Health officials are considering introducing sidestream tests to detect human avian influenza in the UK after the virus has spread to birds around the world at an unprecedented rate over the past 18 months.
The UK Health Security Agency (UKHSA) is stepping up its preparedness for a human outbreak after a highly contagious variant of H5N1 showed signs of a transition to mammals. This includes developing “scenarios for early human transmission”.
As part of enhanced planning and surveillance, the UKHSA is investigating the use of sidestream equipment for testing for H5N1 in humans in cases of asymptomatic person-to-person transmission.
Officials are also considering developing a blood test that can detect antibodies to the virus and analyze genetic mutations that could indicate an increased risk to a person’s health.
The planned measures contrast with the readiness in the early stages of the Covid pandemic, when officials and ministers admitted they were unaware of the extent of asymptomatic transmission of the virus, which allowed it to go unnoticed by people and spread.
The risk of human infection with avian influenza is currently reported to be low, with cases occurring only in poultry farmers or others who come into close contact with infected birds.
In recent weeks, however, cases of the virus have been reported from mammals amid concerns that it could spread more easily between wild animals.
Scientists fear the virus could eventually spread between people and cause the next pandemic.
The most recent UKHSA assessment states: “Scenarios for early human transmission are being developed to facilitate surveillance readiness, planning and improvement. The technical group agreed on parameters for human early outbreak scenarios.
The UKHSA said it was “working with partners to identify ‘knowledge gaps’ about avian influenza, including whether side-flow equipment for H5N1 testing in humans can be used to develop a blood test that will detect antibodies against the virus and analyze genetic mutations. this would indicate an increased risk to human health.”
An epidemiological analysis of avian influenza in the UK shows that the H5N1 virus continues to spread in wild birds despite a ban introduced last fall.
As of October 2021, 131 cases of avian influenza have been reported in mammals.
Since October, officials have taken samples from 2,310 people who had contact with infected birds and no positive cases have been found.
The UKHSA technical briefing said: “While very high transmission rates in wild birds pose an ongoing risk, there is no evidence to date that the virus is better at infecting humans or other mammals.”
But it adds: “While evidence suggests the virus does not spread easily among humans, there is an increased likelihood of human exposure to the virus due to high concentrations in birds.”
The UKHSA urges people to avoid contact with sick or dead wild birds in public areas such as parks or waterways and to wash their hands after feeding wild birds.
Dr Mira Chand, director of avian influenza emergencies at the UKHSA, said: “Recent evidence suggests that the avian influenza viruses that we see in birds are currently not as easily transmitted to humans. However, viruses are constantly evolving, and we remain vigilant when there are signs of changing population risk, working with partners to close gaps in scientific knowledge.