3
European Food Safety Authority (EFSA), Parma, Italy

On request from the European Commission,
Question No EFSA-Q-2014-00838, approved on 05 December 2014.

Suggested citation: European Food Safety Authority, 2014.
Highly pathogenic avian influenza A subtype H5N8.
EFSA Journal 2014;12(12):3941, 32 pp. doi:10.2903/j.efsa.2014.3941

Available online: www.efsa.europa.eu/efsajournal


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TABLE OF CONTENTS
01,Abstract
02,Summary
04,Table of contents
05,Background as provided by European Commission
05,Terms of reference as provided by the European Commission
06,Evaluation
06,1. Introduction
06,2. Description of the reported HPAI H5N8 outbreaks
12,3. Characteristics of the circulating HPAI H5N8 viruses
14,4. Assessment of possible entry routes for H5N8 into Europe
14,4.1. Possible long-distance spread of HPAI H5N8 to Europe via migratory birds
17,4.2. Possible local transmission of HPAI H5N8 from wild birds to poultry in European holdings
22,4.3. Possible introduction by persons, vehicles, equipment and fomites
23,4.4. Possible introduction by movement of live animals or animal-derived products
24,Conclusions and recommendations
25,References
29,Appendix
32,Glossary and abbreviations

 

[gsgs]

Re: EFSA-paper , HPAI H5N8 entry and spread in Europe

page 12, chapters 4 and 5 :

Phylogenetic analyses of all available European and Asian HPAI H5N8 isolates
using Bayesian Markov Chain Monte Carlo analyses suggests that four of the
five outbreaks of HPAI H5N8 virus in the Netherlands were caused by separate
introduction and not by farm-to-farm spread. In addition the analysis suggests
a between-farm transmission between the third and fourth outbreak (both in
Kamperveen), although it cannot be entirely excluded that both outbreaks
resulted from two separate introductions from the same source. The first four
Dutch isolates had maximal 20 nucleotide substitutions across the whole
genome that should have been generated during circulation in poultry during
9 days if it is assumed that between farm spread had continued the spread
after the index case (personal communication, Ruth Bouwstra, CVI Lelystad,
05 December 2014).
During the HPAI H7N7 outbreak in the Netherlands maximal 25 substitutions
were generated in 256 outbreaks in 9 weeks and in Italy 66 substitutions in 9
months (Jonges et al., 2014). Remarkably, H5N8 viruses isolated from non-specified
species of Anatidae in Chiba in Japan in November 2014 most likely derived from
the same precursor as viruses isolated in Europe. These results could be consistent
with a hypothesis that the precursor virus was present in Siberia on the breeding
grounds where migratory birds from the East Atlantic Flyway and East Asian
Australasia Flyways may have mingled during the breeding season in 2014.
The fact that European viruses diverted from the same HPAI H5N8 entry and
spread in Europe ancestor as two Japanese viruses suggests that there has
been little opportunity for the accumulation of mutations during movement
between Asia and Europe. If many bird species were involved, greater number
of nucleotide differences between European and Japanese viruses may be
expected (Personal communication, Ruth Bouwstra, CVI Lelystad, 03
December 2014; Personal communication, Ian Brow, EURL, 05 December 2014).