Clinical presentation and microbiological diagnosis in paediatric respiratory tract infection: a systematic review

Rapid respiratory microbiological point-of-care-testing and antibiotic prescribing in primary care: Protocol for the RAPID-TEST randomised controlled trial

BACKGROUND

Antibiotics are prescribed for over 50% of respiratory tract infections in primary care, despite good evidence of there being no benefit to the patient, and evidence of over prescribing driving microbial resistance. The high treatment rates are attributed to uncertainty regarding microbiological cause and clinical prognosis. Point-of-care-tests have been proposed as potential antibiotic stewardship tools, with some providing microbiological results in 15 minutes. However, there is little research on their impact on antibiotic use and clinical outcomes in primary care.

METHODS

This is a multi-centre, individually randomised controlled trial with mixed-methods investigation of microbial, behavioural and antibiotic mechanisms on outcomes in patients aged 12 months and over presenting to primary care in the UK with a suspected respiratory tract infection, where the clinician and/or patient thinks antibiotic treatment may be, or is, necessary. Once consented, all participants are asked to provide a combined nose and throat swab sample and randomised to have a rapid microbiological point-of-care-test or no point-of-care-test. For intervention patients, clinicians review the result of the test, before contacting the patient to finalise treatment. Treatment decisions are made as per usual care in control group patients. The primary outcome is whether an antibiotic is prescribed at this point. All swab samples are sent to the central laboratory for further testing. Patients are asked to complete a diary to record the severity and duration of symptoms until resolution or day 28, and questionnaires at 2 months about their beliefs and intention to consult for similar future illnesses. Primary care medical records are also reviewed at 6-months to collect further infection consultations, antibiotic prescribing and hospital admissions. The trial aims to recruit 514 patients to achieve 90% power with 5% significance to detect a 15% absolute reduction in antibiotic prescribing. Qualitative interviews are being conducted with approximately 20 clinicians and 30 participants to understand any changes in beliefs and behaviour resulting from the point-of-care-test and generate attributes for clinician and patient discrete choice experiments.

DISCUSSION

This trial will provide evidence of efficacy, acceptability and mechanisms of action of a rapid microbiological point-of-care test on antibiotic prescribing and patient symptoms in primary care.

TRIAL REGISTRATION

ISRCTN16039192, prospectively registered on 08/11/2022.

Respiratory syncytial virus in severe lower respiratory infections in previously healthy young Ethiopian infants

BACKGROUND

Respiratory Syncytial Virus (RSV) is the commonest cause of acute lower respiratory infections (ALRI) in infants. However, the burden of RSV is unknown in Ethiopia. We aimed to determine the prevalence, seasonality and predictors of RSV infection in young infants with ALRI for the first time in Ethiopia.

METHODS

We performed RSV immuno-chromatographic assay from nasopharyngeal swabs of infants, 29 days to 6 months of age. We included the first 10 eligible infants in each month from June 2018 to May 2019 admitted in a tertiary pediatric center. Clinical, laboratory and imaging data were also collected, and chi-square test and regression were used to assess associated factors with RSV infection.

RESULTS

Among a total of 117 study children, 65% were male and mean age was 3 months. Bronchiolitis was the commonest diagnosis (49%). RSV was isolated from 26 subjects (22.2%) of all ALRI, 37% of bronchiolitis and 11% of pneumonia patients. Although RSV infection occurred year round, highest rate extended from June to November. No clinical or laboratory parameter predicted RSV infection and only rainy season (Adjusted Odds Ratio (AOR) 10.46 [95%. C.I. 1.95, 56.18]) was independent predictor of RSV infection.

CONCLUSIONS

RSV was isolated in a fifth of young infants with severe ALRI, mostly in the rainy season. Diagnosis of RSV infection in our setting require specific tests as no clinical parameter predicted RSV infection. Since RSV caused less than a quarter of ALRI in our setting, the other causes should be looked for in future studies.

Accuracy of diagnostic tests for respiratory syncytial virus infection within a paediatric hospital population in Kilifi County, Kenya

Background: Respiratory syncytial virus (RSV)-induced lower respiratory tract disease is a prominent cause of hospitalisation among children aged <5 years in developing countries. Accurate and rapid diagnostic tests are central to informing effective patient management and surveillance efforts geared towards quantifying RSV disease burden. This study sought to estimate the sensitivity (Se), specificity (Sp) (along with the associated factors) and predictive values of a direct immunofluorescence test (IFAT), and two real-time reverse transcription polymerase chain reaction (rRT-PCR) assays for RSV infection within a paediatric hospital population: a multiplex rRT-PCR (MPX) and Fast-Track Diagnostics ® (FTD) Respiratory Pathogens 33 (Resp-33) rRT-PCR. Methods: The study enlisted 1458 paediatrics aged ≤59 months admitted with acute respiratory illness at the Kilifi County Hospital between August 2011 and December 2013. A Bayesian latent class modelling framework was employed to infer the tests' estimates based on the patients' diagnostic data from the three tests. Results: The tests posted statistically similar Se estimates: IFAT (93.7%, [90.7; 95.0]), FTD (97.8%, [94.6; 99.4]) and MPX (97.5%, [94.2; 99.3]). As for Sp, FTD registered a lower estimate (97.4%, [96.2; 98.2]) than MPX (99.7%, [99.0; 100.0]) but similar to IFAT (99.0%, [98.2; 99.6]). The negative and positive predictive values were strong (>91%) and closely mimicked the pattern given by the Se and Sp values respectively. None of the examined covariates (age, sex and pneumonia status) significantly influenced the accuracy of the tests. Conclusions: The evaluation found little to choose between the three diagnostic tests. Nonetheless, with its relative affordability, the conventional IFAT continues to hold promise for use in patient care and surveillance activities for RSV infection within settings where children are hospitalised with severe acute respiratory illness.

Decreased prevalence of Moraxella catarrhalis in addition to Streptococcus pneumoniae in children with upper respiratory tract infection after introduction of conjugated pneumococcal vaccine: a retrospective cohort study

OBJECTIVES

To study effects of the introduction of pneumococcal conjugate vaccines (PCV) on the interspecies dynamics of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in preschool children with respiratory tract infection.

METHODS

Nasopharyngeal samples from children aged ≤6 years with upper respiratory tract infection (n = 14 473) in South Sweden were analysed during 14 consecutive years, 5 years before and 9 years after PCV introduction. The yearly prevalence was calculated, and multivariate count regressions between prevalence and estimated yearly proportions of vaccinated children were performed. Associations between pneumococcal serotypes and the other pathogens were assessed.

RESULTS

When comparing the prevaccine period with the years after introduction, the prevalence of S. pneumoniae decreased by 65.2% (16.4 to 5.7 per 1000 individuals; p < 0.001), whereas M. catarrhalis and H. influenzae decreased by 52.1% (21.5 to 10.3 per 1000 individuals; p < 0.001) and 46.6% (13.6 to 7.3 per 1000 individuals; p < 0.001), respectively. In multivariate negative binomial regressions adjusted for yearly numbers of samples taken, S. pneumoniae and M. catarrhalis were significantly negatively associated with increasing vaccine coverage proportions (adjusted prevalence ratio (aPR) = 0.17; p < 0.001 and aPR = 0.48; p < 0.001, respectively), whereas H. influenzae (aPR = 0.75; p = 0.17) was not. In addition, the proportion of cultures positive for S. pneumoniae as well as M. catarrhalis was significantly lower in the postvaccine period compared to the prevaccine period, while this was not the case for H. influenzae. A significant positive association between certain PCV serotypes and simultaneous growth with M. catarrhalis was observed.

CONCLUSIONS

After introduction of PCV, the prevalence of M. catarrhalis in addition to S. pneumoniae in children with respiratory tract infection decreased; this was also the case after adjusting for reduced numbers of samples taken. This may partly be attributed to a positive association between PCV serotypes and M. catarrhalis.

A mismatch-tolerant RT-quantitative PCR: application to broad-spectrum detection of respiratory syncytial virus

Quantitative PCR (qPCR) is widely used to detect viruses. However, mismatches occurring in the 3'-end of the primers reduce amplification efficiency of qPCR and limit its capacity in detection of highly variable viruses. Here, we reported a mismatch-tolerant RT-qPCR with a small amount of additional high-fidelity DNA polymerase for simultaneous detection of RSV-A and RSV-B. The novel assay had higher amplification efficiency for various variants forming mismatches with the primers than the conventional RT-qPCR, and showed good specificity and sensitivity. It demonstrated a good correlation coefficient with a commercial RSV detection kit and had relatively lower Ct values than the kit for 16 of 20 RSV-positive samples. The mismatch-tolerant qPCR technique is a promising approach for sensitive detection of highly variable viruses.

Assessing the potential of upper respiratory tract point-of-care testing: a systematic review of the prognostic significance of upper respiratory tract microbes

OBJECTIVES

Microbial point-of-care testing (POCT) has potential to revolutionize clinical care. Understanding the prognostic value of microbes identified from the upper respiratory tract (a convenient sampling site) is a necessary first step to understand potential for upper respiratory tract POCTs in assisting antimicrobial treatment decisions for respiratory infections (RTIs). The aim was to investigate the relationship between upper respiratory tract microbial detection and disease prognosis, including effects of antimicrobial use.

METHODS

Data sources were the MEDLINE and Embase databases. Study eligibility criteria consisted of quantitative studies reporting microbiological and prognostic data from patients of all age groups presenting with RTI. Patients presenting to healthcare or research settings with RTI participated. Interventions included upper respiratory tract swab. The methods used were systematic review and meta-analysis.

RESULTS

Searches identified 5156 articles, of which 754 were duplicates and 4258 excluded on title or abstract. A total of 144 full texts were screened; 21 articles were retained. Studies reported data for 15 microbes and 26 prognostic measures (390 potential associations). One hundred and seven (27%) associations were investigated statistically, of which 38 (36%) were significant. Most studies reported only prognostic value of test positive results. Meta-analyses suggested hospitalization duration was longer for patients with respiratory syncytial virus than adenovirus and influenza, but significant heterogeneity was observed between studies.

CONCLUSIONS

A quarter of potential prognostic associations have been investigated. Of these, a third were significant, suggesting considerable potential for POCT. Future research should investigate prognostic value of positive and negative tests, and interactions between test results, use of antimicrobials and microbial resistance.

Estimating age-stratified influenza-associated invasive pneumococcal disease in England: A time-series model based on population surveillance data

BACKGROUND

Measures of the contribution of influenza to Streptococcus pneumoniae infections, both in the seasonal and pandemic setting, are needed to predict the burden of secondary bacterial infections in future pandemics to inform stockpiling. The magnitude of the interaction between these two pathogens has been difficult to quantify because both infections are mainly clinically diagnosed based on signs and symptoms; a combined viral-bacterial testing is rarely performed in routine clinical practice; and surveillance data suffer from confounding problems common to all ecological studies. We proposed a novel multivariate model for age-stratified disease incidence, incorporating contact patterns and estimating disease transmission within and across groups.

METHODS AND FINDINGS

We used surveillance data from England over the years 2009 to 2017. Influenza infections were identified through the virological testing of samples taken from patients diagnosed with influenza-like illness (ILI) within the sentinel scheme run by the Royal College of General Practitioners (RCGP). Invasive pneumococcal disease (IPD) cases were routinely reported to Public Health England (PHE) by all the microbiology laboratories included in the national surveillance system. IPD counts at week t, conditional on the previous time point t-1, were assumed to be negative binomially distributed. Influenza counts were linearly included in the model for the mean IPD counts along with an endemic component describing some seasonal background and an autoregressive component mimicking pneumococcal transmission. Using age-specific counts, Akaike information criterion (AIC)-based model selection suggested that the best fit was obtained when the endemic component was expressed as a function of observed temperature and rainfall. Pneumococcal transmission within the same age group was estimated to explain 33.0% (confidence interval [CI] 24.9%-39.9%) of new cases in the elderly, whereas 50.7% (CI 38.8%-63.2%) of incidence in adults aged 15-44 years was attributed to transmission from another age group. The contribution of influenza on IPD during the 2009 pandemic also appeared to vary greatly across subgroups, being highest in school-age children and adults (18.3%, CI 9.4%-28.2%, and 6.07%, CI 2.83%-9.76%, respectively). Other viral infections, such as respiratory syncytial virus (RSV) and rhinovirus, also seemed to have an impact on IPD: RSV contributed 1.87% (CI 0.89%-3.08%) to pneumococcal infections in the 65+ group, whereas 2.14% (CI 0.87%-3.57%) of cases in the group of 45- to 64-year-olds were attributed to rhinovirus. The validity of this modelling strategy relies on the assumption that viral surveillance adequately represents the true incidence of influenza in the population, whereas the small numbers of IPD cases observed in the younger age groups led to significant uncertainty around some parameter estimates.

CONCLUSIONS

Our estimates suggested that a pandemic wave of influenza A/H1N1 with comparable severity to the 2009 pandemic could have a modest impact on school-age children and adults in terms of IPD and a small to negligible impact on infants and the elderly. The seasonal impact of other viruses such as RSV and rhinovirus was instead more important in the older population groups.

Impact of Rapid Molecular Detection of Respiratory Viruses on Clinical Outcomes and Patient Management

To determine if rapid molecular testing for respiratory viruses in patients with respiratory illnesses can provide advantages to patients and hospitals, rigorous investigations on the impacts of using these assays are required. Well-conducted studies are needed to inform decisions about implementation of new rapid assays to replace standard molecular testing or to initiate testing in laboratories that are currently not doing molecular tests for respiratory viruses due to the complex nature of standard panels. In this issue of the Journal of Clinical Microbiology, N. Wabe et al. (J Clin Microbiol 57:e01727-18, 2019, https://doi.org/10.1128/JCM.01727-18) report the results of their evaluation of the impact of using a rapid molecular test for influenza A/influenza B and RSV on outcomes for adults hospitalized with respiratory illness. The median time from admission to test result of the rapid test was 7.5 h compared to 40.3 h for the standard PCR assay. Compared to the use of the standard molecular assay, use of a rapid test significantly shortened time in the hospital and reduced the number of other microbiology tests performed. The authors concluded that rapid PCR testing of adults hospitalized with respiratory illnesses could provide benefits to both the patients and the hospital. Patients were able to leave the hospital earlier and a greater proportion of them had received their test results before discharge, which would allow appropriate treatment to be provided more quickly.

Can we distinguish respiratory viral infections based on clinical features? A prospective pediatric cohort compared to systematic literature review

Studies have shown that the predictive value of “clinical diagnoses” of influenza and other respiratory viral infections is low, especially in children. In routine care, pediatricians often resort to clinical diagnoses, even in the absence of robust evidence‐based criteria.

We used a dual approach to identify clinical characteristics that may help to differentiate infections with common pathogens including influenza, respiratory syncytial virus, adenovirus, metapneumovirus, rhinovirus, bocavirus‐1, coronaviruses, or parainfluenza virus: (a) systematic review and meta‐analysis of 47 clinical studies published in Medline (June 1996 to March 2017, PROSPERO registration number: CRD42017059557) comprising 49 858 individuals and (b) data‐driven analysis of an inception cohort of 6073 children with ILI (aged 0‐18 years, 56% male, December 2009 to March 2015) examined at the point of care in addition to blinded PCR testing. We determined pooled odds ratios for the literature analysis and compared these to odds ratios based on the clinical cohort dataset.

This combined analysis suggested significant associations between influenza and fever or headache, as well as between respiratory syncytial virus infection and cough, dyspnea, and wheezing. Similarly, literature and cohort data agreed on significant associations between HMPV infection and cough, as well as adenovirus infection and fever. Importantly, none of the abovementioned features were unique to any particular pathogen but were also observed in association with other respiratory viruses.

In summary, our “real‐world” dataset confirmed published literature trends, but no individual feature allows any particular type of viral infection to be ruled in or ruled out. For the time being, laboratory confirmation remains essential. More research is needed to develop scientifically validated decision models to inform best practice guidelines and targeted diagnostic algorithms.

Throat swabs in children with respiratory tract infection: associations with clinical presentation and potential targets for point-of-care testing

BACKGROUND AND OBJECTIVES

Diagnostic uncertainty over respiratory tract infections (RTIs) in primary care contributes to over-prescribing of antibiotics and drives antibiotic resistance. If symptoms and signs predict respiratory tract microbiology, they could help clinicians target antibiotics to bacterial infection. This study aimed to determine relationships between symptoms and signs in children presenting to primary care and microbes from throat swabs.

METHODS

Cross-sectional study of children ≥3 months to <16 years presenting with acute cough and RTI, with subset follow-up. Associations and area under receiver operating curve (AUROC) statistics sought between clinical presentation and baseline microbe detection. Microbe prevalence compared between baseline (symptomatic) and follow-up (asymptomatic) visits.

RESULTS

At baseline, ≥1 bacteria was detected in 1257/2113 (59.5%) children and ≥1 virus in 894/2127 (42%) children. Clinical presentation was not associated with detection of ≥1 bacteria [AUROC 0.54 (95% CI 0.52-0.56)] or ≥1 virus [0.64 (95% CI 0.61-0.66)]. Individually, only respiratory syncytial virus (RSV) was associated with clinical presentation [AUROC 0.80 (0.77-0.84)]. Prevalence fell between baseline and follow-up; more so in viruses (68% versus 26%, P < 0.001) than bacteria (56% versus 40%, P = 0.01); greatest reductions seen in RSV, influenza B and Haemophilus influenzae.

CONCLUSION

Findings demonstrate that clinical presentation cannot distinguish the presence of bacteria or viruses in the upper respiratory tract. However, individual and overall microbe prevalence was greater when children were unwell than when well, providing some evidence that upper respiratory tract microbes may be the cause or consequence of the illness. If causal, selective microbial point-of-care testing could be beneficial.

Rapid and sensitive real-time assay for the detection of respiratory syncytial virus using RT-SIBA®

BACKGROUND

Respiratory syncytial virus (RSV) is one of the most common causes of respiratory tract infections among young children and the elderly. Timely and accurate diagnosis of respiratory tract infections improves patient care and minimizes unnecessary prescriptions of antibiotics. We sought to develop a rapid nucleic acid tests for the detection of RSV within minutes, while retaining the high sensitivity achieved with RT-PCR.

METHODS

We developed and evaluated a reverse transcription isothermal nucleic acid amplification method, reverse transcription strand invasion based amplification (RT-SIBA), for the rapid detection of RSV.

RESULTS

The developed RT-SIBA assay showed good sensitivity by detecting as few as 10 copies of RSV RNA within 20 min compared with reverse transcription polymerase chain reaction, which took approximately 2 h. The performance of the RT-SIBA RSV assay was further investigated using nasopharyngeal swab specimens. The RT-SIBA assay had a sensitivity of 100% (25/25) and a specificity of 100% (15/15).

CONCLUSION

RT-SIBA did not require highly purified RNA for the rapid detection of RSV and was therefore compatible with rapid specimen processing methods. This reduces the complexity of specimen preparation and further shortens the total amount of time needed to detect RSV in clinical specimens. The developed RT-SIBA assay for RSV could be a useful tool for prompt management of this infection.

Evaluation of Alere i RSV for Rapid Detection of Respiratory Syncytial Virus in Children Hospitalized with Acute Respiratory Tract Infection

Alere i RSV is a novel rapid test which applies a nicking enzyme amplification reaction to detect respiratory syncytial virus in point-of-care settings. In this study, we evaluated the Alere i RSV assay by using frozen nasopharyngeal swab samples that were collected in viral transport medium from children hospitalized with acute respiratory tract infection during the 2015-2016 winter season. Alere i RSV assay results were compared to those for Altona RealStar RSV real-time reverse transcription-PCR (RT-PCR). We found that the overall sensitivity and specificity of the Alere i RSV test was 100% (95% confidence intervals [CI], 93% to 100%) and 97% (95% CI, 89% to 100%), respectively. Positive samples were identified within 5 to 7 min from sample collection. Overall, the Alere i RSV test performed well compared to the RT-PCR assay and has the potential to facilitate the detection of RSV in point-of-care settings.

Parent views on the content and potential impact of respiratory tract infection surveillance information: semistructured interviews to inform future research

OBJECTIVES

This study explored the potential value of real-time information regarding respiratory tract infections (RTIs) circulating in the community by eliciting parent views on illustrative surveillance information and its possible impact on primary care consultations.

DESIGN

Semistructured interviews were conducted with parents of children (>3 months-15 years). Participants were presented with example information on circulating viruses, symptoms and symptom duration and asked about its potential impact on perceptions of child illness and management practices. Interviews were analysed using the framework method.

SETTING

Parents participating in a cohort study were selected purposefully using index of multiple deprivation and child age.

PARTICIPANTS

30 mothers of children (>3 months-15years).

RESULTS

Parents anticipated using the information to inform lay diagnoses particularly when child symptoms were severe and thought normal symptom duration awareness might extend the time prior to seeking medical advice, but it also may encourage consultations when symptoms exceed the given duration. The information was not expected to change consultation behaviour if parents felt their child needed a medical evaluation and they felt unable to manage the symptoms. Most parents felt that the information could provide reassurance that could reduce intention to consult, but some felt it could raise concerns, by heightening awareness of circulating viruses. Lastly, parents wanted advice about protecting children from circulating viruses and felt that general practitioners using the information to diagnose child RTIs with greater certainty was acceptable.

CONCLUSIONS

Diverse responses to the surveillance information were elicited, and there was some support for the intended outcomes. This study has important implications for the design of interventions to modify consulting behaviour. Future piloting to measure behaviour change in response to infection surveillance information are needed.

Pre-examination factors affecting molecular diagnostic test results and interpretation: A case-based approach

BACKGROUND

Multiple organizations produce guidance documents that provide opportunities to harmonize quality practices for diagnostic testing. The International Organization for Standardization ISO 15189 standard addresses requirements for quality in management and technical aspects of the clinical laboratory. One technical aspect addresses the complexities of the pre-examination phase prior to diagnostic testing.

METHODS

The Committee for Molecular Diagnostics of the International Federation for Clinical Chemistry and Laboratory Medicine (also known as, IFCC C-MD) conducted a survey of international molecular laboratories and determined ISO 15189 to be the most referenced guidance document. In this review, the IFCC C-MD provides case-based examples illustrating the value of select pre-examination processes as these processes relate to molecular diagnostic testing. Case-based examples in infectious disease, oncology, inherited disease and pharmacogenomics address the utility of: 1) providing information to patients and users, 2) designing requisition forms, 3) obtaining informed consent and 4) maintaining sample integrity prior to testing.

CONCLUSIONS

The pre-examination phase requires extensive and consistent communication between the laboratory, the healthcare provider and the end user. The clinical vignettes presented in this paper illustrate the value of applying select ISO 15189 recommendations for general laboratory to the more specialized area of Molecular Diagnostics.

Epidemiology of laboratory-confirmed respiratory syncytial virus infection in young children in England, 2010–2014: the importance of birth month

The epidemiology of laboratory-confirmed respiratory syncytial virus (RSV) infections in young children has not recently been described in England, and is an essential step in identifying optimal target groups for future licensed RSV vaccines. We used two laboratory surveillance systems to examine the total number and number of positive RSV tests in children aged <5 years in England from 2010 to 2014. We derived odds ratios (ORs) with 95% confidence intervals (CIs) comparing children by birth month, using multivariable logistic regression models adjusted for age, season and sex. Forty-seven percent of RSV tests (29 851/63 827) and 57% (7405/13 034) of positive results in children aged <5 years were in infants aged <6 months. Moreover, 38% (4982/13 034) of positive results were in infants aged <3 months. Infants born in September, October and November had the highest odds of a positive RSV test during their first year of life compared to infants born in January (OR 2·1, 95% CI 1·7–2·7; OR 2·4, 95% CI 2·1–2·8; and OR 2·4, 95% CI 2·1–2·7, respectively). Our results highlight the importance of young age and birth month near the beginning of the RSV season to the risk of laboratory-confirmed RSV infection. Future control measures should consider protection for these groups.

Diagnostic Accuracy of Rapid Antigen Detection Tests for Respiratory Syncytial Virus Infection: Systematic Review and Meta-analysis

Respiratory syncytial virus (RSV) rapid antigen detection tests (RADT) are extensively used in clinical laboratories. We performed a systematic review and meta-analysis to evaluate the accuracy of RADTs for diagnosis of RSV infection and to determine factors associated with accuracy estimates. We searched EMBASE and PubMed for diagnostic-accuracy studies of commercialized RSV RADTs. Studies reporting sensitivity and specificity data compared to a reference standard (reverse transcriptase PCR [RT-PCR], immunofluorescence, or viral culture) were considered. Two reviewers independently extracted data on study characteristics, diagnostic-accuracy estimates, and study quality. Accuracy estimates were pooled using bivariate random-effects regression models. Heterogeneity was investigated with prespecified subgroup analyses. Seventy-one articles met inclusion criteria. Overall, RSV RADT pooled sensitivity and specificity were 80% (95% confidence interval [CI], 76% to 83%) and 97% (95% CI, 96% to 98%), respectively. Positive- and negative-likelihood ratios were 25.5 (95% CI, 18.3 to 35.5) and 0.21 (95% CI, 0.18 to 0.24), respectively. Sensitivity was higher in children (81% [95% CI, 78%, 84%]) than in adults (29% [95% CI, 11% to 48%]). Because of this disparity, further subgroup analyses were restricted to pediatric data (63 studies). Test sensitivity was poorest using RT-PCR as a reference standard and highest using immunofluorescence (74% versus 88%; P < 0.001). Industry-sponsored studies reported significantly higher sensitivity (87% versus 78%; P = 0.01). Our results suggest that the poor sensitivity of RSV RADTs in adults may preclude their use in this population. Furthermore, industry-sponsored studies and those that did not use RT-PCR as a reference standard likely overestimated test sensitivity.