title: Assessing the utility of Xpert(®) MTB/RIF as a screening tool for patients admitted to medical wards in South Africa.
abstract: Many hospital inpatients in South Africa have undiagnosed active and drug-resistant tuberculosis (TB). Early detection of TB is essential to inform immediate infection control actions to minimize transmission risk. We assessed the utility of Xpert(®) MTB/RIF (GeneXpert) as a screening tool for medical admissions at a large public hospital in South Africa. Consecutive adult patients admitted to medical wards between March-June 2013 were enrolled; sputum specimens were collected and tested by GeneXpert, smear microscopy, and culture. Chest X-rays (CXRs) were conducted as standard care for all patients admitted. We evaluated the proportion of patients identified with TB disease through each diagnostic method. Among enrolled patients whose medical charts were available for review post-discharge, 61 (27%) were diagnosed with TB; 34 (56% of diagnosed TB cases) were GeneXpert positive. When patients in whom TB was identified by other means were excluded, GeneXpert yielded only four additional TB cases. However, GeneXpert identified rifampicin-resistant TB in one patient, who was initially diagnosed based on CXR. The utility of GeneXpert for TB screening was limited in an institution where CXR is conducted routinely and which serves a population in which TB and TB/HIV co-infection are highly prevalent, but it allowed for rapid detection of rifampicin resistance.
authors.affiliation: Clinical and Biomedical Tuberculosis Research Unit, Medical Research Council, South Africa.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Heidebrecht
authors.affiliation: Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Podewils
authors.affiliation: KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH), South Africa.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Pym
authors.affiliation: Division of Global Health Equity, Brigham and Women's Hospital, USA.|Department of Epidemiology, Harvard School of Public Health, USA.
authors.forename: Ted
authors.initials: T
authors.lastname: Cohen
authors.affiliation: School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, South Africa.
authors.forename: Thuli
authors.initials: T
authors.lastname: Mthiyane
authors.affiliation: Department of Medicine, Edendale Hospital, South Africa.
authors.forename: Douglas
authors.initials: D
authors.lastname: Wilson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060085:Coinfection; D024881:Drug Resistance, Bacterial; D005260:Female; D015658:HIV Infections; D006801:Humans; D008297:Male; D008403:Mass Screening; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques; D015203:Reproducibility of Results; D012293:Rifampin / Q000494:pharmacology*; D013019:South Africa / Q000453:epidemiology; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D055815:Young Adult
chemical_list: D012293:Rifampin