Evaluation of Xpert® MTB/RIF and Ustar EasyNAT™ TB IAD for diagnosis of tuberculous lymphadenitis of children in Tanzania: a prospective descriptive study.

Abstract

BACKGROUND:

Fine needle aspiration biopsy has become a standard approach for diagnosis of peripheral tuberculous lymphadenitis. The aim of this study was to compare the performance of Xpert MTB/RIF and Ustar EasyNAT TB IAD nucleic acid amplification assays, against acid-fast bacilli microscopy, cytology and mycobacterial culture for the diagnosis of TB lymphadenitis in children from a TB-endemic setting in Tanzania.

METHODS:

Children of 8 weeks to 16 years of age, suspected of having TB lymphadenitis, were recruited at a district hospital in Tanzania. Fine needle aspirates of lymph nodes were analysed using acid-fast bacilli microscopy, liquid TB culture, cytology, Xpert MTB/RIF and EasyNAT. Latent class analysis and comparison against a composite reference standard comprising "culture and/or cytology" was done, to assess the performance of Xpert MTB/RIF and EasyNAT for the diagnosis of TB lymphadenitis.

RESULTS:

Seventy-nine children were recruited; 4 were excluded from analysis. Against a composite reference standard of culture and/or cytology, Xpert MTB/RIF and EasyNAT had a sensitivity and specificity of 58 % and 93 %; and 19 % and 100 % respectively. Relative to latent class definitions, cytology had a sensitivity of 100 % and specificity of 94.7 %.

CONCLUSIONS:

Combining clinical assessment, cytology and Xpert MTB/RIF may allow for a rapid and accurate diagnosis of childhood TB lymphadenitis. Larger diagnostic evaluation studies are recommended to validate these findings and on Xpert MTB/RIF to assess its use as a solitary initial test for TB lymphadenitis in children.

• Authors: Maira Bholla, Neema Kapalata, Edward Masika, Hassan Chande, Levan Jugheli, Mohamed Sasamalo, Tracy R Glass, Hans-Peter Beck, Klaus Reither
• Journal: BMC infectious diseases (BMC Infect Dis) Vol. 16 Pg. 246 (06 06 2016) ISSN: 1471-2334 [Electronic] England
• PMID: 27268404 (Publication Type: Evaluation Study, Journal Article)

Topics

• Adolescent
• Biopsy, Fine-Needle
• Child
• Child, Preschool
• Female
• Humans
• Infant
• Lymph Nodes (microbiology, pathology)
• Male
• Microscopy
• Mycobacterium tuberculosis (genetics)
• Nucleic Acid Amplification Techniques (methods)
• Prospective Studies
• Sensitivity and Specificity
• Tanzania
• Tuberculosis, Lymph Node (diagnosis, microbiology)