Evaluation of the Quidel QuickVue Test for Detection of Influenza A and B Viruses in the Pediatric Emergency Medicine Setting by Use of Three Specimen Collection Methods

Abstract

The Quidel QuickVue influenza test was compared to viral culture and reverse transcriptase PCR by the use of three different respiratory specimen types. Of 122 pediatric subjects enrolled, 59 had influenza virus infections: 44 were infected with influenza A virus and 15 were infected with influenza B virus. The sensitivity of the QuickVue test was 85% with nasopharyngeal swabs, 78% with nasal swabs, and 69% with nasopharyngeal washes. Specificities were equivalent (97% to 98%) for all three collection methods.During annual outbreaks of influenza A and B virus infection, it is estimated that 10 to 20% of the residential population of the United States may be affected and that the highest attack rates occur in school-age children (1,5,6,16,18,20). The rapid and accurate diagnosis of cases of influenza is desirable for management of children presenting to a pediatric hospital's emergency department (ED). A laboratory-confirmed diagnosis of influenza supports the appropriate use of antiviral therapy for patients to be admitted to the hospital as well as for patients to be discharged from the ED and managed as outpatients. A specific diagnosis also decreases the inappropriate use of antibiotics, other diagnostic testing, and the patient's length of stay in the ED (1,15,18,20).Several methods for laboratory diagnosis of influenza are available; these include viral culture, direct antigen detection, and direct nucleic acid amplification and detection. Viral culture is still considered the "gold standard" method, but traditional culture generally requires at least 3 days or longer to obtain a positive result. Rapid viral culture methods using "shell vial" assays have been applied to speed up the time to detection (8-11). Nucleic acid amplification methods offer very high test sensitivities and same-day results, but there are no FDA-cleared nucleic acid amplification tests for influenza virus detection. Respiratory virus antigen detection by direct or indirect immunofluorescence assay is widely used in laboratories with expertise in fluorescence microscopy, but these assays are often performed as "batch tests" a few times per day and are thus not truly rapid. Antigen detection methods which utilize single-use immunoassay test devices offer the potential for widespread test availability, relative ease of testing, and rapid turnaround (2-4, 8, 10, 12-14, 17, 21).There are limited published data on the impact of specimen type from the respiratory tract on the relative efficiencies of rapid immunoassay tests for influenza diagnosis (7, 12). Studies have examined nasopharyngeal (NP) aspirates and washes, posterior NP and throat swabs, and sputa; however, most studies have not included the collection of multiple specimen types from the same subjects. Aspirates and washes are generally considered superior to swab collections for detection of a variety of respiratory viruses, but swab samples are easier and faster to collect and may be preferred by healthcare providers in a busy ambulatory setting. In this study, we evaluated th...

Comparison of Nasal and Nasopharyngeal Swabs for Influenza Detection in Adults

“…5 A 'gold standard' sampling method has not been identified and validated for influenza detection using rRT-PCR, but emerging evidence suggests that less invasive samples may have comparable sensitivity to nasopharyngeal swabs or aspirates when using molecular diagnostic tests.…”

“…The NP wash or aspirate is generally considered the 'gold standard' for virus isolation, but it is cumbersome to perform and unpleasant for patients. [5][6][7] Swabs are easier and faster to collect and may be preferred by providers and patients. Comparative data on the sensitivity of influenza sampling procedures are limited; many studies focus on pediatric populations or use older diagnostic methods.…”

“…Viral culture has historically been considered the 'gold standard' diagnostic test, but traditional culture can require up to 7 days to obtain a positive result. 5 Recent findings from studies utilizing real-time reverse transcriptase polymerase chain reaction (rRT-PCR) for the detection of respiratory pathogens suggest that the use of this current molecular technology may outweigh potential differences in sensitivity due to specimen type. 7,10 We conducted a prospective study to examine differences in the detection of influenza by specimen type.…”

“…Comparative data on the sensitivity of influenza sampling procedures are limited; many studies focus on pediatric populations or use older diagnostic methods. 5,[8][9][10][11][12] Recent literature has focused on NP sampling compared to oropharyngeal or combined nose-throat swabs. 6,7,10,12 To date, no studies have compared paired nasal and NP swabs collected from adults.…”

Emerging point of care tests for influenza: innovation or status quo

“…False‐positive results may also be obtained, particularly when the prevalence of influenza in the community is low. Existing POCTs may not distinguish between influenza types and do not differentiate influenza subtypes, 18 which could aid the management of outbreaks, direct antiviral treatment (where circulating subtypes have different antiviral susceptibilities), allow identification of human infection with avian influenza (in settings where this may be suspected) and provide a useful surveillance tool. In addition, these tests may be relatively expensive to perform per test and have a limited shelf‐life (1–2 years) 19 .…”