Qinghai H5N1 Surveillance Failure in Western Europe
Recombinomics Commentary
June 24, 2007
Three wild birds in Germany have died of the feared H5N1 strain of bird flu, a health official in Nuremberg in southern Germany said on Sunday.
Katja Guenther told AFP tests carried out by the Friedrich Loeffler Institute confirmed that two swans and a duck suffered from the H5N1 strain of the virus.
She said tests were being conducted on another seven birds who died of bird flue to see whether they too had been carriers of H5N1, which is potentially lethal for humans.
The dead wild birds who were infected with the virus were found near Nuremberg in the past week.
The above comments confirm positive H5N1 tests on three dead wild birds in Nuremberg, and strongly suggest that the seven additional fatal bird flu infections will also be confirmed as H5N1. These data raise serious concerns about the H5N1 surveillance in Western Europe.
To date, no EU member country has reported H5N1 in live wild birds, although H5N1 has been reported in dead wild birds in most EU countries. The largest number of reported cases has been in Germany and most reported cases were in the northern Germany outbreak in February, 2006. However, sequence analysis of the wild bird isolates defines three sub-clades (2.2.2.1, 2.2.2.2, and 2.2.2.3). The 2.2.2.2 sub-clade has also been reported in Italy, Czech Republic, Slovenia, and Ukraine. All prior reports have been in wild birds in early 2006. However, the recent outbreak on a turkey farm in the Czech Republic may also be 2.2.2.2 based on detection patterns in 2006. However, Germany has a heavy concentration of H5N1, and detection failures limited analysis of the H5N1 evolution in western Europe in the past year.
The detection failures are cause for concern. This week Ian Brown from Weybridge gave a talk at the Options for the Control of Influenza VI conference on H5N1 in Europe. He noted that there were only two confirmed outbreaks in Western Europe (Hungary and the UK), and the two outbreaks may have been related, based on the close genetic similarity between H5N1 isolates from both countries. He acknowledged that the detection of H5N1 in 2006 in wild birds was limited to dead birds and also noted that most positives were in mute swans in Germany. Austria was second in the number of positives reported in Western Europe.
Ilaria Capua went a step further. She noted the thousands of negatives in test of wild birds in Europe and Africa, and used the negative data to claim that H5N1 in wild birds in Europe was largely limited to 2006 outbreaks.
Similarly, yesterday’s ProMed report on H5N1 on the turkey farm in the Czech Republic cited “sporadic” H5N1 outbreaks: "Worldwide, the H5N1 virus continued to be reported sporadically across Asia, the Middle East, Europe, and Africa during 2007." The FAO indicated that H5N1 in western Europe was significantly lower this season, although at the beginning of the season the group cited concerns over report failures.
Finding H5N1 in at least three wild bird species in Germany in the summer, signal major detection failures. All H5N1 detected in wild birds and poultry west of China has been Clade 2.2 (Qinghai strain), which was first reported at Qinghai Lake in May, 2005. Initially, some thought that the H5N1 in long range migratory birds at Qinghai Lake might burn itself out. However, outbreaks in the summer of 2005 in Russia, Kazakhstan, and Mongolia were also caused by the Qinghai strain, which left little doubt about the transport and spread by migratory birds, such as the healthy crested grebe that was positive for the H5N1 Qinghai strain.
The outbreaks in these three countries, which reported HPAI H5N1 for the first time in the summer of 2005, signal migration of H5N1 into Europe and the Middle East in the fall. Qinghai H5N1 was subsequently detected in the fall of 2005 in the Volga Delta, the Danube Delta, and western Turkey. However, in spited of the confirmed move of H5N1 into the region, no country in the EU reported H5N1 in 2005. H5N1 was also isolated from a healthy teal in the Nile Delta in December, 2005. The sequence of the healthy teal in Egypt was closely related to H5N1 subsequently isolated in Austria in early 2006.
The detection of H5N1 in early 2006 was widespread in the EU. However, all wild bird isolates were in dead or dying birds. To date there have been no reports of H5N1 in live wild birds in the EU.
However, the current outbreak in southern Germany signals endemic H5N1 in wild birds in the center of the EU. This H5N1 in wild birds in Western Europe has largely gone undetected since the spring of 2006.
The time to upgrade the abysmal H5N1 surveillance worldwide, including Western Europe, has long since passed. H5N1 continues to evolve and spread under the radar, and such poor surveillance continues to be hazardous to the world’s health.
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