Experts: Bird flu is a ‘wake-up call’ – WNWO NBC 24

HUNT VALLEY, Md. (TND) It may not be the next pandemic, but scientists are warning its proof were not ready for when the next one comes: the bird flu.

Avian influenza a cousin of the seasonal influenza we deal with every year is not new. Its believed to have been around hundreds of years before the 1918 Spanish avian flu pandemic that killed an estimated 50 to 100 million people worldwide.

There have been numerous outbreaks of avian influenza in various countries among various animal species over the years, as its not just birds that get infected.

The latest outbreak surfaced in 2020 when a severe variant of the H5N1 avian influenza strain (referred to as H5) started spreading in animals around the world. In February 2022, the virus started causing sporadic outbreaks in backyard and commercial poultry flocks in the U.S.

As of May 2024, more than 90 million chickens and turkeys in 47 states have been killed since the outbreak began, according to the U.S. Department of Agriculture. The virus is typically fatal to birds within days of infection, and farmers have to euthanize flocks to stop the spread.

Its also infected alpacas, sea lions, house cats, skunks and more during this most recent outbreak.

But up until this year, it had never infected cows.

As of this week, there have been more than 135 dairy herds in a dozen states reported with H5 infections.

Cows are largely spared of the virus severity; the infection concentrates in the udders of lactating animals, meaning their raw milk is contaminated.

And thats where human H5 infections come in.

According to the Centers for Disease Control and Prevention, four human cases of the bird flu have been reported in the U.S. from exposure to dairy cattle since March 2024. Three of those four got conjunctivitis, otherwise known as pink eye, and the other had mild respiratory symptoms.

Experts say they were likely exposed when milking cows if milk happened to squirt in their eyes.

To date, there havent been any signs of human-to-human transmission.

These do appear, at this point, to be dead-end infections, which is reassuring, said Dr. Amesh Adalja, an infectious disease physician and a senior scholar at the Johns Hopkins Center for Health Security. But because of whats happened with other flu pandemics, were always on the lookout for bird flu viruses behaving differently: infecting more poultry; infecting mammalian species, because that gives these bird flu viruses the opportunity to evolve and become more efficient at infecting humans.

Adalja joins a chorus of scientists who are sounding the alarm that this could be another pandemic slowly unfolding.

On its website, the CDC says the current risk to the general public from bird flu viruses is low, and surveillance so far hasnt shown any unusual influenza activity in people. Dairy farmers and other animal workers are at the highest risk, but even when they contract the virus, they experience very mild symptoms. Some might not even notice.

Experts remind people to never drink unpasteurized milk, which can carry not just the bird flu, but a host of other pathogens and bacteria.

The Food and Drug Administration released a first-of-its-kind study last month further confirming pasteurization is effective at inactivating H5 in milk. The FDA did find traces of the virus in 20% of dairy products sampled from grocery shelves nationwide, but there were no signs of live infectious virus in those samples.

Not all countries have central pasteurization, so if the outbreak becomes more widespread globally, some experts say it could have concerning implications. Raw milk is legal in several European countries.

Because the bird flu is not new, the U.S. already has a strategic national stockpile of two different vaccines against it. The federal government also just paid drug manufacturer Moderna $176 million to develop another one, using the same mRNA technology Moderna used for the COVID-19 vaccine.

Shah says theres no recommendation for use of the H5-specific vaccine right now, and the regular flu season shot will not protect against the bird flu.

Still, he says the CDC is monitoring for any changes in the virus: increased severity; human-to-human transmission; infection in people not exposed to livestock, etc. Any of these would be turning points, and he anticipates, if we get to that point, the CDC would recommend vaccination for risk groups (likely farmworkers and their families), and then move out in concentric rings.

Testing for avian influenza is just like getting tested for regular influenza, meaning we have plenty of tests stockpiled just in case. Adalja says the U.S. has tests that can distinguish between different flu strains.

Adalja and federal agencies agree theres not a need right now for the general public to be tested.

According to Reuters, state health officials say 99 people have been tested for bird flu in Michigan, Texas, Idaho, Colorado and New Mexico. Several other states with bird flu outbreaks either didnt report their human testing data or said they hadnt tested anyone.

Meanwhile, the CDCs website says between March 2024 and now, there have been at least 1,390 people monitored for H5 (asymptomatic people who may have been exposed) and at least 61 people tested for H5 (symptomatic). Four positive cases have been identified.

Whats really of concern for Adalja and other scientists is the testing of cattle themselves, which is up to farmers. The federal government can only test herds before they cross state lines, and state testing efforts are currently inconsistent because, according to experts, some farmers arent quick to want to reveal that their herds might have an outbreak.

Many farm workers are reluctant to be tested and dont want the stigma of testing positive, Adalja said. Theres economic considerations that are constraining their ability. This is occurring in a commodity, and states dont want to have any kind of disruption to the economy.

Adalja points to the negative effects a stigma like this can have in April, Colombia became the first country to officially restrict imports of U.S. beef due to bird flu in cows. The U.S. Meat Export Federation called the restriction unworkable and misguided, arguing the rest of the United States trading partners are following the science, and havent restricted any imports.

But without accurate reporting to show the full scope of the virus spread, Adalja says this creates a lack of situational awareness about the bird flu in the country.

There are likely more dairy cattle herds that are infected across this country. We also expect that there have been more humans that have been infected, he said. Anecdotally, there have been reports of people with flu-like illness or eye infections that did not get tested. In the initial first case acquired from a cow in the U.S., the family members refused to be tested.

Shah says this is an issue public health officials have always dealt with, and when a virus changes or infects a new animal species, it takes time to build up trust among industry workers to agree to testing.

Still, as it stands, H5 does not cause severe illness in humans, which raises the question: if only four people have gotten it and had mild symptoms; if it doesnt impact our commercial milk supply; if sick cows generally recover; and if theres no human-to-human transmission, why risk the negative stigma and cause the economy to take a hit?

Scientists point to the H1N1 virus, often called the swine flu, which was declared a pandemic in 2009, and killed more than 280,000 people worldwide. It had previously spread among pigs and birds, but the different viruses combined to create a more severe strain that started infecting people.

Experts say more surveillance of that virus could have helped authorities prepare and possibly save more lives.

The same goes for the COVID-19 pandemic. Federal agencies have admitted their missteps: taking years to declare the virus as airborne; recommending measures to prevent the spread that werent backed by science; implying vaccines would stop transmission; and failing to prepare hospitals and nursing homes adequately.

A bipartisan group called the COVID Crisis Group published a report on the mistakes made during that pandemic. The primary author, Philip Zelikow, told USA Today, We went into a 21st-century pandemic with a 19th-century system. Weve come out of that pandemic essentially retaining the 19th century structure.

Adalja said many in the public health community agree they dont have a lot of confidence in our current system.

The point is that there will be avian flu viruses in the future that will cause pandemics, just like what happened in 1918, Adalja said. I think what we want to do is think of this bird flu outbreak in cows almost as a trial run and if we cant iron out the differences between agriculture and human health and commerce with a less forgiving virus, its not going to be a good situation."

Shah says the CDC has learned lessons from COVID-19, and state, county and local health officials are checking in with farmers across the country every day. Yet, theres only so much federal agencies can track and require, which is something Shah says his agency has discussed with the scientific community.

One of the challenges with outbreak response is, unfortunately, you never have all the data you want at the time that you need it in order to move forward. And thats the situation were in right now, he said. We absolutely wish that there was more testing happening. We wish we had better data and what is unfolding in real-time. Thats the goal that were moving to. Unfortunately, testing can be a challenge. Testing fundamentally takes trust.

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Experts: Bird flu is a 'wake-up call' - WNWO NBC 24