Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis
Extra pulmonary tuberculosis presents a diagnostic dilemma for both physicians as well as for clinical microbiologists . The laboratory diagnosis of tuberculosis ranges from simple microscopy,culture to complex molecular assays. To evaluate the sensitivity, specificity and turnaround time of microsc...
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| Format: | Article |
| Language: | English |
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Journal of Pure and Applied Microbiology
2018-06-01
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| Series: | Journal of Pure and Applied Microbiology |
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| Online Access: | https://microbiologyjournal.org/evaluation-of-microscopy-culture-and-pcr-assay-in-the-diagnosis-of-extrapulmonary-tuberculosis/ |
| _version_ | 1819005949097017344 |
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| author | Sagar Mali P.M. Beena N. Arvind |
| author_facet | Sagar Mali P.M. Beena N. Arvind |
| author_sort | Sagar Mali |
| collection | DOAJ |
| description | Extra pulmonary tuberculosis presents a diagnostic dilemma for both physicians as well as for clinical microbiologists . The laboratory diagnosis of tuberculosis ranges from simple microscopy,culture to complex molecular assays. To evaluate the sensitivity, specificity and turnaround time of microscopy, culture and PCR in the diagnosis of Extrapulmonary tuberculosis & to evaluate the use of PCR in the early diagnosis of Extrapulmonary tuberculosis. A total of 71 samples patients with strong clinical suspicion of extra-pulmonary tuberculosis were processed and evaluated by ZN staining, fluorescent microscopy, LJ culture, BacT Alert culture and PCR. The positivity rates by microscopy, LJ culture, BacT Alert culture and PCR were 11.26%, 8.45%, 14.08% and 14.08% respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of both staining methods was 50%, 92.3%, 37.5% and 95.2% respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of BacT Alert culture was 83.3%, 92.3%, 50% and 98.4% respectively. The recovery rate was higher by BacT Alert culture (90.9%) compared to LJ culture (63.63%). The mean turnaround time for culture positivity was 36.3 days with LJ culture and 14.6 days with BacT Alert culture. The sensitivity, specificity, positive predictive value and negative predictive value of PCR assay was 66.66%, 90.76%, 40% and 96.72% respectively. PCR has high sensitivity, specificity, substantial level of agreement with BacT Alert culture and shorter turnaround time. Therefore, use of PCR in combination with other diagnostic modalities is a useful tool to detect additional EPTB cases which may be missed otherwise. |
| first_indexed | 2024-12-21T00:00:55Z |
| format | Article |
| id | doaj.art-01a4751ad90f41d4add053c67e753fcf |
| institution | Directory Open Access Journal |
| issn | 0973-7510 0973-7510 |
| language | English |
| last_indexed | 2024-12-21T00:00:55Z |
| publishDate | 2018-06-01 |
| publisher | Journal of Pure and Applied Microbiology |
| record_format | Article |
| series | Journal of Pure and Applied Microbiology |
| spelling | doaj.art-01a4751ad90f41d4add053c67e753fcf2022-12-21T19:22:37ZengJournal of Pure and Applied MicrobiologyJournal of Pure and Applied Microbiology0973-75100973-75102018-06-0112287187710.22207/JPAM.12.2.49Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary TuberculosisSagar Mali0P.M. Beena 1N. Arvind2Department of Microbiology, Sri Devaraj Urs Medical College, Tamaka, Kolar, Karnataka, India.Department of Microbiology, Sri Devaraj Urs Medical College, Tamaka, Kolar, Karnataka, India.Department of Microbiology, Sri Devaraj Urs Medical College, Tamaka, Kolar, Karnataka, India.Extra pulmonary tuberculosis presents a diagnostic dilemma for both physicians as well as for clinical microbiologists . The laboratory diagnosis of tuberculosis ranges from simple microscopy,culture to complex molecular assays. To evaluate the sensitivity, specificity and turnaround time of microscopy, culture and PCR in the diagnosis of Extrapulmonary tuberculosis & to evaluate the use of PCR in the early diagnosis of Extrapulmonary tuberculosis. A total of 71 samples patients with strong clinical suspicion of extra-pulmonary tuberculosis were processed and evaluated by ZN staining, fluorescent microscopy, LJ culture, BacT Alert culture and PCR. The positivity rates by microscopy, LJ culture, BacT Alert culture and PCR were 11.26%, 8.45%, 14.08% and 14.08% respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of both staining methods was 50%, 92.3%, 37.5% and 95.2% respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of BacT Alert culture was 83.3%, 92.3%, 50% and 98.4% respectively. The recovery rate was higher by BacT Alert culture (90.9%) compared to LJ culture (63.63%). The mean turnaround time for culture positivity was 36.3 days with LJ culture and 14.6 days with BacT Alert culture. The sensitivity, specificity, positive predictive value and negative predictive value of PCR assay was 66.66%, 90.76%, 40% and 96.72% respectively. PCR has high sensitivity, specificity, substantial level of agreement with BacT Alert culture and shorter turnaround time. Therefore, use of PCR in combination with other diagnostic modalities is a useful tool to detect additional EPTB cases which may be missed otherwise.https://microbiologyjournal.org/evaluation-of-microscopy-culture-and-pcr-assay-in-the-diagnosis-of-extrapulmonary-tuberculosis/extrapulmonary tuberculosisdiagnostic methods. |
| spellingShingle | Sagar Mali P.M. Beena N. Arvind Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis Journal of Pure and Applied Microbiology extrapulmonary tuberculosis diagnostic methods. |
| title | Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis |
| title_full | Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis |
| title_fullStr | Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis |
| title_full_unstemmed | Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis |
| title_short | Evaluation of Microscopy, Culture and PCR Assay in the Diagnosis of Extrapulmonary Tuberculosis |
| title_sort | evaluation of microscopy culture and pcr assay in the diagnosis of extrapulmonary tuberculosis |
| topic | extrapulmonary tuberculosis diagnostic methods. |
| url | https://microbiologyjournal.org/evaluation-of-microscopy-culture-and-pcr-assay-in-the-diagnosis-of-extrapulmonary-tuberculosis/ |
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