title: A first insight into high prevalence of undiagnosed smear-negative pulmonary tuberculosis in Northern Ethiopian prisons: implications for greater investment and quality control.
abstract: BACKGROUND
  Tuberculosis (TB) transmission in prisons poses significant risks to inmates as well as the general population. Currently, there are no data on smear-negative pulmonary TB cases in prisons and by extension no data on the impact such cases have on TB incidence. This study was designed to obtain initial data on the prevalence of smear-negative cases of TB in prisons as well as preliminary risk factor analysis for such TB cases.
  
  
  METHODS
  This cross-sectional survey was conducted in November 2013 at eight main prisons located in the state of Amhara, Ethiopia. Interviews using a structured and pretested questionnaire were done first to identify symptomatic prisoners. Three consecutive sputum samples were collected and examined using acid fast bacilli (AFB) microscopy at the point of care. All smear-negative sputum samples were taken for culture and Xpert testing. Descriptive and multivariate analysis was done using SPSS version 16.
  
  
  RESULTS
  Overall the prevalence of smear-negative pulmonary TB cases in the study prisons was 8% (16/200). Using multivariate analysis, a contact history to TB patients in prison, educational level, cough and night sweating were found to be predictors of TB positivity among smear-negative pulmonary TB cases (p ≤ 0.05).
  
  
  CONCLUSIONS
  In the studied prisons, high prevalence of undiagnosed TB cases using AFB microscopy was documented, which is an important public health concern that urgently needs to be addressed. Furthermore, patients with night sweating, non-productive cough, a contact history with TB patients and who are illiterate merit special attention, larger studies are warranted in the future to assess the associations more precisely. Further studies are also needed to examine TB transmission dynamics by patients with smear-negative pulmonary TB in a prison setting.
authors.affiliation: Faculty of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia; Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital, University of Leipzig, Leipzig, Germany; Institute of Clinical Immunology, University Hospital, University of Leipzig, Leipzig, Germany; Translational Centre for Regenerative Medicine (TRM)-Leipzig, University of Leipzig, Leipzig, Germany.
authors.forename: Fantahun
authors.initials: F
authors.lastname: Biadglegne
authors.affiliation: Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University Hospital, University of Leipzig, Leipzig, Germany.
authors.forename: Arne C
authors.initials: AC
authors.lastname: Rodloff
authors.affiliation: Institute of Clinical Immunology, University Hospital, University of Leipzig, Leipzig, Germany; Translational Centre for Regenerative Medicine (TRM)-Leipzig, University of Leipzig, Leipzig, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sack
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007449:Investments; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011330:Prisons / Q000706:statistics & numerical data*; D011786:Quality Control; D012307:Risk Factors; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000635:transmission; D055815:Young Adult