Hansen’s disease, commonly identified as leprosy, is perhaps one of the most misinterpreted infectious diseases in contemporary healthcare. This chronic bacterial infection, caused by Mycobacterium leprae, predominantly impacts the skin and peripheral nerves. Left untreated, it can result in loss of sensation, paralysis, even blindness. However, contrary to folklore, leprosy is curable through antibiotics, has a minimal contagion level, and is exceedingly rare in the US.
For professionals in infection prevention and control (IPC), it is pivotal to segregate the myth from the hard facts, thereby ensuring efficient care without eliciting undue apprehension or unnecessary responses. Matthew Pullen, MD, an infectious disease physician, and an assistant professor at the University of Minnesota provides insight on its epidemiology. The incidence of leprosy has been reducing drastically over the years. For context, the global prevalence in 1985 was 21.1 cases per 100,000 people, but as of 2022, it had plunged to 0.21 cases per 100,000, marking a significant decrease.
Today, approximately 180,000 new cases are reported annually worldwide, a significant reduction from close to 5 million cases reported in 1985. This progress stems from early diagnosis and multidrug therapy. In the US, leprosy is extremely rare. The last decade typically notes about 120 to 220 cases per year. Most US cases appear to have a connection to exposure overseas, especially in nations where leprosy is still prevalent such as India, Brazil, Indonesia, and Malaysia. A minor percentage of domestic cases relate to contact with the nine-banded armadillo, the sole recognized nonhuman animal reservoir.
From an IPC perspective, the stigma surrounding the disease poses greater challenges than the risk of transmission. Leprosy does not spread easily and no substantial evidence supports human-to-human transmission, particularly post the commencement of one’s treatment. It is believed to spread predominantly through prolonged respiratory exposure to untreated individuals and not via casual contact. Therefore, in healthcare settings, standard precautions suffice. Timely recognition is key to prevent lasting disability.
Classic symptoms include skin lesions on hands or feet that take time to heal and may be accompanied by numbness or tingling sensation. Once diagnosed, it can be effectively treated using a regimen of 2 or 3 antibiotics over several months to years. It is worth underlining that commencing someone’s treatment significantly reduces the chances of others contracting it.
Individuals and IPC teams suspecting cases can find expert assistance with the National Hansen’s Disease Program Clinical Center in the United States. They provide consultation and can also help with specialized testing. World Leprosy Day serves as a reminder that the disease is present, but the fear need not persist. IPC professionals must remember that evidence-based understanding remains the most potent tool for ensuring the protection of patients and healthcare providers while quashing age-old misconceptions about the disease.