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

Laboratory diagnosis of viral infection

“…Another limitation is the antigenic variability of some targeted viruses, which can vary from year to year, especially for influenza; thus the performance of a particular kit may vary from year to year. When a novel variant emerges, such as pandemic influenza A H1N1, the performance of antigen tests for the detection of the new strain is not known, and indeed for pandemic H1N1 influenza, was lower than for seasonal influenza (Centers for Disease Control and Prevention, 2009;Ginocchio et al, 2009;Landry and Ferguson, 2010). In these cases, clinical diagnosis and other testing modalities are essential.…”

“…Advantages of DFA over other antigen detection methods include greater sensitivity, ability to assess sample adequacy (i.e., sufficient numbers of target cells), and ability to detect multiple viruses in a single test (Chan et al, 2001). Limitations include the need for sufficient target cells, a fluorescence microscope, a dark room, meticulous technique in slide preparation, and expertise in interpretation to distinguish specific from non-specific staining (Landry and Ferguson, 2010). Assay time is 2 hours, which is longer than simpler rapid tests (Landry, 2009b).…”

Comparison of direct fluorescent antibody staining and real-time reverse transcriptase PCR for the detection of novel 2009 influenza A (H1N1) in nasopharyngeal samples

“…[1][2][3][4][5] We compared centrifuge-enhanced DFA staining to real-time reverse transcriptase PCR (rtRT-PCR) for the detection of novel 2009 influenza A (H1N1). Nasopharyngeal (N = 187) specimens were evaluated by the Diagnostic HYBRIDS D 3 Ultra DFA (D 3 ) staining kit and ProdesseProFlu+ assay (PF+) on the Abbott m2000 system.…”

Comparison of Simplexa Flu A/B & RSV PCR with Cytospin-Immunofluorescence and Laboratory-Developed TaqMan PCR in Predominantly Adult Hospitalized Patients

“…A rapid laboratory diagnosis can facilitate early antiviral therapy, discontinuation of antibiotics, and implementation of infection control measures (1). Our laboratory uses the cytospin-enhanced direct fluorescent-antibody assay (DFA) as an initial on-demand screen and laboratory-developed real-time TaqMan (LDT) PCR when greater sensitivity is needed (2). In this report, we evaluated Simplexa Flu A/B & RSV PCR as a potential replacement for DFA and LDT PCR.…”

“…For influenza detection and subtyping, the CDC real-time reverse transcriptase (RT) PCR primers and probes were used (2). For RSV, the protocol published by van Elden et al (4) was used, but the subtypes were not differentiated.…”