Positive Respiratory Specimens Research Articles

Evaluation of the Seegene Allplex™ RV master assay for one-step simultaneous detection of eight respiratory viruses in nasopharyngeal specimens

BackgroundThe Seegene Allplex™ RV Master (RVM) assay is a one-step multiplex real-time reverse transcription polymerase chain reaction (RT-PCR) system for detecting eight viral respiratory pathogens from nasopharyngeal swab, aspirate, and bronchoalveolar lavage specimens. The eight RVM targets are: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Influenza A (Flu A), Influenza B (Flu B), Human respiratory syncytial virus (RSV), adenovirus (AdV), rhinovirus (HRV), parainfluenza virus (PIV), and metapneumovirus (MPV). The assay is based on Seegene’s multiple detection temperature (MuDT) technology and provides cycle threshold (Ct) values for each of its viral targets upon PCR completion. ObjectiveWe aimed to evaluate the diagnostic performance of the RVM assay by calculating sensitivity, specificity, accuracy, Positive Predictive Value (PPV), Negative Predictive Value (NPV), Positive Percent Agreement (PPA), Negative Percent Agreement (NPA), and Overall Percent Agreement (OPA) compared to definite diagnosis and analogous reference assays. Study designDiagnostic sensitivity, specificity, accuracy, PPV, and NPV were calculated by comparing the results of the RVM assay to that of definite diagnosis assays; while PPA, NPA, and OPA were calculated by comparing results of the RVM assay to that of analogous reference products. Definite diagnosis and reference methods comprised whole genome sequencing and PCR genotyping, the Allplex™ SARS-CoV-2/FluA/FluB/RSV and Respiratory Panels 1, 2, and 3 assays (Seegene), and the Xpert® Xpress SARS-CoV-2/FluA/FluB/RSV Plus assay (Cepheid). Reproducibility of the RVM assay using fully-automated and semi-automated nucleic acid (NA) extraction workflows and as performed by independent operators was also assessed. In total, 249 positive respiratory specimens and at least 50 negative specimens for each target tested were used for this evaluation study. ResultsSensitivity, specificity, accuracy, PPV, NPV, PPA, NPA, and OPA ranged from 95.7 % to 100 % for detecting all eight targets tested on the RVM assay. Reproducibility PPA, NPA, and OPA between automated and semi-automated NA extraction workflows were all >97.9 %, while the reproducibility PPA, NPA and OPA between independent operators were all 100 %. ConclusionThese results demonstrate a high level of sensitivity, specificity, accuracy and diagnostic predictive value of the RVM assay and high agreement with comparable reference assays in identifying all eight of its targets. Taken together, our study underscores the diagnostic utility of the RVM assay in detecting eight viral respiratory pathogens.

Two consecutive outbreaks caused by chlorhexidine mouthwash contaminated with Burkholderia contaminans in a two-hospital tertiary care system

Hospital outbreaks caused by Burkholderia spp. have been linked to contamination of several medical solutions and products and are frequently associated with delayed detection and high mortality. To describe the management of two consecutive Burkholderia contaminans outbreaks caused by contaminated mouthwash of different brands during the COVID-19 pandemic. This was a retrospective cohort study of all patients involved in two outbreaks caused by B.contaminans detected in 2021 and 2022. The investigation was initiated after a cluster of positive respiratory specimens, followed by retrospective and prospective case-finding. A total of 69 patients were affected, 47 in 2021 and 22 in 2022. The majority of affected patients had positive respiratory specimens (85.5%); 55.1% of cases had COVID-19, and 72.5% had multidrug-resistant organisms. Almost all (97.1%) patients required ventilation and 42.0% died. Seventeen percent of cases in the first outbreak were deemed to have been acquired by patient-to-patient transmission, whereas all of the cases in the second outbreak were infected directly from using mouthwash. The experience gained from the first outbreak and the formation of a multidisciplinary Infection Control Rapid Response Team resulted in more rapid recognition and control of the second outbreak. Multivariate analysis showed that older age, intensive care unit admission, and COVID-19 infection were independent predictors of mortality. Burkholderia outbreaks at the time of COVID-19 were associated with high mortality. Rapid detection and response by a dedicated experienced team (as in the second outbreak) can reduce mortality and prevent superimposed cross-transmission between patients.

Risk Factors and Mortality of Elderly Patients with Hospital-Acquired Pneumonia of Carbapenem-Resistant Klebsiella pneumoniae Infection.

Hospital-acquired pneumonia (HAP) caused by carbapenem-resistant K. pneumoniae (CRKP), especially in elderly patients, results in high morbidity and mortality. Studies on risk factors, mortality, and antimicrobial susceptibility of CRKP pulmonary infection among elderly patients are lacking. A retrospective case-control study was conducted from January 2019 to December 2021. The elderly inpatients (≥65 years) who were diagnosed with HAP caused by K. pneumoniae were enrolled. Clinical data were collected. Univariate and multivariate logistic regression analyses were used to identify risk factors. Propensity score matching was used to minimize the effect of potential confounding variables. Kaplan-Meier analysis was used to compare survival. A total of 115 patients with CRKP infection and 78 patients with carbapenem-susceptible K. pneumoniae (CSKP) infection were recruited. There were four independent risk factors for CRKP infection: history of intensive care unit (ICU) stays from hospital admission to positive respiratory specimen culture for K. pneumoniae (odds ratio (OR)=2.530), Charlson comorbidity index score ≥3 (OR = 2.420), prior exposure to carbapenems (OR = 5.280), and prior K. pneumoniae infection or colonization in the preceding 3 years (OR = 18.529). The all-cause 30-day mortality was 22.3%, the mortality of CRKP and CSKP infection was 28.7% and 12.8%, respectively. Independent risk factors for mortality included: older age (OR = 1.107), immunocompromised patients (OR = 8.632), severe pneumonia (OR = 51.244), quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥2 (OR = 6.187), exposure to tigecycline before infection (OR = 24.702), and prolonged ICU stay (OR = 0.987). Thirty-day mortality was significantly lower in patients receiving ceftazidime-avibactam (CAZ-AVI) containing regimens than patients receiving polymyxin B sulfate (PB) containing regimens (P = 0.048). qSOFA score had a good prognostic effect [area under receiver operating characteristic curve (AUROC) of 0.838]. Active screening of CRKP for the high-risk populations, especially elderly patients, is significant for early detection and successful management of CRKP infection.

Tracking SARS-CoV-2 variants through pandemic waves using RT-PCR testing in low-resource settings.

COVID-19 resulted in extensive morbidity and mortality worldwide. SARS-CoV-2 evolved rapidly, with increasing transmission due to Variants of Concern (VOC). Identifying VOC became important but genome submissions from low-middle income countries (LMIC) remained low leading to gaps in genomic epidemiology. We demonstrate the use of a specific mutation RT-PCR based approach to identify VOC in SARS-CoV-2 positive samples through the pandemic in Pakistan. We selected 2150 SARS-CoV-2 PCR positive respiratory specimens tested between April 2021 and February 2022, at the Aga Khan University Hospital Clinical Laboratories, Karachi, Pakistan. Commercially available RT-PCR assays were used as required for mutations in Spike protein (N501Y, A570D, E484K, K417N, L452R, P681R and deletion69_70) to identify Alpha, Beta, Gamma, Delta, and Omicron variants respectively. Three pandemic waves associated with Alpha, Delta and Omicron occurred during the study period. Of the samples screened, VOC were identified in 81.7% of cases comprising mainly; Delta (37.2%), Alpha (29.8%) and Omicron (17.1%) variants. During 2021, Alpha variants were predominant in April and May; Beta and Gamma variants emerged in May and peaked in June; the Delta variant peaked in July and remained predominant until November. Omicron (BA.1) emerged in December 2021 and remained predominant until February 2022. The CT values of Alpha, Beta, Gamma and Delta were all significantly higher than that of Omicron variants (p<0.0001). We observed VOC through the pandemic waves using spike mutation specific RT-PCR assays. We show the spike mutation specific RT-PCR assay is a rapid, low-cost and adaptable for the identification of VOC as an adjunct approach to NGS to effectively inform the public health response. Further, by associating the VOC with CT values of its diagnostic PCR we gain information regarding the viral load of samples and therefore the level of transmission and disease severity in the population.

Prevalence and clinical presentation of EV-D68 infections in Kansas City children during the 2022 season

Seasonal EV-D68 infections can strain medical care resources due to increased pediatric hospitalizations for respiratory illness. In this study, we examine Kansas City's 2022 EV-D68 season. Rhinovirus/enterovirus (RV/EV) positive respiratory specimens from standard of care testing were salvaged and tested by EV-D68 specific PCR. Of the 1412 respiratory specimens tested from July 1 to September 15, 2022, 346 (23%) were positive for RV/EV and EV-D68 was detected in 134/319 (42%) salvaged RV/EV positive specimens. The median age of children with EV-D68 infections was 35.2 months (IQR 16.1, 67.3), which was older than children with non-EV-D68 RV/EV infections (16 months, IQR 5, 47.8), but younger than children infected during the 2014 EV-D68 outbreak. EV-D68 infection was more likely to cause severe disease in children with asthma compared to those without asthma. Real-time EV-D68 monitoring for outbreaks could potentially improve resource utilization by hospitals and help prepare for surges of respiratory disease.

Qualitative detection of enterovirus D68 from PrimeStore® molecular transport medium: implications for home- and self-collection

To ensure proper specimen handling for detecting pathogens, like Enterovirus D68 (EV-D68), from home- and self-collection, alternative techniques are needed to ensure safe transport and reliable testing. PrimeStore® Molecular Transport Medium (MTM) may be an option since it does not require cold storage and inactivates virus while preserving RNA for detection. The purpose of this validation study was to demonstrate the ability to detect EV-D68 via rRT-PCR in MTM. Using a quantified EV-D68 positive control standard, MTM limit of detection for EV-D68 RNA is 104 cp/mL and RNA remains stable up to 30 days unfrozen. Positive and negative residual respiratory specimens from the 2018 EV-D68 outbreak were used for clinical testing. There was an 80% positive and 100% negative agreement with samples in MTM compared to reference. This study demonstrates the feasibility of EV-D68 detection from respiratory specimens collected and stored in PrimeStore® MTM, with implications for home- and self-collection.

Description, validation, and review of a decade of experience with a laboratory-developed PCR test for detection of Mycobacterium tuberculosis complex in pulmonary and extrapulmonary specimens

Rapid detection of Mycobacterium tuberculosis complex directly from clinical specimens is critical for patient care. Mycobacterial culture requires days to weeks for results and therefore many laboratories employ rapid molecular methods for the diagnosis of tuberculosis. There are two FDA-cleared molecular assays for the detection of M. tuberculosis complex in the United States and both are cleared for testing of respiratory specimens only. The detection of M. tuberculosis complex in extrapulmonary specimens is often done using laboratory-developed PCR methods. In this work, the verification and subsequent validation of test performance over a decade is detailed for a laboratory-developed PCR assay (MTBRP) that detects M. tuberculosis complex from respiratory and non-respiratory specimens. The assay also provides information about potential isoniazid resistance. The performance of the MTBRP PCR assay was compared to the Cepheid Xpert MTB/RIF assay in acid-fast smear positive and smear negative specimens and mycobacterial culture for acid-fast smear positive specimens. The MTBRP assay demonstrated 99% correlation with the Xpert MTB/RIF assay using 499 respiratory specimens. The performance of the MTBRP PCR assay compared with mycobacterial culture for 867 AFB smear positive respiratory and non-respiratory specimens demonstrated a sensitivity of 100% and a specificity of 99.1%. This work provides longitudinal evidence using real-world clinical laboratory conditions and specimens to demonstrate that laboratory-developed PCR assays such as the MTBRP can provide a rapid and sensitive method for detection of pulmonary and extra-pulmonary tuberculosis from a wide-variety of smear positive specimen sources.

From Clinical Specimen to Whole Genome Sequencing of A(H3N2) Influenza Viruses: A Fast and Reliable High-Throughput Protocol.

(1) Background: Over the last few years, there has been growing interest in the whole genome sequencing (WGS) of rapidly mutating pathogens, such as influenza viruses (IVs), which has led us to carry out in-depth studies on viral evolution in both research and diagnostic settings. We aimed at describing and determining the validity of a WGS protocol that can obtain the complete genome sequence of A(H3N2) IVs directly from clinical specimens. (2) Methods: RNA was extracted from 80 A(H3N2)-positive respiratory specimens. A one-step RT-PCR assay, based on the use of a single set of specific primers, was used to retro-transcribe and amplify the entire IV type A genome in a single reaction, thus avoiding additional enrichment approaches and host genome removal treatments. Purified DNA was quantified; genomic libraries were prepared and sequenced by using Illumina MiSeq platform. The obtained reads were evaluated for sequence quality and read-pair length. (3) Results: All of the study specimens were successfully amplified, and the purified DNA concentration proved to be suitable for NGS (at least 0.2 ng/µL). An acceptable coverage depth for all eight genes of influenza A(H3N2) virus was obtained for 90% (72/80) of the clinical samples with viral loads >105 genome copies/mL. The mean depth of sequencing ranged from 105 to 200 reads per position, with the majority of the mean depth values being above 103 reads per position. The total turnaround time per set of 20 samples was four working days, including sequence analysis. (4) Conclusions: This fast and reliable high-throughput sequencing protocol should be used for influenza surveillance and outbreak investigation.

Nontuberculous Mycobacterial Lung Disease in the Patients with Cystic Fibrosis-A Challenging Diagnostic Problem.

Background: Cystic fibrosis (CF) is an autosomal, recessive genetic disorder, caused by a mutation in the cystic fibrosis transmembrane conductance receptor regulator (CFTR) gene. Dysregulated mucous production, and decreased bronchial mucociliary clearance, results in increased susceptibility to bacterial and fungal infections. Recently, nontuberculous mycobacteria (NTM) infections were identified as an emerging clinical problem in CF patients. Aim: The aim of the present study was to assess the frequency of NTM isolations in CF patients hospitalized in the pulmonary department, serving as a hospital CF center, and to describe challenges concerning the recognition of NTMLD (nontuberculous mycobacterial lung disease) in those patients. Methods: Consecutive CF patients, who were hospitalized due to pulmonary exacerbations (PEX), in a single CF center, between 2010 and 2020, were retrospectively assessed for the presence of NTM in respiratory specimens. Clinical and radiological data were retrospectively reviewed. Results: Positive respiratory specimen cultures for NTM were obtained in 11 out of 151 patients (7%), mean age—35.7 years, mean BMI—20.2 kg/m2, mean FEV1—58.6% pred. Cultures and phenotyping revealed the presence of Mycobacterium avium (M. avium)—in six patients, Mycobacterium chimaera (M. chimaera) in two, Mycobacterium kansasii (M. kansasii)—in one, Mycobacterium abscessus (M. abscessus)—in one, Mycobacterium lentifavum (M. lentiflavum)—in one. Simultaneously, respiratory cultures were positive for fungi in 91% of patients: Candida albicans (C. albicans)—in 82%, Aspergillus fumigatus (A. fumigatus)—in 45%. Clinical signs of NTMLD were non—specific, chest CT indicated NTMLD in five patients only. Conclusion: Due to non-specific clinical presentation, frequent sputum cultures for NTM and analysis of serial chest CT examinations are crucial for NTMLD recognition in CF patients. Further studies concerning the predictive role of fungal pathogens for NTMLD development in CF patients are needed.

Duration of respiratory sample stability at -80ºC for SARS-CoV-2 PCR.

Objective:To determine the stability of respiratory samples for SARS-CoV-2 PCR at standard laboratory ultra-freezer temperatures (-80°C).Methods:Five hundred and sixty-five archived, SARS-CoV-2 PCR positive patient specimens received at the Pathology Department of the Indus Hospital & Health Network between January 2021 and June 2021 were retested in June 2021. Samples had been stored at -70°C or below throughout this duration. Sample integrity following storage was assessed as the percentage of samples with reproducible results, and as consistency of cycle threshold (Ct) values between the original testing and the repeat testing.Results:Of the 565 samples evaluated in this study, 86% gave reproducible results upon retesting. However, there was no correlation between the duration of storage and result reproducibility, though the majority (69% for PCR Target-I and 78% for PCR Target-II respectively) of non-reproducible results had Ct values above 30. Similarly, there was a consistent increase of Ct values upon storage at ultra-freezer temperatures, though the effect again was more contingent upon freezing the sample in the ultra-freezer rather than the duration of storage.Conclusion:SARS-CoV-2 positive respiratory specimens for PCR can be stored for up to six months at -70°C or below without loss of sample integrity, though there is some loss of PCR-detected viral targets as evidenced by an immediate increased in the PCR-generated Ct values. In addition, samples with initial Ct values above 30 are more likely to give non-reproducible results.

Assessment of a Hotel-Based Protective Housing Program for Incidence of SARS-CoV-2 Infection and Management of Chronic Illness Among Persons Experiencing Homelessness

Persons experiencing homelessness (PEH) are at higher risk for SARS-CoV-2 infection and severe illness due to COVID-19 because of a limited ability to physically distance and a higher burden of underlying health conditions. To describe and assess a hotel-based protective housing intervention to reduce incidence of SARS-CoV-2 infection among PEH in Chicago, Illinois, with increased risk of severe illness due to COVID-19. This retrospective cohort study analyzed PEH who were provided protective housing in individual hotel rooms in downtown Chicago during the COVID-19 pandemic from April 2 through September 3, 2020. Participants were PEH at increased risk for severe COVID-19, defined as (1) aged at least 60 years regardless of health conditions, (2) aged at least 55 years with any underlying health condition posing increased risk, or (3) aged less than 55 years with any underlying health condition posing substantially increased risk (eg, HIV/AIDS). Participants were housed in individual hotel rooms to reduce the risk of SARS-CoV-2 infection; on-site health care workers provided daily symptom monitoring, regular SARS-CoV-2 testing, and care for chronic health conditions. Additional on-site services included treatment of mental health and substance use disorders and social services. The main outcome measured was SARS-CoV-2 incidence, with SARS-Cov2 infection defined as a positive upper respiratory specimen using any polymerase chain reaction diagnostic assay authorized for emergency use by the Food and Drug Administration. Secondary outcomes were blood pressure control, glycemic control as measured by hemoglobin A1c, and housing placements at departure. Of 259 participants from 16 homeless shelters in Chicago, 104 (40.2%) were aged at least 65 years, 190 (73.4%) were male, 185 (71.4%) were non-Hispanic Black, and 49 (18.9%) were non-Hispanic White. There was an observed reduction in SARS-CoV-2 incidence during the study period among the protective housing cohort (54.7 per 1000 people [95% CI, 22.4-87.1 per 1000 people]) compared with citywide rates for PEH residing in shelters (137.1 per 1000 people [95% CI, 125.1-149.1 per 1000 people]; P = .001). There was also an adjusted change in systolic blood pressure at a rate of -5.7 mm Hg (95% CI, -9.3 to -2.1 mm Hg) and hemoglobin A1c at a rate of -1.4% (95% CI, -2.4% to -0.4%) compared with baseline. More than half of participants (51% [n = 132]) departed from the intervention to housing of some kind (eg, supportive housing). This cohort study found that protective housing was associated with a reduction in SARS-CoV-2 infection among high-risk PEH during the first wave of the COVID-19 pandemic in Chicago. These findings suggest that with appropriate wraparound supports (ie, multisector services to address complex needs), such housing interventions may reduce the risk of SARS-CoV-2 infection, improve noncommunicable disease control, and provide a pathway to permanent housing.

A low-cost TaqMan minor groove binder probe-based one-step RT-qPCR assay for rapid identification of N501Y variants of SARS-CoV-2

The increasing prevalence of N501Y variants of SARS-CoV-2 has kindled global concern due to their enhanced transmissibility. Genome sequencing is the gold standard method to identify the emerging variants of concern. But it is time-consuming and expensive, limiting the widespread deployment of genome surveillance in some countries. Health authorities surge the development of alternative assay to expand screening capacity with reduced time and cost. In this study, we developed an in-house TaqMan minor groove binder (MGB) probe-based one-step RT-qPCR assay to detect the presence of N501Y mutation in SARS-CoV-2.A total of 168 SARS-CoV-2 positive respiratory specimens were collected to determine diagnostic accuracy of the RT-qPCR assay. As a reference standard, PANGO lineages and the mutation patterns of all samples were characterised by whole-genome sequencing. The analytical sensitivity and the ability of the assay to detect low frequency of N501Y variants were also evaluated.A total of 31 PANGO lineages were identified from 168 SARS-CoV-2 positive cases, in which 34 samples belonged to N501Y variants, including B.1.1.7 (n = 20), B.1.351 (n = 12) and P.3 (n = 2). The N501Y RT-qPCR correctly identified all 34 samples as N501Y-positive and the other 134 samples as wildtype. The limit-of-detection of the assay consistently achieved 1.5 copies/μL on four different qPCR platforms. N501Y mutation was successfully detected at an allele frequency as low as 10 % in a sample with mixed SARS-CoV-2 lineage.The N501Y RT-qPCR is simple and inexpensive (US$1.6 per sample). It enables robust high-throughput screening for surveillance of SARS-CoV-2 variants of concern harbouring N501Y mutation.

Post-exposure prophylaxis against SARS-CoV-2 in close contacts of confirmed COVID-19 cases (CORIPREV): study protocol for a cluster-randomized trial

BackgroundPost-exposure prophylaxis (PEP) is a well-established strategy for the prevention of infectious diseases, in which recently exposed people take a short course of medication to prevent infection. The primary objective of the COVID-19 Ring-based Prevention Trial with lopinavir/ritonavir (CORIPREV-LR) is to evaluate the efficacy of a 14-day course of oral lopinavir/ritonavir as PEP against COVID-19 among individuals with a high-risk exposure to a confirmed case.MethodsThis is an open-label, multicenter, 1:1 cluster-randomized trial of LPV/r 800/200 mg twice daily for 14 days (intervention arm) versus no intervention (control arm), using an adaptive approach to sample size calculation. Participants will be individuals aged > 6 months with a high-risk exposure to a confirmed COVID-19 case within the past 7 days. A combination of remote and in-person study visits at days 1, 7, 14, 35, and 90 includes comprehensive epidemiological, clinical, microbiologic, and serologic sampling. The primary outcome is microbiologically confirmed COVID-19 infection within 14 days after exposure, defined as a positive respiratory tract specimen for SARS-CoV-2 by polymerase chain reaction. Secondary outcomes include safety, symptomatic COVID-19, seropositivity, hospitalization, respiratory failure requiring ventilator support, mortality, psychological impact, and health-related quality of life. Additional analyses will examine the impact of LPV/r on these outcomes in the subset of participants who test positive for SARS-CoV-2 at baseline. To detect a relative risk reduction of 40% with 80% power at α = 0.05, assuming the secondary attack rate in ring members (p0) = 15%, 5 contacts per case and intra-class correlation coefficient (ICC) = 0.05, we require 110 clusters per arm, or 220 clusters overall and approximately 1220 enrollees after accounting for 10% loss-to-follow-up. We will modify the sample size target after 60 clusters, based on preliminary estimates of p0, ICC, and cluster size and consider switching to an alternative drug after interim analyses and as new data emerges. The primary analysis will be a generalized linear mixed model with logit link to estimate the effect of LPV/r on the probability of infection. Participants who test positive at baseline will be excluded from the primary analysis but will be maintained for additional analyses to examine the impact of LPV/r on early treatment.DiscussionHarnessing safe, existing drugs such as LPV/r as PEP could provide an important tool for control of the COVID-19 pandemic. Novel aspects of our design include the ring-based prevention approach, and the incorporation of remote strategies for conducting study visits and biospecimen collection.Trial registrationThis trial was registered at www.ClinicalTrials.gov (NCT04321174) on March 25, 2020.

Shedding of Culturable Virus, Seroconversion, and 6-Month Follow-up Antibody Responses in the First 14 Confirmed Cases of Coronavirus Disease 2019 in the United States.

We aimed to characterize presence of culturable virus in clinical specimens during acute illness, and antibody kinetics up to six months post-onset, among 14 early US COVID-19 patients. We isolated viable SARS-CoV-2 from rRT-PCR-positive respiratory specimens collected during days 0-8 post-onset, but not after. All 13 patients with two or more serum specimens developed anti-spike antibodies; 12 developed detectable neutralizing antibodies. We did not isolate virus after detection of neutralizing antibodies. Eight participants provided serum at six months post-onset; all retained detectable anti-spike IgG, and half had detectable neutralizing antibodies. Two participants reported not feeling fully recovered at six months.

358. Sociodemographic and clinical features of children and adolescents with SARS-CoV-2 infection in Nashville, Tennessee

BackgroundLittle is known regarding the full spectrum of illness among children with SARS-CoV-2 infection across integrated healthcare settings, as many published pediatric cohorts focus on hospitalized patients with SARS-CoV-2 infection.MethodsActive surveillance was performed for SARS-CoV-2 detections among symptomatic and asymptomatic children and adolescents ≤18 years of age in a quaternary care academic hospital laboratory in the Southeastern U.S. For symptomatic patients with a positive respiratory specimen for SARS-CoV-2 by polymerase chain reaction (PCR), and for neonates born to SARS-CoV-2-positive mothers, we performed phone follow-up and medical record review at days 2, 7, and 30 after diagnosis. Testing was initiated 3/12/20 for symptomatic patients and 5/4/20 for screening asymptomatic patients.ResultsBy 6/14/20, SARS-CoV-2 tests were positive in 193/5306 (3.6%) specimens from unique patients ≤18 (Table 1), compared to 2653/36503 (7.2%) specimens in patients >18 years. Specimens from 181/2638 (6.8%) symptomatic and 12/2768 (0.4%) asymptomatic children were positive. Nine infants born to SARS-CoV-2 infected mothers had negative PCR tests at birth; 1 infant subsequently acquired SARS-CoV-2 infection at 5 weeks of age. Sociodemographic and clinical data for 181 SARS-CoV-2-positive symptomatic children are displayed in Table 2 and Figure 1. The most common symptoms were cough (59%), fever (50%), and rhinorrhea (39%). Nine/181 symptomatic patients (5%) were hospitalized, primarily for respiratory symptoms. Symptom resolution occurred by follow-up day 2 in 82/178 (46%) and day 7 in 128/164 (78%) patients with complete assessments to date. 131/181 (72%) of children had known SARS-CoV-2 positive contacts. We observed no cases of multisystem inflammatory syndrome in children. ConclusionIn our community, pediatric SARS-CoV-2 prevalence was low, but was much higher among symptomatic than asymptomatic children. Symptoms were mild, and the duration of symptoms brief, in the majority of these patients captured within an integrated ambulatory and hospital-based healthcare system, capturing the full spectrum of the disease profile in this age group.Disclosures Natasha B. Halasa, MD, MPH, Genentech (Other Financial or Material Support, I receive an honorarium for lectures - it’s a education grant, supported by genetech)Karius (Consultant)Moderna (Consultant)Quidel (Grant/Research Support, Research Grant or Support)Sanofi (Grant/Research Support, Research Grant or Support)

Global Seasonality of Human Coronaviruses: A Systematic Review.

In the context of the coronavirus disease 2019 pandemic, we aimed to systematically address the global seasonal patterns of human coronavirus (HCoV) infections. We identified relevant articles from MEDLINE, EMBASE, and CINAHL Plus as of May 11, 2020. The main outcomes were the peak months of HCoV infections each year and the months during which more than 5% of positive respiratory specimen tests were attributable to HCoV. Of 707 articles reviewed, 22 met the inclusion criteria. The annual percentage of HCoV infections reached a peak in February globally. We found a higher HCoV positivity rate among studies that tested only children (median: 5.9%, range: 0.9%–18.4%), compared with other studies of adults alone (median: 5.2%, range: 3.3%–7.1%) or the entire population (median: 1.9%, range: 0.2%–8.1%). We found the largest global peak of HCoV during the winter season, with the highest rate of positivity among children.

Evaluation of SARS-CoV-2 viral RNA in fecal samples

The need for timely establishment of a complete diagnostic protocol of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is demanded worldwide. We selected 15 positive novel coronavirus disease 19 (COVID-19) patients with mild or no symptom. Initially, fecal samples were negative in the 67% (10/15) of the cases, while 33% (5/10) of the cases were positive. After serial virus RNA testing, 73% (11/15) of the cases resulted positive to fecal specimens. In particular, 15 days after the first positive respiratory specimens test, 6 fecal specimens became positive for SARS-CoV-2 RNA, while 13 respiratory test returned negative result. In conclusion, qRT-PCR assays of fecal specimens, is an important step to control infection, suggesting that samples remained positive for SARS-CoV-2 RNA longer time then respiratory tract samples. Our results enhance the recent knowledge on this emerging infectious disease and offer suggestions for a more complete diagnostic strategy.

Clinical relevance and impact of Corynebacterium isolation in lower respiratory tract of critically ill patients requiring mechanical ventilation.

PurposeCorynebacterium spp. (C. spp.) is commonly considered as a contaminant in respiratory specimens. No study has ever focused on its clinical relevance in the lower respiratory tract of patients admitted to the intensive care unit (ICU) and requiring mechanical ventilation. The aims were to describe the characteristics of ICU patients with a C. spp. positive deep respiratory specimen, to investigate the impact of C. spp. on the occurrence of pneumonia, and to evaluate the outcomes of these pneumonia.MethodsWe retrospectively included all adult patients admitted to ICU in a 1000-bed University Hospital (2007–2017) who had a C. spp. positive lower respiratory tract specimen at a significant quantitative level. We used clinical, radiological, and microbiological criteria to classify the likelihood of such pneumonia.ResultsAmong the 31 patients included, acute respiratory failure and postoperative care after major surgery were the main reasons of admission. SAPS II was 47 [34–60]. C. spp. pneumonia was considered as probable, possible and unlikely in 10, 14, and 7 patients, respectively. Fifty-two and 94% of C. spp. strains were sensitive to amoxicillin, and vancomycin/linezolid, respectively. Seventeen patients had a complete course of antibiotic against C. spp. The overall ICU mortality was 58%.ConclusionCorynebacterium spp seems to be responsible for authentic pneumonia in mechanically ventilated patients. It should be considered as clinically relevant when predominantly present in respiratory specimen from patients suspected with pneumonia in ICU, and empirically treated.

Abstract P113: Increased Incidence of Atrial Fibrillation During Periods of High Influenza Activity

Introduction: Influenza is an important inflammatory illness which results in 3 to 5 million cases of severe illness, and 290,000 to 650,000 deaths per year, worldwide. Influenza’s role in triggering acute coronary syndromes is well established, but influenza’s impact on cardiac arrhythmias has yet to be investigated. Hypothesis: We investigated the effect of influenza on triggering atrial fibrillation (AFib) episodes. Methods: This retrospective observational study included de-identified data from patients who had a Zio patch (iRhythm Technologies, San Francisco), a wearable continuous cardiac monitoring device. Data were available from October 2012 to September 2017. The “influenza activity” was defined as the percentage of positive respiratory specimens that tested for influenza virus during each influenza season reported by the Centers for Disease Control and Prevention (CDC). We included all cases with AFib burden &lt;=90% from the weeks with the highest and lowest influenza activity up to two consecutive weeks after them. An independent-samples t-test was used to compare the burden of AFib in weeks with the highest and lowest influenza activity. Results: We reviewed the records of 825,869 patients (mean age= 61.1 ± 15.3 years; 48.8% male) who had a Zio patch from October 2012 to September 2017. Of these patients, 47,106 met the pre-defined inclusion criteria for our study. There was a significant difference in the AFib burden in high influenza activity (Mean=1.19, SD=0.69) and low influenza activity (Mean=1.03, SD=0.63) conditions; t (47104) = -2.6, p =0.009. The incidence of AFib was 15% higher in high influenzas activity weeks (OR=1.15, 95%CI, 1.03-1.19, p=0.009). The higher burden of AFib in high influenza activity weeks was significant for each influenza season and a similar trend was observed consistently in each individual influenza season. Conclusions: High seasonal influenza activity is associated with increased odds of AFib. Prospective studies are needed to determine the clinical implications of this finding.

2448. Clinical Presentation and Outcomes of Long-Term Care Residents with Coronavirus Respiratory Infection: A Retrospective Cohort Study

BackgroundHuman coronaviruses (CoVs) are a major cause of respiratory infection and institutional outbreaks, yet the epidemiology and clinical outcomes of these viruses is poorly described among the elderly residing in long-term care facilities (LTCFs).MethodsWe performed a retrospective cohort study of LTCF residents with positive nasopharyngeal or mid-turbinate swabs for CoVs (OC43, 229E, NL63 and HKU1) between January 2013 and December 2018. Demographic and clinical data were obtained from resident charts including clinical presentation, treatment, outcome, and transmission to other residents. Variables were compared using univariate analysis.Results3268 residents met inclusion criteria (median age 93 years, 90% male) comprising 7.5% (246/3268) of all positive respiratory virus specimens detected during the study period. 97(39%) of cases were associated with a respiratory outbreak while 149(61%) were sporadic cases that did not result in transmission. OC43 (52%) was the most commonly identified CoV and was more commonly associated with outbreak cases (76% vs. 37%; P < 0.001). In total, 87% of all cases had two or more of runny nose/congestion, cough, sore throat/hoarse voice or fever. The most common symptoms among residents were cough (85%), runny nose/congestion (79%), and sore throat/hoarse voice (59%) and only 17% of residents had a measured temperature of ≥ 37.8C. Only 6% of residents received antibiotic treatment for suspected secondary bacterial pneumonia. The 30-day mortality rate was 3.7% with 67% of deaths attributable to the CoV infection. There was no statistically significant difference in symptoms, treatment or outcomes associated with outbreaks or seasonality.ConclusionCoVs make up an important proportion of respiratory viral infections among LTCF residents and may result in frequent outbreaks. Most residents remain afebrile and have self-limited illness while only a small minority develop secondary bacterial pneumonia and death. Given these findings the benefits of control measures should be weighed against the impact on resident quality of life.Disclosures All authors: No reported disclosures.