The COVID-19 pandemic erased over a year of our lives. 2020 was a year of isolation and death. Experiencing a pandemic should be a once in a lifetime event, but only five years after the Coronavirus pandemic, scientists are already concerned that a new pandemic could be on the horizon. H5N1, a strain of bird flu, has been spreading throughout the U.S for the last four years. The virus originated in birds but has since spread to cattle and now humans. While the current strain, H5N1, can’t spread from human to human yet, experts are worried that as the virus continues to mutate, it could become more easily transmissible between humans. Should this occur, it could lead to the next pandemic.
What is Bird Flu?
Bird flu is a subtype of influenza A, which is the most common form of influenza. According to the CDC, “influenza A viruses are the only influenza viruses known to cause flu pandemics.” There are many different strains of bird flu but the one of most concern is the H5N1 strain. This strand has rapidly mutated, spreading to more species than just birds.
While this may seem to have become an issue only recently, scientists have been raising alarm bells for years. Since 2022, 160 million birds have been killed by the virus or put down to prevent spreading the infection, causing egg prices to hike. The USDA predicted that egg prices will continue to rise another 20.3% by the end of the year with market experts blaming the inflation on bird flu.
In addition to devastating bird populations, the virus mutated and spread to cattle in early 2024, leading to cases of human infections. 70 Americans have contracted H5N1, culminating in one death of a person with underlying health issues. This is a relatively small number but the true number of infections is likely much higher as many cases go undocumented.
Bird flu presents itself the same way as other variants of influenza. Symptoms of bird flu include nasal congestion, sore throat, muscle aches, fatigue, pink eye, cough, fever, nausea, vomiting, and shortness of breath. This means many could have contracted the virus unknowingly. Some cases have also been asymptomatic, making the disease even harder to detect.
History of Bird Flu
The first recorded case of bird flu was in 1878 in Northern Italy. It was associated with poultry and referred to as “fowl plague.” By the 1900s, scientists discovered that it was caused by a virus and in 1955 it was found to be a variant of influenza A. In 1981, the fowl plague’s name was changed to avian influenza A, as it is known now.
Bird flu has two subcategories; highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI). The majority of bird flu cases in birds are classified as LPAI and result in little disease as opposed to the severe disease-inducing HPAI. Despite this, both LPAI and HPAI strains have been shown to cause serious symptoms in humans.
The most notable outbreak of influenza A in history was the 1918 pandemic. More commonly known as the Spanish flu, the virus resulted in the deaths of 50 million people. Scientists have since found that the 1918 virus was derived from avian influenza which mutated and likely spread to mammals just before the 1918 pandemic.
Since then, the world has gone through three influenza pandemics. This includes the 1957 H2N2 pandemic, the 1968 H3N2 pandemic, and the 2009 H1N1 pandemic. “All previous flu pandemics came from a virus that started first in birds and animals (including pigs), then ‘spilled over’ into humans. We worry particularly about H5N1 because it appears to cause more severe illness in humans,” said Dr. Jay Varma, an epidemiologist who worked for the CDC from 2001-2021.
In the history of bird flu outbreaks, human-to-human spread is very rare, with none having yet to occur in the U.S. However, there have been instances of human-to-human transmission of bird flu in the past. The first time bird flu spread from human-to-human was in Hong Kong in 1997 when there was an outbreak of HPAI H5N1.
Other notable outbreaks include in 1983, in the U.S., resulting in 170 million avian deaths. Another notable outbreak was in the years following the 2004 outbreak of H5N1 in Asia in which bird flu spread to 60 countries. By 2022, the H5N1 strain reached the U.S. again.
What’s unique about the current outbreak is that it is the U.S.’s, “largest-ever outbreak of bird flu. In 2024, the virus seemed to jump from just infecting wild birds, chickens, and ducks to also spreading to dairy cows—something we’ve never seen before—and has now infected a small number of cats and humans,” said Dr. Varma.
How does it spread?
According to the CDC, “There is no evidence of sustained human-to-human H5N1 virus transmission in any country, and limited, non-sustained human-to-human H5N1 virus transmission has not been reported worldwide since 2007.” This means that as of now, human-to-human transmission is very rare. The last recorded case was decades ago, and even then there was never any sustained spread of the virus. If one person spread it to another, that second person did not spread it to many others and so on. Essentially, the spread was minimal.
While the H5N1 strain has been spread from human-to-human in other countries, this has not yet been the case in the US. So far the virus has only spread from animals-to-humans. Bird flu is spread by coming into contact with the bodily fluids, such as the excretion and saliva, of infected animals. Dr. Varma reports that those who have been infected had, “close, prolonged contact with infected chickens, cows, or other animals that have been infected. Most people work on farms where they raise animals for food or have been kids who inadvertently come into contact with secretions from these infected animals.”
However, H5N1 has been an issue for decades due to its ability to mutate to infect new hosts. “We worry about this strain because it can mutate even more. If it mutates more, it may not require contact with an infected animal. Instead, you could spread it easily from person-to-person, like the regular seasonal flu does.” said Dr. Varma.
As of now, the majority of cases have occurred in California (38 cases),Washington (11 cases), and Colorado (10 cases). Other cases have occurred throughout the Midwest, and none have been reported on the East Coast. The vast majority of these people were exposed while poultry culling or working on dairy farms.
Bird flu can also be spread through animal products. Many household pets, specifically cats, have fallen sick from consumption or exposure to avian and cattle bodily fluids such as raw milk. While unlikely, it is possible to contract bird flu from an infected pet. There was one case of cat-to-human transmission in 2016 in New York City. However, the probability of this situation repeating itself is very low.
Prevention
If your pet has been exposed to bird flu, you should seek veterinary care immediately. Prevention includes stopping pets from coming into contact with birds, cattle, and other wildlife. Pet owners should also not let their pets consume raw food or milk. The same applies to prevention for humans. It is best to avoid raw animal products. Luckily, heat kills the virus; cooked meat, eggs, and pasteurized milk are safe. Furthermore, anyone who may have been exposed to bird flu should self-monitor their symptoms for 10 days after exposure. Other safety measures include not touching dead birds or their feces, litter, the surfaces of water sources (like ponds and lakes), and using PPE.
PPE is the CDC’s acronym for Personal Prevention Equipment. For those who work in close contact with potentially infected animals, the CDC recommends the use of safety goggles, disposable gloves, rubber boots, an N95 respirator or surgical mask, and coveralls. PPE is meant to be worn in a coop or poultry environment. PPE is not meant to be worn in your home and should be cleaned and disinfected before being exposed to a home or non-poultry environment. The cleaning process entails washing the PPE clothing with soap and water before using an EPA approved disinfectant.
What’s Unique About Bird Flu?
Bird flu is different from other major viruses. While both the seasonal and bird flu are variants of influenza A, “seasonal flu spreads easily between people every year, while bird flu rarely does. But when bird flu does infect humans, it’s often more severe and deadly. The concern is that the virus could evolve to spread more easily between people so that it spreads by people breathing out infected particles when they speak, sing, cough, or sneeze,” said Dr. Varma. “Right now, bird flu is much harder to catch than COVID, but it’s more deadly if you do.”
The risk of pandemic is high. “All of us who are experts in this field believe there will be a bird flu pandemic, but we do not know when. It could be months or years from now,” said Dr. Varma. Bird flu undoubtedly needs to be taken seriously.
Government Response to Bird Flu
Surprisingly, the Biden administration and Trump administration do have something in common: poor responses to bird flu. The Biden administration was slow and varying in its response since the outbreak began in 2022. Former FDA Commissioner Scott Gottlieb and former Director of the National Security Council Luciana Borio released an Op-ed in the Washington Post claiming that the Biden Administration mishandled the situation. The administration only began widespread testing of raw milk over a year after the outbreak initially began. They claimed that Biden’s untimely response increased the possibility of a dangerous, widespread pandemic. Only at the very end of his term did Biden ramp up spending to combat bird flu.
Any small amount of good that was done by Biden was quickly reversed by the Trump Administration’s bull-in-a-china-shop approach to federal health agencies. “The Trump Administration has cut out critical people and programs at the FDA, USDA, and CDC that are essential to detecting the disease [bird flu] in animals and humans,” said Dr. Varma. Such agencies and research groups tasked with responding to bird flu have been severely undercut and lack the resources necessary to have an effective response.
Furthermore, the government’s anti-vaccine stance means that the chances of a human vaccine for bird flu being formed soon are very low. This could be devastating. Dr. Varma warns that, “if bird flu becomes a human pandemic during this administration, we will not have a human vaccine, and it could mean millions of preventable deaths.”
“All of us who are experts in this field believe there will be a bird flu pandemic, but we do not know when. It could be months or years from now,” said Dr. Jay Varma.