The Brief

The U.S. has confirmed its first human case of the New World screwworm, a flesh-eating parasite whose northward creep from South America has put the country's cattle industry on high alert in recent months.

The Centers for Disease Control and Prevention (CDC), in coordination with the Maryland Department of Health, confirmed the case on Aug. 4 in a patient who had returned from travel to El Salvador, Department of Health and Human Services spokesperson Andrew Nixon told NPR on Monday.

"This is the first human case of travel-associated New World screwworm myiasis (parasitic infestation of fly larvae) from an outbreak-affected country identified in the United States," Nixon said. "Currently, the risk to public health in the United States from this introduction is very low."

David McAllister, a spokesperson for the Maryland Department of Health, confirmed to NPR that the individual — a resident of Maryland — has recovered from the infection."The investigation confirmed there is no indication of transmission to any other individuals or animals," he wrote, calling the detection a "timely reminder for health care providers, livestock owners and others to maintain vigilance through routine monitoring."

The New World screwworm is a species of parasitic flies typically found in South America and the Caribbean, according to the CDC. Infestation occurs when fly larvae feed on the tissue or flesh of warm-blooded animals, primarily livestock and, rarely, humans.

"It's a fly, and it's the larvae that does the damage," says Max Scott, a professor in the Department of Entomology and Plant Pathology at North Carolina State University.

He says infestation in humans can be "quite painful," with high mortality rates if left untreated.

"Because once an infestation starts, that often attracts more flies that lay more eggs," he explains. "And depending where the wound is, the maggots can make their way into vulnerable tissue like the brain, or the wound can get quite big and then you get sepsis."

But, Scott says, screwworm is an insect, not a virus — so it's not contagious.

The pest poses a much bigger risk to livestock, and in the past year has been detected in cattle farms in Mexico. As the New World screwworm gets closer to the U.S. border, federal authorities have taken a series of steps to eliminate the threat — which they did successfully in the mid-20th century.

What exactly is New World screwworm?

An adult New World screwworm fly. They are commonly found in South America and the Caribbean.

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Denise Bonilla

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U.S. Department of Agriculture

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Screwworms are a type of blue-gray blowfly that look very similar to black flies found in the U.S.

The difference is that screwworms — specifically females — lay their eggs in live animals, usually in a wound or another entry point like a nasal cavity.

"The females can lay up to, like, 200 eggs at a time," Scott says. "And then when the eggs eat, they eat the animal alive."

After feeding, the larvae fall into the ground, burrow into the soil and emerge as adult screwworm flies, continuing the cycle.

The parasites are named after the screw-like way they burrow into tissue using their sharp mouth hooks. Their Latin name, Cochliomyia hominivorax, "literally means maneater," Scott says.

"It was named after a sort of unfortunate number of cases in the French penal colony of Devil's Island back in the 19th century," he explains.

Human cases are relatively rare these days, though counts are growing in some parts of South America.

The U.S. Embassy in Nicaragua said in July that it had confirmed 124 cases in the past year. In June, the U.S. Embassy in Costa Rica confirmed its seventh case since 2023 — and first human death "since at least the 1990s."

How was screwworm eradicated — and why is it spreading now? 

Screwworm used to be in the U.S., mainly in Florida, Texas and, during the summer, sometimes as far north as the Dakotas, Scott says.

In the 1950s, scientists with the U.S. Department of Agriculture (USDA) pioneered a method of combating them known as the sterile insect technique, which Scott calls "one of the great success stories of the USDA of the 20th century."

Instead of using broad-spectrum insecticides, they decided to use the pest itself as a control agent. That involves mass-rearing insects inside factories, sterilizing them with radiation and then releasing them — either from the ground or, as is the case today, by "planes that fly very precise routes."

"If the females on the ground mate with a sterile male, at least with a screwworm, that's all they'll mate with … so that female won't produce any offspring," Scott says.

Through this technique, the U.S. managed to eradicate New World screwworm in 1966. Mexico followed suit in the 1970s, and Central America in the early 2000s. The U.S. also used this method to eliminate what the CDC calls a "small outbreak" in the Florida Keys in 2017.

"Over a 50-year period, screwworm was pushed back from the United States through Mexico, through Central America, to the Panama-Columbia border. That was about 20 years ago," Scott says. "It was stopped at the border and then was held for a long time until the barrier broke and screwworm came back."

Panama, Costa Rica, Nicaragua and Honduras have documented new cases in recent years, fueling concerns of a northward spread.

Scott says there are probably multiple explanations, including the movement of infested cattle and the possibility that the current strain of sterilized flies is less effective than in the past. The hope, he says, is that a bigger crop of sterilized insects will be able to contain the screwworm threat to southern Mexico, before it can reach the U.S.

The corrals were empty at the Union Ganadera Chihuahua cattle import facility in Santa Teresa, New Mexico, in June, after the U.S. reinstated its pause on cattle imports across the Southern border.

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Paul Ratje

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Bloomberg via Getty Images

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What is the U.S. doing about screwworm?

The U.S. briefly halted live cattle imports from Mexico in November, after a positive case was detected there.

It lifted the ban in February but reinstated it on a month-by-month basis in May, with Agriculture Secretary Brooke Rollins citing "the continued and rapid northward spread of New World Screwworm (NWS) in Mexico." She said it had been detected in farms as far north as Oaxaca and Veracruz, some 700 miles from the U.S. border.

In the months since, the federal government has faced mounting pressure from agricultural groups worried about the threat of screwworm and its potential impact on the supply chain. In an early August letter to Rollins, they used USDA estimates to calculate that a contemporary outbreak could cause a total economic loss of more than $10.6 billion.

The USDA appears to have heard those concerns. Earlier this month, it announced sweeping plans to combat the spread of screwworm, including building the U.S.' only sterile fly production facility at an air force base in Edinburg, Texas. It says it will produce up to 300 million sterile flies per week.

Scott says at its peak, the half-century eradication campaign was run from a facility in Mexico that could produce at least 500 million sterile flies per week. It was shut down for economic reasons in 2012. There is currently only one such facility in operation, in Panama, with a maximum capacity of some 100 million flies per week.

Announcing the new initiative in Texas, Rollins did not specify when the plant will be operational, but has previously said it will take two to three years to build, Reuters reports. The USDA is also supporting a separate facility in Mexico that is slated to open in 2026.

Other steps the USDA says it will take include ramping up the hiring of USDA-employed mounted patrol officers, called "Tick Riders," to focus on border surveillance; training dogs to detect screwworm infestations in livestock at the border and investing $100 million in technologies to combat screwworm.

Agricultural groups welcomed the announcement. Zippy Duvall, president of the American Farm Bureau Federation, said in a statement that the introduction of New World screwworm in the U.S. would only exacerbate an already-volatile cattle market.

"It took decades to eradicate this parasite from within and adjacent to our borders more than a generation ago, and this is a proactive first step," he added.
Copyright 2025 NPR

Psychologist Cami Winkelspecht decided to familiarize herself with artificial intelligence tools like ChatGPT and Gemini, after patients started asking her for advice about how they could use the technology responsibly.

"One of the interesting questions that kids and teenagers, in particular, brought in is how can you utilize AI to help support ideas or editing process or things like that for papers and assignments and presentations, but also make sure that you're not utilizing it to write something for you, [so] that you're not violating your school's honor code" says Winkelspecht, who is a child and adolescent psychologist with a private practice in Wilmington, Delaware.

"So I have also then started to experiment with it to see what these tools will also do," she says, so she could feel "confident and comfortable" in her own understanding of these platforms, their advantages and risks.

Winkelspecht is among the 56% of psychologists recently surveyed by the American Psychological Association who are using AI tools in their practices. That's significantly higher than the 29% who said the same last year. And nearly a third of respondents said they use these tools on a monthly basis — up by more than two fold since last year.

Winkelspecht incorporates AI into some of her office and administrative tasks, like creating templates for letters she has to send to her collaborators — schools and pediatricians. It saves her time, but she can still write and edit the letters each time.

Most psychologists are "using AI to help write emails, to help develop homework assignments, to help maybe with some report writing or using AI scribes to assist with documentation," says psychologist Vaile Wright, senior director of the Office of Health Care Innovation at the APA.

"Psychologists are seeing potential opportunities to incorporate AI into their practices, by making their work more efficient, which we think could have downstream effects to reducing burnout, reducing those aspects of the workplace that people don't particularly enjoy," she adds. "And that would then give them more time to really provide patient care. So I think that that's really promising."

As more psychologists adopt AI tools, Wright says there is also growing awareness about artificial intelligence tools, especially with respect to patient safety and data privacy.

A majority of psychologists said they are concerned about potential harms of this technology, with more than 60% saying they are worried about potential data breaches, biased inputs and outputs and social harms. Many also expressed concerns about hallucinations, where the platforms fabricate facts or present inaccurate information.

"What's clear to us is that we need to help continue to provide both resources to members so that they can and effectively, responsibly incorporate these types of technologies," says Wright. "And we have to ensure that these technologies are regulated in ways that ensure to the best of their ability, safety and efficacy."
Copyright 2025 NPR

Rat poison continues to sicken and kill California’s wildlife at alarming rates, despite legislation designed to prevent the use of such chemicals.

That’s according to a recently published report from the California Department of Fish and Wildlife. The 2024 survey found anticoagulant rodenticides — a fancy name for one of the most toxic types of rat poison — in the bodies of 95% of mountain lions and 83% of bald eagles tested, as well as dozens of other species, including foxes, bobcats, owls, hawks, black bears and endangered California condors.

Even river otters have been poisoned, a sign these chemicals may be seeping into waterways.

“We’re still seeing too many animals being victims of rat poison,” said Lisa Owens-Viani, director of Berkeley-based nonprofit  Raptors Are the Solution.

How we got here

Rats are a big problem in Southern California. And people resort to rat poison to solve the problem, placing it in baits and traps. The problem with that is wild animals also fall for the lures. Or, hungry predators feast on the poison-filled rats.

Anticoagulants were one of the final blows to L.A.’s most famous mountain lion, P-22. He was sickened by such rodenticides likely after eating prey that had ingested them. Disoriented and ill, the beloved puma then wandered into the road and was struck by a car just south of his home in Griffith Park. P-22 later died from his injuries.

Famed mountain lion P-22 suffered from mange linked to rat poisons and died after being struck by a vehicle near Griffith Park.

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Courtesy Center for Biological Diversity

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Why legislation hasn’t solved it

For more than two decades, California has passed laws to limit the use of certain pesticides. Starting in 2020, the state passed a series of legislation banning some of the most toxic types:

• The Ecosystem Protection Act of 2020 (AB1788) placed a moratorium on all second-generation anticoagulant rodenticides, which are stronger and last in animal tissue longer than earlier types. 
• The California Ecosystem Protection Act of 2023 and the Poison-Free Wildlife Act of 2024 expanded that moratorium to first generation anticoagulant rodenticides, including chlorophacinone and warfarin, which are older versions of rat poison that take longer to build up in the body.

However, there are exemptions in those laws, including the use of such rodenticides in agriculture, certain public health settings, such as hospitals, and other sensitive settings.

Owens-Viani thinks that’s a big reason why the number of poisonings continue to be high.

“We're not seeing the decreasing trend that we had hoped for,” she said.

A bobcat sickened by rodenticides is cared for at Simi Valley-based wildlife rescue Wildlife Care of Southern California.

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Anna Reams

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Wildlife Care of Southern California

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Jonathan Evans, the Environmental Health Legal Director for the Center for Biological Diversity, noted that some of the state’s best protections against rat infestations — great-horned owls, hawks and other raptors — are also dying at some of the most alarming rates from rat poisons.

“All of these animals are some of our best rodent control mechanisms. Like these animals feed on rats and mice and can do it very efficiently,” Evans said. “We really should be looking at figuring out why we still have high levels [of poisonings] and what we can do to close the loopholes and make rodent control more ecologically effective."

Why the problem could get worse

There are also gaps in the data, meaning the real numbers of poisonings are likely far higher, Evans said.

As part of its methods to calculate poisoning rates, the Department of Fish and Wildlife has to analyze dead carcasses that often have to be submitted to them by the public, he said.

“Most of these animals that die of rodenticide poisonings are going to die out in the woods where nobody finds them,” Evans said.

A mountain lion photographed with a motion sensor camera in the Verdugo Mountains overlooking the city lights of Los Angeles.

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National Park Service

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And now, the state’s Department of Pesticide Regulation is considering rolling back many of these protections by allowing more than 100,000 new locations, including grocery stores, restaurants and even parks, to use most toxic rat poisons.

Six lawmakers who helped craft the 2024 moratorium on these chemicals sent a letter to the agency earlier this year asking them to rescind the proposal.

Here’s how you can help protect wildlife 

• For one, don’t use rodenticides in your yard. Death by anticoagulant rodenticide poisoning is painful and slow — these poisons cause species to slowly bleed out from the inside, with signs in hawks and other raptors often being blood seeping from their beaks and eyes. Larger mammals, such as mountain lions and coyotes, can also develop mange as a result of the poisons weakening their immune systems.
  
• Securing your trash, pet food and even bird feeders are other important ways to keep rats (and unwanted wildlife) from your home. Evans noted there are also new technologies, such as fertility control, electric traps and improved methods of fortifying buildings from rats. You can find additional resources for wildlife-safe rodent control from the Center for Biological Diversity and Raptors are the Solution at SafeRodentControl.org or here.
  
• And if you do come across wild animal you suspect has been poisoned, report it to your local wildlife rescue agency or animal control office, as well as the California Department of Fish and Wildlife at WHLab@wildlife.ca.gov or (916) 358-2790.

A person was fatally shot on a Los Angeles Metro bus Wednesday afternoon in South L.A.

According to Metro, a group of “young men” got into an altercation on the street.

That altercation then continued on a bus on Route 206, where “a member of the group shot and fatally injured another member of the group,” the transportation agency said to LAist.

The suspects fled before police arrived, according to Metro.

LAist has reached out to the LAPD for further information.

Safety on Metro

Since summer 2024, the transportation agency has been testing scanners that can detect concealed weapons at the entrances to rail stations throughout L.A. County and is in the early stages of possibly adopting the same approach for its buses.

In the latest 12-month-long phase of the pilot, which began in late April, Metro has been testing the technology at two rail stations at a time in two-month increments.

In a September report to its board, Metro staff said the “most frequently encountered” items during screenings have been “bladed objects.”

“In most cases, these were legitimate work-related tools that patrons were lawfully transporting,” staff said, adding that only one firearm had been detected as of the report.

Metro tested its weapons detection system at the San Pedro stop along the A line.

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Samanta Helou Hernandez

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LAist

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In the same September update to its board, Metro staff said the transportation agency remains in “active discussions” with a vendor for its bus-centered program.

Over the summer, the vendor demoed how the scanners would work on different size buses, according to the update.

“Further coordination with the vendor will take place to determine which bus or buses will be equipped and when the installation will occur,” Metro staff said in the update. “The pilot has not yet been finalized.”

According to Metro, systemwide violent crime in September 2025, the latest month for which data is available online, fell nearly 15% compared to last September.

If you’re out in nature this weekend, you might see people combing spots in search of one thing: monarch butterflies.

The community science initiative, known as the Western Monarch Count, is led by the Xerces Society, a conservation nonprofit that looks for the insects annually. This is the last count for the year, and it runs through Jan. 11.

The count is run mostly by hundreds of volunteers and partners of the Xerces Society across the state.

Why the count matters

Across California, monarch butterflies have been in steep decline in recent decades. The count is one of the ways the Xerces Society is trying to understand what’s happening and how we can help them recover.

The count looks specifically at the habits of a specific type of monarch known as overwintering monarchs, which travel hundreds of miles to our coast to escape harsh winters. They have special fat reserves in their tiny bodies, which make them beefier than breeding ones, says Sara Cuadra-Vargas, a  conservation biologist at the Xerces Society.

“ You can think of it … like if your great-great-great-great-grandfather was a superhuman that lived extra long and was extra large,” Cuadra-Vargas said.

The count happens over three periods, starting in October. This period is called the late-season count, which can show biologists how many monarchs are moving away from our sites and what mortality is looking like.

How you can help monarchs

They’re set for volunteers for this count, but you can volunteer for next year’s count by signing up to volunteer here. They require at least 15 hours of commitment — you’ll get set up with training.

Volunteers typically are assigned a site for the season and go out early in the morning when it’s too cold for monarchs to move. You’ll scan for the orange butterflies with binoculars and document things like habit quality and disturbances.

Cuadra-Vargas says our region has dozens of confirmed and potential overwintering sites, but the bulk of monarchs are seen in the central coast. In training, she tempers expectations.

“ We do still get overwintering monarchs here in Southern California, in Los Angeles and Orange counties,” she said, “but it’s a bit of more presence-absence that we’re looking for.”

That means you also may report where monarchs aren’t anymore, which is an important piece of data for biologists.

If you want to help out now, though, there’s still a few ways to do it:

• Help track where monarchs get their nectar by snapping a photo and sharing it through the Monarch Nectar Plant Database submission form.
• Add pictures of monarchs you see to the Xerces Society’s project on iNaturalist.
• If you want to get real high-tech, there’s a separate program that’s asking people to download a phone app to track specially tagged monarchs with solar transmitters.
• You also can go the low-tech, old-school route: Plant milkweed at home to give them something to eat.