Russia reports first human cases of H5N8 bird flu

Seven people at a poultry farm in southern Russia have been infected with H5N8 bird flu, officials say, making it the first time that the highly pathogenic virus has been found in humans. There is no evidence of human-to-human transmission.

“Today, I want to inform you about an important scientific discovery made by scientists at the Vector scientific center,” Anna Popova, the head of Russia’s consumer health watchdog, said on Saturday. “The first cases of human infection with [avian influenza A(H5N8)] have been laboratory confirmed.”

The virus was found in seven employees at a poultry farm in southern Russia, where outbreaks of H5N8 were reported in the bird population in December 2020. Popova described the human cases as “mild,” according to the Interfax news agency.

“The virus can be transmitted from birds to humans, it has overcome the interspecies barrier,” Popova said. “As of today, this variant of the influenza virus is not being transmitted from person to person. Only time will tell how quickly future mutations will allow it to overcome this barrier.”

Popova said the discovery will help researchers prepare for the possibility of human-to-human transmission of the H5N8 virus. Detailed information about the cases has been submitted to the World Health Organization.

H5N8 has been found in birds since at least 1983 and outbreaks have occurred frequently since 2014, when it was found in breeding ducks in South Korea. Numerous outbreaks have been reported during the past 6 months, including in France, Germany, Italy, Spain, the UK, China, Japan, and South Korea.

“The H5N8 type influenza is regarded as pathogenic and is currently manifesting itself in a variety of ways, from asymptomatic and sub-clinical to highly lethal in some populations,” the World Organization for Animal Health (OIE) said in an update about recent outbreaks.

Human cases of H5 viruses are rare but are typically found in those who have contact with sick or dead birds. 

239 human cases of H5N1 bird flu have been reported in China and Southeast Asia since 2003, killing 134 people, according to WHO. More recently, two people in China were infected with the H5N6 variant in January, causing the death of a three-year-old girl.

“Community awareness of the potential dangers for human health is essential to prevent infection in humans,” WHO said in a public health assessment for H5 viruses. “Surveillance should be continued to detect human cases and early changes in transmissibility and infectivity of the viruses.”