First Fatal Case of H5N2 Avian Influenza Reported in Mexico Amid Rising Concerns of Bird Flu Spread to Humans
In a chilling revelation that underscores the persistent threat of avian influenza, the World Health Organization (WHO) has confirmed the first-ever fatal human case of the H5N2 strain of bird flu in Mexico. This development has heightened concerns over the potential for avian influenza viruses to spill over into the human population.
The 59-year-old patient, a resident of Mexico, had no known history of exposure to poultry or other animals, adding a layer of mystery to his infection. According to WHO, the patient developed fever, nausea, diarrhea, shortness of breath, and general malaise on April 17. He was hospitalized on April 24 at the National Institute of Respiratory Diseases in Mexico City but tragically passed away the same day.
Health officials disclosed that the patient had multiple underlying health conditions, including chronic kidney disease, type 2 diabetes, and long-term systemic arterial hypertension. He had been bedridden for three weeks prior to contracting the virus. Despite extensive contact tracing and testing of 17 hospital contacts and 12 people near the patient’s residence, no further cases have been documented, and all tests for H5N2, COVID-19, and other influenza strains have returned negative.
The source of the patient’s infection remains unknown. Notably, there was an H5N2 outbreak reported at a backyard poultry farm in Michoacan, a state neighboring where the patient lived. This raises concerns about potential environmental exposure to the virus.
While H5N2 is a new strain in humans, it is distinct from the H5N1 strain currently circulating in the United States, which has infected dairy cows and led to mild cases in three farmworkers. Despite these infections, the Centers for Disease Control and Prevention (CDC) maintains that the risk to the general public remains low.
The confirmation of H5N2 in a human has alarmed health experts, emphasizing the need for rigorous surveillance. Dr. John Brownstein, an epidemiologist at Boston Children’s Hospital, noted, “This first case is a wake-up call. It reminds us that influenza viruses can evolve, and continued surveillance of these viruses in both animals and humans is crucial.”
In the United States, the H5N1 strain has spread to multiple states, infecting numerous dairy herds and even feral cats. Minnesota and Iowa recently reported their first detections of avian flu in dairy cattle, contributing to a growing outbreak that now spans 86 herds across nine states. Symptoms in cattle include fever, decreased milk production, and changes in manure consistency.
This outbreak has prompted warnings from scientists about the potential for avian influenza viruses to acquire mutations that could facilitate human infection. Dr. Paul Offit of the Vaccine Education Center at Children’s Hospital of Philadelphia cautioned, “The main question among experts is whether the H5N2 has mutated in some way that has made it easier to spread to humans.”
Interestingly, these developments come amid unusual findings in wastewater sampling, where higher-than-average levels of influenza A virus have been detected, suggesting unusual viral activity.
The WHO and CDC continue to monitor the situation closely, emphasizing that while the immediate risk to public health is low, the evolving nature of influenza viruses requires constant vigilance. The recent case in Mexico, coupled with the broader spread of H5N1 in livestock, underscores the critical need for ongoing research, surveillance, and preparedness to mitigate potential outbreaks of avian influenza in humans.