ECDC proposes targeted human testing for avian flu in areas with ongoing outbreaks
In a technical report published today, ECDC proposes a targeted testing approach in areas with ongoing avian influenza outbreaks in poultry and detections in wild birds and other animals, focusing on severe respiratory or unexplained neurological disease.
ECDC also continues to assess the risk of infection with currently circulating avian H5 influenza viruses in Europe as low for the general population in the EU/EEA. The risk also remains low to moderate for occupationally or otherwise exposed people to infected birds or mammals (wild or domesticated); this assessment covers different situations that depend on the level of exposure. Human infections with avian influenza remain a rare event.
During the winter months when seasonal influenza viruses are circulating in the population, testing and sub-typing approaches for avian influenza virus need to be proportionate to the epidemiological situation and the capacities of reference laboratories. To identify human infections with avian influenza virus - without overburdening healthcare and diagnostic laboratories during the influenza season - the following approach is proposed:
- People admitted to hospitals with respiratory symptoms should be asked about exposure to sick or dead birds, wild or other animals in the two weeks before symptom onset or before admission ( if symptom onset date cannot be defined). They should be tested based on an exposure risk assessment by the clinician. Specimens from hospitalised patients with very severe influenza virus infections could be considered for sub typing, particularly if they are believed to be part of a nosocomial outbreak.
- Consideration should be given to testing hospitalised patients with unexplained viral encephalitis/meningoencephalitis for seasonal influenza virus. Specimens positive for type A virus should be further sub typed for seasonal influenza viruses to rule out avian influenza virus.
- Clusters of severe respiratory infections requiring hospitalisation should be investigated and tested for avian and other influenza viruses if routine testing for respiratory
pathogens is inconclusive. - Wastewater surveillance could be considered as an additional monitoring system locally in affected areas, however, so far there is very limited experience and evidence of wastewater surveillance being used to identify low level circulation of zoonotic influenza virus infections in the population.
