Italy has reported the first imported human case of H9N2 avian influenza in the European Region. The patient, a traveler returning from Senegal, was identified through routine surveillance. WHO published the case in its Disease Outbreak News on April 3, 2026, rating the public health risk as low.
This is a single imported case with no secondary spread. But H9N2 occupies a unique and concerning position among avian influenza viruses, one that makes even a single case worth tracking.
What is H9N2?
H9N2 is a low pathogenicity avian influenza (LPAI) virus, meaning it typically causes mild or no disease in poultry. That distinguishes it sharply from H5N1, which is highly pathogenic and kills birds rapidly. Infected chickens with H9N2 may show only a slight drop in egg production or mild respiratory symptoms. Many show no signs at all.
This low profile is part of the problem. Because H9N2 doesn't kill birds dramatically, it circulates widely in poultry populations without triggering the kind of mass die-offs that prompt aggressive veterinary response. H9N2 is now endemic in poultry across large parts of Asia, the Middle East, and Africa. In some regions, seroprevalence surveys suggest that 50-80% of poultry flocks carry antibodies to H9N2.
How many human cases have occurred?
Sporadic human infections with H9N2 have been documented since 1998, when two children in Hong Kong tested positive. Since then, roughly 100 human cases have been confirmed globally, with the majority in China, Egypt, Bangladesh, and other countries with extensive poultry farming and limited biosecurity.
Most human cases present as mild respiratory illness. The case fatality rate among detected cases is low - significantly lower than H5N1's reported CFR of over 50%. However, the total number of human infections is almost certainly underestimated because mild cases rarely get tested for avian influenza subtypes.
Why does H9N2 matter for pandemic preparedness?
H9N2 matters less for what it does to people directly and more for what it does to other influenza viruses. H9N2 has repeatedly donated its internal gene segments to other avian influenza viruses through a process called reassortment, where two different influenza viruses co-infect the same cell and swap gene segments.
The H7N9 virus that killed 616 people in China between 2013 and 2017 carried internal genes from H9N2. Some H5N1 strains circulating in poultry have also incorporated H9N2 gene segments. In laboratory studies, H9N2 internal genes have been shown to enhance the replication efficiency of other influenza subtypes in mammalian cells.
Because H9N2 is so widespread in poultry, it creates enormous opportunities for reassortment with other avian or human influenza viruses. A poultry flock carrying H9N2 that becomes co-infected with H5N1 or a seasonal human flu strain could serve as a mixing vessel for a new virus with characteristics of both parents. This is the scenario that keeps influenza researchers alert whenever H9N2 surfaces.
The Italy case in context
The Italian case fits the established pattern of sporadic human infection through direct poultry contact. The patient traveled to Senegal, where H9N2 circulates in local poultry populations, and likely acquired the infection through direct or close exposure to infected birds. No contacts developed symptoms, and no onward transmission occurred.
This is Europe's first documented imported H9N2 case, which reflects improvements in surveillance rather than a change in the virus's behavior. European countries have strengthened influenza testing protocols following the H5N1 outbreaks in dairy cattle and poultry across the Americas. The fact that this case was caught at all is a sign that detection systems are working.
How does this compare to the H5N1 situation?
The H5N1 avian influenza situation is a fundamentally different risk. H5N1 is highly pathogenic in birds, has caused severe disease and death in mammals (including dairy cattle, foxes, bears, seals, and domestic cats), and has a reported human CFR above 50%. H5N1 has shown worrying mammalian adaptations, including mutations in the PB2 gene that improve replication at human body temperature.
H9N2 has not shown the same trajectory. It remains low pathogenicity in birds, causes mild disease in the humans it infects, and has not acquired the key mutations associated with efficient mammalian transmission. The danger of H9N2 is indirect: it is a gene donor that could help another virus become more dangerous.
What to watch
WHO's risk assessment for this case is low, and PandemicAlarm concurs. The key indicators that would change that assessment: evidence of human-to-human transmission of H9N2, detection of reassortant viruses combining H9N2 internal genes with surface proteins from higher-pathogenicity subtypes, or a cluster of human cases without direct poultry contact.
For now, this case reinforces the importance of maintaining strong avian influenza surveillance in countries where multiple subtypes co-circulate. H9N2's status as a zoonotic disease with pandemic-enabling potential makes every human case worth documenting, even when the individual case is mild. Track avian influenza events on the PandemicAlarm map and check our disease risks by region page for travel-specific guidance.