The UK Health Security Agency (UKHSA) reported Friday that there have been 2 additional asymptomatic human detections of influenza A (H5N1) picked up through the 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.
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.