title: Undiagnosed tuberculosis among HIV clinic attendees: association with antiretroviral therapy and implications for intensified case finding, isoniazid preventive therapy, and infection control.
abstract: OBJECTIVE
  Initiation of antiretroviral therapy (ART) and the 3I's are strategies to prevent HIV-associated tuberculosis (TB). We describe factors associated with undiagnosed TB among HIV-infected patients attending an HIV clinic in South Africa and discuss implications for the 3 Is.
  
  
  METHODS
  Convenience sample of HIV clinic attendees.
  
  
  METHODS
  HIV-infected participants were assessed for TB using a symptom screen, sputum-smear microscopy, sputum and blood mycobacterial culture, fine needle aspiration of enlarged lymph nodes, and chest radiography.
  
  
  RESULTS
  Four hundred twenty-two participants were enrolled. The median age and CD4+ T-cell count were 37 years [interquartile range (IQR): 31-44 years] and 215 cells per microliter (IQR: 107-347 cells/μL). Forty-seven percent had been on ART for a median duration of 8 months (IQR: 3.3-22.8 months). Three hundred sixty-one participants (85.6%) reported TB symptoms. Twenty-seven participants (6.4%) met criteria for bacteriologically confirmed TB and 50 (11.6%) for any form of TB. Bacteriologically confirmed TB was associated with CD4+ T-cell counts ≤100 cells per microliter (odds ratio: 5.05, 95% confidence interval: 1.69 to 15.12) when compared with CD4+ T-cell counts >200 cells per microliter and hemoglobin {hemoglobin < 10 g/dL [odds ratio 3.12 (95% confidence interval: 1.26 to 7.72)]}.
  
  
  CONCLUSIONS
  Undiagnosed TB among HIV-infected ambulatory patients was associated with low CD4+ T-cell counts regardless of ART status. TB screening algorithms which include CD4+ T-cell count and hemoglobin testing may be an effective way to identify HIV-infected clinic attendees at highest risk of undiagnosed TB. Isoniazid preventive therapy and TB infection control are essential for reducing occurrence of HIV-associated TB even after ART initiation.
authors.affiliation: Aurum Institute for Health Research, Johannesburg, South Africa. tkufa@auruminstitute.org
authors.forename: Tendesayi
authors.initials: T
authors.lastname: Kufa
authors.forename: Victor
authors.initials: V
authors.lastname: Mngomezulu
authors.forename: Salome
authors.initials: S
authors.lastname: Charalambous
authors.forename: Yasmeen
authors.initials: Y
authors.lastname: Hanifa
authors.forename: Katherine
authors.initials: K
authors.lastname: Fielding
authors.forename: Alison D
authors.initials: AD
authors.lastname: Grant
authors.forename: Nikolas
authors.initials: N
authors.lastname: Wada
authors.forename: Richard E
authors.initials: RE
authors.lastname: Chaisson
authors.forename: Gavin J
authors.initials: GJ
authors.lastname: Churchyard
authors.forename: Celine R
authors.initials: CR
authors.lastname: Gounder
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D001431:Bacteriological Techniques; D044963:Biopsy, Fine-Needle; D018890:Chemoprevention / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D017053:Infection Control / Q000379:methods*; D007538:Isoniazid / Q000008:administration & dosage*; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*; D008198:Lymph Nodes / Q000382:microbiology / Q000473:pathology; D008297:Male; D015995:Prevalence; D013902:Radiography, Thoracic; D013019:South Africa / Q000453:epidemiology
chemical_list: D007538:Isoniazid