Comparing Nose-Throat Swabs and Nasopharyngeal Aspirates Collected From Children With Symptoms for Respiratory Virus Identification Using Real-Time Polymerase Chain Reaction

MBBS, Queensland Paediatric Infectious Diseases Laboratory, Royal Children's Hospital, Herston Queensland 4029, Australia.
PEDIATRICS (Impact Factor: 5.47). 10/2008; 122(3):e615-20. DOI: 10.1542/peds.2008-0691
Source: PubMed


The objective of this study was to calculate sensitivity values for the detection of major respiratory viruses of childhood by using combined nose-throat swabs and nasopharyngeal aspirates.
Children who had symptoms and presented to a pediatric teaching hospital and had a diagnostic respiratory specimen collected were enrolled, and paired nose-throat swab and nasopharyngeal aspirate specimens were collected. Parents were asked to collect the nose-throat swab specimen in the first instance but could defer to a health care worker if unwilling. Nose-throat swab collectors were asked to rate perceived quality of collection. All nasopharyngeal aspirates were collected by a health care worker by using a standard protocol. Real-time polymerase chain reaction for 8 respiratory viruses was performed in our hospital's diagnostic laboratory.
Paired nose-throat swab/nasopharyngeal aspirate specimens were collected during 303 illnesses, with at least 1 respiratory virus identified in 186 (61%). For the major pathogens of childhood, influenza A virus and respiratory syncytial virus, collection by using the nose-throat swab had a sensitivity of 91.9% and 93.1%, respectively. A health care worker collected 219 (72%) of the nose-throat swab specimens; concordance with the nasopharyngeal aspirate was not related to health care worker collection or perceived quality of collection.
Nose-throat swab specimens, in combination with sensitive molecular testing, are a less invasive diagnostic respiratory specimen with adequate sensitivity for use in the clinic and hospital outpatient settings and large-scale community studies through parent collection. For children who present to a hospital in which an avian or pandemic strain of influenza virus is reasonably part of the differential diagnosis, nasopharyngeal aspirates or a similar collection technique (eg, nasal washes) should continue to be used.

Download full-text


Available from: Theodorus P. Sloots, Aug 14, 2014
  • Source
    • "Importantly, when using highly sensitive polymerase chain reaction (PCR) assays the detection rates for respiratory viruses are similar in both anterior nasal swab specimens and samples collected by the more traditional method of nasopharyngeal aspiration [18,19]. Building on this information, later studies have also shown that PCR testing for respiratory viruses provided similar results for parent-collected anterior nasal swab specimens and either nasal swab or nasoparyngeal aspirates collected by healthcare professionals [16,17]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Carefully conducted, community-based, longitudinal studies are required to gain further understanding of the nature and timing of respiratory viruses causing infections in the population. However, such studies pose unique challenges for field specimen collection, including as we have observed the appearance of mould in some nasal swab specimens. We therefore investigated the impact of sample collection quality and the presence of visible mould in samples upon respiratory virus detection by real-time polymerase chain reaction (PCR) assays. Anterior nasal swab samples were collected from infants participating in an ongoing community-based, longitudinal, dynamic birth cohort study. The samples were first collected from each infant shortly after birth and weekly thereafter. They were then mailed to the laboratory where they were catalogued, stored at -80[degree sign]C and later screened by PCR for 17 respiratory viruses. The quality of specimen collection was assessed by screening for human deoxyribonucleic acid (DNA) using endogenous retrovirus 3 (ERV3). The impact of ERV3 load upon respiratory virus detection and the impact of visible mould observed in a subset of swabs reaching the laboratory upon both ERV3 loads and respiratory virus detection was determined. In total, 4933 nasal swabs were received in the laboratory. ERV3 load in nasal swabs was associated with respiratory virus detection. Reduced respiratory virus detection (odds ratio 0.35; 95% confidence interval 0.27-0.44) was observed in samples where the ERV3 could not be identified. Mould was associated with increased time of samples reaching the laboratory and reduced ERV3 loads and respiratory virus detection. Suboptimal sample collection and high levels of visible mould can impact negatively upon sample quality. Quality control measures, including monitoring human DNA loads using ERV3 as a marker for epithelial cell components in samples should be undertaken to optimize the validity of real-time PCR results for respiratory virus investigations in community-based studies.
    Full-text · Article · Jan 2014 · BMC Infectious Diseases
  • Source
    • "Infectious disease diagnostics traditionally rely heavily on pathogen detection [1], [2], [3]. However, the development of reproducible means for extracting RNA from whole blood, coupled with advanced statistical methods for analysis of complex datasets, has created the possibility of classifying infections based on host gene expression profiling. "
    [Show abstract] [Hide abstract]
    ABSTRACT: There is great potential for host-based gene expression analysis to impact the early diagnosis of infectious diseases. In particular, the influenza pandemic of 2009 highlighted the challenges and limitations of traditional pathogen-based testing for suspected upper respiratory viral infection. We inoculated human volunteers with either influenza A (A/Brisbane/59/2007 (H1N1) or A/Wisconsin/67/2005 (H3N2)), and assayed the peripheral blood transcriptome every 8 hours for 7 days. Of 41 inoculated volunteers, 18 (44%) developed symptomatic infection. Using unbiased sparse latent factor regression analysis, we generated a gene signature (or factor) for symptomatic influenza capable of detecting 94% of infected cases. This gene signature is detectable as early as 29 hours post-exposure and achieves maximal accuracy on average 43 hours (p = 0.003, H1N1) and 38 hours (p-value = 0.005, H3N2) before peak clinical symptoms. In order to test the relevance of these findings in naturally acquired disease, a composite influenza A signature built from these challenge studies was applied to Emergency Department patients where it discriminates between swine-origin influenza A/H1N1 (2009) infected and non-infected individuals with 92% accuracy. The host genomic response to Influenza infection is robust and may provide the means for detection before typical clinical symptoms are apparent.
    Full-text · Article · Jan 2013 · PLoS ONE
  • Source
    • "Data analysis We performed descriptive analyses of demographic and clinical data and are presented as proportions of all participants or all paired specimens collected. Given the sensitivity and specificity of real-time PCR diagnosis, we considered a specimen from either nostril positive for any virus to represent a true-positive, similar to previous studies (Lambert et al. 2008b; Meerhoff et al. 2010). This approach means that the specificity of either specimen type for any virus will be, by definition, 100%. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Surveillance programs and research for acute respiratory infections in remote Aboriginal communities are complicated by difficulties in the storage and transport of frozen samples to urban laboratories for testing. This study assessed the sensitivity of a simple method for transporting respiratory samples from a remote setting for viral PCR compared with frozen specimens. We sampled every individual who presented to a remote Aboriginal community clinic in a non-epidemic respiratory season. Two anterior nasal swabs were collected from each participant. The left nare specimen was mailed to the laboratory via routine postal services. The right nare specimen was transported frozen. Testing for 16 viruses was undertaken using real-time multiplex PCR. A total of 140 participants were enrolled who contributed 150 study visits. Respiratory illnesses accounted for 10% of the reasons for presentation. Sixty-one viruses were identified in 50 (33.3%) presentations for 40 (28.6%) individuals; bocavirus and rhinovirus were the most common viruses identified (14.0% and 12.6% of episodes respectively). The sensitivity for any virus detected in mailed specimens was 67.2% (95%CI 55.4, 78.9) compared to 65.6% (95%CI 53.7, 77.5) for frozen specimens. The mailing of unfrozen nasal specimens from remote communities does not compromise the viability of the specimen for viral studies.
    Full-text · Article · Mar 2011 · Tropical Medicine & International Health
Show more