TestPack Respiratory Syncytial Virus Research Articles

PREDIKTOR ASMA PADA USIA 7 TAHUN SETELAH MENDERITA BRONKIOLITIS AKUT KARENA RESPIRATORY SYNCYTIAL VIRUS: SUATU STUDI PROSPEKTIF

Infants are at increased risk of developing asthma  after RSV (Respiratory Syncytial Virus) acute bronchiolitis. The hypothesis that cytokine production is related to the development of asthma after RSV bronchiolitis. The diagnosis of RSV bronchiolitis was verified using the Abbott test pack RSV, a rapid enzyme immuno assay for direct detection of viral antigen in nasopharyngeal secretion. Changes in FEV1 (Forced Expiratory Volume in 1 second) were determined using spirometri, IL-4 and IFN-γlevels were determined using the enzyme-linked immunosorbant assay (ELISA) method. In this study, 62 children hospitalized for RSV bronchiolitis were followed prospectively, 55 (88.7%) childrencompleted the study and 41 children (74.5%) had asthma at 7 years of age. RSV bronchiolitis children were more frequent among boys (boy /girl ratio: 2). Episodes of wheezing more than 8 had specifity and sensitivity of 100% respectivelly,might be the very useful predictor for asthma. The cut off level over 40.84 pg/ml for IL-4, below 14.12 pg/ml for IFN-γ, IL-4 / IFN-γratio over 3 and episodes of wheezing over 8 may be used to predict asthma after RCV bronchiolitis.

新たに開発されたrespiratory syncytial virus診断キットの性能比較

ImmunoCard STAT! RSV (Meridian Bioscience, Inc, USA) is a rapid immunoassay method newly developed for detection of respiratory syncytial virus (RSV) by immunochromatography. We carried out an evaluation of the ImmunoCard STAT! RSV. One hundred fifty-nine nasal wash samples and nasopharyngeal aspirates from patients were used to evaluate three different kits, which are ImmunoCard STAT! RSV, RSV testpack (Abbott JAPAN) and Directigen EZ RSV (Nippon Becton, Dickinson and Company) . One hundred twenty-eight samples showed equivalent results. When nested reversed transcription-PCR (nested RT-PCR) results for 31 samples showing discrepancies among three kits, 10 samples were positive, and 21 samples were negative by nested RT-PCR. Compared to Nested RT-PCR results, ImmunoCard STAT! RSV showed a sensitivity of 90.5% (19/21) and a specificity of 80.0% (8/10), as well as RSV testpack showed a sensitivity of 10.0% (2/21) and a specificity of 100% (10/10), Directigen EZ RSV showed 95.2% (20/21) and 0.0% (0/ 10), respectively. Furthermore, the detection limits were also evaluated by using ACTT No. VR1540 for RSV A-2 strain, and ACTT No. VR1401 for Wash strain. The detection limit of ImmunoCard STAT! RSV was 5.15 x 10(6) TCID50/mL in subgroup A strain and was 7.58 x 10(5) TCID50/mL in subgroup B strain. This result was similar to RSV testpack, and was better than the detection limit of Directigen EZ RSV. It is concluded that ImmunoCard STAT! RSV is useful in detecting RSV in a clinical setting with equivalent performance to conventional other detecting kits.

Relationship between respiratory syncytial virus infection and acute otitis media in children

Background: Respiratory syncytial virus (RSV) is among the major causes of respiratory tract infection in infants and young children, and concomitant acute otitis media (AOM) often develops. However, there are only a few reports about AOM associated with RSV infection. Methods: Two hundred and thirty children who were diagnosed as having RSV infection were studied by enzyme immunoassay (Testpack RSV®) at the Department of Pediatrics of Tohoku Rosai Hospital from 1 November 2001 to 31 October 2002. In the patients with AOM, bacterial culture and detection of RSV antigen in the middle ear fluid (MEF) by enzyme immunoassay were performed, and the outcome was investigated. Results: Among the 230 children, 120 (52.2%) were found to have AOM. In children under 2 years of age, the incidence of AOM was significantly higher (73.1%) than in the older children (29.7%). RSV antigen was positive in the MEF of 36 out of 52 patients with AOM (69.2%). In 24 of the 46 patients in whom both RSV antigen detection and bacterial culture of MEF were performed, RSV antigen was detected and bacterial culture was negative. Although the outcome of the first episode of AOM following RSV infection was favorable, relapse was observed in 31% of the patients. Conclusion: These results confirm that patients with RSV infection have a high risk of AOM, especially children younger than 2 years of age, and suggest that RSV may be a direct cause of AOM at least in the early stage of infection with this virus. The necessity of performing careful follow-up of AOM after resolution of symptoms is suggested because relapse is common.

Relationship between respiratory syncytial virus infection and acute otitis media in children

Background: Respiratory syncytial virus (RSV) is among the major causes of respiratory tract infection in infants and young children, and concomitant acute otitis media (AOM) often develops. However, there are only a few reports about AOM associated with RSV infection. Methods: Two hundred and thirty children who were diagnosed as having RSV infection were studied by enzyme immunoassay (Testpack RSV ®) at the Department of Pediatrics of Tohoku Rosai Hospital from 1 November 2001 to 31 October 2002. In the patients with AOM, bacterial culture and detection of RSV antigen in the middle ear fluid (MEF) by enzyme immunoassay were performed, and the outcome was investigated. Results: Among the 230 children, 120 (52.2%) were found to have AOM. In children under 2 years of age, the incidence of AOM was significantly higher (73.1%) than in the older children (29.7%). RSV antigen was positive in the MEF of 36 out of 52 patients with AOM (69.2%). In 24 of the 46 patients in whom both RSV antigen detection and bacterial culture of MEF were performed, RSV antigen was detected and bacterial culture was negative. Although the outcome of the first episode of AOM following RSV infection was favorable, relapse was observed in 31% of the patients. Conclusion: These results confirm that patients with RSV infection have a high risk of AOM, especially children younger than 2 years of age, and suggest that RSV may be a direct cause of AOM at least in the early stage of infection with this virus. The necessity of performing careful follow-up of AOM after resolution of symptoms is suggested because relapse is common.

幼若乳児の気道感染症とRespiratory Syncytial Virus

We investigated the role of respiratory syncytial virus (RSV) in respiratory tract infections of up-to-3-months old infants. This prospective study was carried out from April 1993 to March 1994. Detection of RSV antigen in nasopharyngeal specimens was done by enzyme immunoassay using TESTPACK RSV at our out patient clinic. During this study period, 65 young infants with respiratory tract infection visited our clinic. Seventeen patients (26%) were diagnosed as having RSV infection. Fifteen out of the 17 infants with RSV infection were observed in spring and winter. Fourteen out of the 17 infants with RSV infection had acute bronchiolitis or pneumonia. In contrast to RSV infection, only three patients out of the 48 infants with non-RSV infection had lower respiratory tract infection. In conclusion, the majority of young infants infected with RSV suffered from bronchiolitis or pneumonia.

Evaluation of a Rapid Diagnostic Test for Respiratory Syncytial Virus (RSV): Potential for Bedside Diagnosis

Rapid detection of respiratory syncytial virus (RSV) infection can assist clinicians in decisions regarding antiviral therapy with ribavirin as well as instituting infection control measures. The Abbott TestPack RSV is a rapid RSV detection immunoassay that can be performed on respiratory secretions in 20 to 30 minutes without special laboratory equipment. The purpose of this study was to evaluate housestaff performance of the TestPack RSV at bedside as compared with laboratory testing of aliquots of the same specimen by tissue culture inoculation, direct fluorescent antibody (DFA) testing and TestPack RSV. During the 1991 through 1992 RSV season, 137 nasopharyngeal aspirates or washes obtained from pediatric patients < 4 years of age suffering from acute respiratory disease were assayed by the Food and Drug Administration-approved TestPack RSV as well as conventional tube culture and DFA testing. 66 of 137 (48%) specimens were positive for RSV as defined by: isolation and DFA-positive (n = 48) and DFA testing positive with negative culture (n = 18); blocking assay experiments using TestPack RSV confirmed culture-negative DFA-positive specimens as positive in 8/8 instances in which material for retesting was available. Using these definitions, the sensitivity and specificity for the assays were: housestaff TestPack RSV: 92%, 93%; laboratory TestPack RSV: 97%, 98%; virus isolation: 72%, 100%. From these data, it appears that the TestPack RSV EIA in the field setting is reliable, although laboratory confirmation of results is important.

The Rhino-Probe nasal curette for detecting respiratory syncytial virus in children.

During two outbreaks of respiratory syncytial virus (RSV) infection, 68 children with acute respiratory illnesses were cultured for RSV using a Rhino-Probe (RP) nasal curette and either a nasopharyngeal (NP) swab or a nasal wash (NW). In the first outbreak isolations of RSV by the RP nasal curette and NP swab methods were compared. RSV was cultured from 25 of 42 (60%) subjects using the RP nasal curette and from 20 of 42 (48%) subjects using the NP swab. In the second outbreak the RP nasal curette and the NW collection techniques were compared. RSV was isolated from 15 of 26 (58%) children evaluated. RSV was cultured from 14 of 15 (93%) patients by RP and 13 of 15 (87%) when using NW. In the group of culture-positive subjects, the TESTPACK RSV rapid antigen test was positive in 10 of 15 (67%) using the RP and in 6 of 15 (40%) using the NW. Like the NP swab the RP nasal curette was simple, noninvasive and relatively inexpensive, yet it was as sensitive as the NW for detection of RSV.

Evaluation of abbott TestPack RSV for the diagnosis of respiratory syncytial virus infections

Abbott TestPack RSV, a 20-minute enzyme immunoassay, is available for the rapid diagnosis of respiratory syncytial virus (RSV) infections. We have compared TestPack with a “gold standard” method of virus isolation in traditional tube cultures and shell vials to determine the sensitivity and specificity of this rapid method. Respiratory specimens were collected prospectively from 402 children and assayed by the rapid antigen detection method and isolation in culture. Virus was isolated by inculation of specimen in a total of eight tubes and 2–3 shell vials. Isolation of RSV was confirmed by characteristic cytopathic effect and immunofluorescence using monoclonal antibodies to RSV. Of the 402 specimens tested, there were only 18 discrepant results (seven TestPack-positive, culture-negative, and 11 TestPack-negative, culture-positive specimens). The sensitivity of TestPack RSV versus culture was 93.6% (162 of 173) and the specificity was 97.0% (222 of 229). Using a very rigorous culture system, we have obtained high values for the sensitivity and specificity of TestPack RSV. This assay is an excellent method for the rapid diagnosis of RSV infections in young children.

Comparison of two rapid methods for detection of respiratory syncytial virus (RSV) (Testpack RSV and ortho RSV ELISA) with direct immunofluorescence and virus isolation for the diagnosis of pediatric RSV infection

The ability of two commercial immunoassays to detect respiratory syncytial virus (RSV) in respiratory specimens was evaluated as follows: 152 specimens were tested by TestPack RSV (Abbott), and 72 were tested by Ortho RSV ELISA (Ortho). Test outcomes were compared with those of virus isolation alone, direct immunofluorescence assay (DFA) alone, or virus isolation and/or DFA. TestPack RSV versus virus isolation showed 91% sensitivity, 96% specificity, 93% positive predictive value (PPV), and 95% negative predictive value (NPV). TestPack RSV versus DFA showed 89% sensitivity, 97% specificity, 96% PPV, and 93% NPV. When TestPack RSV performance was compared with that of virus isolation and DFA, the sensitivity was 87% and the specificity was 100%. Ortho RSV ELISA versus virus isolation showed 88% sensitivity, 87% specificity, 79% PPV, and 93% NPV. Ortho RSV ELISA versus DFA showed 91% sensitivity, 88% specificity, 81% PPV and 95% NPV. When Ortho RSV ELISA performance was compared with that of virus isolation and DFA, the sensitivity was 86%, the specificity was 89%, the PPV was 86%, and the NPV was 89%. The accuracy of the TestPack RSV in combination with ease of performance and no need for specialized equipment or special skills make it an attractive alternative to DFA for rapid direct detection of RSV.