What is avian flu?
Avian influenza, commonly called avian flu or bird flu, is an illness that primarily affects birds. It is caused by influenza viruses that circulate in bird populations. While most infections occur in birds, some strains can infect humans and other animals, prompting health authorities to monitor outbreaks closely.
How many strains exist?
Influenza viruses are diverse, with multiple subtypes. In birds, there are 16 H (hemagglutinin) subtypes and 9 N (neuraminidase) subtypes identified. Bird flu subtypes that have raised concern in humans and poultry include H5, H7, and H10, among others. The combinations of these surface proteins determine the virus’s characteristics and potential risk to animals and humans.
Why are certain subtypes more worrisome?
Some subtypes are more likely to spread among birds or cross the species barrier to humans. H5 and H7 subtypes have caused significant poultry outbreaks and have, in rare cases, led to human infections. Even when human cases are uncommon, these viruses can mutate or reassort, potentially increasing their ability to infect people or transmit in mammals. Health authorities keep a close watch on evolving strains and outbreak patterns.
How is avian flu transmitted?
In birds, avian flu spreads mainly through direct contact with infected birds, contaminated water, feed, surfaces, or secretions. For humans, transmission is rare and usually requires close, prolonged exposure to infected birds or contaminated environments. It is not typically spread from person to person, but certain circumstances can change that, which is why surveillance and biosecurity are critical during outbreaks.
What are the signs in birds and humans?
In poultry, signs can include sudden die-offs, decreased egg production, swelling, respiratory symptoms, and sudden behavioral changes. In humans, symptoms resemble seasonal flu and may include fever, cough, sore throat, muscle aches, and fatigue. Severe cases can lead to pneumonia or other complications, particularly in vulnerable individuals.
Prevention and control
Preventing avian flu relies on strict biosecurity in farms, rapid detection, and controlled culling of infected flocks when necessary. Vaccines for birds exist in some regions but are used selectively due to regulatory and trade considerations. For people, preventive measures include avoiding contact with wild or visibly sick birds, washing hands regularly, and following guidance from public health authorities during outbreaks. Vaccination for humans against avian strains is not routinely available and is typically targeted to high-risk groups during outbreaks.
Global impact and surveillance
Avian flu outbreaks can affect poultry industries, food security, and economies, particularly in regions with large-scale poultry farming. International surveillance networks track outbreaks in birds and, when human cases occur, monitor for signs of human-to-human transmission. Early detection, transparent reporting, and strong biosecurity are essential components of reducing spread and protecting public health.
What you can do
– Stay informed through official health organizations and trusted news sources.
– Practice good biosecurity if you handle poultry or visit farms.
– Avoid handling or consuming sick or dead birds.
– If you work with birds, follow workplace safety protocols and report unusual illness in birds promptly.
