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This undated photo from the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, which is also known as a deer tick and carries Lyme disease. (AP) This undated photo from the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, which is also known as a deer tick and carries Lyme disease. (AP)

This undated photo from the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, which is also known as a deer tick and carries Lyme disease. (AP)

Sofia Ahmed
By Sofia Ahmed May 16, 2024

Was Lyme disease spread as a bioweapon? No, that theory is Pants on Fire!

If Your Time is short

  • Research has shown that the Lyme disease bacterium, Borrelia burgdorferi, has existed for at least 60,000 years, long before the United States’ biological weapons program began in 1942. 

  • Lyme became endemic in the U.S. in the 1970s because of changing environmental factors, not because of bioweapons research, experts said. 

  • Experts told PolitiFact that Lyme disease would make a "terrible bioweapon" because of its slow rate of transmission and low mortality rate; it’s almost never fatal.

People contract Lyme disease through tick bites. But was the disease spread by the government, as former Fox News anchor Tucker Carlson wrote on Instagram? 

"In the late 1960s, government bioweapons labs started injecting ticks with exotic diseases," Carlson wrote in a May 9 Instagram caption. "Soon, people nearby began to get those diseases. Now, tick-borne Lyme is endemic. Naturally, the government has admitted nothing." 

Contrary to Carlson’s claim, experts said Lyme disease has proliferated in recent decades because of environmental factors — not because the government spread the disease as a bioweapon.  

Carlson’s post shows clips of him interviewing author Kris Newby on his online show, "Tucker Carlson Uncensored." The Instagram post’s caption has a link to Carlson’s website, where there’s a longer video of the interview.

In the Instagram clip, Newby said, "Lyme disease wasn’t a problem until the peak of the biological weapons program in the U.S., the mid-’70s." 

Newby added that during this peak, "three freaky diseases" showed up, Rocky Mountain spotted fever, babesia (a parasite that causes babesiosis) and Lyme arthritis, which Lyme disease triggers. 

"So, you have a cluster of these three previously rare diseases right across the water from the U.S. government’s biological weapons testing facility, is that what you’re saying?" Carlson said in the clip.

Newby said, "This is the perfect stealth weapon, it’s poor man’s nuke." She later added, "If we’re going to play God and make these new germs inside ticks, there could be blowback."

The Instagram post was flagged as part of Meta’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook and Instagram.)

Tucker Carlson Network did not answer PolitiFact’s request for comment. 

Newby wrote about the theory that biological weapons caused Lyme disease’s spread in her 2019 book, "Bitten: The Secret History of Lyme Disease and Biological Weapons." Newby told PolitiFact in a May 14 email, "I have never said Lyme is a bioweapon, but the U.S. weaponized ticks, which turbo-charged its spread." 

But Lyme disease experts told PolitiFact the theory that the U.S. government spread Lyme disease is scientifically unsound. 

The United States had a biological weapons program from 1942 to 1969. Conspiracy theories about Lyme disease’s origins have been circulating for decades, but Lyme disease bacterium existed long before the bioweapons program began. 

Experts also said biological weapons research did not cause the doubling of Lyme disease cases in the U.S. since 1991. 

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The disease became endemic in the U.S. in the 1970s because of a warming climate and changing landscapes from suburbanization, which sparked an increase in ticks that carry the disease and the animals they feed on, specifically white-tailed deer, said Katharine Walter, an assistant epidemiology professor at the University of Utah and a researcher who estimated the Lyme disease bacterium’s age. 

Maria Diuk-Wasser, a professor in Columbia University’s Department of Ecology, Evolution, and Environmental Biology Department, said that at the same time, people began living closer to deer populations that carried the disease, which spurred its spread in the last 50 years.  

People contract Lyme disease when bitten by a tick carrying Borrelia burgdorferi, a bacterium. Although the disease was first identified in 1976 in Lyme, Connecticut, researchers led by Yale University’s School of Public Health found in 2017 that the bacterium that causes Lyme disease has existed for at least 60,000 years. And Walter said illnesses consistent with Lyme disease were found in several locations well before the Connecticut discovery, including in Ötzi, also known as "the Iceman," a 5,000-year-old mummy found in the Tyrol Alps near the Austria-Italy border. 

Lyme disease-infected people can experience a rash, fever, muscle aches, fatigue and swollen lymph nodes. Left untreated, the symptoms can worsen and spark vision loss, facial palsy, irregular heartbeat, nerve pain, muscle weakness and arthritis.  

But Lyme disease is rarely fatal. The Centers for Disease Control and Prevention reported that 11 people worldwide died from the disease from 1985 to 2019. 

In a longer version of the Instagram clip, Newby said that a Lyme disease outbreak emerged in Connecticut in the late 1960s, across from the U.S. headquarters for the biological weapons program on Plum Island in New York. 

But Andrea Love, executive director of the American Lyme Disease Foundation, said Plum Island "had no capacity or infrastructure in place to work with human pathogens." She added that Plum Island researchers studied African swine fever virus, a tick-borne disease that doesn’t affect humans. 

The U.S. Department of Homeland Security said Plum Island research was used to prevent foreign animal diseases, primarily foot-and-mouth disease, which is spread among domestic animals and doesn’t threaten humans

Further, Diuk-Wasser said, Lyme disease would be a "terrible bioweapon" because the bacteria and ticks grow very slowly, need specific habitats to survive and are transferred through tick bites, which have a slower transmission rate than diseases spread through other means, such as respiratory viruses. 

Love agreed with Diuk-Wasser that Lyme disease would make a poor biological weapon. 

"Infection only occurs via the bite of an infected tick of certain tick species (and only after feeding for at least 24 hours)," Love said. "More than that, it is almost never fatal."

Our ruling

Tucker Carlson said in an Instagram caption that Lyme disease became endemic because of U.S. government bioweapons labs. 

The bacterium that causes Lyme disease is at least 60,000 years old and existed long before the U.S. bioweapons program. Scientists have observed suspected cases of Lyme disease in several locations well before the first identified case of the disease in the 1970s, including in a 5,000-year-old mummy near the Austria-Italy border. 

Lyme disease became endemic in the U.S. in the 1970s because of suburbanization and a warming climate, which increased both ticks carrying the Lyme disease bacterium and the number of animals, such as the white-tailed deer, on which the ticks feed. Humans also began living closer to these animal populations, spurring the disease to spread more rapidly. 

Experts also said Lyme disease would make a poor bioweapon because of its low fatality rate and its transmission through ticks. 

We rate the claim Pants on Fire! 

PolitiFact Researcher Caryn Baird contributed to this report.

Our Sources

Instagram post (archived), May 9, 2024

Yale School of Medicine, Ancient History of Lyme Disease in North America Revealed with Bacteria Genomes, Aug. 28, 2017

Centers for Disease Control and Prevention, Lyme Disease, accessed May 13, 2024

Phone interview, Katharine Walter, assistant professor of epidemiology, University of Utah, May 13, 2024

Email interview, Maria Diuk-Wasser, professor, Columbia University’s department of Ecology, Evolution and Environmental Biology, May 10, 2024

Email interview, Andrea Love, executive director, American Lyme Disease Foundation, May 13, 2024

Amazon, Lab 257: The Disturbing Story of the Government’s Secret Plum Island Germ Laboratory, Feb. 17, 2004 

Carnegie Endowment for International Peace, The New Killer Pathogens: Countering the Coming Bioweapons, April 17, 2018

United States Environmental Protection Agency, Climate Change Indicators: Lyme Disease, accessed May 14, 2024

YouTube, The True Origins of Lyme Disease, May 9, 2024

University of Toronto, U of T researchers find that ancient Iceman’s infection helps Lyme disease bone loss discovery, Jan. 5, 2017

Centers for Disease Control and Prevention, Lyme carditis, accessed May 14, 2024

University of Pennsylvania Museum of Archaeology and Anthropology, Ötzi the Iceman: Examining New Evidence from the Famous Cooper Age Mummy, 2016

Mayo Clinic, Lyme disease, accessed May 14, 2024

Centers for Disease Control and Prevention, Signs and Symptoms, accessed May 14, 2024

Email interview, Kris Newby, author, May 14, 2024 

U.S. Department of Agriculture, Expanding on the Legacy of the Plum Island Animal Disease Center, accessed May 15, 2024


U.S. Department of Homeland Security, The Plum Island Story: Protecting America’s Flora and Fauna for More than 50 Years, accessed May 15, 2024


U.S. Department of Homeland Security, Foot-and-Mouth Disease: An Omnipresent Transboundary Disease Livestock Threat, accessed May 15, 2024


U.S. Department of Agriculture, Foot-and-Mouth Disease, accessed May 15, 2024


European Centre for Disease Prevention and Control, Transmission of Foot and Mouth disease to humans visiting affected areas, Feb. 21, 2012 


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