Two poultry workers have tested positive for bird flu in England. Health officials say there are no signs of person-to-person transmission and contact tracing is being done as a precaution.
The cases are believed to be linked to exposure to sick birds on a single poultry farm where the two people were known to have recently worked. Neither worker suffered symptoms of infection and both cases were found during routine asymptomatic screening.
The UK Health Security Agency (UKHSA) said the H5 virus had been detected in the two workers, but further sequencing would be carried out. The agency is running a programme of testing workers who deal with birds infected with avian flu.
Here are more details about bird flu:
What is bird flu?
Bird flu is a disease of birds caused by influenza viruses.
What strain of bird flu has been circulating?
A Eurasian strain of H5N1 highly pathogenic avian influenza has been circulating in the UK and Europe.
This strain is a very strong and infectious virus to poultry and other birds, but the risk to human health is considered very low.
What are the signs of bird flu?
Symptoms in birds who are infected with the most serious strain include swollen head, closed and runny eyes, lethargy and depression, lying down and unresponsiveness, lack of co-ordination, eating less than usual and a sudden increase or decrease in water consumption.
Some species such as ducks, geese and swans can carry the avian influenza virus and spread it without showing any signs of illness.
Birds infected with the less serious strain of bird flu, called low pathogenic avian influenza (LPAI), may not show clear signs of infection. They may have mild breathing problems. These signs can indicate bird flu, but the avian influenza virus can only be confirmed through laboratory tests.
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Is bird flu a risk to humans?
The advice from the UK Health Security Agency (UKHSA) is that the risk to public health from the virus is very low. People are advised not to touch or pick up any dead or visibly sick birds that they find.
The UKHSA said it has not detected evidence of human-to-human transmission and that the two newly-announced detections do not change the level of risk to human health, which remains very low to the general population.
What measures have been in place?
A “mandatory housing order” for England and Wales was lifted on April 18, meaning poultry and captive birds could be kept outside again.
Bird keepers had been subject to a national housing order since November 7 to help curb an unprecedented number of bird flu cases – more than 330 had been confirmed in the UK since October 2021.
The Government said poultry and other captive birds could be kept outside again unless they were in a specified protection zone.
Is the virus still circulating in the environment?
In April, Dr Christine Middlemiss, the UK’s chief veterinary officer, said the risk of bird flu infection had reduced following restrictive measures throughout the winter, although bird keepers were encouraged to observe “stringent standards of biosecurity”. The Department for Environment, Food and Rural Affairs (Defra) said the strict rules brought in under the avian influenza prevention zone will still apply, as the virus may still be circulating in the environment for several more weeks.
Places with poor biosecurity had been assessed as medium risk of infection and those with good biosecurity are seen as low risk.