H5N6 avian flu reassortant found in recent Korean outbreak

Genetic research petri dish
Genetic research petri dish

Pogonici / iStock

South Korean government officials today announced tests on the highly pathogenic H5N6 avian flu virus found in a recent outbreak in North Jeolla province is a new reassortant and not the version that has sparked earlier outbreaks in Asian countries and in some instances sickened humans.

In other avian flu developments, Japan reported more H5N6 findings in wild birds, Italy and Russia detailed more H5N8 events, and Germany noted an outbreak involving low-pathogenic H5N2.

Genetic testing part of outbreak probe

South Korea's Animal and Plant Quarantine Agency (APQA) said H5N6 genetic findings were part of an investigation into the source of an outbreak in Gochang County in North Jeolla province, Yonhap News reported today. Scientists analyzed viruses from 852 bird corpses and droppings from wild birds.

The genomic study revealed a new H5N6 strain that resulted from a reassortment between highly pathogenic H5N8 that hit Europe especially hard last winter and a low-pathogenic H3N6 virus found occasionally in European wild birds.

According to a brief announcement from the APQA translated and posted by Avian Flu Diary, an infectious disease news blog, the H5N6 reassortant viruses were from ducks.

The H5N6 virus identified this year is different from the strain that fueled several outbreaks across South Korea last winter, the agency said, adding that migratory birds presumably brought the virus into the country in October.

An epidemiologic investigation is also under way into another recent H5N6 detection in South Korea, in which the virus was found in wild bird droppings on the island of Jeju, with results expected in the coming week.

The latest development is similar to the identification of a different H5N6 strain found in Greece in the wake of last winter's outbreaks across Europe. First thought to be the first H5N6 outbreak detected outside of Asia, a preliminary analysis of the virus in Greece suggested a reassortant of highly pathogenic H5N8 and endemic Eurasian viruses.

Meanwhile, Japan last week reported three more H5N6 detections in wild birds, the third such report this month. In a Nov 24 report to the World Organization for Animal Health (OIE), the country's agriculture ministry said the outbreaks involved two mute swans and a tufted duck found dead on Nov 11 and Nov 12 near Matsue, the capital of Shimane prefecture on the southwestern part of the main Honshu island.

So far it's not known if the H5N6 strain in Japan is the same as the reassortant identified in South Korea.

Italy, Russia report more H5N8

Italy—hit hard by H5N8 outbreaks that continued over the summer months—reported seven more events, according to a Nov 23 report from the OIE. The outbreaks began from Nov 8 to Nov 22, and all occurred in Lombardy region in the north central part of the country.

The virus struck four layer farms, two broiler farms, and a turkey-fattening farm. The virus killed 448 of 251,044 susceptible birds, and authorities destroyed the remaining ones to curb the spread of the disease.

In Russia, the agriculture ministry reported an H5N8 outbreak in village birds in Rostov oblast in the country's southwest, according to a Nov 23 OIE notification. The outbreak began Nov 15, killing three birds.

Low-path H5N2 detection in Germany

In other avian flu developments, tests on ducks and geese that showed mild clinical signs at a farm in Lower Saxony state in the northwestern part of Germany revealed low-pathogenic H5N2, according to a Nov 23 report from the OIE.

The outbreak began on Nov 20, sickening 43 of 1,011 birds. So far the source of the virus isn't known. Early results from the investigation found that none of the poultry have been moved to other parts of Germany or to other countries.

See also:

Nov 27 Yonhap news story

Nov 27 Avian Flu Diary post

Nov 24 OIE report on H5N6 in Japan

Nov 23 OIE report on H5N8 in Italy

Nov 23 OIE report on H5N8 in Russia

Nov 23 OIE report on low-path H5N2 in Germany

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