The Lancet Paper Calls for Earlier Diagnosis as Leprosy Persists Globally

OKLAHOMA CITY – Although often considered a disease of the past, leprosy remains a global health issue, causing preventable disability due to delayed diagnosis and gaps in care. In a paper published in The Lancet, a professor of infectious diseases from the University of Oklahoma College of Medicine calls for stronger awareness, earlier detection and improved long-term management.

Nelson Agudelo, M.D., an OU Health infectious disease physician, is the lead author of the paper, which details the current state of leprosy worldwide. Although the condition, also known as Hansen’s disease, is considered eliminated in some countries, it still exacts a toll, especially in impoverished and underserved communities.

“Leprosy is still a real problem today,” Agudelo said. “It continues to cause preventable disability because it is often diagnosed late and poorly managed over time. Ongoing cases highlight the need for policymakers to strengthen access to diagnosis, long-term management and public health support.”

Globally, about 180,000 new cases of leprosy are reported each year, likely an underestimate because many cases are missed or diagnosed late. It is rare in the United States – about 200 new cases are reported each year, including some Oklahoma cases. Agudelo said the condition causes pale or red skin patches, numbness, tingling, weakness and thickened nerves. If untreated, it can cause wounds, deformities, chronic pain and vision problems.

The exact way leprosy spreads is not known, he said, although evidence suggests that it usually requires long-term close contact, probably through droplets from the nose or mouth of someone with untreated disease. However, most people who are exposed never get sick. Transmission likely involves multiple factors, including a person’s immune system, living conditions and environmental exposure.

While many U.S. cases are linked to exposure abroad, some appear to be acquired in the United States. In parts of the southern U.S., armadillos have been found to carry the same bacteria that cause the disease in humans. Agudelo is helping to plan a leprosy surveillance study of armadillos in Oklahoma to determine if they also carry the bacteria.

Early diagnosis of leprosy is crucial, Agudelo said, although that does not always happen for a variety of reasons.

“Leprosy is often missed because symptoms can look like other conditions, and many health care providers – especially in high-income countries – have little experience with it,” he said. “Combined with limited diagnostic tests and fragmented long-term care, these gaps result in avoidable disability and ongoing transmission.”

Stigma also plays a role, sometimes even from health care providers, and leads to dismissal of symptoms, delayed referrals and discomfort in managing patients, Agudelo said. Stigma also makes people afraid to seek care and worsens mental health.

For centuries, people with leprosy endured forced isolation. A well-known example is in Hawaii, where people with leprosy were sent to isolation settlements like Kalaupapa on the island of Molokai. A major turning point came in the mid-20^th century with the discovery of effective antibiotics. By the 1980s, multidrug therapy made leprosy fully curable, allowing patients to be treated without isolation.

Agudelo said he is hopeful that leprosy cases will decrease over time. A supportive community of researchers, health care professionals and public health teams is dedicated to patients around the world.

“Their commitment, together with improvements in diagnostic testing, the development of shorter and safer treatment regimens, preventive therapy for close contacts, ongoing vaccine research, and increasing attention to stigma reduction and patient rights, provides a strong foundation for continued progress,” he said.

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About the project

The paper, titled “Leprosy,” is at https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)01963-4/fulltext.

About the University of Oklahoma

Founded in 1890, the University of Oklahoma is a public research university with campuses in Norman, Oklahoma City and Tulsa. As the state’s flagship university, OU serves the educational, cultural, economic and health care needs of the state, region and nation. In Oklahoma City, the OU Health Campus is one of the nation’s few academic health centers with seven health profession colleges located on the same campus. The OU Health Campus serves approximately 4,000 students in more than 70 undergraduate and graduate degree programs spanning Oklahoma City and Tulsa and is the leading research institution in Oklahoma. For more information about the OU Health Campus, visit www.ouhsc.edu.