title: The additional yield of GeneXpert MTB/RIF test in the diagnosis of pulmonary tuberculosis among household contacts of smear positive TB cases.
abstract: OBJECTIVE
  The objective of this study was to compare the diagnostic yield of GeneXpert MTB/RIF with Ziehl-Neelson (ZN) sputum smear microscopy among index TB cases and their household contacts.
  
  
  METHODS
  A cross sectional study was conducted among sputum smear positive index TB cases and their household contacts in Northern Ethiopia.
  
  
  RESULTS
  Of 353 contacts screened, 41 (11%) were found to have presumptive TB. GeneXpert test done among 39 presumptive TB cases diagnosed 14 (35.9%) cases of TB (one being rifampicin resistant), whereas the number of TB cases diagnosed by microscopy was only 5 (12.8%): a 64.3% increased positivity rate by GeneXpert versus ZN microscopy. The number needed to screen and number needed to test to diagnose a single case of TB was significantly lower with the use of GeneXpert than ZN microscopy. Of 119 index TB cases, GeneXpert test revealed that 106 (89.1%) and 5 (4.2%) were positive for rifampicin sensitive and rifampicin resistant TB, respectively.
  
  
  CONCLUSIONS
  GeneXpert test led to increased TB case detection among household contacts in addition to its advantage in the diagnosis of Rifampicin resistance among contacts and index TB cases. There should be a consideration in using GeneXpert MTB/RIF as a point of care TB testing tool among high risk groups.
authors.affiliation: Management Sciences for Health, Help Ethiopia Address the Low Performance of Tuberculosis (HEAL TB) Project, Addis Ababa, Ethiopia. Electronic address: dhabte@msh.org.
authors.forename: Dereje
authors.initials: D
authors.lastname: Habte
authors.affiliation: Management Sciences for Health, Help Ethiopia Address the Low Performance of Tuberculosis (HEAL TB) Project, Addis Ababa, Ethiopia.
authors.forename: Muluken
authors.initials: M
authors.lastname: Melese
authors.affiliation: Management Sciences for Health, Help Ethiopia Address the Low Performance of Tuberculosis (HEAL TB) Project, Addis Ababa, Ethiopia.
authors.forename: Nebiyu
authors.initials: N
authors.lastname: Hiruy
authors.affiliation: Management Sciences for Health, Help Ethiopia Address the Low Performance of Tuberculosis (HEAL TB) Project, Addis Ababa, Ethiopia.
authors.forename: Zewdu
authors.initials: Z
authors.lastname: Gashu
authors.affiliation: Management Sciences for Health, Help Ethiopia Address the Low Performance of Tuberculosis (HEAL TB) Project, Addis Ababa, Ethiopia.
authors.forename: Degu
authors.initials: D
authors.lastname: Jerene
authors.affiliation: Department of Medical Microbiology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
authors.forename: Feleke
authors.initials: F
authors.lastname: Moges
authors.affiliation: Department of Pediatrics, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
authors.forename: Sisay
authors.initials: S
authors.lastname: Yifru
authors.affiliation: Monitoring and Evaluation Unit, National Tuberculosis Program, Lilongwe, Malawi.
authors.forename: Belaineh
authors.initials: B
authors.lastname: Girma
authors.affiliation: United States Agency for International Development (USAID), Addis Ababa, Ethiopia.
authors.forename: Yewulsew
authors.initials: Y
authors.lastname: Kassie
authors.affiliation: United States Agency for International Development (USAID), Addis Ababa, Ethiopia.
authors.forename: Yared Kebede
authors.initials: YK
authors.lastname: Haile
authors.affiliation: Management Sciences for Health, Health Programs Group, Arlington, Virginia, USA.
authors.forename: Pedro Guillermo
authors.initials: PG
authors.lastname: Suarez
authors.affiliation: Department of Medical Microbiology, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
authors.forename: Belay
authors.initials: B
authors.lastname: Tessema
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification; D012293:Rifampin / Q000494:pharmacology*; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
chemical_list: D012293:Rifampin
keywords: Ethiopia; GeneXpert; Household contact; Tuberculosis