Public health officials are considering introducing lateral flow tests to detect avian flu in people in the UK after an unprecedented spread of the virus in birds worldwide in the past 18 months.
The UK Health Security Agency is stepping up its preparedness for an outbreak of the virus in humans after the highly infectious H5N1 variant showed signs of jumping to mammals. This includes developing “scenarios for early human transmission”.
As part of the increased planning and surveillance, the UKHSA said it is looking at whether lateral flow devices could be deployed to test for H5N1 in humans in the event of asymptomatic transmission among people.
Officials are also looking at developing a blood test that could detect antibodies against the virus and analysis of the genetic mutations that would signal an increased risk to human health.
The planned measures are in contrast to the preparedness in the early stages of the Covid pandemic, when officials and ministers have admitted they were not aware of the extent of asymptomatic transmission of the virus, allowing it to spread undetected through human populations.
At present, the risk of bird flu in humans is described as low, and the only cases have been among poultry workers or others who come into close contact with infected birds.
But in recent weeks there have been recorded incidents of the virus affecting mammals, with fears that it could evolve to spread more easily between wildlife.
Scientists are concerned that the virus could at some stage evolve further to spread between humans and trigger the next pandemic.
The latest assessment from the UKHSA says: “To facilitate preparedness, planning and improvements to surveillance, scenarios of early human transmission are being developed. Parameters for early human outbreak scenarios were agreed by the Technical Group.”
The UKHSA said it is “working with partners to identify ‘knowledge gaps’ around avian influenza, including whether lateral flow devices could be deployed to test for H5N1 in humans, developing a blood test that detects antibodies against the virus and analysis of the genetic mutations that would signal an increased risk to human health”.
Epidemiological analysis of avian flu in the UK shows that, despite a compulsory housing order imposed last autumn, the H5N1 virus has continued to spread in the wild bird population.
There have been 131 cases of avian flu in mammals since October 2021.
Since October, officials have been taking samples from 2,310 people who have had contact with infected birds and no positive cases have been found.
The UKHSA technical briefing says “whilst the very high levels of transmission in wild birds presents a constant risk, there is no evidence so far that the virus is getting better at infecting humans or other mammals”.
But it adds: “While the evidence suggests that the virus does not pass easily to people, there is an increased chance of people coming into contact with the virus due to the high levels in birds.”
The UKHSA urges people to avoid contact with sick or dead wild birds in public areas such as parks or waterways, and wash hands after feeding wild birds.
Dr Meera Chand, incident director for avian influenza at UKHSA, said: “The latest evidence suggests that the avian influenza viruses we’re seeing circulating in birds do not currently spread easily to people. However, viruses constantly evolve, and we remain vigilant for any evidence of changing risk to the population, as well as working with partners to address gaps in the scientific evidence.