3-year-old girl critically ill with H5N1 in Mexico; 1st human case in country

Mexican health officials have confirmed the country’s first human case of H5N1 bird flu, involving a three-year-old girl who remains in critical condition at a hospital in northern Mexico.

The case, reported in the state of Durango, brings the total number of confirmed human infections in the Americas to 75 since April 2022, according to data from the Pan American Health Organization (PAHO).

In a statement issued on Friday, Mexico’s Health Ministry said the child is a resident of the state of Durango and is currently hospitalized at a tertiary care center in Torreón, Coahuila. Local media reported that she lives in the rural community of La Aurora, in the municipality of Gómez Palacio.

The National Institute of Epidemiological Diagnosis and Reference (InDRE) confirmed the H5N1 infection on April 1. The girl initially received treatment with oseltamivir, an antiviral medication commonly used for influenza.

Local health authorities said the girl began showing symptoms in late March and was hospitalized with severe respiratory distress. As of now, no additional suspected human cases have been identified among her family members, all of whom have tested negative for the virus.

Officials in Durango stated on Saturday that the child may have had contact with infected birds, but they are not ruling out other possible transmission routes, including the consumption of undercooked poultry. The origin of infection remains under investigation.

Residents in nearby communities told El Sol de la Laguna that authorities have visited local properties to collect samples from birds in homes and backyard poultry farms. Inhabitants said that samples were taken from chickens and roosters that had died suddenly, and some families have begun burning the carcasses to prevent further spread. As of the latest update, Mexico has not reported any active cases of bird flu in commercial poultry facilities.

Mexico reported the world’s first confirmed human case of H5N2 bird flu in June 2024. The case involved a 59-year-old man from the State of Mexico who had no known contact with poultry and later died from complications. Several outbreaks of H5N2 in poultry had been detected in the region in the months preceding the infection.

LINK: A list of all human cases of H5N1 bird flu since 2021

The specific clade involved in Mexico’s H5N1 case has not yet been identified, but it is believed it may belong to clade 2.3.4.4b, which has been the predominant strain detected in the Americas since 2022. This clade has been reported in human cases across a wide geographic range, from Chile to Canada, and has been especially prevalent in the United States.

Globally, concerns about avian influenza have intensified since the emergence of clade 2.3.4.4b, which has spread widely among birds and mammals in recent years. Although most human cases have been linked to direct contact with infected poultry and dairy cattle, the virus’s growing geographic reach and increasing number of mammalian infections have raised alarm among public health experts.

So far, one death from H5N1 has been confirmed in the Americas during the current outbreak: a case in the U.S. state of Louisiana. Investigations into the Durango case are ongoing.