Senegal - Base Map Credit Wikipedia
#19,114
In late March we learned of the first (imported) human infection with H9N2 in Europe when Italy's MOH announced a hospitalized case (see Italy: MOH Statement on First LPAI H9N2 Human Case in Europe (imported)).
At that time, few details were made available, including the country of origin.
Yesterday the WHO released a detailed DON (Disease Outbreak News) report, where we learn that the infected individual was a man who had traveled to Italy after staying in Senegal for more than 6 months - who presented at a local hospital with fever and persistent cough - and who tested positive for both Mycobacterium tuberculosis and LPAI H9N2.
Unlike most H9N2 infections we've seen in Asia and (less often) in Africa, this patient denied having contact with poultry, birds, wildlife, or a rural environment. The source of his infection remains unknown.
This is the second human case to be reported from Senegal.
The first occurred during the opening wave of COVID (January 2020); no WHO DON was generated, and most of what we know about it comes from a report (Genetic characterization of the first detected human case of low pathogenic avian influenza A/H9N2 in sub-Saharan Africa, Senegal) published several months later.
The first case - involving a 16 month-old child - occurred before H9N2 had been identified in Senegal's poultry. While details on this 2020 case are scant, I can find no indication of a likely exposure.
In 2023's Influenza A Virus in Pigs in Senegal & Risk Assessment of AIV Emergence and Transmission to Humans, we saw a study that found evidence of A/H9N2, A/H5N1, A/H7N7 and A/H5N2 in local pigs, with H9N2 and H7N7 antibodies detected in > 50% of samples tested.
The authors wrote:
Serological analyses revealed that 83.5% (95%CI = 81.6–85.3) of the 1636 sera tested were positive for the presence of antibodies against either H9N2, H5N1, H7N7 or H5N2. Influenza H7N7 (54.3%) and H9N2 (53.6%) were the dominant avian subtypes detected in Senegalese pigs.
Given the co-circulation of multiple subtypes of influenza viruses among Senegalese pigs, the potential exists for the emergence of new hybrid viruses of unpredictable zoonotic and pandemic potential in the future.
In 2024, Ghana (also in West Africa) reported a human case; that of a 5 y.o. (see WHO DON: Avian Influenza A(H9N2) - Ghana), who once again, reportedly had `. . . no known history of exposure to poultry or any sick person with similar symptoms prior to onset of symptoms.'
Avian Influenza A(H9N2) - Italy
10 April 2026
Situation at a glance
On 21 March 2026, the National International Health Regulations (IHR) Focal Point for Italy notified the World Health Organization (WHO) of the identification of a human case of avian influenza A(H9) in an adult male returning from Senegal. Next generation sequencing confirmed Influenza A(H9N2). According to epidemiological investigations, the patient had no known history of exposure to poultry or any person with similar symptoms prior to the onset of symptoms.
Authorities in Italy have implemented a series of measures aimed at monitoring, preventing and controlling the situation. According to the IHR (2005), a human infection caused by a novel influenza A virus subtype is an event that has the potential for high public health impact and must be notified to the WHO. This is the first imported human case of avian Influenza A(H9N2) reported in the European Region. Based on currently available information, WHO assesses the current risk to the general population posed by A(H9N2) viruses as low but continues to monitor these viruses and the situation globally.
Description of the situation
On 21 March 2026, the National IHR Focal Point for Italy notified WHO of the identification of a human case of avian influenza A(H9) in an adult male.
The patient had been in Senegal for more than six months and traveled to Italy in mid-March. Upon arrival, he visited the emergency department with a fever and a persistent cough.
On 16 March, a bronchoalveolar lavage specimen was collected, which showed a positive Mycobacterium tuberculosis result, as well as detection of un-subtypeable influenza A virus. The patient was placed in a negative-pressure isolation room with airborne precautions. He was treated with antitubercular medication and antiviral oseltamivir. By 9 April, his condition was stable and improving.
On 20 March, a regional reference laboratory identified the A(H9) subtype, and on 21 March, next-generation sequencing confirmed influenza A(H9N2). Initial genetic findings suggest the infection was likely acquired from an avian source linked to Senegal. Additional samples have been sent to Italy’s National Influenza Center, where further characterization confirmed virus subtype Influenza A(H9N2), with close genetic similarity to strains previously identified in poultry in Senegal.
No direct exposure to animals, wildlife or rural environments was identified. There was also no reported contact with symptomatic or confirmed human cases. Further epidemiological investigations on the source of exposure are ongoing.
Contacts identified in Senegal were asymptomatic. All identified and traced contacts in Italy have tested negative for influenza and completed the period of active monitoring for the onset of symptoms and the quarantine required by national guidelines. They also received oseltamivir as a preventive measure.
Epidemiology
Animal influenza viruses normally circulate in animals but can also infect people. Infections in humans have primarily been acquired through direct contact with infected animals or through indirect contact with contaminated environments. Depending on the original host, influenza A viruses can be classified as avian influenza, swine influenza, or other types of animal influenza viruses.
Avian influenza virus infections in humans may cause diseases ranging from mild upper respiratory tract infection to more severe diseases and can be fatal. Conjunctivitis, gastrointestinal symptoms, encephalitis and encephalopathy have also been reported.
Laboratory tests are required to diagnose human infection with influenza. WHO periodically updates technical guidance protocols for the detection of zoonotic influenza using molecular methods.
Human infections with influenza A(H9) viruses have been reported from countries in Africa and Asia, where these viruses are also detected in poultry. The majority of cases of human avian influenza A(H9N2) infection have been reported from China. This is the first imported human case of avian Influenza A(H9N2) virus infection reported in the European Region.
Public health response
Contact tracing procedures have been initiated, and relevant authorities in Italy, as well as internationally (National IHR Focal Point for Senegal, WHO, and European Centre for Disease Prevention and Control (ECDC)) have been informed through IHR channels. Once avian influenza was suspected, the response moved quickly from hospital-level management to regional laboratory confirmation and national coordination. Additionally, the regional surveillance system was notified, integrated within the One Health avian influenza reporting framework.
WHO risk assessment
Most reported human cases of A(H9N2) virus infection have been linked to exposure to infected poultry or contaminated environments, with the majority of cases experiencing mild clinical illness. Sporadic human cases following exposure to infected birds or contaminated environments can be expected since the virus remains enzootic in poultry populations.
Avian influenza A(H9N2) viruses have been detected in poultry and environmental samples collected at live bird markets in Senegal and authorities in the country reported a human case of infection with an A(H9N2) virus in 2020.
Current epidemiological and virological evidence indicates that none of the characterized influenza A(H9N2) viruses thus far have acquired the ability for sustained transmission among humans. Thus, the likelihood of sustained human-to-human spread is low at this time. Infected individuals traveling internationally from affected areas may be identified in another country during or after arrival. However, if this were to occur, further community-level spread is considered unlikely. The risk assessment would be revisited if and when further epidemiological and virological information becomes available.
WHO advice
This case does not change the current WHO recommendations on public health measures and surveillance of influenza.
The public should avoid contact with high-risk environments such as live animal markets/farms or surfaces that might be contaminated by poultry feces. Respiratory protection is highly recommended for those handling live or dead (including slaughtering) poultry in occupational or backyard-farming settings. Good hand hygiene, i.e. frequent washing of hands or the use of alcohol-based hand sanitizer is recommended. WHO does not recommend any specific additional measures for travelers.
Under Article 6 of the IHR, all human infections caused by a new subtype of influenza virus are notifiable. The case definition for notification of human influenza infection caused by a new subtype under the IHR is provided here. State Parties to the IHR are required to immediately notify WHO of any laboratory-confirmed case of a human infection caused by such an influenza A virus.
WHO advises against the application of any travel or trade restrictions based on the current information available on this event.
In 2024 the ECDC issued guidance for member nations on Enhanced Influenza Surveillance to Detect Avian Influenza Virus Infections in the EU/EEA During the Inter-Seasonal Period., which cautioned:
Sentinel surveillance systems are important for the monitoring of respiratory viruses in the EU/EEA, but these systems are not designed and are not sufficiently sensitive to identify a newly emerging virus such as avian influenza in the general population early enough for the purpose of implementing control measures in a timely way.
It is fair to assume that novel flu detection is even less likely in medically underserved communities. Which means there could easily be more community cases in West Africa than have been reported.
