Two outbreaks of H5N1 avian flu have hit thousands of ducks in Siem Reap and Battambang provinces, according to data from the World Organisation for Animal Health published on Monday.

About 2,100 infected ducks died in Battambang and 180 more in Siem Reap as of November 12, according to the organisation’s report. Currently, 8,800 ducks in the country remain susceptible to the illness.

The infected birds came from free-ranging backyard flocks.

“After having been informed by the owners that their duck flocks were sick and were dying, the district and provincial veterinary services went there to investigate and took some samples,” the report reads. “The result of test samples were confirmed positive with H5N1.”

The latest outbreaks have yet to spread to human patients, according to Ly Sovann, director of the Health Ministry’s Department of Communicable Disease Control.

“We sent our response teams yesterday to monitor the human health of those who live in or near the affected areas,” Sovann said. “Up to now, they collected five suspected human samples but all were negative.”

The last detected human case of H5N1 avian flu in Cambodia was in March, said Sovann. The Ministry of Agriculture has not yet given a reason for these latest outbreaks.

At least 100 ducks remain sick in Siem Reap’s Puok district, according to district animal health official Marn Cheb. They were among the 6,500 ducks who arrived from Banteay Meanchey’s Mongkol Borei district on Sunday.

“After arriving in Puok district, some ducks started to get sick and some of them died. Seeing the ducks dead, the owner separated the sick ducks to a separate cage, then informed the district officials,” Cheb said.

Prum Vich, chief of the Agriculture Ministry’s animal health and production office in Siem Reap, said that the ducks were transported to the district under heat and heavy rain, and the sick ducks will be buried to prevent the disease spread.

“The flu cannot spread to humans if we know how to prevent it correctly,” he said.

Agriculture Ministry officials in Battambang were not available for comment yesterday.

According to Sovann, H5N1 is a “high-mortality” disease, which killed five people out of a total of nine cases in 2014.

The World Health Organization found that in human cases, the mortality rate hovers at around 60 per cent.

Nonetheless, the disease has “limited transmission”, Sovann said. People become infected by eating sick birds or touching contaminated surfaces.

“If any people cough or have a sore throat, please visit a health centre or hospital and inform them about the history of contact” with sick birds, said Sovann.

Additional reporting by Igor Kossov