• Users Online: 769
  • Home
  • Print this page
  • Email this page
ORIGINAL ARTICLE
Year : 2019  |  Volume : 8  |  Issue : 2  |  Page : 175-179

The importance of multiple samples in mycobacterial recovery: A 10-year retrospective study


1 Department of Clinical Pathology, São João Hospital Centre; Epidemiology Unit, Institute of Public Health, University of Porto, Porto, Portugal
2 Department of Clinical Pathology, São João Hospital Centre, Porto, Portugal
3 Department of Clinical Pathology, São João Hospital Centre; Epidemiology Unit, Institute of Public Health; Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal

Correspondence Address:
Angélica Ramos
Department of Clinical Pathology, São João Hospital Centre, Alameda Professor Hernâni Monteiro, 4200-319 Porto
Portugal
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijmy.ijmy_68_19

Rights and Permissions

Background: Instead of the three samples previously recommended, the World Health Organization considered that two sputum samples are sufficient for the diagnosis of pulmonary tuberculosis. Our goal is to evaluate the value of multiple samples in the microscopic and cultural examination of Mycobacterium tuberculosis complex (MTBc) and nontuberculous mycobacteria (NTM). Methods: Through a 10-year retrospective study, including 38,887 sputum samples from 11,676 patients, the relative contribution of each sputum specimen for acid-fast bacilli detection and mycobacteria isolation was determined by calculating the yield of the first sample and the incremental yield of the second, third, and more than three samples. Results: With regard to patients with MTBc isolation, we found that 95.2% (435/457) of the cases could be detected in the first and second smear and 97.9% (659/673) in the first and second culture, with a very low increment of the third sample, corresponding to 3.1% (14/457) in smear and 1.3% (9/673) in culture. Among patients with an NTM strain, the percentage of cases detected in the first and second smear and culture was 69% (20/29) and 86.5% (316/365), respectively. In these patients, we found an increment yield of the third sample of 20.7% (6/29) for smear and 10.5% (38/365) for culture. The incremental yield of third and above-third sample for NTM detection was of 31% (9/29) in smear and 13.5% (49 of 365) in culture. Conclusions: We found an added value of multiple samples in NTM recovery. However, our findings suggest that only two samples are required for the diagnosis of pulmonary tuberculosis.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed171    
    Printed10    
    Emailed0    
    PDF Downloaded33    
    Comments [Add]    

Recommend this journal