Evaluation of the Directigen FluA+B test for rapid diagnosis of influenza virus type A and B infections.
Directigen FluA+B (BD Diagnostic Systems, Sparks, Md.), a new rapid test for the detection of influenza virus types A and B, was evaluated with nasopharyngeal aspirate specimens collected from 250 patients in comparison with culture and direct fluorescent antigen (DFA) detection tests. The patients studied were predominantly children, 80% being </=6 years old. Specimens negative by culture but positive by the Directigen FluA+B or DFA tests were analyzed by reverse transcription-PCR to resolve the discrepant results. The resolved sensitivity, specificity, and positive and negative predictive values of the Directigen FluA+B test for influenza virus type A were 96%, 99.6%, 96%, and 99.6%, respectively, and for influenza virus type B they were 87.5%, 96.8%, 80%, and 98%, respectively. Storage of nasopharyngeal aspirates in virus transport medium at 2 to 8 degrees C for 48 h had little adverse effect on the detection of influenza virus type A, but diagnosis of influenza virus type B is best carried out with fresh specimens. The test detected a range of human and animal influenza virus A subtypes, including the H5N1 and H9N2 viruses that recently caused human disease in Hong Kong.
Chan
K H
KH
Department of Microbiology, The University of Hong Kong and Queen Mary Hospital, Pokfulam, Hong Kong, SAR.
Maldeis
N
N
Pope
W
W
Yup
A
A
Ozinskas
A
A
Gill
J
J
Seto
W H
WH
Shortridge
K F
KF
Peiris
J S M
JS
D003937:Diagnosis, Differential; D005843:Geography; D006801:Humans; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000145:classification / Q000175:diagnosis*; D009305:Nasopharynx / Q000821:virology; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction