UKHSA update on avian influenza
Latest update from the UK Health Security Agency (UKHSA) on the risk to human health from avian influenza (influenza A H5N1).
Latest update
The UK Health Security Agency (UKHSA) has published its latest technical briefing on avian influenza.
Since the last update, published at the beginning of June, there have been 2 additional asymptomatic human detections of influenza A (H5N1) picked up through our surveillance programme of individuals with direct exposure to infected birds.
Asymptomatic detection may represent contamination of the respiratory tract or infection. Precautionary contact tracing was undertaken, but there is still no evidence of human-to-human transmission and these findings do not change the assessment of human health risk, which remains at Level 3.
There have now been a total of 4 detections through this programme, which was launched in March and aims to detect possible animal to human infections in people who are exposed to infected birds. As of 10 July 2023, 144 individuals from 8 infected premises have been tested through enhanced surveillance of poultry workers.
Dr Meera Chand, Director of Clinical and Emerging Infections at UKHSA, said:
Current evidence suggests that the avian influenza viruses we’re seeing circulating in birds around the world do not spread easily to people.
However, we know already that the virus can spread to people following close contact with infected birds and this is why, through surveillance programmes like this one, we are monitoring people who have been exposed to learn more about these risks.
These detections can follow contamination of the nose and throat from breathing in material from the environment, or can be due to infection. It can be difficult to distinguish these in people who have no symptoms. Following any detection, we will immediately initiate the appropriate public health response.
Previous
2 June 2023
The UK Health Security Agency (UKHSA) has published its latest technical briefing on avian influenza.
Dr Meera Chand, Deputy Director at UKHSA, said:
The evidence suggests that the avian influenza viruses we’re seeing circulating in birds around the world do not spread easily to people. Globally, there is no evidence of human-to-human transmission having occurred. However, viruses evolve all the time and UKHSA continues to closely monitor the situation for any evidence of changing risk to the public, including through our surveillance of people who have come into contact with infected poultry. Our latest risk assessment shows that the risk to the general public remains very low.
29 March 2023
The UK Health Security Agency (UKHSA) has published its latest technical briefing on avian influenza.
UKHSA continues to work closely with the Animal and Plant Health Agency (APHA) to assess the risk to human health from avian influenza. The current assessment does not find any change in the risk to human health since the last briefing.
UKHSA continues to work to improve detection of emerging infections of all kinds. At the current risk level for avian influenza, we have taken precautionary measures to enhance influenza surveillance, including surveillance for evidence of severe disease via NHS Intensive Care Units. To date, no cases have been detected.
In this briefing we include estimates of the time it would take to detect a first case of avian influenza, based on a variety of different testing and surveillance approaches - whether testing asymptomatic individuals in the community, testing all people admitted to hospital with influenza-like illness, or those admitted to intensive care with these symptoms - with a variety of different assumptions about disease severity and infectivity. These are all illustrative scenarios, which are to be used for planning purposes, and are not predictions of what will happen in the future.
As there has been no evidence globally of sustained human-to-human transmission of influenza A(H5N1), and as we cannot predict the characteristics of a novel influenza virus, we have looked to outbreaks of other respiratory viruses to help us design which testing and surveillance systems would be necessary at the beginning of an outbreak to detect human cases of avian influenza. These scenarios include different options for clinical severity and age profiles of those suffering severe disease to allow us to look at a range of different options for testing and estimate when these would allow us to find a case of avian influenza.
UKHSA and APHA are committed to open data sharing and the data and code for this briefing are available in our repository or in international genomic databases to facilitate discussion between countries as well as continued work with academic partners.
Dr Meera Chand, Deputy Director 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. It is right that we prepare for the emergence of novel influenza viruses and we are working with partners to ensure that we have the tools and capabilities in place for these and other emerging infections.
23 February 2023
The UK Health Security Agency (UKHSA) has published its latest technical briefing on avian influenza. UKHSA continues to work with partners including the Animal and Plant Health Agency (APHA) to assess the risk to human health from avian influenza and improve our understanding of the virus. While the very high levels of transmission in wild birds present a constant risk, there is no evidence so far that the virus is getting better at infecting humans or other mammals.
People who have had contact with infected birds enter a period of monitoring by UKHSA health protection teams, with the level of monitoring dependent of whether individuals were wearing adequate personal protective equipment (PPE). Between 1 October 2022 and 14 February 2023, 2,310 people were monitored through this process, with samples taken from people who developed any flu or cold like symptoms in the 21 days following their contact with an infected bird. No positive cases have been found to date.
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. There are simple steps that individuals can take to reduce their exposure to avian influenza in wild birds:
- avoid contact with sick or dead wild birds in public areas such as parks or waterways
- 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.
UKHSA 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.
Last updated 14 July 2023 + show all updates
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