Cargando…
Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania
Diagnosis of pulmonary tuberculosis (TB) in technology-limited countries is widely achieved by smear microscopy, which has limited sensitivity and specificity. The frequency and clinical implication of smear-positive but culture-negative among presumptive TB patients remains unclear. A cross-section...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Dove Medical Press
2017
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513826/ https://www.ncbi.nlm.nih.gov/pubmed/28744153 http://dx.doi.org/10.2147/IJGM.S137469 |
_version_ | 1783250719613124608 |
---|---|
author | Mnyambwa, Nicholaus Peter Ngadaya, Esther S Kimaro, Godfather Kim, Dong-Jin Kazwala, Rudovick Petrucka, Pammla Mfinanga, Sayoki G |
author_facet | Mnyambwa, Nicholaus Peter Ngadaya, Esther S Kimaro, Godfather Kim, Dong-Jin Kazwala, Rudovick Petrucka, Pammla Mfinanga, Sayoki G |
author_sort | Mnyambwa, Nicholaus Peter |
collection | PubMed |
description | Diagnosis of pulmonary tuberculosis (TB) in technology-limited countries is widely achieved by smear microscopy, which has limited sensitivity and specificity. The frequency and clinical implication of smear-positive but culture-negative among presumptive TB patients remains unclear. A cross-sectional substudy was conducted which aimed to identify the proportion of nontuberculous mycobacteria (NTM) infections among 94 “smear-positive culture-negative” patients diagnosed between January 2013 and June 2016 in selected health facilities in Tanzania. Out of 94 sputa, 25 (26.60%) were GeneXpert® mycobacteria TB positive and 11/94 (11.70%) repeat-culture positive; 5 were Capilia TB-Neo positive and confirmed by GenoType MTBC to be Mycobacterium tuberculosis/Mycobacterium canettii. The remaining 6 Capilia TB-Neo negative samples were genotyped by GenoType® CM/AS, identifying 3 (3.19%) NTM, 2 Gram positive bacteria, and 1 isolate testing negative, together, making a total of 6/94 (6.38%) confirmed false smear-positives. Twenty-eight (29.79%) were confirmed TB cases, while 60 (63.83%) remained unconfirmed cases. Out of 6 (6.38%) patients who were HIV positive, 2 patients were possibly coinfected with mycobacteria. The isolation of NTM and other bacteria among smear-positive culture-negative samples and the presence of over two third of unconfirmed TB cases emphasize the need of both advanced differential TB diagnostic techniques and good clinical laboratory practices to avoid unnecessary administration of anti-TB drugs. |
format | Online Article Text |
id | pubmed-5513826 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Dove Medical Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-55138262017-07-25 Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania Mnyambwa, Nicholaus Peter Ngadaya, Esther S Kimaro, Godfather Kim, Dong-Jin Kazwala, Rudovick Petrucka, Pammla Mfinanga, Sayoki G Int J Gen Med Original Research Diagnosis of pulmonary tuberculosis (TB) in technology-limited countries is widely achieved by smear microscopy, which has limited sensitivity and specificity. The frequency and clinical implication of smear-positive but culture-negative among presumptive TB patients remains unclear. A cross-sectional substudy was conducted which aimed to identify the proportion of nontuberculous mycobacteria (NTM) infections among 94 “smear-positive culture-negative” patients diagnosed between January 2013 and June 2016 in selected health facilities in Tanzania. Out of 94 sputa, 25 (26.60%) were GeneXpert® mycobacteria TB positive and 11/94 (11.70%) repeat-culture positive; 5 were Capilia TB-Neo positive and confirmed by GenoType MTBC to be Mycobacterium tuberculosis/Mycobacterium canettii. The remaining 6 Capilia TB-Neo negative samples were genotyped by GenoType® CM/AS, identifying 3 (3.19%) NTM, 2 Gram positive bacteria, and 1 isolate testing negative, together, making a total of 6/94 (6.38%) confirmed false smear-positives. Twenty-eight (29.79%) were confirmed TB cases, while 60 (63.83%) remained unconfirmed cases. Out of 6 (6.38%) patients who were HIV positive, 2 patients were possibly coinfected with mycobacteria. The isolation of NTM and other bacteria among smear-positive culture-negative samples and the presence of over two third of unconfirmed TB cases emphasize the need of both advanced differential TB diagnostic techniques and good clinical laboratory practices to avoid unnecessary administration of anti-TB drugs. Dove Medical Press 2017-07-12 /pmc/articles/PMC5513826/ /pubmed/28744153 http://dx.doi.org/10.2147/IJGM.S137469 Text en © 2017 Mnyambwa et al. This work is published and licensed by Dove Medical Press Limited The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. |
spellingShingle | Original Research Mnyambwa, Nicholaus Peter Ngadaya, Esther S Kimaro, Godfather Kim, Dong-Jin Kazwala, Rudovick Petrucka, Pammla Mfinanga, Sayoki G Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title | Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title_full | Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title_fullStr | Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title_full_unstemmed | Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title_short | Assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in Tanzania |
title_sort | assessment of sputum smear-positive but culture-negative results among newly diagnosed pulmonary tuberculosis patients in tanzania |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513826/ https://www.ncbi.nlm.nih.gov/pubmed/28744153 http://dx.doi.org/10.2147/IJGM.S137469 |
work_keys_str_mv | AT mnyambwanicholauspeter assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT ngadayaesthers assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT kimarogodfather assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT kimdongjin assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT kazwalarudovick assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT petruckapammla assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania AT mfinangasayokig assessmentofsputumsmearpositivebutculturenegativeresultsamongnewlydiagnosedpulmonarytuberculosispatientsintanzania |