Leprosy is a multifactorial chronic disease caused by Mycobacterium leprae or Mycobacterium lepromatosis that affects the skin and nerves. More than 200.000 new cases are diagnosed per year; thus,... Show moreLeprosy is a multifactorial chronic disease caused by Mycobacterium leprae or Mycobacterium lepromatosis that affects the skin and nerves. More than 200.000 new cases are diagnosed per year; thus, transmission is still ongoing. The most likely way of transmission is the respiratory route form human-to-human; however, transmission is still not clearly understood. Early diagnosis of leprosy is crucial to reduce and avoid transmission as well as leprosy-associated disabilities, which are also a cause of stigma. Currently, diagnosis is performed based on clinical signs and symptoms and late- or mis-diagnosis are not uncommon.In this thesis, we combined the study of pathogen transmission with host transcriptomic and genomic biomarkers. To explore M. leprae transmission a One Health approach was followed, where human, animal and environmental samples were studied.The combination of demographic characteristics, pathogen detection, genetic and/or transcriptomic biomarkers can be applied in a multifactorial leprosy signature applicable for early diagnosis of leprosy and/or to guide intervention strategies. Identification of predictive biomarkers will in due course lead to prompt treatment, preventing leprosy-associated irreversible disabilities as well as reducing M. leprae transmission. Show less