Bird flu is becoming a very human concern — one you shouldn’t ignore.
This year there have been 55 human cases of bird flu reported in the US, including one case in California where a child was infected, according to the CDC. As the spread continues and the busiest travel holiday approaches, experts are raising concerns.
“We have a lot to learn about these viruses,” said Gregory C. Gray, MD, MPH, professor of infectious disease epidemiology at the University of Texas Medical Branch. “They have spilled over to many wild and domestic livestock species in ways we haven’t seen frequently in this country before.”
How can you protect yourself? And is your Thanksgiving turkey still safe to eat? Here’s what to know.
The Problem With Bird Flu
While it may feel like a recent thing, bird flu isn’t new. The avian influenza virus — H5N1 — was discovered in 1996, and other bird flu viruses have been circulating the globe since the 19th century. Wild migratory birds — like geese and gulls — carry the virus to poultry and mammals, and from there it can spread to humans.
Since 1997, more than 900 people worldwide have been infected with H5N1, causing symptoms that range from mild conjunctivitis (pink eye) to severe pneumonia. Americans avoided infection until 2022, when a farm worker in Colorado caught a mild case.
That was just after the viral genomic sequence of H5N1 started shifting, in late 2021, said Benjamin Anderson, PhD, MPH, assistant professor of environmental and global health at the University of Florida. Now, the virus has spread to poultry in almost every state — and it’s become even better at infecting mammals, including more than 50 species to date.
“Anytime we start to see some changes in the presentation of infection and which species and how often and how much it changes, that’s a big concern,” said Anderson.
Earlier this year, US dairy cattle caught H5N1 for the first time, putting humans at risk. Milk from infected cows splashing into dairy workers’ eyes has caused workers to become sick with symptoms of pink eye.
Now experts are raising concerns that other farm animals could transmit H5N1 through body fluids.
“There are four other groups of animals I’m concerned about: beef cattle, goats, alpacas, and pigs,” said Gray. Because the virus doesn’t sicken these animals as severely as it does birds, in these populations “it may be missed.”
Most infections have been reported in people who work directly with infected animals in agricultural settings, and the cases we know about might undercount the true total, said Gray.
However, “Those are just the ones that we know about,” said Gray. “There’s likely a large population of [infected] people who have not had signs or symptoms, or who have had mild signs or symptoms, or who have not been tested.”
One bright spot is that the current H5N1 virus seems less lethal than previous variants. Before the recent outbreak, the death rate for H5N1 was around 50%. But of the 53 Americans infected this year, zero deaths have been reported. Another plus: The current virus isn’t spreading from human to human.
A big question now is whether the virus will mutate in a way that allows human-to-human spread, opening the door to a new pandemic. Experts are divided on how significant this threat could be.
“It’s probably really difficult for this virus to make the changes it needs to go human to human,” said Richard Webby, PhD, director of the World Health Organization Collaborating Centre for Studies on the Ecology of Influenza in Animals and Birds. “But it probably has the capacity to do [so] given the right situation.”
Antiviral medicines like oseltamivir (Tamiflu) are used for treatment. “But the CDC has at least two vaccine candidates that are ready to mass produce,” said Luis Martinez-Sobrido, PhD, professor of infectious disease and prevention at the Texas Biomedical Research Institute.
Why Your Turkey Is Probably Safe
No one has caught bird flu from eating turkey. That’s probably because bird flu makes chickens and turkeys deathly ill within days, so outbreaks at poultry farms are quickly detected and contained.
“The chances of an H5N1-infected chicken or turkey getting into the food chain are very, very, very low,” said Webby.
If an infected bird did end up at a processing plant, the infected tissue — usually the gastrointestinal tract and the lung — would likely be removed before the meat went to market, said Ahmed Moustafa Mohamed Elsayed, PhD, a virologist at the Texas Biomedical Research Institute.
Proper cooking would kill any remaining virus. Standard safety tips apply: Cook the bird to an internal temperature of 165 degrees Fahrenheit, wash your hands after touching raw meat, and clean any surfaces that touch the meat or its juices.
If you hunt for a wild turkey, put on goggles, a face mask, and gloves before handling your catch, Webby said. Avoid touching your eyes, mouth, or nose, where contaminated fluids could enter your body. And of course, wash your hands.
How to Protect Yourself From Bird Flu
Avoid rawmilk. Mammary cells (responsible for producing milk) are rich in receptors for H5N1 binding, making milk a welcoming home for the virus. Pasteurized milk is safe because it’s heated to a temperature that kills viruses.
Don’t touch dead birds. See a dead wild bird on your property? Call animal control. If you have backyard chickens that die without explanation, call a veterinarian for advice.
Get the flu shot. While the flu vaccine wasn’t formulated to fight bird flu, “there are theoretical reasons that it might give you some protection against the H5N1,” said Webby. But it could also help prevent you from catching seasonal flu viruses, which may complicate diagnoses.
Watch your cat. Outdoor cats, and farm cats especially, can be at risk. Some have been infected after drinking raw milk. Catching and eating birds may also expose them, said Anderson. If your cat has symptoms like loss of appetite or fever, contact your veterinarian. Tell them if your cat has spent time around other animals.
Skip the petting zoo. Touching farm animals is a bad idea as bird flu spreads. “They can be infected with a lot of influenza, not only this H5N1, but other subtypes circulating,” said Martinez-Sobrido.
Get tested if you’re concerned. People who have direct contact with animals — primarily livestock, poultry, dairy cattle, or swine — are at greatest risk, said Anderson. If that’s you, and you notice pink eye or feel sick, get a flu test, said Webby. If it comes back positive for influenza A but not one of the seasonal flu viruses, that could mean bird flu. Tell your doctor, who may help connect you with a state laboratory or the CDC for further testing.
SOURCES:
CDC: “Past Reported Global Human Cases with Highly Pathogenic Avian Influenza A (H5N1) (HPAI H5N1) by Country, 1997-2024,” “Highly Pathogenic Avian Influenza A (H5N1) Virus: Interim Recommendations for Prevention, Monitoring, and Public Health Investigations.”
World Organisation for Animal Health: “What is avian influenza and how does it spread?”
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Publish date : 2024-11-26 06:50:17
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