The recent outbreak of the H5N1 avian influenza virus strain has incited public health concerns and resulted in egg shortages across the nation. So far, there has been one American death in January resulting from the bird flu.
But many of its impacts have gone under the radar. With over 168 million birds infected by the avian flu since January of 2022, scientists who conduct research on birds susceptible to the flu have been directly affected. In addition, for the first time in the US, the flu has been detected in species other than birds, such as cows, cats and seals.
The outbreak of the past few months isn’t the first of its kind. Since the 1920s, there have been sporadic outbreaks of the bird flu, most notably in 1996 when an outbreak of the virus in the Guangdong province of China culminated in a mortality rate over 40% in aquatic birds. A subsequent Hong Kong outbreak in 1997 resulted in 18 human infections, six of whom died. It was the first time a human death from the virus was recorded.
For Scott Shaffer, a biology professor at San Jose State University, the virus has directly affected his field work, which heavily involves interactions with birds. Shaffer mainly studies bird behavior and physiology, specifically examining how birds use energy and water. Most of his data comes from conducting field measurements, such as attaching data log tags to birds at Año Nuevo State Park in Pescadero.
“The birds that I study have shown impacts from the virus, either dying outright or going into rescue shelters, where most of the time they don’t survive,” Shaffer said.
As a result, Shaffer and his team must wear Personal Protection Equipment such as gloves, eyewear and masks in accordance with protocol instructions from the California Fish and Wildlife Department. His team must also clean their equipment between tests to prevent cross contamination between birds.
Shaffer believes that there should be a healthy amount of concern for the bird flu.
“People still have a memory of COVID and people don’t want to be too over reactive because of that,” Shaffer said. “People are aware of it because they go grocery shopping and see the price of eggs so that is certainly at the forefront of people’s minds.”
Origins and effects of the current outbreak
The current strain is only one of many other substrains of the avian flu, a highly contagious fowl disease with a high mortality rate dating back to 19th-century Italy. In 1955, that flu was proven to be a type A influenza virus, an infection that can cause widespread flu outbreaks in poultry.
A subtype of the H5N1 virus, the current strain was first identified in China in 1966 before reaching North America in 2014 and reemerging in February 2022. Pascale Guiton, assistant professor of biology at Santa Clara University, explained to The Falcon that the strain is also a branch of a virus family that contains highly pathogenic strains.
Fortunately, according to Guiton, this strain is not as contagious for humans as prior strains of the H5N1 virus have been. Out of the 70 people who have been affected, there has been only one death. Historically, Guiton explained, the global mortality rate is 50%, making this strain seem milder. Nevertheless, the current strain still kills poultry and causes dairy cows to produce less milk.
According to Guiton, more than 160 million chickens have been culled, which has introduced major shortages within the nation. As a result, egg prices have peaked to a record high of $6.23 per dozen in April.
For the science community, alarm bells for the current outbreak of the bird flu were raised once it started infecting more animals; what started as a virus within birds in March 2022 spread to dairy cows in February 2024. So far, there have been no cases of any human to human transmission — which would be the worst case scenario, Guiton said.
“The virus has been active for over a year and it doesn’t show any sign of disappearing,” Guiton said. “But the fact that it’s infecting not only birds but seals, cats and jumped into cows makes people worry.”
As a result, the virus has more chances to replicate and multiply, which means it has a high chance of accumulating mutations that may cause it to become more dangerous for humans and other species alike.
Limiting the spread of avian flu
The majority of the 70 Americans infected with the bird flu work with dairy herds and poultry — 41 were from exposure to sick dairy cows and 26 were from exposure to infected birds. Symptoms include fevers, coughs and shortness of breath — it can lead to serious illness and death.
Avian influenza is currently classified by the CDC as having a low public risk, but the organization is actively monitoring the situation on dairy cows, people and other animals. There have been no known cases of the virus in Santa Clara County.
The CDC recommends avoiding infection by limiting contact with sources of exposure such as an infected animal’s saliva, mucus and feces. People should also avoid direct contact with dead or sick birds and are advised to not consume raw milk and raw milk products.
So far, the US has avoided using vaccines on vulnerable birds to mitigate the spread of the virus. The government has hesitated to do so in order to protect the interests of the poultry industry; many trading partners in other countries would not accept exports that are vaccinated.
Though the virus could result in silent spreading, where the bird is vaccinated but still able to transmit disease, Guiton believes that the main goal should be to limit the spread of the bird flu.
However, some politicians — including controversial Secretary of Health and Human Services Robert F. Kennedy Jr. — have instead released statements encouraging the flu to run through the flocks in hopes of achieving herd immunity.
“It’s the worst of ideas to let natural immunity run its course,” Guiton said. “If you give [the virus] a lot of hosts, you’re going to have a mutation, and it just takes one mutation or two for the virus to [transmit between] species. The idea should not be to let the virus run free.”
Instead, Guiton and the CDC recommend active monitoring of the virus situation, including mandated bird flu antibody testing for hospitalized humans and wild specimens.
Government investments from the USDA will also provide $100 million to develop a bird flu vaccine for humans. Conditional licenses have been approved to Zoetis, a New Jersey-based vaccine manufacturer, for its avian influenza vaccine. While such licenses are usually issued in times of emergency, they must still meet an index of efficacy.
For now, the CDC is aiming to work with the USDA and FDA to track the virus and prepare for any human infections, amidst the Trump administration’s personnel cuts to those responsible for federal response to the bird flu; about 140 staff members of the 700-person agency have been fired, limiting the agency’s ability to oversee the bird flu. Nevertheless, the CDC promises to continue genetic sequencing of the evolving virus.
“The bird flu is not a joke. It’s affecting the economy and the consumers,” Guiton said. “We cannot let the flu go and let it run its course.”
