With ever more cases of highly pathogenic avian influenza detected in its wild population, Australia is preparing to vaccinate some endangered native birds against the H5N1 virus serotype.

Jackie Linden

Further spread of H5N1 avian flu virus in Australian wild birds | WATTPoultry.com

August 14, 2026

BeyhanYazar | iStock.comArticle Summary

H5N1 avian flu cases in Australian wild birds have surged to 205 across six states as of mid-August, more than doubling in nine days, prompting the world’s largest wildlife vaccination campaign targeting 5,000 little penguins in Victoria.

• 205 confirmed H5N1 cases across six Australian states as of August 13, with South Australia accounting for 139 cases
• 60 additional wild birds tested positive in the past week, primarily swift terns found in South Australia and Victoria
• World’s largest wildlife vaccination campaign underway with 5,000 little penguins on Philip Island receiving two-dose vaccine protection
• Rapid geographic expansion from first detection in mid-June to six states including newly affected Tasmania
• Regional context: New Zealand remains stable with only 2 cases, while Nepal reports 162 affected poultry flocks with over 835,000 birds culled

Over the past week, a further 60 wild birds have tested positive for the H5N1 highly pathogenic avian influenza (HPAI) virus in Australia.

Majority of the birds were swift terns, according to the latest notification from the veterinary authority to the World Organisation for Animal Health (WOAH). They were found around the end of July and early August in the states of South Australia and Victoria.

The H5N1 virus was first identified in Australia in mid-June. Since then, 88 wild birds had tested positive for the virus across five states of the country up to that date.

This week, the Australian Broadcasting Corporation (ABC) reported that the first wild bird case had been confirmed in the island state of Tasmania.

Latest update on the disease situation from the federal government (dated August 13) puts the total number of cases at 205 — more than double the number of reported nine days previously. — across six states (including Tasmania).

Recording by far the most cases to date has been South Australia with 139 virus-positive birds, while outbreaks have also been recorded in Western Australia, Victoria, New South Wales and Queensland.

In order to protect key endangered bird populations from the disease, around 5,000 little penguins on Philip Island in Victoria will be rounded up to receive the first of two doses of vaccine, reports ABC. This is thought to be the largest wildlife vaccination campaign anywhere in the world.

According to the same source, Australia’s federal government has so far acquired around 1,500 doses of vaccine. 

Update on the disease situation in New Zealand

No more wild birds have tested positive for the H5N1 virus serotype in New Zealand.

Since the country’s first ever cases of this virus were detected in mid-July, the number of infected wild birds remains at two, reported the Ministry for Primary Industries on August 12. Both of the infected birds were found in the Wellington area in the south of the North Island.

To date, the H5N1 HPAI virus has not been detected in any of New Zealand’s poultry flocks. 

More outbreaks in Nepal’s poultry flocks

Based on notifications to WOAH, poultry at 91 of the nation’s farms tested positive for the H5N1 virus variant between mid-March and the start of July this year.

However, Kathmandu Post reported recently that the number of affected flocks stood at 162 (as of July 23). Officials confirmed that more than 835,000 poultry have been culled in order to control the spread of the infection, along with over 1.22 million eggs and 264 metric tons of feed.

According to this source, the virus was first detected in Nepal in this disease series in mid-February, and that cases had been identified in 12 districts up to mid-July.

To compensate affected poultry owners, the government is reported to have paid 507 million rupees (NPR; US$3.3 million) to 104 farmers, this source reports. 

Avian flu developments elsewhere in Asian poultry

In the Philippines, the Department of Agriculture’s Bureau of Animal Industry reports that new H5N1 HPAI infections have been detected in just one municipality in the previous 31 days (up to August 7).

This latest outbreak appears to have been at a chicken farm in Kalinga, a province in the Cordillera Administrative Region on the island of Luzon. Meanwhile. the outbreak situation remains on-going in Pangasinan province in the Ilocos Region — also on Luzon — where the virus has been detected in 27 flocks of chickens and ducks.

Taiwan’s animal health agency has recently declared to WOAH that an earlier HPAI outbreak series has been “resolved.”

Between July of last year and the end of the same month in 2026, the H5N1 virus serotype was detected at 28 locations in eight cities/counties, according to the closing report. Directly impacted through mortality or preventative culling were more than 873,000 commercial poultry.

In the past week, the authorities in India have also declared an end to earlier H5N1 HPAI outbreak series.

Two declarations followed six outbreaks in poultry in the northeastern state of Sikkim, and another in wild birds in Bihar the east of the country. Both series commenced in January of this year, and were considered closed in late July.