Rapid assays for the diagnosis of influenza A and B viruses in patients evaluated at a large tertiary care children's hospital during two consecutive winter seasons.

BACKGROUND: The rapid and accurate diagnosis of influenza facilitates antiviral therapy, judicious antibiotic usage, and cohorting patients to decrease nosocomial infection. OBJECTIVE: To determine the utility of rapid influenza tests in a children's hospital. STUDY DESIGN: Two in vitro rapid immunochromatographic assays that detect and distinguish influenza A and B viruses were compared to the reference standard of viral culture. RESULTS: In 9186 patients tested, overall sensitivity of the rapid assays for influenza A was 64.4% and specificity was 98.3%. Sensitivity and specificity were 28% and 99.9%, respectively, for influenza B. Overall sensitivity and specificity for Remel Xpect (2004/2005) were 47.7% and 98.7% for influenza A, and 20.3% and 99.8% for influenza B, respectively. Overall sensitivity and specificity of Binax NOW Flu A&B (2005/2006) were 78.3% and 98% for influenza A, and 35.9% and 99.9% for influenza B, respectively. The results for influenza B with both assays were significantly lower than previously reported and lower than stated in the manufacturer's package insert. CONCLUSIONS: In a contemporary clinical setting, rapid assays for influenza displayed significantly lower sensitivities, especially for influenza B, than prior reports. Differences in pre- and post-licensure performance demonstrate the importance of continuous evaluation of rapid diagnostic tests for influenza.

Performance of a rapid assay (Binax NOW) for detection of respiratory syncytial virus at a children's hospital over a 3-year period.

A rapid assay, Binax NOW RSV, was compared to viral culture for 14,756 pediatric respiratory specimens obtained from 2003 to 2006. There were 794 viral culture-confirmed respiratory syncytial virus infections. Sensitivity was 81%, and specificity was 93.2%. Sensitivity was greatest for neonates (91.1% versus 80.7% [P < 0.01]).

Pantoea agglomerans, a plant pathogen causing human disease.

We present 53 pediatric cases of Pantoea agglomerans infections cultured from normally sterile sites in patients seen at a children's hospital over 6 years. Isolates included 23 from the bloodstream, 14 from abscesses, 10 from joints/bones, 4 from the urinary tract, and 1 each from the peritoneum and the thorax. P. agglomerans was most associated with penetrating trauma by vegetative material and catheter-related bacteremia.

Performance characteristics of a rapid immunochromatographic assay for detection of influenza virus in children during the 2003 to 2004 influenza season.

STUDY OBJECTIVE: We evaluate the performance of a rapid assay (Binax NOW) for the detection of influenza A virus in children. METHODS: The performance of an in vitro rapid immunochromatographic assay for detection of influenza A virus was compared to viral culture in 4,383 consecutive respiratory specimens received during the 2003 to 2004 season, which included an influenza A epidemic in October and November of 2003. RESULTS: The overall test sensitivity was 61.6% (95% confidence interval [CI] 60.3% to 63.2%) and specificity was 95.8% (95% CI 95.1% to 96.3%). In preplanned subset analyses, we found the test more sensitive in infants aged 90 days or younger (sensitivity 70.3%; specificity 96.6%) and less specific during the epidemic (sensitivity 61.7%; specificity 90.4%). CONCLUSION: This rapid assay was highly specific for detecting influenza A in children and thus appears useful for confirming this infection. Because of its limited sensitivity, however, a negative test cannot rule out influenza A.

Neurologic complications associated with influenza A in children during the 2003-2004 influenza season in Houston, Texas.

OBJECTIVES: Our objectives were to (1) describe the clinical characteristics of and viruses isolated from patients who presented with neurologic symptoms associated with influenza A infection and were hospitalized at Texas Children's Hospital during October and November 2003 and (2) to raise awareness of the neurologic complications of influenza among US children. METHODS: We reviewed the medical and laboratory records of all children who were hospitalized with neurologic symptoms and who also had evidence of influenza virus infection by rapid antigen testing or viral isolation. RESULTS: Eight children aged 5 months to 9 years with neurologic complications associated with influenza A were identified. None of the children had received the influenza vaccine. Four presented with seizures, 3 with mental status changes, and 1 with mutism. All but 1 of the patients had influenza A viral antigen detected in nasal wash samples. Influenza A virus was isolated in culture from nasal wash specimens obtained from 6 of the patients; influenza A virus was also isolated from the cerebrospinal fluid of 1 of these patients. None of the patients had serum metabolic abnormalities or other cerebrospinal fluid abnormalities. Three of the patients had brain imaging abnormalities. Five of the patients were treated with antivirals. All 8 of the patients survived, 6 with complete recovery and 2 with sequelae (1 mild and 1 severe). CONCLUSIONS: Neurologic symptoms and sequelae were associated with influenza A virus infection in children during the 2003-2004 influenza season in Houston, Texas. Influenza should be considered in the differential diagnosis in patients with seizures and mental status changes, especially if they present with respiratory symptoms or during an influenza outbreak.

Comparison of a new lateral-flow chromatographic membrane immunoassay to viral culture for rapid detection and differentiation of influenza A and B viruses in respiratory specimens.

The performance of a new rapid lateral-flow chromatographic membrane immunoassay test kit for detection of influenza virus was evaluated and compared to that of viral culture in respiratory secretions collected from 400 adults and children seen at three large university hospitals during the recent 2003 influenza season. The rapid test provided results in 15 min, with excellent overall performance statistics (sensitivity, 94.4%; specificity, 100%; positive predictive value, 100%; negative predictive value, 97.5%). Both influenza A and B type viruses were reliably detected, with no significant difference in performance statistics noted by influenza virus type or by the center performing the test.

Comparison of the directigen flu A+B membrane enzyme immunoassay with viral culture for rapid detection of influenza A and B viruses in respiratory specimens.

The performance of a commercially available, rapid membrane enzyme immunoassay for influenza A and B virus detection was compared to that of viral culture in 4,092 respiratory specimens collected from patients presenting with respiratory symptoms during the 2002-2003 influenza season. The test's overall sensitivity was 43.83%, lower than previously reported but similar for detection of both influenza A and B viruses (42.98 versus 44.76%). However, specificity, 99.74%, was excellent for both influenza A and B viruses (99.82 versus 99.92%). These values make this test a very good confirmatory test when clinical suspicion is high, but a less accurate screening test for large populations.

Comparison of lateral-flow immunoassay and enzyme immunoassay with viral culture for rapid detection of influenza virus in nasal wash specimens from children.

The performance of two commercially available rapid test kits for influenza virus detection was compared to that of viral culture by using 356 nasal wash specimens collected during the 2001 to 2002 influenza season. Overall, the two rapid tests were easy to perform and showed comparable sensitivities (70.4 and 72.2%) and specificities (97.7 and 98.3%); for both test kit groups, most of the specimens that yielded false-negative results were found to be growing influenza B virus.