Differential diagnoses of influenza A virus, influenza B virus, and respiratory syncytial virus infections by direct immunofluorescence using mixtures of monoclonal antibodies of different isotypes

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

A comparison of Thermo Electron RSV OIA to viral culture and direct fluorescent assay testing for respiratory syncytial virus

BACKGROUND

Rapid diagnostic methods for respiratory syncytial virus are useful tools available for the clinician.

OBJECTIVES

The Thermo Electron RSV OIA (optical immunoassay kit) was prospectively compared with direct immunofluorescent assay and viral culture at Primary Children's Medical Center, Salt Lake City, Utah.

STUDY DESIGN

Specimens from three hundred and thirty patients exhibiting respiratory symptoms were collected for testing by the three methods above. Several specimens were positive by both OIA and DFA with a negative culture result. These culture results were verified by RT-PCR analysis.

RESULTS

Overall, 107 specimens were positive for RSV by the reference tests (culture or RT-PCR). DFA analysis identified an additional 40 patient specimens positive for other respiratory viruses. Compared to the reference tests the sensitivity, specificity, positive, and negative predictive values of the OIA for detection of RSV were 87.9%, 99.6%, 98.9% and 94.5%, respectively.

CONCLUSIONS

The rapid OIA assay format proved to be cost effective, and simple to use in comparison to DFA and viral culture. Negative rapid test results should still be confirmed with a secondary test.

A comparison of Binax NOW to viral culture and direct fluorescent assay testing for respiratory syncytial virus

The Binax NOW immunochromatographic assay for respiratory syncytial virus was prospectively compared with direct fluorescent assay and viral culture at Primary Children's Medical Center, Salt Lake City, Utah during February 2003. Three hundred ten patient specimens were collected for testing, of which 102 specimens were positive for respiratory syncytial virus by the reference tests, direct immunofluorescence assay (DFA), and culture or molecular analysis. DFA analysis identified an additional 40 patient specimens positive for other respiratory viruses. Compared to the reference tests, the sensitivity, specificity, and positive and negative predictive values of the rapid immunochromatographic assay for detection of respiratory syncytial virus were 89.2%, 100.0%, 100.0%, and 94.9%, respectively. This rapid assay format proved to be cost-effective and simple to use in comparison to DFA and viral culture. Negative rapid test results should still be confirmed with a secondary test.

Rapid detection of respiratory viruses by shell vial assay using simultaneous culture of HEp-2, LLC-MK2, and MDCK cells in a single vial

A shell vial assay with simultaneous culture of HEp-2, LLC-MK2, and MDCK cell lines in a single tube (CoHLM SV assay) was compared with traditional tube culture (TC) for the detection of the main respiratory viruses in 358 nasal wash specimens. A total of 170 strains were isolated from 168 virus-positive samples. A total of 94. 1% of the strains (160 strains; 128 respiratory syncytial viruses and 32 other viruses) were detected by the CoHLM SV assay in 48 h, whereas 98.2% of the strains (167 strains; 132 respiratory syncytial viruses and 35 other viruses) were detected by TC in a mean time of 6 days. The CoHLM SV assay may be useful for the rapid detection of respiratory viruses.