Soil-transmitted helminth infections and leprosy: a cross-sectional study of the association between two major neglected tropical diseases in Indonesia

BACKGROUND The clinical spectrum of leprosy is dependent on the host immune response against Mycobacterium leprae or the newly discovered Mycobacterium lepromatosis antigen. Helminth infections have been shown to affect the development of several diseases through immune regulation and thus may play a role in the clinical manifestations of leprosy and leprosy reactions. The purpose of this study is to determine the proportion of helminth infections in leprosy and its association with the type of leprosy and type 2 leprosy reaction (T2R). METHODS History or episode of T2R was obtained and direct smear, formalin-ether sedimentation technique, and Kato-Katz smear were performed on 20 paucibacillary (PB) and 61 multibacillary (MB) leprosy participants. RESULTS There are more helminth-positive participants in MB leprosy compared to PB (11/61 versus 0/20, p = 0.034) and in T2R participants compared to non-T2R (8/31 versus 3/50, p = 0.018). CONCLUSIONS Our results suggest that soil-transmitted helminth infections may have a role in the progression to a more severe type of leprosy, as well as the occurrence of T2R. These findings could serve as a fundamental base for clinicians to perform parasitological feces examination in patients who have MB leprosy and severe recurrent reactions to rule out the possibility of helminth infection. Further secondary confirmation of findings are needed to support these conclusions.