Asymptomatic leprosy infection among blood donors may predict disease development and suggests a potential mode of transmission.

Blood donors' samples (1007) were assessed for anti-PGL-1 IgM antibodies and Mycobacterium leprae DNA presence, with 3.8% and 0.3% positivity, respectively. After a five-year follow-up period, six individuals with positive markers developed leprosy, raising the hypothesis that asymptomatic infection among blood donors may be an undisclosed mode of leprosy transmission via transfusion.