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Detection of respiratory pathogens by real-time PCR in clinical practice

Abstract number: o63

Rossen  J.W.A., Klein Breteler  E.G., Weersink  A.J., Schuurman  R., van Loon  A.M.

Objectives: 

Few hospitals have introduced nucleic amplification techniques for the routine diagnosis of all respiratory tract infections in adults. These diagnostic tests are costly, and the diagnostic yield and feasibility of implementation in routine diagnostic work-up has not been evaluated sufficiently. The diagnostic value of real-time PCR compared to conventional virus detection methods is evaluated in a prospective study during one respiratory season.

Methods: 

Nose-throat swabs, nasopharyngeal washes, nasopharyngeal aspirates, sputum samples, and bronchoalveolar lavages of patients admitted to our general hospital or to the children's hospital were evaluated by virus culture, direct immunofluorescence assays (DIF) for adenovirus, influenzavirus A/B, parainfluenzavirus 1 to 3 and RSV virus and by real-time PCR for adenoviruses, coronavirus OC43, 229E and NL63, influenzavirus A/B, parainfluenzavirus 1 to 4, rhinoviruses, RS virus A/B, human metapneumovirus and Chlamydia pneumoniae and Mycoplasma pneumoniae.

Results: 

Samples of 110 adults and 240 children were included in this study. In adults, respiratory viruses were detected by virus culture in 4 patients (4%) and by real-time PCR in 65 patients (59%). Most frequent pathogens detected were: rhinovirus (n = 22), influenzavirus (n = 20) and RSV (n = 12). In 10 of the 65 positive patients (15%) more than one virus was detected by real-time PCR. In children, respiratory viruses were detected by virus culture in 34 patients (14%), by DIF-assays in 63 patients (26%) and by real-time PCR in 179 patients (75%). The most frequent pathogens detected were: RSV (n = 74), rhinovirus (n = 67), coronaviruses (n = 32) and influenzavirus (n = 24). In 57 of the 179 positive patients (32%) more than one virus was detected by real-time PCR. Real-time PCR for RSV and adenovirus revealed significant differences in Ct-values between DIF positive and DIF negative samples.

Conclusion: 

The sensitivity of real-time PCR is significantly higher compared to that of virus culture and DIF-assays. Moreover, mixed infections were only detected using real-time PCR and were not found by virus culture and/or DIF assays. Thus, rapid detection of respiratory viruses by means of real-time PCR increased the number of detected pathogens considerably. The results of this study will be used to develop a diagnostic algorithm for selective detection of specific respiratory pathogens in different patient groups.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Subject:
Location: Oxford, UK
Presentation type:
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