World Leprosy Day: What Infection Prevention Professionals Need to Know Beyond the Stigma

Hansen’s disease, more commonly known as leprosy, remains one of the most misunderstood infectious diseases in modern health care. Caused by Mycobacterium leprae, the chronic bacterial infection primarily affects the skin and peripheral nerves and, if untreated, can lead to loss of sensation, paralysis, or blindness.

Yet despite its historical reputation, leprosy is curable with antibiotics, not highly contagious, and rare in the US. For infection prevention and control (IPC) professionals, separating fact from fiction is essential to ensure appropriate care without unnecessary fear or overreaction.

“Over the last 40 years, the incidence is down several orders of magnitude,” said Matthew Pullen, MD, infectious disease physician and assistant professor at the University of Minnesota. “If you look back to 1985, the prevalence globally was 21.1 cases per 100,000 people. As of 2022, that was down to 0.21 cases per 100,000—about a 2-order-of-magnitude decrease.”

Globally, approximately 180,000 new cases are still reported each year, down from nearly 5 million cases in 1985, reflecting decades of progress driven by early diagnosis and multidrug therapy. In the US, leprosy is exceedingly uncommon. “In 2024, there were only 205 new cases documented in the US,” Pullen said. “Over the last decade, we typically see about 120 to 220 cases per year.”

Most US cases are linked to exposure abroad, particularly in countries where leprosy remains endemic, including India, Brazil, Indonesia, and Malaysia. A small number of domestic cases have been associated with contact with nine-banded armadillos, the only known nonhuman animal reservoir. “Don’t handle nine-banded armadillos. Don’t eat nine-banded armadillos,” Pullen said.

From an IPC standpoint, the greatest challenge is often stigma, not transmission risk. “Leprosy really is actually not highly contagious,” Pullen emphasized. “There’s no real documented human-to-human transmission, especially once someone has started on treatment.” Transmission is believed to occur primarily through prolonged respiratory exposure to untreated individuals, not casual contact.

In health care settings, standard precautions are sufficient. “Even in the hospital, we would just recommend standard precautions, especially once you get someone started on treatment,” Pullen said. “I would honestly be more worried about Clostridioides difficile or methicillin-resistant Staphylococcus aureus transmission than leprosy.”

Early recognition remains critical to preventing long-term disability. IPC professionals should maintain awareness of classic clinical clues, particularly when geographic risk factors are present. “Skin lesions on the hands or feet that are slow to heal and have numbness or tingling—that’s a classic thing for leprosy,” Pullen said. “Those chronic wounds lose sensation because the bacteria damage peripheral nerves.”

Once diagnosed, treatment is highly effective. Depending on disease classification, therapy involves 2 or 3 antibiotics administered over months to years. “Getting someone started on treatment reduces the risk that anyone else will get it markedly,” Pullen noted. “Our monitoring and treatment initiation is so potent that we don’t even routinely recommend prophylaxis for close contacts anymore.”

For clinicians and IPC teams encountering suspected cases, expert support is readily available. “We have a great resource in the United States called the National Hansen’s Disease Program Clinical Center,” Pullen said. “They’re always available for consultations and can even assist with specialized testing.”

National Hansen's Disease Program Clinical Center 800.642.2477. https://www.hrsa.gov/hansens-disease

Ultimately, World Leprosy Day serves as a reminder that while the disease persists, fear should not. “Don’t be afraid of it,” Pullen said. “Don’t let that stop you from examining the patient, caring for them, and giving them the attention they need and deserve because you’re likely not putting yourself at any real risk.”

For IPC professionals, evidence-based knowledge remains the most powerful tool for protecting both patients and providers while dismantling centuries-old misconceptions.