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Hello from Nairobi.
The realities of public health hit home for me this weekend. My daughter just started pre-K, a touching milestone I was repeatedly warned would bring more illness into our home. (I took this to mean perpetual sniffles.) Instead, after about a week, she shared a lovely bout of norovirus with me.
My name is William Herkewitz, and I’m a journalist based in Nairobi, Kenya. This is the Global Health Checkup, where I highlight five of the week’s most important stories on outbreaks, medicine, science, and survival from around the world.
With that, as we say in Swahili: karibu katika habari — welcome to the news.
Vaccine conspiracies as global health policy
Gavi, the global organization that finances and distributes vaccines in poorer countries, finds itself in a funding standoff with the United States, Reuters reports.
For reference, “the U.S. previously contributed around 13% of Gavi’s funding,” and still has outstanding funds owed to the organization from the Biden era.
The issue at hand?
You might assume this is tied to America’s broader reworking of the global health budget, but… it is not. Instead, the Trump administration has told the global vaccine group “to phase out shots containing thimerosal as a condition of providing the group with funding.”
If you (like me) have made it this far in your life without needing to know what thimerosal is, let me present you with the disappointing news: It is a benign preservative at the center of several vaccine/autism conspiracy theories.
I reached out to Peter Hotez, director of the Texas Children’s Hospital Center for Vaccine Development, and one of the world’s foremost experts on vaccine development and vaccine misinformation to get his take.
He cautioned against “sanewashing” conspiracy claims or even detailing them next to mainstream vaccine science, which creates a “false equivalency,” as if both sides deserve equal weight.
“The thimerosal/autism link was debunked many years ago through both large epidemiological studies and even nonhuman primate neurodevelopment studies,” Hotez said, with the overwhelming fatigue of somebody who has explained this several hundred times before. “Many of these false links were popularized by [U.S. Health and Human Services Secretary Robert F. Kennedy Jr.’s] discredited 2005 article published in Rolling Stone and Salon magazines, since retracted by the editors.” As for the ultimate impact on Gavi, it remains to be seen whether the administration follows through, or whether Gavi decides to cave to the anti-science demand.
But “it’s tragic for the world’s children that now their access to vaccines and immunizations could be imperiled by this kind of pseudoscience,” Hotez said.
We’re winning the worm war
Guinea worm disease is on the verge of eradication, with just 10 infections reported worldwide last year, the Washington Post reports.
- Disease breakdown: Guinea worm (also known as Dracunculiasis) is a parasite that spreads through drinking contaminated water, or eating infected animals. I’ll spare you the gory details (because this one is a true stomach turner), but it forms a terrible worm-filled blister. Though not lethal, at its peak in the 1980s, it was endemic across 20 countries and infected about 3.5 million people per year. Four decades later, there is still no treatment beyond pain meds.
The global effort to eliminate the disease has been led by the Carter Center since the 1980s. Last year’s total caseload is a drop from 15 cases in 2024 and consists of “four human cases … reported in Chad, four in Ethiopia, and two in South Sudan.”
The organization reports that the global aid pullback “has not stopped the Guinea worm program at ground level.”
What’s particularly incredible about the ongoing elimination project is that there is no vaccine or cure for guinea worm. This global effort’s success is largely the byproduct of sustained, committed gruntwork, with decades of programs to “educate the public, train volunteers, and distribute water filters in affected areas.”
I have two takeaways: First, we are clearly winning this war against the worm. If Guinea worm cases reach zero, it would be only the second human disease ever eradicated, after smallpox. (That said, I’m still hopeful we’ll first eliminate polio before the decade is out.)
Second, the last mile will be the hardest. Unlike polio or smallpox, Guinea worm also has animal hosts. Officials say the grunt work must continue, even after zero human cases. The disease can bounce back unless animal transmission (including dogs, domestic cats, and freshwater fish) is stopped, too.
Still, if Guinea worm fades into history, the credit belongs to the community health workers and volunteers who kept at the slow, quiet work for decades, moving village by village.
ChatDNA
Last week I was admittedly a bit flippant about a story on artificial intelligence helping pharma companies speed up the “unsexy” side of drug trials. Well, this week brings a more humbling piece on AI’s promise in driving real medical advancement.
Smithsonian magazine reports that researchers at Google DeepMind have unveiled a new artificial intelligence tool called AlphaGenome.
The tool leverages what AI does best (processing and learning from enormous datasets) to crunch the full book of our DNA. Essentially, it’s meant to help scientists predict how the parts of DNA we still cannot fully explain help tell our cells what to make, and when and how to make it.
The piece has a world-class explainer on the fundamental science:
“DNA is made of four different units called nucleotides: adenine (A), cytosine (C), guanine (G), and thymine (T). These letters pair up and act as an instruction manual for cells, yet only 2% of human DNA tells our cells how to build proteins, the building blocks of life. The remaining genetic code was long dismissed as “junk DNA,” but now, scientists know it plays an important role in regulating gene activation. Certain variants and mutations in the genome can lead to disease — and AlphaGenome’s goal is to predict what those changes are.”
So what’s the promise? The designers of the AlphaGenome believe the tool “can help experts develop new genetic therapies and ways to diagnose rare diseases.” Especially by pointing human researchers toward complex genetic links that are hard to spot on their own. Best of all: “The new resource is freely available to other researchers, who can modify the program based on their own needs.”
The tool has limitations, of course, including issues predicting the impact of DNA regions that influence each other at a great distance (meaning the segments are several hundred thousand letters away).
Still, I will be looping back in the coming months. As Pushmeet Kohli, vice president of science at Google DeepMind, put it: “I think we are at the start of a new era of scientific progress, and AI is going to enable a number of different breakthroughs.”
I have to admit … I believe it.
We. Declare. ‘Water bankruptcy!’
The United Nations says the world has entered a new kind of water crisis, one it calls “global water bankruptcy,” Health Policy Watch reports. That means rivers, lakes, and underground sources that once bounced back after droughts or heavy use are being drained faster than they can recover.
Perhaps the starkest example is the Aral sea in central Asia. In the late ’80s it was still the world’s fourth-largest lake. Today it barely exists.
Not to lay it on thick, but the report hits you with some staggering facts:
“More than half of the world’s large lakes have lost water since the early 1990s, over 30% of glacier mass since 1970 has disappeared in certain regions, while about 410 million hectares of natural wetlands — a land mass nearly equal to that of the European Union — have been destroyed over the past five decades.”
And the human impact?
Today about “4 billion people — nearly two-thirds of the global population — face severe water scarcity for at least one month every year.” The report particularly points to farmers in dry regions who pump groundwater for irrigation year after year, a practice that physically cannot continue indefinitely.
What’s my takeaway?
I find these reports largely overwhelming, because the solutions are not mysterious. National governments across the world need to act to protect water sources, manage them better, and plan for scarcity. Will they? Not anytime soon.
Tangent here, but I’m reading What We Can Know by Ian McEwan, which is set in a future Britain after a climate collapse. In the book, historians look back on our current era as a period they call “The Derangement,” when people had clear knowledge of climate change but failed to act at the needed scale.
With this report it is, uh … uncomfortably on the nose.
Mosquitoes keep moving
I’m leaving you this week on a story with a somewhat fascinating twist.
Chile is on high alert after finding an Aedes aegypti mosquito in the capital of Santiago, reports El Mercurio, the country’s largest newspaper.
Why is this such bad news? The mosquito, which is still absent from large parts of the country, is known as a major vector for a host of highly transmissible diseases including dengue, chikungunya, Zika, and yellow fever. Enough so that it’s commonly called the “dengue mosquito” or “yellow fever mosquito.” It also particularly thrives in cities, breeding in locations like flower vases, plastic bottles, gutters, and even old tires.
As we reported in October, this is an insect that sticks around. “Once Aedes aegypti mosquitoes establish themselves in an area warm enough for them to survive the winter, it becomes extremely difficult to eliminate them,” Dr. Marietjie Venter, an animal-borne virus expert, told me last year.
Granted, this is not the first time the mosquito has appeared in Chile. But as climate change makes the country increasingly habitable for it, health officials are worried sightings this year could signal the mosquito establishing a foothold … and introducing a perpetual risk of terrible tropical diseases. It would not take much. After all, as Chile’s head of health emergencies, Ester Alywin, warned on Friday, “a single female mosquito can lay up to 1,500 eggs in her lifetime.”
What’s the twist?
The singular mosquito was identified by eye by an airport staff member at a warehouse in Santiago International, then caught and then sent for analysis at a public laboratory.
Readers, I’ve searched for more detail on how staff could possibly be trained well enough to recognize and capture a single, specific mosquito (!) rather than just swatting it … but I’ve come up empty. Apparently, someone took their annual public health briefings seriously.
Anyhow, you’re my hero of the week, anonymous Chilean airport warehouse worker.
I’ll see you next week.
William Herkewitz is a reporter covering global public health for Healthbeat. He is based in Nairobi. Contact William at wherkewitz@healthbeat.org.
