title: High prevalence of subclinical tuberculosis in HIV-1-infected persons without advanced immunodeficiency: implications for TB screening.
abstract: BACKGROUND
  The prevalence of asymptomatic tuberculosis (TB) in recently diagnosed HIV-1-infected persons attending pre-antiretroviral therapy (ART) clinics is not well described. In addition, it is unclear if the detection of Mycobacterium tuberculosis in these patients clearly represents an early asymptomatic phase leading to progressive disease or transient excretion of bacilli.
  
  
  OBJECTIVE
  To describe the prevalence and outcome of subclinical TB disease in HIV-1-infected persons not eligible for ART.
  
  
  METHODS
  The study was conducted in 274 asymptomatic ART-naïve HIV-1-infected persons in Khayelitsha Day Hospital, Cape Town, South Africa. All participants were screened for TB using a symptom screen and spoligotyping was performed to determine genotypes.
  
  
  RESULTS
  The prevalence of subclinical TB disease was 8.5% (95% CI 5.1% to 13.0%) (n=18; median days to culture positivity 17&emsp14;days), with 22% of patients being smear-positive. Spoligotyping showed a diverse variety of genotypes with all paired isolates being of the same spoligotype, effectively excluding cross-contamination. 56% of patients followed up developed symptoms 3 days to 2 months later. All were well and still in care 6-12 months after TB diagnosis; 60% were started on ART. A positive tuberculin skin test (OR 4.96, p=0.064), low CD4 count (OR 0.996, p=0.06) and number of years since HIV diagnosis (OR 1.006, p=0.056) showed trends towards predicting TB disease. Conclusion This study found a high prevalence but good outcome (retained in care) of subclinical TB disease in HIV-1-infected persons. The results suggest that, in high HIV/TB endemic settings, a positive HIV-1 test should prompt TB screening by sputum culture irrespective of symptoms, particularly in those with a positive tuberculin skin test, longer history of HIV infection and low CD4 count. Operational difficulties in resource-constrained settings with respect to screening with TB culture highlight the need for rapid and affordable point-of-care tests to identify persons with clinical and subclinical TB disease.
authors.affiliation: 3.03 Wolfson Pavillion, Institute of Infectious Diseases and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory 7925, South Africa. tolullahoni@doctors.org.uk
authors.forename: Tolu
authors.initials: T
authors.lastname: Oni
authors.forename: Rachael
authors.initials: R
authors.lastname: Burke
authors.forename: Relebohile
authors.initials: R
authors.lastname: Tsekela
authors.forename: Nonzwakazi
authors.initials: N
authors.lastname: Bangani
authors.forename: Ronnett
authors.initials: R
authors.lastname: Seldon
authors.forename: Hannah P
authors.initials: HP
authors.lastname: Gideon
authors.forename: Kathryn
authors.initials: K
authors.lastname: Wood
authors.forename: Katalin A
authors.initials: KA
authors.lastname: Wilkinson
authors.forename: Tom H M
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Wilkinson
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D000328:Adult; D018791:CD4 Lymphocyte Count; D004812:Epidemiologic Methods; D005260:Female; D015497:HIV-1; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D013019:South Africa / Q000453:epidemiology; D013183:Sputum / Q000382:microbiology; D013997:Time Factors; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology