HPAI A(H5N1) = "highly pathogenic avian influenza virus of type A of subtype H5N1" - Cause for concern with new cases reported

The inevitability of a wide scale flu pandemic seems to be getting clearer and the details of the jigsaw of the global spread from birds to humans of H5NI virus and its variants seems to be more clearly etched as DNA sequencing reveals the tale and trail of the virus.

There have been eight cases of the H5N1 bird flu virus in Poland this month. H5N1 is a subtype of the Influenza A virus which can cause illness in humans and many other animal species. The strain that had adapted to grow in birds is technically decribed as called HPAI A(H5N1) = "highly pathogenic avian influenza virus of type A of subtype H5N1"

There have now been 3 recent reports of infected poultry in Brandenburg, Germany , the latest on a small farm in the town of Blumenthal in the Ostprignitz-Ruppin district had tested positive for the virus.

Earlier in December two chickens in the Oberhavel district further west tested positive for H5N1 and another in the town of Bensdorf in the Potsdam-Mittelmark district.

Highly pathogenic H5N1 avian influenza emerged in Hong Kong in 1996–1997 (1) and by early October 2006 had subsequently caused outbreaks in poultry or wild birds in 53 countries and 256 human cases, including 151 deaths (www.who.int/csr/disease/avian
influenza/en/).

Hundreds of millions of chickens, ducks, turkeys, and geese have died or have been culled to prevent the spread of the virus. Coupled with export bans on affected countries the disease has had an economic impact of US$10 billion

The samples from Blumenthal were immediately transferred to the OIE (World Organization for Animal Health) and National Reference Laboratory for Avian Influenza at the Friedrich-Loeffler-Institut. Real-time RT-PCR specific for Qinghai-like strains of HPAIV confirmed the presence of HPAIV H5N1 in these samples.

Preliminary results of the sequencing analysis of the HA-gene showed a close relationship to HPAIV H5N1 isolates detected earlier in 2007 in Germany (HPAIV H5N1 subclade 2.2.3; Starick et al., 2007).

The above comments on initial sequence data from the H5N1 isolates from Germany indicate that the sequences are related to the Uva Lake sequences detected throughout Europe since the summer. These results are not a surprise. The sequences were first reported in a massive wild bird outbreak in the summer of 2006.

It appears that these outbreaks were related to contact with wild brid populations - this summer , the Uva Lake strain was first reported at a poultry outbreak in the Czech Republic which was quickly followed by detection in wild birds in the Czech Republic and Germany. The detection in Germany spread to multiple locations in central and southern Germany. Although all outbreaks were related to Uva Lake, each location represented an independent introduction.

These outbreaks were followed by wild bird outbreaks in France and domestic poultry in Germany. In the fall H5N1 was reported in poultry and wild birds in Krasnodar. The whooper swan and chicken sequences from Krasnodar were published and were 99.95% identical. The were also the Uva Lake sub-clade and were closely related to sequences from three of the wild bird outbreaks in Germany.

More recently, the sequences from an outbreak in turkeys in Suffolk, England were described, and these sequences were also Uva Lake sequences closely related to the earlier outbreaks. The proximity of the farm to a large ornamental lake and the lack of new bird introductions was highly indicative of infection of awild bird source.

This was the first reported case of H5N1 in free range poultry in England.

The data described by the Fredrich Loeffler researchers indicates H5N1 in northeastern Germany is also the Uva Lake strain, which suggest that the recent outbreaks in adjacent Poland will also be the Uva Lake strain.

The first H5N1 case this season in Egypt was reported days ago - Oula Yunes Ali, 25, died on Tuesday after being admitted to hospital on Friday with a high fever, Health ministry spokesman Abdel Rahmane Shahin said. She had worked with poultry.

Birds migrate through Egypt at this time and there was a cluster of such cases last year. (see below)

OIE reports define 5 outbreaks surrounding Riyadh (see Satellite map). Media reports have described several outbreaks, which are largely concentrated in Riyadh and surrounding suburbs. Media reports have also described culling of more than 4 million birds in Riyadh.

AP reports that Iran has started to cull out birds in Tehran, Eastern Azerbaijan and Zangan Provinces although authorities deny existence of any bird flu.

With H5N1 evidently spreading in Germany, Poland, and Rostov(A fifth case of bird flu has recently been confirmed at a farm in the Rostov Region, south Russia, close to the site of previous outbreaks last year.) H5N1 has been confirmed in western Turkey, Romania, and Ukraine. This possibly signals migration of H5N1 into the region.

A reported outbreak in the NW Border provinces of Pakistan (AP report) also suggests new human cases in the Middle East are to be expected. According to the World Health Organization (WHO) on December 18th , the eight people in Pakistan who became infected with the H5N1 bird flu strain probably got ill as a result of contact with poultry and some degree of human-to-human transmission. The WHO stressed that nothing has been confirmed yet. Human-to-human transmission of H5N1 bird flu is extremely rare, but not unheard of.

See local Pakistani press stories of the outbreak being suppressed NWFP caretaker Health Minister Syed Kamal Shah "....poultry is a big industry with many stakeholders, some of whom may want to hush up the issue."

Pakistan has alerted hospitals to human cases, while Egypt and Jordan have raised alert levels for infected poultry, while Azerbaijan has banned poultry products from Iran based on rumored H5N1 infections. Iranian Health Minister Karman Bagheri affirmed on 24th December that no bird flu case has been discovered in the country so far.

Which all leads to the conclusion that H5NI strains with Uva Lake sequences are circulating in the Middle East, are infecting humans and will proably infect birds flying northwards again in the spring.

There is some concern that Osletamivir (Tamiflu - Hoffman La Roche ) is very widely used in Egypt and could lead to the selection of Tamiflu resistant strains circulating in the area.

Last year Egypt reported the largest H5N1 cluster in Gharbiya. The H5N1 sequences from the cluster gave cause for concern. In addition to two receptor binding domain changes, which could lead to more efficient transmission, the NA sequence also had N294S, which is linked to resistance to Tamiflu - the changes have been independently confirmed by the CDC in Atlanta.

Elsewhere Indonesia, the worst hit by the H5N1 virus, announced on 14th December its 93rd death and the 115th Indonesian infected with the disease. Siti Supari, the controversial Indonesian Health Minister has not made things easy for her country, by taking on the WHO and other global agencies by refusing to let the world scientific community have the tssue samples, from the Indonesian victims of theBird Flu virus.

In the UK, Health Authorities are on the ball and Benin (Nigeria) has been added to the list of statutory reporting requirements for travellers presenting a febrile illness on arrival. (Dec 18th) see HPA Guidelines

With the approach of Christmas and Muslims marking Sallah, poultry consumption in Nigeria is expected to reach an all-time high this month. As Gilbert da Costa reports for VOA from Abuja, recent reports indicating the virus remains entrenched in Nigeria (first reported in Nigeria nearly two years ago) and an outbreak in neighboring Benin have prompted fresh concerns about bird flu infecting humans in Nigeria.

UK DeFRA Home Page on Avian Flu

Useful site for world news stories on Bird Flu "Bird Flu NewsFlash" also "Bird Flu Breaking News"