While further cases of highly pathogenic avian influenza (HPAI) have been confirmed among poultry in Australia, Taiwan and Vietnam, multiple outbreaks have been reported in North Korea. For the first time in seven years, the mild form of the disease has been detected in two Australian flocks.
In Australia, a second HPAI infection of the H5N7 virus variant has been detected at a poultry farm in the Lethbridge area of the state of Victoria.
Affected were a number of egg-laying hens at the premises, which uses free-range, barn, and cage systems for housing. More than 211,000 of the 355,000 birds at the farm showed signs of the disease, according to the official report to the World Organisation for Animal Health (OIE). Almost 200 hens died.
Just last week, the agriculture department recorded the country’s first HPAI outbreak for more than six years. At the end of July, the virus was detected in a free-range flock in the same area after elevated mortality was observed. Contact with wild birds was thought to be source of infection.
Following confirmation of the initial outbreak, farmers were ordered to keep all free-range birds housed.
Depopulation of the first infected flock has been completed, reports the agriculture department. Disposal and decontamination of the premises were underway.
Mild form of avian flu detected in Australian poultry flocks
As a result of enhanced sampling and surveillance following the HPAI outbreak in Victoria, Australia’s veterinary authority has uncovered the presence of an H5N2 low-pathogenic avian influenza (LPAI) virus in two poultry flocks in the same state.
First found to be infected was a commercial turkey farm in Bairnsdale. Included among the 5,440 growing turkeys at the site was one flock of around 2,440 3- to 4-week-old turkeys. A second flock comprised 3,000 18-week-old birds. Of these, 7,000-8,000 were recent arrivals from a farm in Lethbridge.
Subsequent testing revealed that the farm of origin in Lethbridge was also infected with this virus. Located within the restricted zone for HPAI, this premises had a total of 7,200 poultry. This included 4,500 turkeys of various ages, and 2,700 spent hens and roosters. Around 30 birds at this premises died, and sampling was undertaken after clinical signs were observed.
The Bairnsdale property has been quarantined, and movement controls have been put in place around it, according to Agriculture Victoria. The controls ban the movements of birds, equipment, and products within or out of the designated Restricted Area and Control Area without a permit from the authority. Similar regulations were already in place around Lethbridge.
H5N2 LPAI virus was last detected in Australia in June of 2013.
Four recent HPAI outbreaks in Taiwan
Latest in a series of HPAI outbreaks linked to the H5N5 virus variant have been reported to the OIE.
In the week beginning July 23, four outbreaks — two in Yunlin county, one in Changhua, and on in Tainan city — were reported by the Council of Agriculture. Affecting a total of almost 90,000 poultry, the virus was detected among two flocks of native chickens, one of meat geese, and one of broiler breeders. More than 5,700 of the birds died, and the rest have been destroyed.
One additional outbreak has been reported in recent days by Taiwan News. Following abnormal deaths, the presence of the H5N5 HPAI virus was detected at a farm in Erlin township, which is in Changhua county. Just over 16,000 chickens at the premises have already been culled, and the area has been disinfected.
In Taiwan, the H5N5 HPAI virus was first detected at a Kaohsiung city farm in September of 2019. The latest outbreaks bring the total to 38. Prior to these cases, the most recent outbreak was in mid-June.
Mixed HPAI news from Vietnam
After a brief absence, the H5N1 HPAI virus has been detected again in southern Vietnam.
During the last week of July, the infection was confirmed in a flock of village poultry in the province of Tra Vinh, according to the official report to the OIE. The agriculture ministry records that of the 1,040 birds involved, around 200 died, and the rest have been destroyed.
Tra Vinh is in the Mekong Delta region. OIE records indicate that the last HPAI outbreak was in early June.
Following two confirmed outbreaks, the ministry has declared to the OIE that the H5N6 HPAI situation in the Southern Coastal Region has been “resolved.” The virus had been detected in two village flocks in Quang Ngai province at the end of June.
North Korea records new avian flu outbreaks
After eight outbreaks of avian influenza were confirmed at poultry farms, North Korea has stepped up biosecurity. According to Daily NK, the affected premises are in South Hamgyong province.
On July 20, the nation’s authorities ordered a strengthening of animal disease controls across the country. As a result, provincial authorities are now responsible for culling and disposing of birds that are infected with the virus, or those that may be infected. Meanwhile, police are monitoring farms and markets to ensure that sick or culled birds are not being sold. In each province, livestock agencies have been called on to disinfect farms, and to monitor for signs of disease.
According to Daily NK, any reemergence of avian flu among poultry will be treated as a violation of party orders, not just a “simple mistake.” Those responsible for future outbreaks will be subject to dismissal or demotion.
HPAI was last known to be present in poultry in North Korea in 2016, according to OIE reports.
Mortalities among the poultry are reported by Daily NK to have been “sudden.” No indications are given in the report regarding the scale of the losses, nor the pathogenicity and type of virus involved.
South Hamgyong is an eastern coastal province of North Korea.
No new outbreaks in the Philippines
According to the latest report to the OIE, the Department of Agriculture has reported no new cases of HPAI.
In early July, the H5N6 HPAI virus was detected on a commercial egg farm in Pampanga province on the island of Luzon.
In the U.S., South Carolina can now consider itself free of HPAI. In the declaration to the OIE, the USDA animal health agency reported that there has been no further detections of the H7N3 HPAI virus since a single outbreak of the disease among a commercial turkey flock in April of this year.
View our continuing coverage of the global avian influenza situation.
