The United States has confirmed the first known serious human infection of H5N1 bird flu, in a person in Louisiana who is believed to have contracted the virus through contact with sick or dead birds in a backyard flock.
The Centers for Disease Control and Prevention announced Wednesday that its labs were able to confirm Louisiana’s case reported on Friday.
So far this year, 61 cases of H5N1 bird flu have been confirmed in humans in the US. Until the Louisiana case, all had very mild symptoms.
Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, confirmed the case during a news conference on the H5N1 situation in the country. But Daskalakis deferred all questions about the Louisiana individual’s age, previous health status and symptomology to the state health department. Louisiana has declined to release any information other than the fact that the person lives in the southwestern part of the state.
“Due to patient confidentiality and the ongoing public health investigation, we are unable to provide additional information or comment on the individual’s condition,” communications director Emma Herrock told STAT via email.
Daskalakis did reveal that genetic sequencing of the virus shows it is not the version of H5N1 circulating in US dairy cows, clade 2.3.4.4b genotype B3.13. Instead, it is a version of the virus – 2.3.4.4b genotype D1.1 – that is circulating among wild birds. A recent serious illness in a teenager in British Columbia, Canada, was also caused by viruses of the D1.1 genotype.
The Canadian teenager spent weeks in critical condition in hospital, on a ventilator because he or she could not breathe on his own. A British Columbia official told STAT on Tuesday that the teen is no longer in intensive care, although he or she remains in hospital.