Arginase 1 is a marker of protection against illness in contacts of leprosy patients.

Leprosy household contacts are generally more prone to develop the disease compared to the general population. Previous studies have demonstrated that genes related to the alternative activation (M2) profile in macrophages are associated with the increased bacillary load in multibacillary leprosy patients (MB), and that contacts of MB patients have a higher risk of contracting the disease. In addition, positive serological responses to PGL-1 or LID-1 are associated with a higher risk of disease.

Leprosy incidence and risk estimates in a 33-year contact cohort of leprosy patients.

Reduction in incidence has been associated with the introduction of novel approaches, like chemo/immune-prophylaxis. Incidence determined through follow-up cohort studies can evaluate the implementation of these innovative policies towards control and prevention. We have assessed the incidence in our contacts cohort over past 33 years, considering the effect of demographic and clinical variables.

Emergence of Mycobacterium leprae Rifampin Resistance Evaluated by Whole-Genome Sequencing after 48 Years of Irregular Treatment.

A case of rifampin resistance after irregular antileprosy treatments since 1971 is reported. Whole-genome sequencing from four longitudinal samples indicated relapse due to acquired rifampin resistance and not to reinfection with another strain. A putative compensatory mutation in was also detected.