Mycobacterium leprae infection, Hansen's disease, and helminth infections: A cross-sectional study in southeastern...

Prior studies have demonstrated associations between helminths and mycobacterial infections, suggesting a can alter the susceptibility do mycobacterial infection or disease. Our goal was to assess the association of Mycobacterium leprae infection with parasitic infections in a highly endemic area for Hansen's disease in Minas Gerais, Brazil.

Adults and children ages 3 years and older were enrolled from communities in Governador Valadares, Minas Gerais, Brazil, and nearby municipalities. Questionnaires on demographics and infection history were administered. Serological reactivity against M. leprae and parasitic infections was assessed by multiplexed bead assay (MBA). Data were analyzed by multivariable logistic regression with both anti-LID-1 antibody positivity and history of HD as outcomes in separate models. Exposures in the analysis included history of parasites (both antibody results and self-reports) and several pertinent socio-demographics like area of residence (i.e. urban vs. rural).

Of 1,311 enrollees, 72 (5.5%) reported a prior history of HD, 94 (7.2%) tested positive for anti-LID-1, 836 (63.8%) reported having one or more parasitic diseases in the past, 153 (11.7%) tested positive for antibodies to schistosoma egg antigen (SEA), and 69 (5.3%) for antibodies to the Strongyloides stercoralis antigen NIE. There was an association between rural residence and history of HD (aOR, 1.97, CI: 1.14 - 3.38). Rural residence and anti-LID-1 also showed a positive assocation (aOR 1.79, CI: 1.07- 3.38). While not statistically significant, there was a positive association between anti-LID-1 and NIE antibodies (aOR 1.57, CI: 0.69-3.57), and a negative association between anti-LID-1 and SEA antibodies (aOR 0.79, CI: 0.38 - 1.61).

This study utilized a novel methodology (multiplex bead assay) to simultaneously measure seroreactivity among various pathogens. While we did not find that a history of HD and anti-LID-1 positivity were associated with seropositivity to NIE or SEA, our study found a high burden of several neglected tropical diseases (NTDs). There was also a strong association with rural residence and LID-1 positivity. This warrants further investigation into the prevalence and epidemiology of M. leprae infection, as well as potential spatial and environmental risk factors.