Clinical Characteristics and Predictors of Hospitalization of Leprosy in the United States: A Multicenter Network Analysis

ABSTRACT. Leprosy, also known as Hansen’s disease, is a chronic infection caused by Mycobacterium leprae or Mycobacterium lepromatosis . Although global prevalence has decreased, the number of cases each year has plateaued at ∼200,000. In the United States, sporadic cases continue to occur, primarily in the southern states. A retrospective cohort study was conducted from 1992 to 2024 using the TriNetX Research Network (Cambridge, MA, USA), an international electronic health record network, to characterize the clinical features of leprosy and identify factors predicting hospitalization among individuals diagnosed with the disease. Of 215 patients, 30 (14%) required hospitalization. These hospitalized patients were generally older and had other health conditions. Stepwise logistic regression was used to identify a higher absolute neutrophil count and a higher Charlson Comorbidity Index value as predictors of hospitalization. Most patients were from the United States, and the slight majority of cases were clustered in the southern states. These results provide one of the largest recent descriptions of leprosy, highlighting how leprosy reactions and other health issues may influence outcomes, including hospitalization, and emphasizing the importance of ongoing surveillance of leprosy in the southern United States and other regions.