title: Limited value of whole blood Xpert(®) MTB/RIF for diagnosing tuberculosis in children.
abstract: We evaluated the ability of the Xpert(®) MTB/RIF assay to detect Mycobacterium tuberculosis in whole blood of children with tuberculosis in tuberculosis endemic settings with high rates of HIV infection.
  
  
  
  From June 2011 to September 2012 we prospectively enrolled children with symptoms or signs suggestive of tuberculosis at three research centres in Tanzania and Uganda. After clinical assessment, respiratory specimens were collected for microscopy and culture, as well as whole blood for Xpert(®) MTB/RIF. Children were classified according to standardised case definitions.
  
  
  
  A total of 232 children were evaluated; 14 (6.0%) had culture-confirmed tuberculosis. The Xpert(®) MTB/RIF assay detected M. tuberculosis in 5/232 (2.2%) blood samples with 1 (0.4%) error reading and presumably 1 (0.4%) false-positive result. The sensitivity of the assay in children with culture-confirmed (1/14) versus no tuberculosis (1/117) was 7.1% (95% CI, 1.3-31.5). Three of the five Xpert(®) MTB/RIF positive patients had negative cultures, but were classified as probable tuberculosis cases. Assay sensitivity against a composite reference standard (culture-confirmed, highly probable or probable tuberculosis) was 5.4% (95% CI, 2.1-13.1).
  
  
  
  Whole blood Xpert(®) MTB/RIF demonstrated very poor sensitivity, although it may enhance the diagnostic yield in select cases, with culture-negative tuberculosis.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania. Electronic address: christian.pohl@unibas.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Pohl
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Liliana K
authors.initials: LK
authors.lastname: Rutaihwa
authors.affiliation: Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Frederick
authors.initials: F
authors.lastname: Haraka
authors.affiliation: St. Francis Hospital Nsambya, AISPO, Kampala, Uganda.
authors.forename: Martin
authors.initials: M
authors.lastname: Nsubuga
authors.affiliation: St. Francis Hospital Nsambya, AISPO, Kampala, Uganda.
authors.forename: Francesco
authors.initials: F
authors.lastname: Aloi
authors.affiliation: NIMR-Mbeya Medical Research Center, Mbeya, Tanzania.
authors.forename: Nyanda E
authors.initials: NE
authors.lastname: Ntinginya
authors.affiliation: NIMR-Mbeya Medical Research Center, Mbeya, Tanzania.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mapamba
authors.affiliation: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich, Munich, Germany; German Center for Infection Research, Munich, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Heinrich
authors.affiliation: Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich, Munich, Germany; German Center for Infection Research, Munich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hoelscher
authors.affiliation: The Children's Hospital at Westmead, Sydney Medical School, University of Sydney, Sydney, Australia; Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, Australia.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Marais
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Levan
authors.initials: L
authors.lastname: Jugheli
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Klaus
authors.initials: K
authors.lastname: Reither
mesh_terms: D001769:Blood / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D006801:Humans; D008297:Male; D008853:Microscopy; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D013636:Tanzania / Q000453:epidemiology; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology*; D014454:Uganda / Q000453:epidemiology; D014944:World Health Organization
keywords: Childhood; Diagnosis; Tuberculosis; Whole blood; Xpert MTB/RIF