Comparison of SmartCycler Real-Time Reverse Transcription-PCR Assay in a Public Health Laboratory with Direct Immunofluorescence and Cell Culture Assays in a Medical Center for Detection of Influenza A Virus

Effectiveness of two rapid influenza tests in comparison to reverse transcription-PCR for influenza A diagnosis

“…The sensitivity of DFA found in this study was 68.97%, which is higher than the 62% found in some evaluations [20] but lower than that reported in some other studies (83% [7], 98.7% [17], and even 100% [21]). In these other studies, the specificities reported were greater than 95%, higher than the 76.63% found in this study.…”

“…It is important to note that the pandemic outbreak of influenza A H1N1/09 occurred during the study period; for this reason, the frequency is higher than that reported in other studies (10% [14], 16.63% [7], 21.6% [10], 37.6% [15] and 38.6% [16]). Nonetheless, Habib-Bein et al found a similar frequency when they analyzed 238 respiratory specimens using qRT-PCR [17].…”

“…However, this technique is hampered by the need to quickly inoculate clinical samples in multiple cell lines, and it requires time to yield reliable results due to the variability in the time that the virus takes to cause a cytopathic effect (in the case of influenza A, this can range from two days to two weeks [17]). …”

Cytospin-Enhanced Immunofluorescence and Impact of Sample Quality on Detection of Novel Swine Origin (H1N1) Influenza Virus

“…To date, two studies have been published on direct immunofluorescence antibody testing (DFA) with very different results (3,7). The Clinical Virology Laboratory at Yale New Haven Hospital has performed cytospin-enhanced DFA for 10 years and has reported an overall sensitivity for seasonal influenza of over 95% compared to cell culture (4)(5)(6). In this paper, we present our experience with cytospin-DFA in detecting S-OIV, or novel H1N1, compared to the Centers for Disease Control and Prevention (CDC) real-time PCR protocol.…”

“…One swab was collected per patient and placed in M4 medium (Remel, Lenexa, KS). After centrifugation to pellet cells and resuspension in a small amount of phosphate-buffered saline (PBS), a 200-l aliquot of concentrated cell suspension was applied to single-well slides using a cytospin and then fixed and stained as previously described (4). PCR was performed using the CDC real-time reverse transcriptase PCR (RT-PCR) protocol for influenza (www.who.int /csr/resources/publications/swineflu/realtimeptpcr/en/index.html) using 45 cycles of amplification on an ABI 7500 instrument (Foster City, CA).…”