Tuberculosis

Abstract

This chapter will review the basic biology of Mycobacterium tuberculosis and then focus on the epidemiology, clinical manifestations, and diagnosis in transplant patients. Prevention and treatment will be considered elsewhere. Tuberculosis (TB) remains a leading cause of human mortality in resource-limited settings, in part because it is still a diagnostic and treatment challenge. These challenges are compounded in immunocompromised hosts such as transplant patients because the performance of diagnostic tests is poor, the clinical presentation is often atypical, and treatment is complicated by toxicity and drug-drug interactions. While there have been significant recent advances in our understanding of bacterial pathogenesis and host responses, the picture remains incomplete. Conventional tuberculin skin testing, acid-fast bacilli smear, mycobacterial culture, and antibiotic sensitivity testing are imperfect tools. New molecular techniques improve the speed and certainty with which a diagnosis can be made, but little data exist on their use in the transplant patient. The prevalence of TB is low in the countries that have historically had access to organ transplantation. However, immigration to such countries and the expansion of transplants to countries with higher incidences of TB have made tuberculosis an increasingly important posttransplant complication. When tuberculosis does happen in transplant patients, the morbidity and mortality are substantial.