An HIV Diagnostic Testing Algorithm Using the cobas HIV-1/HIV-2 Qualitative Assay for HIV Type Differentiation and Confirmation.

Human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) diagnostic testing algorithms recommended by the Centers for Disease Control involve up to three tests and rely mostly on detection of viral antigen and host antibody responses. HIV-1 p24 antigen/HIV-1/HIV-2 antibody-reactive specimens are confirmed with an immunochromatographic HIV-1/HIV-2 antibody differentiation assay, and negative or indeterminate results from the differentiation assay are resolved by an HIV-1-specific nucleic acid amplification test (NAT). The performance of a proposed alternative algorithm using the cobas HIV-1/HIV-2 qualitative NAT as the differentiation assay was evaluated in subjects known to be infected with HIV-1 (n = 876) or HIV-2 (n = 139), at low (n = 6,017) or high (n = 1,020) risk of HIV-1 infection, or at high-risk for HIV-2 infection (n = 498) (study A). The performance of the cobas HIV-1/HIV-2 qualitative test was also evaluated by comparison to an HIV-1 or HIV-2 alternative NAT (study B). The HIV-1 and HIV-2 overall percent agreements (OPA) in study A ranged from 95% to 100% in all groups. The positive percent agreements (PPA) for HIV-1 and HIV-2 were 100% (876/876) and 99.4% (167/168), respectively, for known positive groups. The negative percent agreement in the HIV low-risk group was 100% for both HIV-1 and HIV-2. In study B, the HIV-1 and HIV-2 OPA ranged from 99% to 100% in all groups evaluated (n = 183 to 1,030), and the PPA for HIV-1 and HIV-2 were 100% and 99.5%, respectively, for known positive groups. The cobas HIV-1/HIV-2 qualitative assay can discriminate between HIV-1 and HIV-2 based on HIV RNA and can be included in an alternative diagnostic algorithm for HIV.

Outcomes of transplant recipients treated with cidofovir for resistant or refractory cytomegalovirus infection.

BACKGROUND: Treatment of ganciclovir-resistant (GCV-R)/refractory cytomegalovirus (CMV) infections in blood/marrow transplant (BMT) and solid organ transplant (SOT) recipients remains suboptimal. Cidofovir (CDV), a nucleotide analogue with anti-CMV activity, is nephrotoxic and oculotoxic. METHODS: We retrospectively evaluated the outcomes of SOT and BMT patients with GCV-R/refractory CMV treated with CDV between 1/1/2008 and 12/31/2017. DATA COLLECTED: baseline demographics, CMV serostatus, clinical and virologic presentations and outcomes, UL97 and UL54 genotype mutations, drug toxicities, and cause of death. Descriptive statistics were used. RESULTS: 16 patients received CDV for treatment of CMV: six BMT and 10 SOT. Seven (47%) of the patients had high-risk donor/recipient serostatus: six (60%) SOT were D+/R-; one (16.7%) BMT was D-/R+. Median time to CMV DNAemia was 131 days post-transplant (IQR, 37.5-230.3). Proven tissue invasive disease was present in three patients (18.8%). Twelve (75%) had genotype testing; 10 (83.3%) of those had antiviral resistance mutations. While on CDV, six (37.5%) developed nephrotoxicity, and four (25%) developed uveitis (two had both uveitis and nephrotoxicity). Eight (50%) had failure to clear CMV DNAemia despite CDV treatment. Eight (50%) of the patients died; median time to death, after initiation of CDV, was 33.5 days [IQR22-988]. CONCLUSIONS: In the absence of good therapeutic alternatives, CDV is used in GCV-R/refractory CMV infection. However, it is associated with a substantial risk of toxicity and failure to clear CMV DNAemia, highlighting the need for development of newer and less toxic therapies. The high mortality in this group of patients underscores the severity of illness in this population.

Routine HIV Test Results in 6 US Clinical Laboratories Using the Recommended Laboratory HIV Testing Algorithm With Geenius HIV 1/2 Supplemental Assay.

BACKGROUND: Geenius HIV 1/2 Supplemental Assay (Geenius; Bio-Rad Laboratories) is the only Food and Drug Administration-approved HIV-1/HIV-2 antibody differentiation test for the second step in the HIV laboratory testing algorithm. We characterized the occurrence of true HIV-1 and HIV-2 infections as well as false results in 6 US clinical laboratories using Geenius. METHODS: We examined routine HIV testing outcome data from the time the laboratories began using the algorithm with Geenius until September 30, 2017. We calculated the positive predictive value for Geenius HIV-1 and HIV-2 reactivity separately. RESULTS: Of 5,046,684 specimens tested, 41,791 had reactive antigen/antibody test results. Most specimens with reactive antigen/antibody results were HIV-1 antibody-positive established infections (n = 32,421), 1,865 of which also had indeterminate HIV-2 bands present. Ninety-three specimens were HIV-2 antibody positive or untypable for HIV-1/HIV-2 antibody. Acute HIV-1 infections were found in 528 specimens; 881 specimens lacked the nucleic acid test to determine the possibility of acute HIV-1 infection. False-positive antigen/antibody test results were present in 7505 specimens. Few specimens (n = 363) had false-positive antigen/antibody results with indeterminate Geenius and negative HIV-1 nucleic acid test results. The positive predictive values of Geenius reactivity were 99.4% for HIV-1 and 4.3% for HIV-2. CONCLUSIONS: Routine testing using the laboratory testing algorithm with Geenius resulted in most specimens resolving as HIV negative or HIV-1 positive. The occurrence of indeterminate HIV-2 bands with a Geenius final assay interpretation of HIV-1 positive was more common than true HIV-2 infections. Reporting indeterminate HIV-2 results in this situation may cause confusion with interpreting HIV infection status.

The clinical significance of EBV DNA in the plasma and peripheral blood mononuclear cells of patients with or without EBV diseases.

Epstein-Barr virus (EBV) is a ubiquitous virus that establishes a latent infection within the host and in some cases can lead to the development of EBV-associated lymphomas, lymphoproliferative disorders, hemophagocytic lymphohistiocytosis, solid tumors, and other diseases. We studied the clinical significance of detecting EBV DNA in the plasma and peripheral blood mononuclear cells (PBMCs) of 2146 patients who had blood specimens sent to the Johns Hopkins Hospital clinical laboratory for viral quantitative real-time polymerase chain reaction assay over a 5-year period. Within this largely immunocompromised and hospitalized cohort, 535 patients (25%) had EBV detected in plasma or PBMCs. When EBV was detected in the absence of an EBV(+)disease (n = 402), it was present only in PBMCs in 69% of cases. Immunocompromised patients were less likely to have EBV in plasma than in PBMCs in the absence of EBV(+)disease. In patients with active, systemic EBV(+)diseases (n = 105), EBV was detected in plasma in 99% of cases but detected in PBMCs in only 54%. Across a range of copy number cutoffs, EBV in plasma had higher specificity and sensitivity for EBV(+)disease as compared with EBV in PBMCs. EBV copy number in plasma distinguished untreated, EBV(+)lymphoma from EBV(+)lymphoma in remission and EBV(-)lymphoma, and also distinguished untreated, EBV(+)posttransplantation lymphoproliferative disorder (PTLD) from EBV(+)PTLD in remission and EBV(-)PTLD. EBV copy number quantification is a useful diagnostic marker across the spectrum of EBV(+)diseases, even among immunocompromised patients, with plasma specimens more indicative of EBV(+)disease than PBMCs.

Clinical diagnosis of influenza in the ED.

BACKGROUND: Timely and accurate diagnosis of influenza remains a challenge but is critical for patients who may benefit from antiviral therapy. This study determined the test characteristics of provider diagnosis of influenza, final ED electronic medical record (EMR) diagnosis of influenza, and influenza-like illness (ILI) in patients recommended to receive antiviral treatment according to Centers for Disease Control and Prevention (CDC) guidelines. In addition, we evaluated the compliance with CDC antiviral guidelines. METHODS: A prospective cohort of adults presenting to a tertiary care ED with an acute respiratory illness who met CDC criteria for recommended antiviral treatment were enrolled and tested for influenza. A clinical diagnosis of influenza was assessed by asking the clinician: "Do you think this patient has influenza?" Influenza-like illness was defined according to current CDC criteria. RESULTS: In this cohort of 270 subjects, 42 (16%; 95% confidence interval [CI], 11%-20%) had influenza. Clinician diagnosis had a sensitivity of 36% (95% CI, 22%-52%) and specificity of 78% (95% CI, 72%-83%); EMR final ED diagnosis had a sensitivity of 26% (95% CI, 14%-42%) and specificity of 97% (95% CI, 94%-99%); ILI had a sensitivity of 31% (95% CI, 18%-47%) and specificity of 88% (95% CI, 83%-92%). Only 15 influenza-positive patients (36%) received antiviral treatment. CONCLUSION: Clinician diagnosis, final ED EMR diagnosis, and ILI have low sensitivity for diagnosing influenza, and there is overall poor compliance with CDC antiviral treatment recommendations. Improved methods of influenza diagnosis are needed to help guide management in the clinical setting.

Evaluation of the Xpert Flu rapid PCR assay in high-risk emergency department patients.

We prospectively evaluated the performance of Cepheid's GeneXpert Xpert Flu assay in a target population of 281 adults presenting to the emergency department with an acute respiratory illness who met Centers for Disease Control and Prevention (CDC) criteria for recommended antiviral treatment. Compared with the Prodesse ProFlu+ assay, Xpert Flu had an overall sensitivity of 95.3% and specificity of 99.2%.

A Natural History Study of Timothy Syndrome.

Timothy syndrome (OMIM #601005) is a rare disease caused by variants in the gene CACNA1C . Timothy syndrome patients were first identified as having a cardiac presentation of Long QT and syndactyly of the fingers and/or toes, and an identical variant in CACNA1C , Gly406Arg. However, since this original identification, more individuals harboring diverse variants in CACNA1C have been identified and have presented with various cardiac and extra-cardiac symptoms. Furthermore, it has remained underexplored whether individuals harboring canonical Gly406Arg variants in mutually exclusive exon 8A (Timothy syndrome 1) or exon 8 (Timothy syndrome 2) have additional symptoms. Here, we describe the first Natural History Study for Timothy syndrome, providing a thorough resource describing the current understanding of disease manifestation in Timothy syndrome patients. Parents of Timothy syndrome children were queried regarding a wide-ranging set of symptoms and features via a survey. Importantly, we find that in addition to cardiac concerns, Timothy syndrome patients commonly share extra-cardiac features including neurodevelopmental impairments, hypoglycemia, and respiratory problems. Our work expands the current understanding of the disorder to better inform the care of Timothy syndrome patients.

An international multicenter performance analysis of cytomegalovirus load tests.

BACKGROUND: Quantification of cytomegalovirus (CMV) load is central to the management of CMV infections in immunocompromised patients, but quantitative results currently differ significantly across methods and laboratories. METHODS: The COBAS AmpliPrep/COBAS TaqMan CMV Test (CAP/CTM CMV test), developed using the first World Health Organization CMV standard in the calibration process, was compared to local assays used by 5 laboratories at transplant centers in the United States and Europe. Blinded plasma panels (n = 90) spiked with 2.18-6.7 log(10) copies/mL and clinical plasma samples from immunocompromised patients (n = 660) were tested. RESULTS: Observed mean panel member concentrations by site and 95% confidence intervals (CIs) of the data combined across sites were narrower for CAP/CTM CMV test compared with local assays. The 95% CI in log(10) copies/mL of the combined data per panel member for CAP/CTM CMV test vs comparator assays was .17 vs 1.5 at 2.18 log(10) copies/mL; .14 vs .52 at 2.74 log(10) copies/mL; .16 vs .6 at 3.3 log(10) copies/mL; .2 vs 1.11 at 4.3 log(10) copies/mL; .21 vs 1.13 at 4.7 log(10) copies/mL; and .18 vs 1.4 at 6.7 log(10) copies/mL. In clinical specimens, constant and variable quantification differences between the CAP/CTM CMV test and comparator assays were observed. CONCLUSIONS: High interlaboratory agreement and precision of CAP/CTM CMV test results across 5 different laboratories over 4 orders of magnitude suggest that this assay could be valuable in prospective studies identifying clinical viral load thresholds for CMV treatment.

Detection of cytomegalovirus DNA in plasma as an adjunct diagnostic for gastrointestinal tract disease in kidney and liver transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) disease is the most common infectious complication after solid organ transplantation, frequently affecting the gastrointestinal (GI) tract. There are limited data on quantitative polymerase chain reaction (qPCR) for plasma CMV DNA as an adjunct diagnostic method for GI tract disease in kidney and liver transplant recipients. METHODS: We reviewed all records of adult kidney and liver transplant recipients with a GI tract biopsy and plasma CMV qPCR result within 15 days of biopsy during a 6.5-year period at our center. CMV GI tract disease was defined as histopathologic evidence of CMV on biopsy by immunohistochemistry or visualization of inclusion bodies. RESULTS: GI tract biopsy and qPCR results were available for 81 kidney and liver transplant recipients; 20 cases of confirmed CMV GI tract disease were identified. Overall, the sensitivity of qPCR for diagnosing CMV GI tract disease was 85% (95% confidence interval [CI], 61%-96%), and the specificity was 95% (95% CI, 85%-99%). For CMV-seronegative recipients (R(-)) with CMV-seropositive donors (D(+)), the sensitivity of qPCR was 100% (95% CI, 59%-99%), and the specificity was 80% (95% CI, 30%-99%). The lowest sensitivity was observed in CMV D(+)/R(+) cases (72.7%; 95% CI, 39%-93%). The mean plasma CMV copy number in patients with GI tract disease was 3.84 log10 (38 334 copies/mL). CONCLUSIONS: Plasma CMV qPCR had good sensitivity and excellent specificity for CMV GI tract disease in kidney and liver transplant recipients. Its sensitivity was 100% in CMV D(+)/R(-) cases but 72.7% in CMV D(+)/R(+) cases. This variation in assay performance according to host serostatus may reflect differences in disease pathogenesis.

Clinical accuracy of a PLEX-ID flu device for simultaneous detection and identification of influenza viruses A and B.

Respiratory tract infections caused by influenza A and B viruses often present nonspecifically, and a rapid, high-throughput laboratory technique that can identify influenza viruses is clinically and epidemiologically desirable. The PLEX-ID Flu assay (Abbott Molecular Inc., Des Plaines, IL) incorporates multilocus PCR and electrospray ionization-mass spectrometry to detect and differentiate influenza A 2009 H1N1 (H1N1-p), seasonal H1N1 (H1N1-s), influenza A H3N2, and influenza B viruses in nasopharyngeal swab (NPS) specimens. The clinical performance characteristics of the PLEX-ID Flu assay in symptomatic patients were determined in this multicenter trial. A total of 2,617 prospectively and retrospectively collected NPS specimens from patients with influenza-like illness between February 2008 and 28 May 2010 were eligible for inclusion in the study. Each specimen was tested in parallel by the PLEX-ID Flu assay and by the Prodesse ProFLU+ assay (Prodesse Inc., Madison, WI), to detect influenza A and B viruses. Specimens testing positive for influenza A virus by ProFLU+ were subtyped as H1N1-p, H1N1-s, or H3N2 by using the ProFAST+ assay (Gen-Probe Prodesse Inc.). The reproducibility of the PLEX-ID Flu assay ranged from 98.3 to 100.0%, as determined by testing a nine-specimen panel at three clinical sites on each of 5 days. Positive percent agreements (PPAs) and negative percent agreements (NPAs) of the PLEX-ID Flu assay were 94.5% and 99.0% for influenza A virus and 96.0% and 99.9% for influenza B virus, respectively. For the influenza A virus subtyping characterization, the PLEX-ID Flu assay had PPAs and NPAs of 98.3% and 97.5% for H1N1-p, 88.6% and 100.0% for H1N1-s, and 98.0% and 99.9% for H3N2, respectively. The overall agreements between the PLEX-ID and Prodesse ProFLU+/ProFAST+ assays were 97.1 to 100.0%. Bidirectional Sanger sequencing analysis revealed that 87.5% of 96 discrepant results between the PLEX-ID Flu and ProFLU+/ProFAST+ assays were found upon influenza A virus detection and H1N1-p subtyping. The PLEX-ID Flu assay demonstrated a high level of accuracy for the simultaneous detection and identification of influenza A and B viruses in patient specimens, providing a new laboratory tool for the rapid diagnosis and management of influenza A and B virus infections.

Derivation of a clinical prediction rule to predict hospitalization for influenza in EDs.

BACKGROUND: Early, rapid, and accurate identification of those patients who have severe influenza is important for emergency physicians. Influenza viral load, which has been proposed as a predictor of severe influenza, could be useful in facilitating decision making of resource use. We aimed to derive a clinical prediction rule to indicate probability for inpatient hospitalization for patients with influenza, which includes influenza viral load in addition to other clinical information commonly collected in the emergency department (ED). METHODS: We conducted a 3-year prospective cohort study (2007-2009) of patients with probable influenza infection as suspected by the emergency physician from 3 study sites. Eligible patients were those with excess nasopharyngeal aspirate samples. Influenza viral load was measured using reverse transcription polymerase chain reaction and electrospray ionization mass spectrometry. Clinical information including demographics, underlying illness, vaccination history, hospitalization, and results from clinical laboratory were abstracted from electronic patient records and questionnaires. The prediction rule for hospitalization was derived by the recursive partitioning algorithm (decision tree-type approach) and evaluated by internal 10-fold cross-validation for performance characteristics. RESULTS: Of 424 ED patients with nasopharyngeal aspirates, 146 infected with influenza were enrolled (median age, 10 years [interquartile range, 4-26]; race, 55% African American; median inpatient length of stay, 3 days [interquartile range, 1-4]; high viral load group [defined as >2.5 million genome copies/mL], 34%). Predictors for hospitalization included underlying illness, age, influenza viral load level, and vaccination history (c statistics, 0.84; sensitivity, 83%; specificity, 76%). CONCLUSIONS: The clinical prediction rule incorporating influenza viral load into the clinical information was indicative of hospitalization and merits further evaluation for determination of ED resource use for patients with influenza.

Lead Time to Recurrence After Posttreatment Plasma and Saliva HPV DNA Testing in Patients With Low-Risk HPV Oropharynx Cancer.

Importance: Head and neck squamous cell carcinoma is a highly lethal cancer that is often associated with human papillomavirus (HPV). Recent studies have shown promise in the use of HPV DNA detection in salivary rinses and plasma as a factor associated with a future diagnosis of HPV-positive oropharynx cancer (HPVOPC). However, the use of plasma and salivary HPV DNA detection in defining risk for recurrence in the context of a prospective, phase 3, clinical trial coupled with standardized clinical surveillance has not been reported. Objective: To identify patients with low-risk HPVOPC at risk for recurrence by detection of HPV16 DNA in plasma and salivary rinses. Design, Setting, and Participants: In this cohort study, 233 low-risk patients were recruited from 32 head and neck treatment centers in Ireland (1 [3.1%]), the Netherlands (1 [3.1%]), and the UK (30 [93.8%]) as part of the DE-ESCALATE HPV trial, an open-label, phase 3 randomized clinical trial examining treatment with cetuximab vs cisplatin for HPVOPC. Patients were assayed for the presence of HPV16 DNA in plasma and salivary rinse via a quantitative polymerase chain reaction-based assay. Main Outcomes and Measures: Assay results were associated with risk of recurrence and lead time from HPV16 DNA detection to recurrence. Results: Of 233 patients, 45 (19.3%) were women, and the mean (SD) age was 57.01 (8.45) years. A total 1040 salivary or blood samples were collected during the course of the study. With a median follow-up of 760 days, the sensitivity and specificity of combined plasma and salivary rinse HPV DNA assays for detecting recurrence were 65% and 87%, respectively. There was a median lead time of positive test to event/recurrence date of 19 days (range, 0-536 days) and mean (SD) of 122 (169.8) days. Conclusion and Relevance: The results of this cohort study suggest that in the setting of a randomized, prospective, phase 3 trial for low-risk patients with HPVOPC, posttreatment presence of HPV DNA in plasma and salivary rinses is associated with recurrence; a lead time between test positivity and clinical recurrence offers a potential opportunity for earlier detection of recurrence.

The combination of ribavirin and peginterferon is superior to peginterferon and placebo for children and adolescents with chronic hepatitis C.

BACKGROUND & AIMS: Although randomized trials of adults infected with hepatitis C virus (HCV) have shown that ribavirin increases the efficacy of pegylated interferon (PEG), such trials have not been performed in children. We conducted a randomized controlled trial of PEG and ribavirin, compared with PEG and placebo, in children 5 to 17 years old with chronic hepatitis C. METHODS: HCV RNA-positive children from 11 university medical centers were randomly assigned to receive either PEG alfa-2a (PEG-2a; 180 µg/1.73 m(2) body surface area, subcutaneously each week; n = 55) and ribavirin (15 mg/kg orally in 2 doses daily) or PEG-2a and placebo (n = 59) for 48 weeks. The primary end point was sustained virologic response (SVR; lack of detectable HCV RNA at least 24 weeks after stopping therapy). RESULTS: SVR was achieved in 53% of children treated with PEG-2a and ribavirin, compared with 21% of children who received PEG-2a and placebo (P < .001). Early virologic response (HCV RNA reduction >2 log(10) IU at 12 weeks) had a negative predictive value of only 0.89 in children with genotype 1, indicating that these children might benefit from 24 weeks of therapy before stopping treatment. Side effects, especially neutropenia, led to dose modification in 40% of children. Eighty-two percent of the PEG/ribavirin and 86% of the PEG/placebo group were in compliance with the year 2 follow-up visit; the durability of virologic response was 100% in both groups. CONCLUSIONS: The combination of PEG and ribavirin is superior to PEG and placebo as therapy for chronic hepatitis C in children and adolescents.

Severe pandemic H1N1 and seasonal influenza in children and young adults with sickle cell disease.

Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993-2009). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P = .006) and had less asthma (24% vs 56%, P = .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P = .01) and required intensive care (17% vs 3%, P = .02), including mechanical ventilation (10% vs 0%, P = .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P = .04) and H1N1 influenza (OR 3.0, P = .04) were associated with ACS, and older age (OR 1.1 per year, P = .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented.

Cytomegalovirus DNA quantification using an automated platform for nucleic acid extraction and real-time PCR assay setup.

Analytical performance characteristics of the QIAsymphony RGQ system with artus cytomegalovirus (CMV) reagents were determined. Measurable range spanned 2.0 to ≥ 7.0 log(10) copies/ml. The detection limit was 23 copies/ml. Intrarun and interrun coefficients of variation were ≤ 2.1% at 3.0 and 5.0 log(10) copies/ml. In clinical specimens, RGQ values were ~0.2 log(10) copies/ml higher than those in an assay using a BioRobot M48 extraction/manual reaction setup/7500 Real-Time PCR instrument. No cross-contamination was observed.

Clinical performance of the GenMark Dx ePlex respiratory pathogen panels for upper and lower respiratory tract infections.

The GenMark Dx ePlex Respiratory Pathogen Panel (RP) is a multiplexed nucleic acid test for the qualitative detection of common viral and a few bacterial causes of respiratory tract infections. The ePlex RP has received FDA clearance for nasopharyngeal swab (NPS) specimens collected in viral transport media. In this study, we evaluated the performance of the ePlex RP panel in comparison to the NxTAG Respiratory Pathogen Panel (NxTAG-RPP) from Luminex in use in our laboratory, not only for NPS but also for bronchoalveolar lavage specimens (BAL). We also evaluated the impact of implementing the ePlex RP on the test turn-around time (TAT). The newest panel from GenMark Dx, the ePlex Respiratory Pathogen Panel 2 (RP2), which added the SARS-CoV-2 target to the RP was also evaluated for NPS. Verification of the performance of the ePlex RP for both NPS and BAL showed 93.3 % and 84.9 % total agreement with the NxTAG-RPP respectively. An overall comparison of the TAT after implementing the ePlex RP as compared to the NxTAG-RPP assay showed an average decrease of almost seven-fold.

Multicenter study of clinical performance of the 3M Rapid Detection RSV test.

This multicenter study evaluated the clinical performance of the 3M Rapid Detection RSV test (3MRSV) compared to a composite reference standard of R-Mix culture and direct specimen immunofluorescence for detection of respiratory syncytial virus (RSV). The performance of the BinaxNOW RSV test was also evaluated using this reference standard. In a secondary analysis, discordant results were arbitrated using the Gen-Probe/Prodesse ProFlu+ reverse transcription-PCR (RT-PCR) assay. Subjects were stratified into three groups as follows: group 1 (G1), all ages; G2, subjects <22 years old (FDA-cleared ages for 3MRSV testing); and G3, subjects <5 years old (FDA-cleared ages for BinaxNOW RSV testing). A total of 1,306 specimens (G1, n = 1,306; G2, n = 1,140; G3, n = 953) from subjects of all ages presenting with respiratory symptoms met study criteria for analysis. Sensitivities, specificities, positive predictive values, and negative predictive values of 3MRSV for G1 were 86.5%, 95.8%, 91.4%, and 93.2%, respectively, and those for G2 were 87.3%, 95.6%, 92.4%, and 92.5%, respectively. For those samples analyzed by both 3MRSV and BinaxNOW, the 3MRSV was more sensitive (G1, 86.3%; G2, 87.2%; and G3, 89.9%) than was BinaxNOW (G1, 70.84%; G2, 72.0%; and G3, 72.4%) (P < 0.05). Specificities for RSV detection from nasopharyngeal (NP) aspirates and NP swabs for all groups were comparable for 3MRSV and BinaxNOW, but 3MRSV was less specific than BinaxNOW when nasal washes/aspirates were tested (P < 0.05). The 3MRSV assay performed well for the detection of RSV, and the overall assay performance was superior to that of BinaxNOW. The 3MRSV reader eliminated user misinterpretation and provided test result and quality control documentation.

The critically ill child with novel H1N1 influenza A: a case series.

OBJECTIVE: To describe the presentation, course, and outcome of critically ill children with novel H1N1 influenza disease. DESIGN: Retrospective case series. SETTING: Pediatric intensive care unit in an urban tertiary academic center. PATIENTS: Thirteen consecutive patients admitted between June 2009 and August 2009 and known or subsequently found to be infected with novel H1N1 influenza A. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Clinical, laboratory, and radiographic data were reviewed. The patients were predominantly male (62%), aged 5 months to 21 yrs, and most (92%) had known risk factors for severe disease. Direct fluorescent antibody testing had a high false-negative rate (62%) and delayed treatment in some cases. The respiratory illness presented clinically with both bronchoconstriction and alveolar consolidation to varying degrees. Bacterial superinfection occurred frequently (23%). Forty-six percent of patients required mechanical ventilation and 23% required inotropic support for hypotension. None of the patients in this series required extracorporeal membrane oxygenation. Intensive care unit length of stay did not differ between an early (within 48 hrs) oseltamivir treatment group (length of stay, 4.2 +/- 4.4 days) vs. a late treatment group (length of stay, 6.8 +/- 8.8 days). All patients survived to hospital discharge. CONCLUSIONS: Underlying chronic illness (especially respiratory illness) seems associated with critical novel H1N1 influenza disease in children. Respiratory manifestations are highly variable among patients and within a single patient involving both bronchoconstriction and alveolar disease. Therapies must be individualized and rapidly adjusted. The duration of critical illness was not different between early and late treatment groups. Whether this is reflective of sample size or indicative of the importance of therapeutic intervention at any time early during infection in critically ill patients is unclear. Bacterial superinfection was more common than previously reported for seasonal influenza A. Moderate novel H1N1 influenza disease, including respiratory failure and hypotension, had 100% survival in our series.