In 2008, bacilli from 2 Hansen disease (leprosy) cases were identified as a new species, Mycobacterium lepromatosis. We conducted a systematic review of studies investigating M. lepromatosis as a cause of HD. Twenty-one case reports described 27 patients with PCR-confirmed M. lepromatosis infection (6 dual M. leprae/M. lepromatosis): 10 case-patients in the United States (7 originally from Mexico), 6 in Mexico, 3 in the Dominican Republic, 2 each in Singapore and Myanmar, and 1 each in Indonesia, Paraguay, Cuba, and Canada. Twelve specimen surveys reported 1,098 PCR-positive findings from 1,428 specimens, including M. lepromatosis in 44.9% (133/296) from Mexico, 3.8% (5/133) in Colombia, 12.5% (10/80) in Brazil, and 0.9% (2/224) from the Asia-Pacific region. Biases toward investigating M. lepromatosis as an agent in cases of diffuse lepromatous leprosy or from Mesoamerica precluded conclusions about clinicopathologic manifestations and geographic distribution. Current multidrug treatments seem effective for this infection.

Leprosy is a neglected tropical disease (NTD) that continues to burden low- and middle-income countries (LMICs), despite being eliminated as a public health concern by the World Health Organization (WHO) in 2000. The causative agents, Mycobacterium leprae and Mycobacterium lepromatosis, affect nearly 200,000 individuals globally each year, with over 19,000 new cases detected in the Americas in 2020 alone. Canada has experienced an increasing incidence of leprosy, due to rising levels of travel and migration from endemic areas, reaching over 37,000 individuals with leprosy by the end of 2020. Patients experience a spectrum of signs and symptoms including hypopigmented cutaneous macules alongside peripheral neuropathy including peripheral neuropathic pain (PNP) and disabling sensory neuropathies. Despite the development of effective and curative therapeutics via multidrug therapy (MDT), many barriers to treatment adherence and effective immunological control of the pathogen challenge the care of patients with leprosy. Socioeconomic barriers, such as disability-related social stigma and often undiagnosed nutritional deficiencies, have resulted in heightened disease severity. PNP therapeutics are associated with significant side effects and remain ineffective as the majority of individuals will not experience a greater than 30% reduction of symptoms. Nutrient supplementation is known to be instrumental in reducing host oxidative stress, strengthening the immune system and mitigating comorbidities. Likewise, dietary lifestyle interventions known to be physiologically beneficial have recently emerged as powerful tools conferring neuroprotective effects, potentially mitigating PNP severity. However, a significant knowledge gap concerning the effect of adequate nutrition on host immunological control of leprosy and PNP severity exists. Further evaluation of this relationship will provide key insight into the pathogenesis of leprosy, strengthening the current body of literature.

Leprosy is a chronic neglected infectious disease that affects over 200,000 people each year and causes disabilities in more than four million people in Asia, Africa, and Latin America. The disease can appear with a wide spectrum of clinical forms, and therefore the clinical suspicion is often difficult. Refugees and migrants from endemic countries affected by leprosy can remain undiagnosed in Europe due to the unpreparedness of clinicians. We retrospectively describe the characteristics of 55 refugees/migrants with a diagnosis of leprosy established in Italy from 2009 to 2018. Continents of origin were Africa (42%), Asia (40%), and South and Central America (18%). The symptoms reported were skin lesions (91%), neuropathy (71%), edema (7%), eye involvement (6%), fever (6%), arthritis (4%), and lymphadenopathy (4%). Seven patients (13%) had irreversible complications. Overall, 35% were relapses and 66% multibacillary leprosy. Furthermore, we conducted a review of 17 case reports or case series and five nationwide reports, published in the same decade, describing 280 migrant patients with leprosy in Europe. In Europe, leprosy is a rare chronic infectious disease, but it has not completely disappeared. Diagnosis and treatment of leprosy in refugees and migrants from endemic countries are a challenge. European guidelines for this neglected disease in this high-risk population would be beneficial.