America had a national leprosarium—a leper colony—in Louisiana until 1999

Read an account of what life was like in America's national leprosarium—its leper colony

José Ramirez Jr. shares an account of his eight years at the 300-acre national leprosarium in Carville, Louisiana, from 1968 through the mid-1970s. Mostly staffed by nuns with nursing degrees, this facility was home to hundreds of people at a time, and it's also the site where they were required to be buried.

In 1865, Hawaii's king authorized forcible removal, quarantining of those with leprosy

King Kamehameha V authorized the removal of anyone with leprosy symptoms and for them to be placed in a medical facility later maintained by the Catholic Church on Moloka'i, Hawaii's fifth largest island. Patients weren't allowed to transfer to other medical facilities until 1969.

Read excerpted accounts from some of the 8,000 residents with leprosy on Moloka'i

Accounts preserved by the Kalaupapa National Historical Park describe how residents felt about being sent to live in this remote location and knowing they would never be allowed to leave. In 2012, 20 residents with the disease continued to voluntarily live in the area.

Up to 225 cases of leprosy in the US are diagnosed each year

Most cases in the US are imported, meaning someone was infected in a country where it was more common. Since symptoms can sometimes take decades to appear, tracing the origin of the disease can be hard.

Recent research indicates leprosy was present in the Americas before European settlers

New research published in 2025 upended long-held notions that the disease was introduced to the Americas by European colonizers. Evidence of a lesser-known leprosy-causing bacterium was found in ancient human remains that date back 4,000 years.

Listen to what it was like living as a medieval leper

This podcast uses paleopathological and anthropological findings to reconstruct what it was like for people diagnosed with leprosy in medieval times on the Eurasian continent. If a town lacked a leprosarium—an isolated leper asylum or colony—or the suspected leper was a foreigner or a Jew, which would make them ineligible for leprosarium admission, they'd be expelled.

81% of Florida's leprosy cases occur in central Florida, raising concerns

Researchers noted in 2023 that about one-fifth of new US leprosy cases were reported in the central part of the Sunshine State. What's more, about a third of the new US cases overall appear to have been acquired locally, raising questions about whether the disease is now naturally occurring in parts of the southeastern US.

About 95% of people are naturally immune to leprosy.

More than 200,000 people are diagnosed with leprosy annually

The disease still occurs in more than 120 countries. Brazil, India, and Indonesia continue to report more than 10,000 new cases annually.

Leprosy affects the skin, eyes, and upper respiratory tract

Untreated, the disease can lead to permanent nerve damage and the loss of sensation in arms, legs, and other extremities. The exact form of transmission remains unclear, but scientists suspect it is spread via respiratory droplets over a prolonged period. (Warning: Graphic content, including photos of deformities.)

See examples of leprosy in the Bible—a broad term for skin ailments in ancient times

People afflicted with leprosy in the Bible may have had a range of different skin diseases, rather than what's clinically diagnosed as Hansen's disease (leprosy) today. In the Bible, as in many traditional societies, those with the disease were often considered unclean or sinful.

See what regions report new leprosy cases

This graphic shows the burden of leprosy by region for 2023, based on data provided from the World Health Organization, which collates this information. Southeast Asia leads in the number of cases by region. (Some readers may experience a paywall.)

Leprosy symptoms may appear 20 years after infection, so contact tracing isn't possible.

Louisiana has parishes instead of counties

Louisiana is the only US state that uses parishes rather than counties as its primary local government unit. The distinction traces back to the state's French and Spanish Catholic colonial heritage.

Watch how doctors examine leprosy patients for signs of vision impairment

Clinicians must screen for symptoms of eye and vision damage in leprosy patients, including loss of sensation, reduced blink reflex, and inability to close or keep the eyes closed.

Nerve axons become damaged by leprosy, so patients may lose feeling in their skin

Infection of the peripheral nerves—nerves outside the brain and spinal cord—is a known complication of leprosy. That damage can cause patients to lose their sense of touch and the ability to feel pain or temperature in affected areas, leading to accidental injury.

Leprosy bacteria replicate extremely slowly—only once every two weeks

Mycobacterium leprae has a long incubation period and a very slow replication rate, taking roughly 12 to 14 days to make a copy of itself and divide. In contrast, bacteria like E. coli can replicate in about 20 minutes in ideal conditions. Someone can be infected for years without experiencing any symptoms. This also makes the disease difficult to treat. This video describes the knowns—and unknowns—about this infectious bacterium.

People can—and have—contracted leprosy from armadillos

A 2011 study linked multiple human cases to the handling of armadillos or the consumption of their meat. The research couldn't document direct transmission, but did find that the animals and humans shared the same exact strain of the disease.

Leprosy bacteria are sometimes grown on mouse feet for research since the pathogens can't be grown in a petri dish.

A French Army surgeon discovered that malaria is a parasitic disease in 1880—but scientists were initially skeptical.

Wild chimpanzees have been spotted with leprosy lesions

In research published in 2021, scientists reported discovering cases of leprosy in wild chimpanzees from Guinea-Bissau and the Ivory Coast—marking the first time the disease has been found in any nonhuman species in Africa. They confirmed that leprosy was the cause of the deformities by testing the animals' poop for the presence of the disease-causing bacteria.

Legionnaires' disease is named after a 1976 outbreak at a state convention of the American Legion in Philadelphia.

Grosse Île, the quarantine island of the Port of Quebec

As tens of thousands of Irish emigrated to North America to escape the Great Famine in the mid-19th century, many port cities set up quarantine areas amid an epidemic of cholera. In Quebec City on the St. Lawrence River, one island became a mass graveyard where over 3,000 Irish immigrants died over a decade as they waited in quarantine. Listen to the history here.

Lyme disease was first identified in Lyme, Connecticut in 1975

A cluster of 51 children and adults in the town all began experiencing uncommon arthritic symptoms and the cases were reported to the state health department. A quarter of the cases were preceded by a skin lesion. The patients tended to live near the woods.

Louisiana's 'Cancer Alley,' an area with hundreds of industrial plants and petrochemical production, has cancer rates 50% above the national average.

Explore how close you live to some of the most contaminated places in the US

Known as Superfund sites, these toxic locations undergo long-term cleanup to remove hazardous waste, protect health, and restore land for safe reuse. As of 2025, the EPA lists around 1,300 active Superfund sites on its National Priorities List, with more than 450 cleaned and removed since 1980.

Leprosy has been detected in British red squirrels

The animals have been infected with both strains of the bacterium that cause leprosy. Researchers have found that squirrels living in different parts of the UK were infected with different species of the disease-causing bacteria. (Some users may experience a paywall.)

See the incidence of Lyme disease across all 50 states in 2023

The US states with the highest rate of Lyme disease—meaning cases per 100,000 people—were Rhode Island, Vermont, and Maine, in 2023. Rhode Island had 260 cases per 100,000 people, based on cases reported to the US Centers for Disease Control and Prevention. (Some users may encounter a paywall.)

The peer support movement may date back to 18th century France

At the Bicêtre Hospital, an asylum near Paris, Jean-Baptiste Pussin (who had previously been a patient but later led the hospital administration) tried to hire as many staff as possible from among recovered patients. Chief physician Philippe Pinel found these individuals to be kinder than other staff and "averse from active cruelty" which was common at the time. This approach allowed the facility to move away from shackling patients and other violent methods.

Private education offered an alternative for Black Americans

The early public school system was ostensibly designed for all Americans, but it was also racially segregated, offering substandard schools for Black Americans. Some private schools were founded to combat that problem, including St. Frances Academy in Baltimore, the United States' oldest predominantly Black Catholic high school.

Read a study about racial differences in Lyme disease diagnosis

The research published in September 2025 examined differences in Lyme disease diagnosis among Medicaid and Medicare beneficiaries using data from 2016 to 2021. It notes that though US Lyme disease surveillance data indicates more than 90% of diagnosed Lyme cases are among white people, people of color—particularly those who identify as Black or African American—have higher rates of more severe disease of Lyme, with symptoms including arthritis and neurologic impacts.

The most haunted locations in the US

This TimeOut guide presents some of the most notorious places in the United States, profiling the creepy histories of Eastern State Penitentiary in Philadelphia, the Waverly Hills Sanitorium in Louisville, Kentucky, and the lingering effects of the witch trials in Salem, Massachusetts.

See the total number of Lyme cases per state in 2023

New York, Pennsylvania, and Massachusetts had the highest total number of Lyme disease cases in 2023. New York had more than 22,000 cases that year. Maine had one of the highest Lyme incidence rates of disease that year—213 per 100,000 people—but only 2,942 cases overall.

Americans touring the Louvre were inspired to create their own grand museums

The one-time royal residence was first transformed into a public museum in 1793 amid the French Revolution. Americans visiting in the early 1800s were both turned off by the aristocratic grandeur and compelled by the open access to the public. James Fenimore Cooper, the author of "The Last of the Mohicans," apparently came and measured the length of galleries.

The first recorded American Mardi Gras was in Alabama

French explorers observed celebrations in what would become the United States in the late 1600s, but the first recognized modern American Mardi Gras took place in Mobile, Alabama, on New Year's Eve, running from 1830 into 1831. By 1840, the town had incorporated costumes, masks, and themes into its parade. After the Civil War, Mobile's Mardi Gras was moved to the more traditional date of Fat Tuesday. By 1850, a group from Mobile migrated to New Orleans, bringing the city's traditions with it.

In 1939, baseball star Lou Gehrig delivered his 'Luckiest Man' speech after retiring due to a health condition

Gehrig's diagnosis of amyotrophic lateral sclerosis, a disease that now bears his name, forced him to retire early. Weeks later, he spoke with gratitude and stated, "For the past two weeks, you have been reading about a bad break. Yet today I consider myself the luckiest man on the face of the earth." Gehrig died at the age of 37, about two years later.

In 2011, a mysterious illness spread around LeRoy, New York

A handful of girls were stricken with bizarre twitches, tics, and spasms — all apparently involuntary. Some believed the incident to be conversion disorder, an illness where emotional troubles have physical symptoms.

Lyme disease-causing bacteria predate any suspected biological weapons testing

Borrelia bacteria existed long before any US biological weapons program—or human presence in North America. One study comparing genomes of the bacteria behind Lyme disease collected samples of the bacteria over three decades and calculated that the bacterium has been in North America longer than humans, at least 60,000 years. Other work found related bacteria preserved in amber from millions of years ago.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

Leprosy doesn't cause fingers or toes to fall off

The nerve damage that results from infection sometimes causes loss of feeling in extremities so injuries like cuts or burns may be missed. In such cases, resulting infections can lead to digit loss. Fingers or toes can also appear to shorten with this disease because nerve damage can sometimes make muscles in fingers and toes so weak that they're reabsorbed by the body.

The canal carried germs as well as goods

In 1832, North America’s first cholera epidemic spread inland by way of the Erie Canal, carried by immigrants arriving on ships. Fearful towns barred passengers from disembarking, yet cholera, smallpox, and other diseases still traveled the waterway.

How the National Science Foundation helped cement the use of American Sign Language

Before the 1960s, deaf students were taught to read lips and pronounce words without signing, which was not considered a true language. After noticing that students nonetheless signed when communicating, American linguist William Stokoe conducted NSF-funded research that showed that signing met the definition of oral languages, thus establishing ASL.

Maryland required cholera researchers to fly a yellow warning flag—signifying quarantine dangers in the 1970s

University of Maryland Hospital researchers intentionally infected volunteers with the cholera bacterium in the late 1970s to further their understanding of the disease. They proceeded with this work following the recommendation of a US government panel. (Some users may encounter a paywall.)

Meriwether Lewis grew up in the same neighborhood as Jefferson

Hailing from Jefferson’s Albemarle County neighborhood in Virginia, Lewis was a trusted aide and former Army officer. After leading the Corps of Discovery, he became Louisiana Territory governor in 1806, dying three years later under mysterious circumstances.

Benjamin Franklin founded America's first lending library, the Library Company of Philadelphia, in 1731.

What's the role of forced prison labor in a land where slavery is illegal?

Companies across the South profited off the forced labor of people in prison after the Civil War. This hourlong investigative podcast episode explores the role forced (and often unpaid) prison labor has played in the US since slavery was abolished.

Explore what it's like Inside a patient isolation unit.

Gambling and lotteries funded America's early expansion, funding infrastructure and capital projects.

Explore the components of the linear particle accelerator at Los Alamos

Located at the site of bomb design and development for the Manhattan Project, LANSCE features an injector system for hydrogen ions, a series of tanks with alternating electric fields for proton acceleration, and an isotope production facility that creates radioisotopes for medical treatments.

The earliest colonial schools were often religious

The earliest American schools were far from our notions of “public” or “private”—they were neighborhood institutions, often founded by religious groups, that sought to educate children academically and spiritually.