title: Is tuberculous lymphadenitis over-diagnosed in Ethiopia? Comparative performance of diagnostic tests for mycobacterial lymphadenitis in a high-burden country.
abstract: Ethiopia reports the third highest number of extrapulmonary TB cases globally, most of which are lymph node TB (TBLN). We investigated the performance of the available diagnostic tests for TBLN. Fine needle aspirate (FNA) and excision biopsy samples from affected lymph nodes were collected from 150 consenting patients with suspected TBLN visiting regional hospitals in Ethiopia. The sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of histopathology against culture as reference was 92%, 88%, 97% and 77% and of FNA cytology (FNAC) 76%, 88%, 100% and 55%, respectively. Naked eye examination of FNA had 67% sensitivity and 64% specificity. HIV coinfection did not diminish the performance of macroscopic examination, Ziehl-Neelsen stain, histology or cytology examinations. When any positive result in ZN, histopathology or culture was considered confirmatory, clinical diagnosis could be confirmed in 85% of the patients, suggesting that TBLN is over-diagnosed in up to 15% of cases. With combined criteria as reference standard, the sensitivity, specificity, PPV and NPV of FNAC was 72%, 100%, 100% and 55%, respectively. FNAC is a practical tool that can improve the diagnosis of TBLN in high-burden settings. Over-diagnosis alone cannot explain the high burden of LNTB in Ethiopia.
authors.affiliation: Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.
authors.forename: Rahel
authors.initials: R
authors.lastname: Iwnetu
authors.forename: Jan
authors.initials: J
authors.lastname: van den Hombergh
authors.forename: Yimtubezinash
authors.initials: Y
authors.lastname: Woldeamanuel
authors.forename: Mulat
authors.initials: M
authors.lastname: Asfaw
authors.forename: Cherinet
authors.initials: C
authors.lastname: Gebrekirstos
authors.forename: Yared
authors.initials: Y
authors.lastname: Negussie
authors.forename: Teklu
authors.initials: T
authors.lastname: Bekele
authors.forename: Senait
authors.initials: S
authors.lastname: Ashenafi
authors.forename: Berhanu
authors.initials: B
authors.lastname: Seyoum
authors.forename: Kibrebeal
authors.initials: K
authors.lastname: Melaku
authors.forename: Lawrence
authors.initials: L
authors.lastname: Yamuah
authors.forename: Hiwot
authors.initials: H
authors.lastname: Tilahun
authors.forename: Zerihun
authors.initials: Z
authors.lastname: Tadesse
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005002:Ethiopia; D005260:Female; D006651:Histocytochemistry / Q000379:methods; D006801:Humans; D008198:Lymph Nodes / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014388:Tuberculosis, Lymph Node / Q000175:diagnosis* / Q000382:microbiology; D055815:Young Adult