Tuberculosis (TB) remains one of the most important infectious diseases worldwide, with approximately one-third of the world's population infected with the Mycobacterium tuberculosis bacillus and more than 9 million new cases and 1.7 million deaths annually. Stigma may act as a barrier to TB care, treatment, and control in areas where quality services are available. Health-related stigma is defined as a social process or related personal experience characterized by exclusion, rejection, blame, or devaluation that results from experience or reasonable anticipation of an adverse social judgment because of specific health problem. Few measures of TB stigma exist, making it difficult to understand its determinants and effect on health behaviors. Data were collected in southern Thailand where culturally relevant TB and AIDS stigma scales were developed. Using these scales, a survey of 300 healthy community members, and a cohort of 480 newly diagnosed TB patients, the aims of this dissertation were to 1) to identify socio-demographic, TB knowledge, and clinical factors associated with TB stigma, 2) to estimate the association between stigma and patient delay in seeking care for TB symptoms, and 3) to estimate the effect of stigma on adherence to TB treatment. We found high levels of both TB and AIDS stigma, but few factors were identified that could contribute to TB stigma. Knowledge of the link between TB and AIDS, higher AIDS stigma, and knowing someone who died of TB were consistently associated with TB stigma. However, neither TB nor AIDS stigma had an overall effect on delay in seeking care for TB symptoms or adherence to treatment. Effects were observed within sub-groups of gender, HIV status, and presenting symptoms, where higher stigma increased delay and non-adherence among some, while decreasing delay and improving adherence among others. These findings have important implications for future stigma research and interventions. Specifically, stigma research conducted at the general population level (community or patient) may miss important effects. Future research should recognize that stigma may serve as a motivator or barrier, and therefore identify specific sub-groups in which stigma has an adverse effect and who would therefore benefit from stigma reduction interventions
