Bird Flu Outbreak Details
What is Bird Flu?
Bird flu, an avian influenza virus, is highly pathogenic to birds. Known as Influenza A (H5N1), it has other subtypes like H1N1 and H3N2 that infect humans. Identified initially in 1996, the current H5N1 strain emerged in farmed geese in Guangdong, China, and has since spread globally.
Spread and Impact on Birds
From 1996, the virus spread through Southern Asia, the Middle East, Africa, Europe, and appeared in North America in 2014. Post-2021, it has spread across North and South America. It primarily affects birds, leading to the depopulation of millions of poultry in the U.S. Mammals, particularly those predatory or scavenging, have also been infected, but inter-mammal viral transmission is rare.
Human Infections
Since 2003, 868 global human infections of H5N1 have been reported, with a 53% fatality rate. The US witnessed two mild cases: one in Colorado (2022) and another in Texas (2024).
Dairy Cows and Milk Safety
In March 2024, bird flu was detected in Texas dairy cows, spreading to 36 herds across nine states. The virus, found in 1 out of 5 milk samples, is inactive in pasteurized milk, making it safe for consumption. However, raw milk is highly advised against, given reports of severe outcomes in barn cats consuming it.
Wastewater Monitoring
Researchers analyzing wastewater from 190 sites in 41 states reported a surge in Influenza A, suggesting that bird flu might be widespread. Efforts are ongoing to monitor virus levels, especially in wastewater from cities with known cattle infections.
These findings are critical as health officials continue to grapple with the implications of this avian flu strain.