A Louisiana patient hospitalized with H5N1 bird flu has died, marking the first human fatality in the United States associated with the virus. Despite this development, health officials maintain that the risk to the broader U.S. population remains low.
The Louisiana Department of Health confirmed in a statement that the individual contracted H5N1 through exposure to backyard flocks and wild birds. The patient, who was over 65 and had underlying health conditions, was part of a high-risk group for severe complications.
“While the current public health risk for the general population remains low, individuals who work with birds, poultry, or livestock, or have recreational exposure to these animals, are at higher risk,” the department stated.
Details of the Case
The patient was hospitalized on December 18 and represented the only severe case of H5N1 in Louisiana. It remains the sole confirmed hospitalization linked to the virus in the U.S. during this outbreak. In total, 66 cases of H5N1 have been reported in the United States since the outbreak began, with the first case identified in April 2024. All confirmed cases have been attributed to animal exposure, with no evidence of human-to-human transmission.
H5N1 Mortality Rates and Historical Context
H5N1, first identified during a 1996 outbreak in China, has infected around 900 people globally between 2003 and 2024, according to the World Health Organization (WHO). The virus has caused several notable outbreaks involving human transmission, including in Vietnam (89 cases from 2004-2005), Indonesia (159 cases from 2005-2009), and Egypt (346 cases from 2006-2015).
Globally, the virus has shown a high mortality rate, with approximately 50% of cases resulting in death. In contrast, the U.S. has reported only one death among 66 cases, prompting questions about why the fatality rate appears lower in North America. Experts such as Jeanne Marrazzo and Michael Ison suggest further research is needed to understand these differences.
Monitoring and Preparedness
The U.S. Centers for Disease Control and Prevention (CDC) continues to monitor the spread of H5N1 in livestock and poultry populations. In a statement, the CDC noted that death from the virus is not unexpected given its potential to cause severe illness, including pneumonia, respiratory failure, kidney damage, and septic shock.
The National Institute of Allergy and Infectious Diseases (NIAID) has emphasized the availability of “candidate” vaccines that could be mass-produced in the event of a significant outbreak. A recent trial using Moderna’s technology successfully tested one such vaccine in ferrets, providing hope for mitigating severe cases if the virus spreads more widely.
Safety Recommendations
U.S. health officials advise the public to avoid contact with sick or dead animals and to use personal protective equipment when handling poultry or other animals potentially infected with H5N1. This includes taking precautions around animal feces to reduce exposure risk.
While the situation warrants continued vigilance, health authorities reiterate that the risk to the general public remains low at this time.
