Graphic // CDC
By: Ashley Bergeron
Staff-Writer
With the first confirmed human death on Jan. 6, Avian Influenza – commonly known as Bird Flu – is being discussed more often. Let’s talk about what exactly Avian Influenza is, its symptoms and what you can do to prevent yourself and your loved ones (including furry and feathery ones) from getting the disease.
Influenza viruses can be classified into four different types: A, B, C and D. The majority of human influenza viruses and all avian viruses are classified as type A. Influenza A viruses are then divided into various subtypes depending on the combination of two proteins: Hemagglutinin (H) and Neuraminidase (N). Hemagglutinin has 18 variations, and Neuraminidase has 11 variations. In birds, 16 H and 9 N have been detected. Only two types of Influenza A viruses (H17N10 and H18N11) cannot affect birds, but they do infect bats.
Avian influenza viruses are then divided into two categories: low-pathogenic avian influenza (LPAI) and highly pathogenic avian influenza (HPAI). LPAIs cause mild disease in poultry and account for the majority of avian influenza strains. HPAIs can cause severe disease and death in poultry and can potentially infect people and other animals. The subtype of bird flu that has people worried is H5N1.
H5N1 is an HPAI and has resulted in millions of deaths, specifically in poultry and wild birds. According to the World Organization for Animal Health (WOAH), about 9.1 million poultry birds died or were culled in December 2024, mostly in the Americas. This is a worldwide epidemic that is affecting numerous poultry birds across the globe. Poultry outbreaks of H5N1 mainly occur in spring and fall, as that’s when migratory birds (primary vectors) migrate from one location to the next.
Cases of mammals being infected with bird flu have also risen over the last year. Since March 26, 2024, 928 dairy cattle herds have been infected with H5N1 in 16 states (including Michigan). Also, since February 2024, 49 domestic cats have been affected with H5N1, which has a mortality rate of 67% in felines.
Symptoms of H5N1 are similar to other influenza viruses with mild fever, headaches, sore throat, runny or stuffy nose, muscle aches, fatigue and cough. If you or your cat have severe symptoms like seizures, difficulty breathing, lethargy or altered consciousness, seek immediate medical help. It is unlikely for you to get sick with H5N1 from your cat, but it is not impossible.
There are many ways to protect yourself from bird flu. The first thing is to not drink raw (unpasteurized) milk. As there is currently a H5N1 outbreak in dairy cattle, drinking unpasteurized milk is a way to get the virus into your system. Pasteurization is the process of heating milk to a certain temperature to kill bacteria and viruses without affecting the taste or nutrition value. If you are going to drink raw milk, regularly check to see if there is an outbreak of H5N1 at the source or a recall of the milk.
People who are more at risk are poultry and dairy farmers, food processing workers, public health workers, slaughterhouse workers, hunters, veterinarians and veterinary staff, wild animal faculty workers and backyard flock owners.
If you work in a food processing plant or on a poultry farm, your employer should already have preventative measures in place, such as personal protective equipment and hygiene guidelines.
Backyard flock owners can follow preventive measures given by the CDC like wearing the proper PPE. If you are a poultry owner and suspect that one of your birds is sick, call your closest food production vet or emergency vet for help.
Currently, H5N1 or any other avian influenza viruses do not spread by human-to-human contact, and human cases to date have been contracted from animals and animal products. According to the CDC, this virus has a low risk of affecting public health.
For more information on avian flu, visit woah.org.
Graphic // Delaware Department of Agriculture