Learning from mycobacterial infections in animals: immunodiagnotics for leprosy and tuberculosis in humans and animals

Abstract

Tuberculosis and leprosy are major mycobacterial diseases affecting humans, caused by Mycobacterium tuberculosis complex and M. leprae/ M. lepromatosis, respectively. Despite effective antibiotics, these diseases remain prevalent, particularly in developing regions. This thesis adopts a “One Health” approach—integrating human, animal, and environmental studies—to explore diagnostic tools and the role of animals in disease transmission. A systematic review of Chinese literature confirmed that anti-M. leprae antibody seroprevalence in children is a reliable indicator of recent transmission. Using armadillo models, we demonstrated that a field-friendly test (UCP-LFA) detects early M.leprae infection and monitors intervention outcomes. In the UK, red squirrels were found to carry M. leprae and M. lepromatosis, highlighting a potential wildlife reservoir. For bovine tuberculosis, anti-M. bovis PGL IgM showed promise as a specific diagnostic marker. Additionally, in nonhuman primates, lateral flow assays effectively detected TB-related biomarkers (SAA1, IP-10, IL-6), correlating with disease progression and treatment response. Overall, this research establishes animal-compatible diagnostic tools based on human assays, improves understanding of zoonotic potential, and supports control strategies for TB and leprosy through integrated human-animal health surveillance.