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As national wastewater testing expands, Texas researchers identify bird flu in nine cities

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As national wastewater testing expands, Texas researchers identify bird flu in nine cities

As researchers increasingly rely on wastewater testing to monitor the spread of bird flu, some are questioning the reliability of the tests being used. Above, the Hyperion Water Reclamation Plant in Playa Del Rey.

(Jason Armond / Los Angeles Times)

As health officials turn increasingly toward wastewater testing as a means of tracking the spread of H5N1 bird flu among U.S. dairy herds, some researchers are raising questions about the effectiveness of the sewage assays.

Although the U.S. Centers for Disease Control and Prevention says current testing is standardized and will detect bird flu, some researchers voiced skepticism.

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“Right now we are using these sort of broad tests” to test for influenza A viruses in wastewater, said epidemiologist Denis Nash, referring to a category of viruses that includes normal human flu and the bird flu that is circulating in dairy cattle, wild birds, and domestic poultry.

“It’s possible there are some locations around the country where the primers being used in these tests … might not work for H5N1,” said Nash, distinguished professor of epidemiology and executive director of City University of New York’s Institute for Implementation Science in Population Health.

The reason for this is that the tests most commonly used — polymerase chain reaction, or PCR, tests — are designed to detect genetic material from a specific organism, such as a flu virus.

But in order for them to identify the virus, they must be “primed” to know what they are looking for. Depending on what part of the virus researchers are looking for, they may not identify the bird flu subtype.

There are two common human influenza A viruses: H1N1 and H3N2. The “H” stands for hemagglutinin, which is an identifiable protein in the virus. The “N” stands for neuraminidase.

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The bird flu, on the other hand, is also an influenza A virus. But it has the subtype H5N1.

That means that while the human and avian flu virus share the N1 signal, they don’t share an H.

If a test is designed to look for only the H1 and H3 as indicators of influenza A virus, they’re going to miss the bird flu.

Marc Johnson, a professor of molecular microbiology and immunology at the University of Missouri, said he doesn’t think that’s too likely. He said the generic panels that most labs use will capture H1, H3 and H5.

He said while his lab specifically looks for H1 and H3, “I think we may be the only ones doing that.”

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It’s been just in the last few years that health officials have started using wastewater as a sentinel for community health.

Alexandria Boehm, professor of civil and environmental engineering at Stanford University and principal investigator and program director for WastewaterSCAN, said wastewater surveillance really got going during the pandemic. It’s become a routine way to look for hundreds if not thousands of viruses and other pathogens in municipal wastewater.

“Three years or four years ago, no one was doing it,” said Boehm, who collaborates with a network of researchers at labs at Stanford, Emory University and Alphabet Inc.’s life sciences research organization. “It sort of evolved in response to the pandemic and has continued to evolve.”

Since late March, when the bird flu was first reported in Texas dairy cattle, researchers and public health officials have been combing through wastewater samples. Most are using the influenza A tests they had already built into their systems — most of which were designed to detect human flu viruses, not bird flu.

On Tuesday, the CDC released its own dashboard showing wastewater sites where it has detected influenza A in the last two weeks.

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Displaying a network of more than 650 sites across the nation, there were only three sites — in Florida, Illinois and Kansas — where levels of influenza A were considered high enough to warrant further agency investigation. There were more than 400 where data were insufficient to allow a determination.

Jonathan Yoder, deputy director of the CDC’s Division of Infectious Disease Readiness and Innovation, said those sites were deemed to have insufficient data because testing hasn’t been in place long enough, or there may not have been enough positive influenza A samples to include.

Asked if some of the tests being used could miss bird flu because of the way they were designed, he said: “We don’t have any evidence of that. It does seem like we’re at at a broad enough level that we don’t have any evidence that we would not pick up H5.”

He also said the tests were standardized across the network.

“I’m pretty sure that it’s the same assay being used at all the sites,” he said. “They’re all based on … what the CDC has published as a clinical assay for for influenza A, so it’s based on clinical tests.”

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But there are discrepancies between the CDC’s findings and others’.

Earlier this week, a team of scientists from Baylor College of Medicine, the University of Texas Health Science Center at Houston, the Texas Epidemic Health Institute and the El Paso Water Utility, published a report showing high levels of bird flu from wastewater in nine Texas cities. Their data show that H5N1 is the dominant form of influenza A swirling in these Texas towns’ wastewater.

But unlike other research teams, including the CDC, they used an “agnostic” approach known as hybrid-capture sequencing.

“So it’s not just targeting one virus or one of several viruses,” as one does with PCR testing, said Eric Boerwinkle, dean of the UTHealth Houston School of Public Health and a member of the Texas team. “We’re actually in a very complex mixture, which is wastewater, pulling down viruses and sequencing them.”

“What’s critical here is it’s very specific to H5N1,” he said, noting they’d been doing this kind of testing for approximately two years, and hadn’t ever seen H5N1 before the middle of March.

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Blake Hanson, an assistant professor at the University of Texas Health Science Center at Houston School of Public Health and a member of the Texas wastewater team, agreed, saying that PCR-based methods are “exquisite” and “highly accurate.”

“But we have the ability to look at the representation of the entire genome, not just a marker component of it. And so that has allowed us to look at H5N1, differentiate it from some of our seasonal fluids like H1N1 and H3N2,” he said. “It’s what gave us high confidence that it is entirely H5N1, whereas the other papers are using a part of the H5 gene as a marker for H5.”

Boerwinkle and Hanson underscored that while they could identify H5N1 in the wastewater, they cannot tell where it came from.

“Texas is really a confluence of a couple of different flyways for migratory birds, and Texas is also an agricultural state, despite having quite large cities,” Boerwinkle said. “It’s probably correct that if you had to put your dime and gamble what was happening, it’s probably coming from not just one source but from multiple sources. We have no reason to think that one source is more likely any one of those things.”

But they are pretty confident it’s not coming from people.

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“Because we are looking at the entirety of the genome, when we look at the single human H5N1 case, the genomic sequence … has a hallmark amino acid change … compared to all of the cattle from that same time point,” Hanson said. “We do not see that hallmark amino acid present in any of our sequencing data. And we’ve looked very carefully for that, which gives us some confidence that we’re not seeing human-human transmission.”

The Texas’ team approach was really exciting, said Devabhaktuni Srikrishna, the CEO and founder of PatientKnowHow.com, noting it exhibited “proof of principle” for employing this kind of metagenomic testing protocol for wastewater and air.

He said government agencies, private companies and academics have been searching for a reliable way to test for thousands of microscopic organisms — such as pathogens — quickly, reliably and at low cost.

“They showed it can be done,” he said.

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What’s in a Name? For These Snails, Legal Protection

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What’s in a Name? For These Snails, Legal Protection

The sun had barely risen over the Pacific Ocean when a small motorboat carrying a team of Indigenous artisans and Mexican biologists dropped anchor in a rocky cove near Bahías de Huatulco.

Mauro Habacuc Avendaño Luis, one of the craftsmen, was the first to wade to shore. With an agility belying his age, he struck out over the boulders exposed by low tide. Crouching on a slippery ledge pounded by surf, he reached inside a crevice between two rocks. There, lodged among the urchins, was a snail with a knobby gray shell the size of a walnut. The sight might not dazzle tourists who travel here to see humpback whales, but for Mr. Avendaño, 85, these drab little mollusks represent a way of life.

Marine snails in the genus Plicopurpura are sacred to the Mixtec people of Pinotepa de Don Luis, a small town in southwestern Oaxaca. Men like Mr. Avendaño have been sustainably “milking” them for radiant purple dye for at least 1,500 years. The color suffuses Mixtec textiles and spiritual beliefs. Called tixinda, it symbolizes fertility and death, as well as mythic ties between lunar cycles, women and the sea.

The future of these traditions — and the fate of the snails — are uncertain. The mollusks are subject to intense poaching pressure despite federal protections intended to protect them. Fishermen break them (and the other mollusks they eat) open and sell the meat to local restaurants. Tourists who comb the beaches pluck snails off the rocks and toss them aside.

A severe earthquake in 2020 thrust formerly submerged parts of their habitat above sea level, fatally tossing other mollusks in the snail’s food web to the air, and making once inaccessible places more available to poachers.

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Decades ago, dense clusters of snails the size of doorknobs were easy to find, according to Mr. Avendaño. “Full of snails,” he said, sweeping a calloused, violet-stained hand across the coves. Now, most of the snails he finds are small, just over an inch, and yield only a few milliliters of dye.

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Video: This Parrot Has No Beak, But Is at the Top of the Pecking Order

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Video: This Parrot Has No Beak, But Is at the Top of the Pecking Order

new video loaded: This Parrot Has No Beak, But Is at the Top of the Pecking Order

Bruce, a disabled kea parrot, is missing his top beak. The bird uses tools to keep himself healthy and developed a jousting technique that has made him the alpha male of his group.

By Meg Felling and Carl Zimmer

April 20, 2026

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Contributor: Focus on the real causes of the shortage in hormone treatments

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Contributor: Focus on the real causes of the shortage in hormone treatments

For months now, menopausal women across the U.S. have been unable to fill prescriptions for the estradiol patch, a long-established and safe hormone treatment. The news media has whipped up a frenzy over this scarcity, warning of a long-lasting nationwide shortage. The problem is real — but the explanations in the media coverage miss the mark. Real solutions depend on an accurate understanding of the causes.

Reporters, pharmaceutical companies and even some doctors have blamed women for causing the shortage, saying they were inspired by a “menopause moment” that has driven unprecedented demand. Such framing does a dangerous disservice to essential health advocacy.

In this narrative, there has been unprecedented demand, and it is explained in part by the Food and Drug Administration’s recent removal of the “black-box warning” from estradiol patches’ packaging. That inaccurate (and, quite frankly, terrifying) label had been required since a 2002 announcement overstated the link between certain menopause hormone treatments and breast cancer. Right-sizing and rewording the warning was long overdue. But the trouble with this narrative is that even after the black-box warning was removed, there has not been unprecedented demand.

Around 40% of menopausal women were prescribed hormone treatments in some form before the 2002 announcement. Use plummeted in its aftermath, dipping to less than 5% in 2020 and just 1.8% in 2024. According to the most recent data, the number has now settled back at the 5% mark. Unprecedented? Hardly. Modest at best.

Nor is estradiol a new or complex drug; the patch formulation has existed for decades, and generic versions are widely manufactured. There is no exotic ingredient, no rare supply chain dependency, no fluke that explains why women are suddenly being told their pharmacy is out of stock month after month.

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The story is far more an indictment of the broken insurance industry: market concentration, perverse incentives and the consequences of allowing insurance companies to own the pharmacy benefit managers that effectively control drug access for the majority of users. Three companies — CVS Caremark, Express Scripts and OptumRx — manage 79% of all prescription drug claims in the United States. Those companies are wholly owned subsidiaries of three insurance behemoths: CVS Health, Cigna and UnitedHealth Group, respectively. This means that the same corporation that sells you your insurance plan also decides which drugs get covered, at what price, and whether your pharmacy can stock them. This is called vertical integration. In another era, we might have called it a cartel. The resulting problems are not unique to hormone treatments; they have affected widely used medications including blood thinners, inhalers and antibiotics. When a low-cost generic such as estradiol — a medication with no blockbuster profit margins and no patent protection — runs into friction in this system, the friction is not random. It is structural. Every decision in that chain is filtered through the same corporate profit motive. And when the drug in question is an off-patent estradiol patch that has negligible profit margins because of generic competition but requires logistical investment to keep consistently in stock? The math on “how much does this company care about ensuring access” is not complicated.

Unfortunately, there is little financial incentive to ensure smooth, consistent access. There is, however, significant financial incentive to steer patients toward branded alternatives, or simply to let supply tighten — because the companies aren’t losing much profit if sales of that product dwindle. This is not a conspiracy theory: The Federal Trade Commission noted this dynamic in a report that documented how pharmacy benefit managers’ practices inflate costs, reduce competition and harm patient access, particularly for independent pharmacies and for generic drugs.

Any claim that the estradiol patch shortage is meaningfully caused by more women now demanding hormone treatments is a distraction. It is also misogyny, pure and simple, to imply that the solution to the shortage is for women’s health advocates to dial it down and for women to temper their expectations. The scarcity of estradiol patches is the outcome of a broken system refusing to provide adequate supply.

Meanwhile, there are a few strategies to cope.

  • Ask your prescriber about alternatives. Estradiol is available in multiple formulations, including gel, spray, cream, oral tablet, vaginal ring and weekly transdermal patch, which is a different product from the twice-weekly patch and may be more consistently available depending on manufacturer and region.
  • Consider an online pharmacy. Many are doing a good job locating and filling these prescriptions from outside the pharmacy benefit manager system.
  • Call ahead. Patch shortages are inconsistent across regions and distributors. A call to pharmacies in your area, or a broader geographic radius if you’re able, can locate stock that your regular pharmacy doesn’t have.
  • Consider a compounding pharmacy. These sources can sometimes meet needs when commercially manufactured products are inaccessible. The hormones used are the same FDA-regulated bulk ingredients.

Beyond those Band-Aid solutions, more Americans need to fight for systemic change. The FTC report exists because Congress asked for it and committed to legislation that will address at least some of the problems. The FDA took action to change the labeling on estrogen in the face of citizen and medical experts’ pressure; it should do more now to demand transparency from patch manufacturers.

Most importantly, it is on all of us to call out the cracks in the current system. Instead of repeating “there’s a patch shortage” or a “surge in demand,” say that a shockingly small minority of menopausal women still even get hormonal treatments prescribed at all, and three drug companies control the vast majority of claims in this country. Those are the real problems that need real solutions.

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Jennifer Weiss-Wolf, the executive director of the Birnbaum Women’s Leadership Center at New York University School of Law, is the author of the forthcoming book When in Menopause: A User’s Manual & Citizen’s Guide. Suzanne Gilberg, an obstetrician and gynecologist in Los Angeles, is the author of “Menopause Bootcamp.”

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