title: Extensively Drug-Resistant Tuberculosis: Principles of Resistance, Diagnosis, and Management.
abstract: Extensively drug-resistant (XDR) tuberculosis (TB) is an unfortunate by-product of mankind's medical and pharmaceutical ingenuity during the past 60 years. Although new drug developments have enabled TB to be more readily curable, inappropriate TB management has led to the emergence of drug-resistant disease. Extensively drug-resistant TB describes Mycobacterium tuberculosis that is collectively resistant to isoniazid, rifampin, a fluoroquinolone, and an injectable agent. It proliferates when established case management and infection control procedures are not followed. Optimized treatment outcomes necessitate time-sensitive diagnoses, along with expanded combinations and prolonged durations of antimicrobial drug therapy. The challenges to public health institutions are immense and most noteworthy in underresourced communities and in patients coinfected with human immunodeficiency virus. A comprehensive and multidisciplinary case management approach is required to optimize outcomes. We review the principles of TB drug resistance and the risk factors, diagnosis, and managerial approaches for extensively drug-resistant TB. Treatment outcomes, cost, and unresolved medical issues are also discussed.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, Mayo Clinic, Rochester, MN. Electronic address: wilson.john@mayo.edu.
authors.forename: John W
authors.initials: JW
authors.lastname: Wilson
authors.affiliation: Division of Infectious Diseases and Internal Medicine, University of Minnesota, Hennepin County Medical Center, Minneapolis, MN.
authors.forename: Dean T
authors.initials: DT
authors.lastname: Tsukayama
mesh_terms: D000995:Antitubercular Agents / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D054908:Extensively Drug-Resistant Tuberculosis / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D000995:Antitubercular Agents