• Laboratory Medicine Online
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• v.1 no.1
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• pp.26-34
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• 2011

Background: Laboratory diagnosis of new influenza A (H1N1) is crucial for managing patients and establishing control and prevention measures. We compared the diagnostic accuracies of the real time RT-PCR (rRT-PCR) test recommended for the confirmation of the new flu and the viral culture method used conventionally for viral disease with that of the rapid antigen test (RAT). Methods: We performed RAT, R-mix culture, and real-time PCR by using 861 respiratory samples collected from December 2009 to January 2010 and evaluated the abilities of these methods to detect new influenza A. The relationship among the positive rates of RAT, grades of culture, and the cycle threshold (Ct) values of rRT-PCR was also evaluated. Results: Of the 861 patients, 308 (35.8%) were diagnosed with new influenza A. The sensitivities, specificities, positive predictive values, and negative predictive values of the tests were respectively as follows: 59.7%, 99.5%, 98.4%, and 81.6% for RAT; 93.2%, 100%, 100%, and 96.3% for R-mix culture; and 95.8%, 100%, 100%, and 97.7% for rRT-PCR. Samples with weak positive grade in culture and those with Ct values of 30-37 in rRT-PCR showed positivities as low as 25.3% and 2.3% in RAT, respectively. The hospitalization rate and death rate of the confirmed patients were 3.2% and 0.3%, respectively, and gastrointestinal symptoms were observed in 7.2% of the patients. Conclusions: R-mix culture and rRT-PCR tests showed excellent reliability in the diagnosis of new influenza A and could be very useful, especially for samples with low viral load.

• Pediatric Infection and Vaccine
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• v.11 no.2
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• pp.158-169
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• 2004

Purpose : Although influenza is one of the most important cause of acute respiratory tract infections in children, virus isolation is not popular and there are only a few clinical studies on influenza and diagnostic methods. We evaluated the epidemiological and clinical features of influenza in children and rapid antigen detection test(QuickVue influenza test) on fist half of the year 2004 in Busan. Methods : From January 2004 to June 2004, throat swab and nasal secretion were obtained and cultured for the isolation of influenza virus and tested by rapid antigen detection test(QuickVue influenza test) in children with suspected influenza infections. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Influenza viruses were isolated in 79(17.2%) out of 621 patients examined. Influenza virus was isolated mainly from March to April 2004. The ratio of male and female with influenza virus infection was 1.2 : 1 with median age of 4 years 6month. The most common clinical diagnosis of influenza virus infection was bronchitis. There was no difference between influenza A and B infection in clinical diagnosis and symptoms. All patients recovered without severe complication. The sensitivity obtained for rapid antigen detection test (QuickVue influenza test) was 93.6% and the specificity was 80.2%, the positive predictive value 40.8%, the negative predictive value 98.8%. Conclusion : With rapid antigen detection test, it is possible early detection of influenza in children. reduction in use of antimicrobial agent and early use of antiviral agent.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.671-682
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• 1996

Background : Endobronchial tuberculosis is definded as tuberculous infection of the tracheobronchial tree with microbiological and histopathological evidence. Endobronchial tuberculosis has clinical significance due to its sequela of cicatrical stenosis which causes atelectasis, dyspnea and secondary pneumonia and may mimic bronchial asthma and pulmanary malignancy. Method : The authors carried out, retrospectively, a clinical study on 201 patients confirmed with endobronchial tuberculosis who visited the Department of Pulmonary Medicine at Hangyang University Hospital from January 1990 10 April 1996. The following results were obtained. Results: 1) Total 201 parients(l9.5%) were confirmed as endobronchial tuberculosis among 1031 patients who had been undergone flexible bronchofiberscopic examination. The number of male patients were 55 and that of female patients were 146. and the male to female ratio was 1 : 2.7. 2) The age distribution were as follows: there were 61(30.3%) cases in the third decade, 40 cases(19.9%) in the fourth decade, 27 cases(13.4%) in the sixth decade, 21 cases(10.4%) in the fifth decade, 19 cases(9.5%) in the age group between 15 and 19 years, 19 cases(9.5%) in the seventh decade, and 14 cases(7.0%) over 70 years, in decreasing order. 3) The most common symptom, in 192 cases, was cough 74.5%, followed by sputum 55.2%, dyspnea 28.6%, chest discomfort 19.8%, fever 17.2%, hemoptysis 11.5%, in decreasing order, and localized wheezing was heard in 15.6%. 4) In chest X-ray of 189 cases, consolidation was the most frequent finding in 67.7%, followed by collapse 43.9%. cavitary lesion 11.6%, pleural effusion 7.4%, in decreasing order, and there was no abnormal findings in 3.2%. 5) In the 76 pulmanary function tests, a normal pattern was found in 44.7%, restrictive pattern in 39.5 %, obstructive pattern in 11.8%, and combined pattern in 3.9%. 6) Among total 201 patients, bronchoscopy showed caseous pseudomembrane in 70 cases(34.8%), mucosal erythema and edema in 54 cases(26.9%), hyperplastic lesion in 52 cases(25.9%), fibrous s.enosis in 22 cases(10.9%), and erosion or ulcer in 3 cases(1.5%). 7) In total 201 cases, bronchial washing AFB stain was positive in 103 cases(51.2%), bronchial washing culture for tuberculous bacilli in 55 cases(27.4%). In the 99 bronchoscopic biopsies, AFB slain positive in 36.4%. granuloma without AFB stain positive in 13.1%, chronic inflammation only in 36.4%. and non diagnostic biopsy finding in 14.1%. Conclusions : Young female patients, whose cough resistant to genenal antitussive agents, should be evaluated for endobronchial tuberculosis, even with clear chest roentgenogram and negative sputum AFB stain. Furthermore, we would like to emphasize that the bronchoscopic approach is a substantially useful means of making a differential diagnosis of atelectasis in older patients of cancer age. At this time we have to make a standard endoscopic classification of endobronchial tuberculosis, and well designed prospective studies are required to elucidate the effect of combination therapy using antituberculous chemotherapy with steroids on bronchial stenosis in patients with endobronchial tuberculosis.