Efficacy of Directigen RSV testing in patient management following admission from a paediatric emergency department.
ABSTRACT We investigated the use of the Directigen Respiratory Syncytial Virus test performed under 'Stat Laboratory' conditions, in the management of infants after admission from the Paediatric Emergency Department (ED). The study group consisted of 242 consecutive paediatric ED patients tested by Directigen in the Stat laboratory during the winter 1995-1996 respiratory virus season. Specimens were submitted to the Virology Laboratory for confirmatory consensus testing utilizing in part, an in-house multiplex immunofluorescence assay (IFA) and conventional virus isolation methodologies. The sensitivity, specificity, positive and negative predictive values for Directigen, IFA, and isolation, were 71, 91, 85, 80%; 98, 100, 100, 99%; and 51, 100, 100, 72% respectively. Re-testing of 17 discordant original NP aspirates using Directigen, suggested that errors were due to technologist interpretation as well as to overt assay failure. The low analytical sensitivity and specificity of Directigen precludes its use in the clinical setting described in this study. Evening or weekend specimen collection, followed by IFA testing in a centralized Virology Laboratory at the start of the next working day, produces reliable test results. Among the small number of pediatric patients who might be candidates for antiviral therapy IFA testing should be made available on an on-call basis by Virology Laboratory.
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ABSTRACT: Respiratory syncytial virus (RSV) infection, which primarily manifests as bronchiolitis or pneumonia, is the leading cause of lower respiratory tract infection in infants and young children. It is associated with more than 100,000 pediatric hospitalizations each year in the United States. Infants who were premature; have chronic lung disease, congenital heart disease, or immunodeficiency disorders; or have underlying metabolic or neuromuscular disorders are at increased risk for especially severe RSV disease. Treatment of children hospitalized with RSV disease is primarily supportive, with administration of supplemental oxygen and fluid replacement therapy. Bronchodilators may benefit at least a subset of such patients. Antiviral therapy with aerosolized ribavirin is available for high-risk, severely ill patients. Handwashing, cleaning of environmental surfaces, and cohorting in hospital settings may decrease RSV transmission. In children born premature and younger than 1 year of age, and in patients with bronchopulmonary dysplasia younger than 2 years of age, passive protection against severe RSV disease may be achieved through monthly injections of anti-RSV antibody (palivizumab) during winter months. No vaccine is available to provide active immunity against RSV, but live attenuated and subunit cloned surface protein vaccines are in development.Current Infectious Disease Reports 07/2001; 3(3):242-246.
- Journal of Clinical Microbiology 03/2002; 40(2):733-4. · 4.07 Impact Factor
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ABSTRACT: This study investigated the efficacy of a commercial enzyme immunoassay (Directigen RSV, ColorPAC) in comparison with the shell vial culture method (using Hep-2 cells) for the detection of respiratory syncytial virus (RSV) in nasopharyngeal aspirates from children with bronchiolitis. During the period 1995-2002, 4950 samples were examined. RSV was detected in 1660 (33.5%) samples, with a sensitivity of 80.9%, a specificity of 97.5%, a positive predictive value of 93.8%, a negative predictive value of 91.6%, and a testing efficiency value of 92.2% compared with shell vial culture. In 83 (5%) samples, the ColorPAC was positive and the shell vial assay was negative. Of these, 71 (85.6%) were false-negative by cell culture. The true false-positive results obtained by ColorPAC represented only 0.7% of all RSV-positive samples. In general, no statistically significant differences were detected between the different months and epidemic periods studied. Compared with ColorPAC, the shell vial culture method displayed a sensitivity of 95.8% and a specificity of 100%. Overall, the ColorPAC assay was an acceptable, simple and rapid method for the antigenic detection of RSV in paediatric respiratory samples.Clinical Microbiology and Infection 12/2004; 10(11):967-71. · 4.58 Impact Factor