Rapid Influenza A Testing for Novel H1N1: Point-of-Care Performance
ABSTRACT The 2009 outbreak of novel influenza A H1N1 reached a pandemic status on June 11, 2009. Early detection is a key factor for management and infection-control practices. Recent studies have suggested a difference in performance of rapid influenza kits for influenza A H1N1. Our goal was to evaluate the performance of the QuickVue influenza A+B test (Quidel Corp., San Diego, CA) in an emergency department setting and determine the most current epidemiologic trends in our community.
Results from 1137 samples for influenza A collected between April 8, 2009 and June 30, 2009 were retrospectively reviewed. Results of QuickVue influenza A+B test were compared with R-Mix viral culture and DFA results. Age distribution and hospitalization rates by age group were analyzed to further delineate the epidemiology of influenza A in a suburban hospital.
The sensitivity of the rapid test was 77%, the specificity was 85%, the positive predictive value was 74%, and the negative predictive value was 87%. We found a similar age distribution for positive influenza tests and admissions when compared with the national Centers for Disease Control and Prevention data.
The QuickVue influenza A+B test is a sensitive assay for the novel H1N1 strain of influenza. In our hospital, the group with highest risk of hospital admission was patients aged < 25 years.
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ABSTRACT: To evaluate the clinical reliability of two rapid influenza detection tests (RIDTs), we analyzed 107 specimens from patients with clinically suspected pandemic influenza A/H1N1v by these tests as well as by real-time PCR as a standard. Both RIDTs had a moderate sensitivity (28-32%), a high specificity (93-99%) and a negative predictive value of 80%. These results will impact on the clinical management and isolation precautions in patients with suspected infection. Although a positive RITD is mostly confirmatory, a negative result in the presence of high clinical likelihood of infection should be interpreted with caution and be re-evaluated by PCR.Clinical Microbiology and Infection 04/2010; 17(2):235-7. DOI:10.1111/j.1469-0691.2010.03235.x · 5.20 Impact Factor
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ABSTRACT: Simple and rapid diagnosis of influenza is useful for making treatment decisions in the clinical setting. Although many influenza rapid diagnostic tests (IRDTs) are available for the detection of seasonal influenza virus infections, their sensitivity for other viruses, such as H5N1 viruses and the recently emerged swine origin pandemic (H1N1) 2009 virus, remains largely unknown. Here, we examined the sensitivity of 20 IRDTs to various influenza virus strains, including H5N1 and 2009 pandemic H1N1 viruses. Our results indicate that the detection sensitivity to swine origin H1N1 viruses varies widely among IRDTs, with some tests lacking sufficient sensitivity to detect the early stages of infection when the virus load is low.Journal of clinical microbiology 08/2010; 48(8):2872-7. DOI:10.1128/JCM.00439-10 · 4.23 Impact Factor
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ABSTRACT: A new nucleic acid amplification-based rapid test for diagnosis of pandemic influenza (H1N1) 2009 virus was developed. The molecular test for pandemic H1N1, SAMBA (simple amplification-based assay), is based on isothermal amplification and visual detection on a dipstick characterized by high sensitivity, high specificity, a short turnaround time, and minimal technical requirements. The amplification step is monitored with an internal control to ensure correct interpretation of test results. The clinical performance of this assay was evaluated using blinded RNA samples extracted from nasal/throat swab specimens from 262 patients exhibiting influenza-like illness. Compared with the United Kingdom National Standard Method, based on quantitative reverse transcription-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value of the new assay were 95.3% (95% confidence interval, 88.5 to 98.7%), 99.4% (95% confidence interval, 96.9 to 99.9%), 98.8% (95% confidence interval, 93.5 to 99.9%), and 97.8% (95% confidence interval, 94.4 to 99.4%), respectively. The SAMBA for pandemic H1N1 provides a new technology that could potentially facilitate timely diagnosis and management of infected individuals, thereby informing decision making with regard to patient isolation during a pandemic outbreak.Journal of clinical microbiology 10/2010; 48(10):3608-13. DOI:10.1128/JCM.00981-10 · 4.23 Impact Factor