Rapid and sensitive detection of respiratory virus infections for directed antiviral treatment using R-Mix cultures

• Published in: Journal of clinical virology 2002-02, Vol.24 (1), p.107-115
• Main Authors: St. George, Kirsten, Patel, Navin M., Hartwig, Robert A., Scholl, David R., Jollick, Joseph A., Kauffmann, Lynn M., Evans, Martin R., Rinaldo, Charles R.
• Format: Article
• Language: English
• Subjects: Adenoviridae - isolation & purification; Biological and medical sciences; Cell Line; Fluorescent Antibody Technique, Direct; Fundamental and applied biological sciences. Psychology; Humans; Influenza; Influenza, Human - diagnosis; Influenza, Human - virology; Microbiology; Orthomyxoviridae - isolation & purification; Parainfluenza Virus 3, Human - isolation & purification; Rapid culture; Rapid detection; Reagent Kits, Diagnostic; Respiratory Tract Infections - diagnosis; Respiratory Tract Infections - virology; Respirovirus Infections - diagnosis; Respirovirus Infections - virology; Time Factors; Virus culture
• ISSN: 1386-6532; 1873-5967
• DOI: 10.1016/S1386-6532(01)00239-6

Background: The development of new anti-influenza drugs has led to concerns regarding the impact on healthcare costs if they are used indiscriminately. Restricting their use to proven influenza virus infections has the potential to overcome costly inappropriate therapy. However, conventional culture (CC) does not generate results quickly enough to facilitate the timely initiation of treatment, and rapid detection tests have suboptimal sensitivity. We therefore investigated a new rapid culture system (R-Mix) that contains a mixture of two cell lines and detects respiratory viruses within 24 h. Objectives: To compare the analytical sensitivity of R-Mix with CC and rapid detection methods, for the detection of influenza and other respiratory viruses. To compare the clinical sensitivity of R-Mix with CC and direct antigen detection for the detection of respiratory viruses in primary and acute care settings. Study design: Stock cultures of influenza virus were titrated and tested by R-Mix, ZstatFlu and FLU OIA. Stock cultures of adenovirus and parainfluenza virus type 3 were titrated and tested by R-Mix and CC. Specimens, which had previously tested positive for influenza viruses, were titrated and tested by R-Mix and CC. In symptomatic patients, the majority of whom were from primary care settings, 124 sequential specimens were tested for influenza viruses by immunofluorescent direct antigen detection and R-Mix. A separate set of 111 sequential specimens, from various symptomatic patient groups, were tested for influenza viruses by CC and R-Mix. Additionally, in acute care patients being surveillance tested during periods of immunosuppression, 155 specimens were tested for respiratory viruses (influenza A and B, parainfluenza 1–3, adenovirus and respiratory syncytial virus (RSV)) by CC and R-Mix. Results: With titrated stock cultures, R-Mix showed an analytical limit of detection of ten infectious virus particles per vial for influenza A, compared with 100 000 particles per test for FLU OIA and 1000 000 for ZstatFlu. R-Mix also showed a 100-fold greater sensitivity for the detection of influenza A and equivalent sensitivity for the detection of influenza B when compared with CC in titrated known positive specimens. Further, it showed equivalent sensitivity to CC for the detection of adenovirus and parainfluenza virus type 3 in titrated stock cultures. Among prospective specimens from symptomatic patients, the sensitivity of R-Mix, CC and direct antigen detecti