ABSTRACT
Tuberculosis (TB) control programs prevent transmission of Mycobacterium tuberculosis by identifying and treating active cases of TB disease and ensuring that contacts of infectious cases are also identified, screened, and treated for active disease or latent infection. The chapter reviews the use of genotyping to investigate transmission as well as how genotyping methods have been applied to study transmission dynamics, lineage, recurrent TB disease, mixed infections, and laboratory contamination. A common outbreak investigation goal is to combine genotyping data with different sources of clinical, epidemiological, and programmatic data through partnerships that lead investigators to the best conclusions and public health action for control of recent transmission. Although spatial analyses of TB case distributions are common, they are heterogeneous in their methods and findings. The central problem with using genotype clustering to estimate recent transmission has been that clustered cases are not necessarily part of the same chain of transmission.
