Mexico: first human case of AI A(H5N2)
On 23 May 2024, Mexican health authorities reported to PAHO/WHO a deceased case of human infection with avian influenza A(H5N2) virus, detected in Mexico. The patient was a 59-year-old male, with multiple underlying conditions, who developed respiratory infection on 17 April, sought medical attention on 24 April and was hospitalised, but died on the same day. The case had no reported travel in the three weeks prior to symptom onset. An investigation is ongoing to understand the source of infection. A respiratory sample taken on 24 April was analysed on 8 May at the National Institute of Respiratory Diseases and on 20 May at the Institute of Epidemiological Diagnosis and Reference in Mexico using RT-PCR analysis and sequencing. The subtype was confirmed as A(H5N2) but no further information on sequence deposition, genetic clade or mutational analyses are available at this time. No additional cases have been detected among close contacts of the case. These included household contacts (no reported illness, no sampling possible), contacts among healthcare workers (all asymptomatic, only sampled on 27 May) and twelve additional contacts from the vicinity of the case's residence (seven with and five without symptoms, test results also as of 28 May). In March 2024, a high pathogenicity avian influenza A (H5N2) outbreak was detected in a backyard poultry farm in the state of Michoacán. So far it has not been possible to establish a link between the human case and the outbreak in poultry.
