The two complementary approaches for improving early detection of TB are illustrated in Fig. 2.1 The primary approach is to optimize the patient-initiated pathway to TB diagnosis and treatment (for details see 2.1.1). This approach does not constitute screening and is a passive form of case detection. Because it relies on initiation by people with TB disease and on health systems to respond, this approach is beset with delays associated with societal norms, stigmatization and discrimination, illness behaviour, limitations in health coverage, barriers to accessing services, and constraints of resources and capacity at health service entry points and referral pathways within the health system. The other approach to enhance case detection is screening, or the provider-initiated screening pathway to TB diagnosis and is the focus of this operational handbook.