title: Diagnostic accuracy of the rapid urine lipoarabinomannan test for pulmonary tuberculosis among HIV-infected adults in Ghana-findings from the DETECT HIV-TB study.
abstract: BACKGROUND
  Rapid diagnostic tests are urgently needed to mitigate HIV-associated tuberculosis (TB) mortality. We evaluated diagnostic accuracy of the rapid urine lipoarabinomannan (LAM) test for pulmonary TB and assessed the effect of a two-sample strategy.
  
  
  METHODS
  HIV-infected adults eligible for antiretroviral therapy were prospectively enrolled from Korle-Bu Teaching Hospital in Ghana and followed for minimum 6 months. We applied the LAM test on urine collected as a spot and early morning sample. Diagnostic accuracy was analysed for a microbiological TB reference standard based on sputum culture and Gene Xpert MTB/RIF results and for a composite reference standard including clinical follow-up data. Performance of sputum smear microscopy was included for comparison.
  
  
  RESULTS
  Of 469 patients investigated for TB, the LAM test correctly identified 24/55 (44 %) of microbiologically confirmed TB cases. Sensitivity of the LAM test was positively associated with hospitalisation (67 %), Modified Early Warning Score > 4 (57 %) and subsequent death (71 %). LAM test specificity was 95 % increasing to 98 % for the composite reference standard. A two-sample LAM test strategy did not improve test performance. Using concentrated sputum for Ziehl-Neelsen and fluorescence microscopy in combination yielded a sensitivity of 31/55 (56 %) that increased to 35/55 (64 %) when the LAM test was added. Surprisingly, nontuberculous mycobacteria were cultured in 34/469 (7 %) and associated with a positive LAM test (p = 0.008).
  
  
  CONCLUSIONS
  LAM test sensitivity was highest in patients with poor prognosis and subsequent death and did not increase with a two-sample strategy. A rigorous sputum microscopy strategy had superior sensitivity, but the simplicity of the LAM test holds operational possibilities as a TB screening method among severely sick patients.
authors.affiliation: Department of Infectious Diseases, Odense University Hospital, Odense, Denmark. steph@medicinsk.dk.|Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. steph@medicinsk.dk.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Bjerrum
authors.affiliation: Fevers Unit, Korle-Bu Teaching Hospital, Accra, Ghana. ernest_kenu@yahoo.com.
authors.forename: Ernest
authors.initials: E
authors.lastname: Kenu
authors.affiliation: Fevers Unit, Korle-Bu Teaching Hospital, Accra, Ghana. malart38@yahoo.com.|Department of Medicine, University of Ghana Medical and Dental School, Accra, Ghana. malart38@yahoo.com.
authors.forename: Margaret
authors.initials: M
authors.lastname: Lartey
authors.affiliation: Department of Medical Microbiology, School of Biomedical and Allied Sciences, College of Health Sciences, University of Ghana, Accra, Ghana. mjnewmangh@gmail.com.
authors.forename: Mercy Jemina
authors.initials: MJ
authors.lastname: Newman
authors.affiliation: Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana. kaddo@noguchi.ug.edu.gh.
authors.forename: Kennedy Kwasi
authors.initials: KK
authors.lastname: Addo
authors.affiliation: Department of Infectious Diseases, Odense University Hospital, Odense, Denmark. abandersen@dadlnet.dk.
authors.forename: Aase Bengaard
authors.initials: AB
authors.lastname: Andersen
authors.affiliation: Department of Infectious Diseases, Odense University Hospital, Odense, Denmark. isik@dadlnet.dk.
authors.forename: Isik Somuncu
authors.initials: IS
authors.lastname: Johansen
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D019540:Area Under Curve; D005260:Female; D005869:Ghana; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy; D006760:Hospitalization; D006801:Humans; D008070:Lipopolysaccharides / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000401:mortality
chemical_list: D019380:Anti-HIV Agents; D008070:Lipopolysaccharides; C050016:lipoarabinomannan