Six patients had false-positive CA results. However, considering the sequence of bronchoscopy, the order of bronchoscope washing, and the result of outward PCR analysis, there was no evidence of contamination through the bronchoscopes or bronchoscope washer. Of the six patients with false-positive results, three patients had a strong likelihood of tuberculosis based on clinical criteria.
In the remaining three patients, we could not find any possible causes of false-positive results. Of the 20 patients (23 specimens) with false-negative CA results, all but one were AFB smear-negative. All bacteriologically confirmed positive patients produced a culture of < 10 colonies, indicating a low colony count Reading here canadian family pharmacy.. Three AFB smear-positive patients were not considered to have tuberculosis because cultures were negative for M tuberculosis. In two patients who showed an AFB smear of one to two AFB per 300 high-power field (X 1,000), with no clinical or radiologic evidence of tuberculosis, CA gave negative results for M tuberculosis. In the other patient, who seemed to have pulmonary tuberculosis on radiologic examination and showed gradual improvement with antituberculosis treatment, CA had positive findings for M tuberculosis.
In summary, the CA tests were positive in 53% (26 of 49 cases) of confirmed tuberculosis and 33% (3 of 9 cases) of clinical tuberculosis cases. After combining the confirmed and clinical tuberculosis (58 specimens in 52 tuberculosis patients) cases, the sensitivity, specificity, PPV, and NPV of CA tests were 50% (29 of 58 cases), 99% (331 of 334 cases), 91% (29 of 32 cases), and 92% (331 of 360 cases), respectively.