The United Kingdom today reported its third highly pathogenic H5N6 avian flu outbreak in wild birds, this time in Hertfordshire in the southeast, as agriculture officials there upgraded the risk of the virus spreading to other parts of the country.
The virus—a new reassortant between H5N8 that circulated widely last winter and endemic Eurasian viruses—has turned up in a few European countries this season, as well as some in Asia, including in South Korea and Japan.
In other avian flu developments, Afghanistan confirmed a second H5 outbreak, and Hong Kong warned residents that H5 has been detected in samples from chilled chickens at a market.
UK outbreak in overwintering area
The latest UK outbreak began on Jan 13 at a nature preserve, with a die-off involving at least 19 birds, including ducks, geese, a gull, and other unspecified birds, according to a report today from the World Organization for Animal Health (OIE). Earlier this month the same virus struck wild birds in two other locations west of Hertfordshire, Dorset, and Warwickshire.
Yesterday, the UK's Department for Environment, Food, and Rural Affairs (DEFRA) updated the risk assessment it issued on Jan 14 in response to the first outbreak. The agency initially assessed the risk level as medium.
In the new assessment, however, DEFRA said the site in Hertfordshire is a high-risk area because of the many migratory birds that overwinter there. As a result, it said the threat of finding more H5N6 in wild birds in England and Wales has increased to high. It said the site in Warwickshire is a roosting site for many gull species, which can travel relatively long distances for feeding and may act as a bridging species with the capacity to spread the virus to other wild bird species and to poultry.
DEFRA also raised the risk of spread to poultry from low to medium. So far, no poultry outbreaks involving the new reassortant have been reported in the country.
Afghanistan H5 outbreaks
Elsewhere, Afghanistan's agriculture ministry reported two highly pathogenic H5 avian influenza outbreaks, both in Kabul province, according to a notification today from the OIE.
One of the events began on Jan 14, affecting backyard birds in the city of Kabul. The other started on Jan 18 among village birds in the city of Bagrami.
Taken together, the virus killed 21 of 29 susceptible birds, and the survivors were culled as one of the control measures.
Earlier this month, Afghanistan reported highly pathogenic H5 in a crow die-off in a forested area near the city of Khost. So far, officials haven't revealed any information about the subtype. Two other countries in the Middle East—Saudi Arabia and Iraq—have recently reported H5N8 outbreaks.
H5 in Hong Kong poultry carcasses
Hong Kong's Centre for Health Protection (CHP), meanwhile, warned the public today to be vigilant for avian flu following the detection of H5 in oropharyngeal samples from chilled chickens that were imported from China's mainland.
The agency urged people who handled chilled chickens with a production date of Jan 15 from a specific processing plant who develop flulike symptoms to seek medical treatment and tell their doctors about potential exposure.
The chilled chickens were part of a batch from a market in Mong Kok. The CHP said it is monitoring staff and other known contacts and has also stepped up its surveillance for other possible detections.
The report didn't note the subtype, but earlier this month, Hong Kong reported finding traces of H5N6 on a chopping block and on duck skin at another market in the area. And China has reported two H5N6 patients since November, both of whom had contact with live poultry before they got sick.
H5N8 in South Africa; low-path H5N3 in France
In other outbreak developments, South Africa today reported two more H5N8 outbreaks that occurred in the fall, both involving commercial ostriches in Western Cape province. The virus sickened 6 of 2,211 susceptible birds.
A few days ago France's agriculture ministry reported another low-pathogenic H5N3 outbreak at a foie gras duck farm, according to a Jan 19 report from the OIE. The outbreak began on Jan 16 in Landes department in the country's southwest.
The birds were tested as part of surveillance and didn't show any illness signs. The 3,660 birds at the facility are slated for culling. France reported its most recent previous H5N3 outbreak in December at a turkey breeding farm in Maine et Loire department in the west.
Jan 23 OIE report on H5N6 in the UK
Jan 23 OIE report on H5 in Afghanistan
Jan 23 Hong Kong CHP statement
Jan 12 Hong Kong CHP statement
Jan 23 OIE report on H5N8 in South Africa
Jan 19 OIE report on H5N3 in France