Source: United Kingdom – Executive Government & Departments
Scientists comment on the first human case of Avian flu detected in the UK, as announced by UKHSA.
Dr Alastair Ward, Associate Professor of Biodiversity and Ecosystem; Programme Lead for Zoology, University of Leeds, said:
How likely is it that the virus has or will spread human-to-human from this case?
“Highly unlikely. The person infected with H5N1 was asymptomatic. Their contacts have been traced and all have tested negative. Very specific genetic changes are required for avian influenzas to become transmissible among humans, and these changes are not present in the viruses isolated in this case.
What could be done to prevent future cases of H5N1?
“Adherence to biosecurity best practice, including the use of PPE and disinfection when handing poultry or material that may have been contaminated by them, may limit transmission of H5N1 from infected poultry to humans. Reporting of symptoms observed within a poultry flock to the Animal and Plant Health Agency, and subsequent statutory testing and control measures are critical for preventing further spread among birds, as they have been in this case.
How worried should we be about this? How does the risk of contracting bird flu differ between people working in close contact with birds versus the general public?
“The UKHSA and APHA have avian influenzas under ongoing surveillance. We know what the genetic changes are that make the viruses more likely to jump to humans and to transmit between humans, and they have not been detected in the UK. Risks to the general public likely remain very low. Risks to people who work in close contact with birds, particularly ducks, geese, swans, chickens and turkeys are greater, but can be reduced by implementing biosecurity best-practice, including use of PPE and disinfection when making contact with birds or material that has been contaminated by them.
Any other information should readers know about the situation?
“This was an isolated case involving a man in his early 80s and who kept a large flock of Muscovy ducks in a domestic setting. The man has isolated since his diagnosis and has been administered a course of antiviral medication as a precautionary measure. His contacts have been traced and tested negative. 19 of the 20 ducks tested were positive for H5N1 and so the flock was culled. These statutory measures seem to have been successful in preventing further spread among birds and to humans.”
Prof Andrew Preston from the Milner Centre of Evolution, and Department of Life Sciences at the University of Bath, said:
“This announcement will rightly provoke concern. The evolution of an influenza virus derived from a high pathogenicity avian influenza clone to one that is adapted to human-to-human spread is one of the most feared infectious disease threats we face. Thankfully, this is yet to happen during the current, prolonged H5N1 outbreak. This case appears to result from high levels of exposure of the individual to the virus due to their workplace contact with infected birds, a known risk factor for contracting the virus. The swift response that include tracing contacts of the individual and their monitoring and prophylactic treatment, is key to minimising any small chance of virus being passed from human to another human host.
“However, this case highlights the continued threat posed by these avian viruses. The mixing of infected birds and other species is the major risk factor for adaptation of the virus to new host species and high vigilance for instances of this is essential to containing any possible onward transmission.”
Professor Wendy Barclay, Regius Professor of Infectious Disease at Imperial College London, said:
“Since the number of cases of H5N1 in poultry premises has increased again this winter, this is not unexpected.
“It’s important to remember that bird flu does not transmit readily between people without several simultaneous adaptive mutations in different genes.
“Genetic sequencing would confirm if this has happened, but with just one individual case, it is highly unlikely.”
Declared interests
Dr Alastair Ward I am a member of the FluMAP and Flu:TrailMAP consortia: multi-disciplinary groups of scientists funded by UKRI and Defra to better understand the ongoing H5N1 panzootic and how to better control it.
Prof Andrew Preston I have received research funding from several companies that make vaccines, but not for any work related to influenza.
For all other experts, no reply to our request for DOIs was received.