First cases of H5N8 bird flu detected in humans

Seven cases have been reported to the World Health Organisation following an outbreak on a poultry farm in south Russia last December

The first cases of the H5N8 bird flu strain have been detected in humans, scientists have said - though there are no signs of transmission between people.

Authorities in Russia have sent information to the World Health Organisation on seven cases that were detected in workers at a poultry farm last December in the south of the country.

The cases were reported "several days ago, just as we became absolutely certain of our results," said Anna Popova, head of Russia's health watchdog Rospotrebnadzor.

The workers were infected with H5N8 following an outbreak of the virus at the farm, but did not suffer any serious health consequences and have since made a full recovery.

"This situation did not develop further," Ms Popova added.

The highly contagious strain is lethal for birds but this is the first reported instance of H5N8 passing from the animals into humans.

Analysis suggests the virus is not transmitted from person to person, according to Rospotrebnadzor.

“But only time will tell how soon future mutations will allow it to overcome this barrier,” said Ms Popova.

The discovery of this strain “gives us all, the whole world, time to prepare for possible mutations and the possibility to react in a timely way and develop test systems and vaccines,” she added.

Siberia's Vector Institute said on Saturday it would start developing human tests and a vaccine against H5N8, RIA news agency reported.

The WHO has yet to comment on the incident.

Another strain of bird flu - H5N1 - has previously been known to spread to humans.

Almost all cases of avian flu infection in people have been associated with close contact with infected live or dead birds.

Bird flu outbreaks often prompt poultry plants to kill their birds to prevent the virus from spreading.

The vast majority of cases are spread by migrating wild birds, so producing countries tend to keep their poultry indoors or protected from contact with wildlife.

Five outbreaks of the H5N8 strain were detected in poultry farms across the UK last November, leading to the implementation of a prevention zone in England, Wales and Scotland.

Cases were found in Gloucestershire, Dorset, Devon, Cheshire and Kent.

Birds in all affected zones were culled “humanely”, the Department for Environment, Food and Rural Affairs said at the time, and control zones were put in place.

An Avian Influenza Prevention Zone (AIPZ) means it is a legal requirement for all bird keepers to follow strict biosecurity measures.