The potential benefits of delaying seasonal influenza vaccine selections for the Northern Hemisphere: a retrospective modeling study in the United States

BACKGROUNDS

Antigenic similarity between vaccine viruses and circulating viruses is crucial for achieving high vaccine effectiveness against seasonal influenza. New non-egg-based vaccine production technologies could revise current vaccine formulation schedules. We aim to assess the potential benefit of delaying seasonal influenza vaccine virus selection decisions.

METHODS

We identified seasons where season-dominant viruses presented increasing prevalence after vaccine formulation had been decided in February for the Northern Hemisphere, contributing to their antigenic discrepancy with vaccine viruses. Using a SEIR model of seasonal influenza in the United States, we evaluated the impact of updating vaccine decisions with more antigenically-similar vaccine viruses on the influenza burden in the United States.

RESULTS

In 2014/15 and 2019/20, the season-dominant A(H3N2) subclade and B/Victoria clade respectively presented increasing prevalence after vaccine decisions were already made for the Northern Hemisphere. Our model showed that the updated A(H3N2) vaccine could have averted 5,000-65,000 influenza hospitalizations in the United States in 2014/15, whereas updating the B/Victoria vaccine component did not substantially change influenza burden in 2019/20 season.

CONCLUSIONS

With rapid vaccine production, revising current timelines for vaccine selection could result in substantial epidemiological benefits, particularly when additional data could help improve the antigenic match between vaccine and circulating viruses.

Microbiota Predict Infections and Acute Graft-Versus-Host Disease After Pediatric Allogeneic Hematopoietic Stem Cell Transplantation

BACKGROUND

Despite preventive measures, infections continue to pose significant risks to pediatric allogeneic hematopoietic cell transplantation (allo-HCT) recipients. The gut microbiota has been linked to clinical outcomes following adult allo-HCT. This study evaluated whether similar disruptions or differing microbiota patterns were associated with infection risk in pediatric allo-HCT.

METHODS

In a prospective observational study, fecal samples were obtained from 74 children before conditioning and upon neutrophil recovery. Microbiome signatures identified through sequencing were examined for their associations with infections or acute graft-versus-host disease (aGVHD) in the first-year post-HCT using Cox proportional hazards analysis.

RESULTS

Microbiome disruption in adults, did not predict infection risk in pediatric allo-HCT. Unique microbiota signatures were associated with different infections or aGVHD. A ratio of strict and facultative anaerobes (eg, Lachnoclostridium, Parabacteroides) prior to conditioning predicted bacteremia risk (Cox hazard ratio [HR], 3.89). A distinct ratio of oral (eg, Rothia, Veillonella) to intestinal anaerobes (eg, Anaerobutyricum, Romboutsia) at neutrophil recovery predicted likelihood of bacterial infections (Cox HR, 1.81) and viral enterocolitis (Cox HR, 1.96).

CONCLUSIONS

Interactions between medical interventions, pediatric hosts, and microbial communities contribute to microbiota signatures that predict infections. Further multicenter study is necessary to validate the generalizability of these ratios as biomarkers.

SARS-CoV-2 RNA positive pediatric organ donors: A case report

BACKGROUND

Preliminary evidence suggests that non-lung organ donation from resolved, asymptomatic or mildly symptomatic SARS-CoV-2 infected adults may be safe. However, several biological aspects of SARS-CoV-2 infection differ in children and the risk for transmission and outcomes of recipients from pediatric donors with SARS-CoV-2 infection are not well described.

METHODS

We report two unvaccinated asymptomatic pediatric non-lung organ deceased donors who tested positive for SARS-CoV-2 RNA by RT-PCR. Donor One unexpectedly had SARS-CoV-2 RNA detected in nasopharyngeal swab and plasma specimens at autopsy despite several negative tests (upper and lower respiratory tract) in the days prior to organ recovery. Donor Two had SARS-CoV- 2 RNA detected in multiple nasopharyngeal swabs but not lower respiratory tract specimens (endotracheal aspirate and bronchoalveolar lavage) during routine surveillance prior to organ recovery and was managed with remdesivir and monoclonal antibodies prior to organ recovery.

RESULTS

Two hearts, two livers and four kidneys were successfully transplanted into seven recipients. No donor to recipient transmission of SARS-CoV-2 was observed and graft function of all organs has remained excellent for up to 7 months of followup.

CONCLUSIONS

Due to the persistent gap between organ availability and the number of children waiting for transplants, deceased pediatric patients with non-disseminated SARS-CoV-2 infection, isolated to upper and/or lower respiratory tract, should be considered as potential non-lung organ donors.

CASCADIA: a prospective community-based study protocol for assessing SARS-CoV-2 vaccine effectiveness in children and adults using a remote nasal swab collection and web-based survey design

INTRODUCTION

Although SARS-CoV-2 vaccines were first approved under Emergency Use Authorization by the Food and Drug Administration in late 2020 for adults, authorisation for young children 6 months to <5 years of age did not occur until 2022. These authorisations were based on clinical trials, understanding real-world vaccine effectiveness (VE) in the setting of emerging variants is critical. The primary goal of this study is to evaluate SARS-CoV-2 VE against infection among children aged >6 months and adults aged <50 years.

METHODS

CASCADIA is a 4-year community-based prospective study of SARS-CoV-2 VE among 3500 adults and paediatric populations aged 6 months to 49 years in Oregon and Washington, USA. At enrolment and regular intervals, participants complete a sociodemographic questionnaire. Individuals provide a blood sample at enrolment and annually thereafter, with optional blood draws every 6 months and after infection and vaccination. Participants complete weekly self-collection of anterior nasal swabs and symptom questionnaires. Swabs are tested for SARS-CoV-2 and other respiratory pathogens by reverse transcription-PCR, with results of selected pathogens returned to participants; nasal swabs with SARS-CoV-2 detected will undergo whole genome sequencing. Participants who test positive for SARS-CoV-2 undergo serial swab collection every 3 days for 21 days. Serum samples are tested for SARS-CoV-2 antibody by binding and neutralisation assays.

ANALYSIS

The primary outcome is SARS-CoV-2 infection. Cox regression models will be used to estimate the incidence rate ratio associated with SARS-CoV-2 vaccination among the paediatric and adult population, controlling for demographic factors and other potential confounders.

ETHICS AND DISSEMINATION

All study materials including the protocol, consent forms, data collection instruments, participant communication and recruitment materials, were approved by the Kaiser Permanente Interregional Institutional Review Board, the IRB of record for the study. Results will be disseminated through peer-reviewed publications, presentations, participant newsletters and appropriate general news media.

Incidence of SARS-CoV-2 infection and associated risk factors among staff and residents at homeless shelters in King County, Washington: an active surveillance study

Homeless shelter residents and staff may be at higher risk of SARS-CoV-2 infection. However, SARS-CoV-2 infection estimates in this population have been reliant on cross-sectional or outbreak investigation data. We conducted routine surveillance and outbreak testing in 23 homeless shelters in King County, Washington, to estimate the occurrence of laboratory-confirmed SARS-CoV-2 infection and risk factors during 1 January 2020-31 May 2021. Symptom surveys and nasal swabs were collected for SARS-CoV-2 testing by RT-PCR for residents aged ≥3 months and staff. We collected 12,915 specimens from 2,930 unique participants. We identified 4.74 (95% CI 4.00-5.58) SARS-CoV-2 infections per 100 individuals (residents: 4.96, 95% CI 4.12-5.91; staff: 3.86, 95% CI 2.43-5.79). Most infections were asymptomatic at the time of detection (74%) and detected during routine surveillance (73%). Outbreak testing yielded higher test positivity than routine surveillance (2.7% versus 0.9%). Among those infected, residents were less likely to report symptoms than staff. Participants who were vaccinated against seasonal influenza and were current smokers had lower odds of having an infection detected. Active surveillance that includes SARS-CoV-2 testing of all persons is essential in ascertaining the true burden of SARS-CoV-2 infections among residents and staff of congregate settings.

Streptococcus pneumoniae nasal carriage patterns with and without common respiratory virus detections in households in Seattle, WA, USA before and during the COVID-19 pandemic

Background

Respiratory viruses might influence Streptococcus pneumoniae nasal carriage and subsequent disease risk. We estimated the association between common respiratory viruses and semiquantitative S. pneumoniae nasal carriage density in a household setting before and during the COVID-19 pandemic.

Methods

From November 2019-June 2021, we enrolled participants in a remote household surveillance study of respiratory pathogens. Participants submitted weekly reports of acute respiratory illness (ARI) symptoms. Mid-turbinate or anterior nasal swabs were self-collected at enrollment, when ARI occurred, and, in the second year of the study only, from household contacts after SARS-CoV-2 was detected in a household member. Specimens were tested using multiplex reverse-transcription PCR for respiratory pathogens, including S. pneumoniae, rhinovirus, adenovirus, common human coronavirus, influenza A/B virus, respiratory syncytial virus (RSV) A/B, human metapneumovirus, enterovirus, and human parainfluenza virus. We estimated differences in semiquantitative S. pneumoniae nasal carriage density, estimated by the inverse of S. pneumoniae relative cycle threshold (Crt) values, with and without viral detection for any virus and for specific respiratory viruses using linear generalized estimating equations of S. pneumoniae Crt values on virus detection adjusted for age and swab type and accounting for clustering of swabs within households.

Results

We collected 346 swabs from 239 individuals in 151 households that tested positive for S. pneumoniae (n = 157 with and 189 without ≥1 viruses co-detected). Difficulty breathing, cough, and runny nose were more commonly reported among individuals with specimens with viral co-detection compared to without (15%, 80% and 93% vs. 8%, 57%, and 51%, respectively) and ear pain and headache were less commonly reported (3% and 26% vs. 16% and 41%, respectively). For specific viruses among all ages, semiquantitative S. pneumoniae nasal carriage density was greater with viral co-detection for enterovirus, RSV A/B, adenovirus, rhinovirus, and common human coronavirus (P < 0.01 for each). When stratified by age, semiquantitative S. pneumoniae nasal carriage density was significantly greater with viral co-detection among children aged <5 (P = 0.002) and 5-17 years (P = 0.005), but not among adults aged 18-64 years (P = 0.29).

Conclusion

Detection of common respiratory viruses was associated with greater concurrent S. pneumoniae semiquantitative nasal carriage density in a household setting among children, but not adults.

Care-seeking correlates of acute respiratory illness among sheltered adults experiencing homelessness in Seattle, WA, 2019: a community-based cross-sectional study

Objective

Multifarious barriers to accessing healthcare services among people experiencing homelessness (PEH) lead to delays in seeking care for acute infections, including those caused by respiratory viruses. PEH are at high risk of acute respiratory illness (ARI)-related complications, especially in shelter settings that may facilitate virus spread, yet data characterizing healthcare utilization for ARI episodes among sheltered PEH remained limited.

Methods

We conducted a cross-sectional study of viral respiratory infection among adult residents at two homeless shelters in Seattle, Washington between January and May 2019. We assessed factors associated with seeking medical care for ARI via self-report. We collected illness questionnaires and nasal swabs were tested for respiratory viruses by reverse transcription quantitative real-time PCR (RT-qPCR).

Results

We observed 825 encounters from 649 unique participants; 241 (29.2%) encounters reported seeking healthcare for their ARI episode. Seasonal influenza vaccine receipt (adjusted prevalence ratio [aPR] 1.39, 95% CI 1.02-1.88), having health insurance (aPR 2.77, 95% CI 1.27-6.02), chronic lung conditions (aPR 1.55, 95% CI 1.12-2.15), and experiencing influenza-like-illness symptoms (aPR 1.63, 95% CI 1.20 - 2.20) were associated with increased likelihood of seeking care. Smoking (aPR 0.65, 95% CI 0.45-0.92) was associated with decreased likelihood of seeking care.

Discussion

Findings suggest that care seeking for viral respiratory illness among PEH may be supported by prior engagement with primary healthcare services. Strategies to increase healthcare utilization may lead to earlier detection of respiratory viruses.

Nausea, Vomiting, and Diarrhea Are Common in Community-Acquired Acute Viral Respiratory Illness

BACKGROUND

Gastrointestinal (GI) symptoms are recognized sequelae of acute respiratory illness (ARI), but their prevalence is not well documented. Our study aim was to assess the incidence of GI symptoms in community ARI cases for persons of all ages and their association with clinical outcomes.

METHODS

We collected mid-nasal swabs, clinical, and symptom data from Seattle-area individuals during the 2018-2019 winter season as part of a large-scale prospective community surveillance study. Swabs were tested by polymerase chain reaction (PCR) for 26 respiratory pathogens. Likelihood of GI symptoms given demographic, clinical, and microbiological covariates were analyzed with Fisher's exact, Wilcoxon-rank-sum, and t-tests and multivariable logistic regression.

RESULTS

In 3183 ARI episodes, 29.4% had GI symptoms (n = 937). GI symptoms were significantly associated with pathogen detection, illness interfering with daily life, seeking care for the illness, and greater symptom burden (all p < 0.05). Controlling for age, > 3 symptoms, and month, influenza (p < 0.001), human metapneumovirus (p = 0.004), and enterovirus D68 (p = 0.05) were significantly more likely to be associated with GI symptoms than episodes with no pathogen detected. Seasonal coronaviruses (p = 0.005) and rhinovirus (p = 0.04) were significantly less likely to be associated with GI symptoms.

CONCLUSION

In this community-surveillance study of ARI, GI symptoms were common and associated with illness severity and respiratory pathogen detection. GI symptoms did not track with known GI tropism, suggesting GI symptoms may be nonspecific rather than pathogen-mediated. Patients presenting with GI and respiratory symptoms should have respiratory virus testing, even if the respiratory symptom is not the primary concern.

Paediatric healthcare and hospital worker SARS-CoV-2 IgG antibody: A longitudinal cohort study

Background

This study sought to determine the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) nucleocapsid (N) and spike (S) protein immunoglobulin G (IgG) antibodies in healthcare and hospital workers (HCHWs), and changes in IgG N antibody levels over time.

Methods

Longitudinal study of HCHWs at a freestanding, urban paediatric tertiary care hospital. Asymptomatic HCHWs aged ≥18 years working in clinical areas were eligible to enrol. Participants completed four surveys and blood draws over 12 months. Specimens were tested for IgG N at four timepoints and IgG S at 12 months.

Results

In total, 531 HCHWs enrolled in this study; of these, 481 (91%), 429 (81%) and 383 (72%) completed follow-up blood draws at 2, 6 and 12 months, respectively. Five of 531 (1%), 5/481 (1%), 6/429 (1%) and 5/383 (1.3%) participants were seropositive for IgG N at baseline, 2, 6 and 12 months, respectively. All (374/374; 100%) participants who received one or two doses of either mRNA COVID-19 vaccine were seropositive for IgG S. One of nine unvaccinated participants was seropositive for IgG S.

Conclusions

In this paediatric hospital, IgG N and IgG S were detected in 1.9% and 97.9% of HCHWs, respectively. This study demonstrated low transmission of SARS-CoV-2 among HCHWs with appropriate infection prevention measures.

Respiratory syncytial virus and other respiratory virus infections in residents of homeless shelters - King County, Washington, 2019-2021

Respiratory syncytial virus (RSV) causes disproportionate morbidity and mortality in vulnerable populations. We tested residents of homeless shelters in Seattle, Washington for RSV in a repeated cross-sectional study as part of community surveillance for respiratory viruses. Of 15 364 specimens tested, 35 had RSV detected, compared to 77 with influenza. The most common symptoms for both RSV and influenza were cough and rhinorrhea. Many individuals with RSV (39%) and influenza (58%) reported that their illness significantly impacted their ability to perform their regular activities. RSV and influenza demonstrated similar clinical presentations and burden of illness in vulnerable populations living in congregate settings.

Respiratory Syncytial Virus-An Update for Prenatal and Primary Health Providers

Respiratory syncytial virus (RSV) infection is a significant cause of morbidity and mortality among infants aged younger than 1 year, adults aged 65 years or older, and immunocompromised persons. Limited data exist on RSV infection in pregnancy and further research is needed. Strides are being made to develop vaccines, including vaccines for maternal immunization, as well as monoclonal antibodies for disease prevention.

Evaluation of clinical case definitions for respiratory syncytial virus lower respiratory tract infection in young children

BACKGROUND

Various case definitions of respiratory syncytial virus lower respiratory tract infection (RSV-LRTI) are currently proposed. We assessed the performance of three clinical case definitions against the World Health Organization definition recommended in 2015 (WHO 2015).

METHODS

In this prospective cohort study conducted in eight countries, 2401 children were followed up during 2 years from birth. Suspected LRTIs were detected via active and passive surveillance, followed by in-person clinical evaluation including single timepoint respiratory rate and oxygen saturation (by pulse oximetry) assessment, and nasopharyngeal sampling for RSV testing by polymerase chain reaction. Agreement between case definitions was evaluated using Cohen's κ statistics.

RESULTS

Of 1652 suspected LRTIs, 227 met the WHO 2015 criteria for RSV-LRTI; 73 were classified as severe. All alternative definitions were highly concordant with the WHO 2015 definition for RSV-LRTI (κ: 0.95-1.00), but less concordant for severe RSV-LRTI (κ: 0.47-0.82). Tachypnea was present for 196/226 (86.7%) WHO 2015 RSV-LRTIs and 168/243 (69.1%) LRTI/bronchiolitis/pneumonia cases, clinically diagnosed by non-study physicians. Low oxygen saturation levels were observed in only 55/226 (24.3%) WHO 2015 RSV-LRTIs.

CONCLUSION

Three case definitions for RSV-LRTI showed high concordance with the WHO 2015 definition, while agreement was lower for severe RSV-LRTI. In contrast to increased respiratory rate, low oxygen saturation was not a consistent finding in RSV-LRTIs and severe RSV-LRTIs. This study demonstrates that current definitions are highly concordant for RSV-LRTIs, but a standard definition is still needed for severe RSV-LRTI.

School-Based Interventions to Increase Student COVID-19 Vaccination Coverage in Public School Populations with Low Coverage - Seattle, Washington, December 2021-June 2022

COVID-19 can lead to severe outcomes in children (1). Vaccination decreases risk for COVID-19 illness, severe disease, and death (2). On December 13, 2020, CDC recommended COVID-19 vaccination for persons aged ≥16 years, with expansion on May 12, 2021, to children and adolescents (children) aged 12-15 years, and on November 2, 2021, to children aged 5-11 years (3). As of March 8, 2023, COVID-19 vaccination coverage among school-aged children remained low nationwide, with 61.7% of children aged 12-17 years and approximately one third (32.7%) of those aged 5-11 years having completed the primary series (3). Intention to receive COVID-19 vaccine and vaccination coverage vary by demographic characteristics, including race and ethnicity and socioeconomic status (4-6). Seattle Public Schools (SPS) implemented a program to increase COVID-19 vaccination coverage during the 2021-22 school year, focusing on children aged 5-11 years during November 2021-June 2022, with an added focus on populations with low vaccine coverage during January 2022-June 2022.^† The program included strategic messaging, school-located vaccination clinics, and school-led community engagement. Vaccination data from the Washington State Immunization Information System (WAIIS) were analyzed to examine disparities in COVID-19 vaccination by demographic and school characteristics and trends over time. In December 2021, 56.5% of all SPS students, 33.7% of children aged 5-11 years, and 81.3% of children aged 12-18 years had completed a COVID-19 primary vaccination series. By June 2022, overall series completion had increased to 80.3% and was 74.0% and 86.6% among children aged 5-11 years and 12-18 years, respectively. School-led vaccination programs can leverage community partnerships and relationships with families to improve COVID-19 vaccine access and coverage.

Evaluation of BNT162b2 Covid-19 Vaccine in Children Younger than 5 Years of Age

BACKGROUND

Safe and effective vaccines against coronavirus disease 2019 (Covid-19) are urgently needed in young children.

METHODS

We conducted a phase 1 dose-finding study and are conducting an ongoing phase 2-3 safety, immunogenicity, and efficacy trial of the BNT162b2 vaccine in healthy children 6 months to 11 years of age. We present results for children 6 months to less than 2 years of age and those 2 to 4 years of age through the data-cutoff dates (April 29, 2022, for safety and immunogenicity and June 17, 2022, for efficacy). In the phase 2-3 trial, participants were randomly assigned (in a 2:1 ratio) to receive two 3-μg doses of BNT162b2 or placebo. On the basis of preliminary immunogenicity results, a third 3-μg dose (≥8 weeks after dose 2) was administered starting in January 2022, which coincided with the emergence of the B.1.1.529 (omicron) variant. Immune responses at 1 month after doses 2 and 3 in children 6 months to less than 2 years of age and those 2 to 4 years of age were immunologically bridged to responses after dose 2 in persons 16 to 25 years of age who received 30 μg of BNT162b2 in the pivotal trial.

RESULTS

During the phase 1 dose-finding study, two doses of BNT162b2 were administered 21 days apart to 16 children 6 months to less than 2 years of age (3-μg dose) and 48 children 2 to 4 years of age (3-μg or 10-μg dose). The 3-μg dose level was selected for the phase 2-3 trial; 1178 children 6 months to less than 2 years of age and 1835 children 2 to 4 years of age received BNT162b2, and 598 and 915, respectively, received placebo. Immunobridging success criteria for the geometric mean ratio and seroresponse at 1 month after dose 3 were met in both age groups. BNT162b2 reactogenicity events were mostly mild to moderate, with no grade 4 events. Low, similar incidences of fever were reported after receipt of BNT162b2 (7% among children 6 months to <2 years of age and 5% among those 2 to 4 years of age) and placebo (6 to 7% among children 6 months to <2 years of age and 4 to 5% among those 2 to 4 years of age). The observed overall vaccine efficacy against symptomatic Covid-19 in children 6 months to 4 years of age was 73.2% (95% confidence interval, 43.8 to 87.6) from 7 days after dose 3 (on the basis of 34 cases).

CONCLUSIONS

A three-dose primary series of 3-μg BNT162b2 was safe, immunogenic, and efficacious in children 6 months to 4 years of age. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04816643.).

Sustained Within-season Vaccine Effectiveness Against Influenza-associated Hospitalization in Children: Evidence From the New Vaccine Surveillance Network, 2015-2016 Through 2019-2020

BACKGROUND

Adult studies have demonstrated within-season declines in influenza vaccine effectiveness (VE); data in children are limited.

METHODS

We conducted a prospective, test-negative study of children 6 months through 17 years hospitalized with acute respiratory illness at 7 pediatric medical centers during the 2015-2016 through 2019-2020 influenza seasons. Case-patients were children with an influenza-positive molecular test matched by illness onset to influenza-negative control-patients. We estimated VE [100% × (1 - odds ratio)] by comparing the odds of receipt of ≥1 dose of influenza vaccine ≥14 days before illness onset among influenza-positive children to influenza-negative children. Changes in VE over time between vaccination date and illness onset date were estimated using multivariable logistic regression.

RESULTS

Of 8430 children, 4653 (55%) received ≥1 dose of influenza vaccine. On average, 48% were vaccinated through October and 85% through December each season. Influenza vaccine receipt was lower in case-patients than control-patients (39% vs 57%, P < .001); overall VE against hospitalization was 53% (95% confidence interval [CI]: 46, 60%). Pooling data across 5 seasons, the odds of influenza-associated hospitalization increased 4.2% (-3.2%, 12.2%) per month since vaccination, with an average VE decrease of 1.9% per month (n = 4000, P = .275). Odds of hospitalization increased 2.9% (95% CI: -5.4%, 11.8%) and 9.6% (95% CI: -7.0%, 29.1%) per month in children ≤8 years (n = 3084) and 9-17 years (n = 916), respectively. These findings were not statistically significant.

CONCLUSIONS

We observed minimal, not statistically significant within-season declines in VE. Vaccination following current Advisory Committee on Immunization Practices (ACIP) guidelines for timing of vaccine receipt remains the best strategy for preventing influenza-associated hospitalizations in children.

Circulation of Rhinoviruses and/or Enteroviruses in Pediatric Patients With Acute Respiratory Illness Before and During the COVID-19 Pandemic in the US

IMPORTANCE

Rhinoviruses and/or enteroviruses, which continued to circulate during the COVID-19 pandemic, are commonly detected in pediatric patients with acute respiratory illness (ARI). Yet detailed characterization of rhinovirus and/or enterovirus detection over time is limited, especially by age group and health care setting.

OBJECTIVE

To quantify and characterize rhinovirus and/or enterovirus detection before and during the COVID-19 pandemic among children and adolescents seeking medical care for ARI at emergency departments (EDs) or hospitals.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used data from the New Vaccine Surveillance Network (NVSN), a multicenter, active, prospective surveillance platform, for pediatric patients who sought medical care for fever and/or respiratory symptoms at 7 EDs or hospitals within NVSN across the US between December 2016 and February 2021. Persons younger than 18 years were enrolled in NVSN, and respiratory specimens were collected and tested for multiple viruses.

MAIN OUTCOMES AND MEASURES

Proportion of patients in whom rhinovirus and/or enterovirus, or another virus, was detected by calendar month and by prepandemic (December 1, 2016, to March 11, 2020) or pandemic (March 12, 2020, to February 28, 2021) periods. Month-specific adjusted odds ratios (aORs) for rhinovirus and/or enterovirus-positive test results (among all tested) by setting (ED or inpatient) and age group (<2, 2-4, or 5-17 years) were calculated, comparing each month during the pandemic to equivalent months of previous years.

RESULTS

Of the 38 198 children and adolescents who were enrolled and tested, 11 303 (29.6%; mean [SD] age, 2.8 [3.7] years; 6733 boys [59.6%]) had rhinovirus and/or enterovirus-positive test results. In prepandemic and pandemic periods, rhinoviruses and/or enteroviruses were detected in 29.4% (9795 of 33 317) and 30.9% (1508 of 4881) of all patients who were enrolled and tested and in 42.2% (9795 of 23 236) and 73.0% (1508 of 2066) of those with test positivity for any virus, respectively. Rhinoviruses and/or enteroviruses were the most frequently detected viruses in both periods and all age groups in the ED and inpatient setting. From April to September 2020 (pandemic period), rhinoviruses and/or enteroviruses were detectable at similar or lower odds than in prepandemic years, with aORs ranging from 0.08 (95% CI, 0.04-0.19) to 0.76 (95% CI, 0.55-1.05) in the ED and 0.04 (95% CI, 0.01-0.11) to 0.71 (95% CI, 0.47-1.07) in the inpatient setting. However, unlike some other viruses, rhinoviruses and/or enteroviruses soon returned to prepandemic levels and from October 2020 to February 2021 were detected at similar or higher odds than in prepandemic months in both settings, with aORs ranging from 1.47 (95% CI, 1.12-1.93) to 3.01 (95% CI, 2.30-3.94) in the ED and 1.36 (95% CI, 1.03-1.79) to 2.44 (95% CI, 1.78-3.34) in the inpatient setting, and in all age groups. Compared with prepandemic years, during the pandemic, rhinoviruses and/or enteroviruses were detected in patients who were slightly older, although most (74.5% [1124 of 1508]) were younger than 5 years.

CONCLUSIONS AND RELEVANCE

Results of this study show that rhinoviruses and/or enteroviruses persisted and were the most common respiratory virus group detected across all pediatric age groups and in both ED and inpatient settings. Rhinoviruses and/or enteroviruses remain a leading factor in ARI health care burden, and active ARI surveillance in children and adolescents remains critical for defining the health care burden of respiratory viruses.

The Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19: Antigen Testing

BACKGROUND

Immunoassays designed to detect SARS-CoV-2 protein antigens (Ag) are commonly used to diagnose COVID-19. The most widely used tests are lateral flow assays that generate results in approximately 15 minutes for diagnosis at the point-of-care. Higher throughput, laboratory-based SARS-CoV-2 Ag assays have also been developed. The number of commercially available SARS-CoV-2 Ag detection tests has increased rapidly, as has the COVID-19 diagnostic literature. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the literature and develop best practice guidance related to SARS-CoV-2 Ag testing. This guideline is an update to the third in a series of frequently updated COVID-19 diagnostic guidelines developed by the IDSA.

OBJECTIVE

The IDSA's goal was to develop evidence-based recommendations or suggestions that assist clinicians, clinical laboratories, patients, public health authorities, administrators and policymakers in decisions related to the optimal use of SARS-CoV-2 Ag tests in both medical and non-medical settings.

METHODS

A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists and experts in systematic literature review identified and prioritized clinical questions related to the use of SARS-CoV-2 Ag tests. A review of relevant, peer-reviewed published literature was conducted through April 1, 2022. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations.

RESULTS

The panel made ten diagnostic recommendations. These recommendations address Ag testing in symptomatic and asymptomatic individuals and assess single versus repeat testing strategies.

CONCLUSIONS

U.S. Food and Drug Administration (FDA) SARS-CoV-2 Ag tests with Emergency Use Authorization (EUA) have high specificity and low to moderate sensitivity compared to nucleic acid amplification testing (NAAT). Ag test sensitivity is dependent on the presence or absence of symptoms, and in symptomatic patients, on timing of testing after symptom onset. In contrast, Ag tests have high specificity, and, in most cases, positive Ag results can be acted upon without confirmation. Results of point-of-care testing are comparable to those of laboratory-based testing, and observed or unobserved self-collection of specimens for testing yields similar results. Modeling suggests that repeat Ag testing increases sensitivity compared to testing once, but no empirical data were available to inform this question. Based on these observations, rapid RT-PCR or laboratory-based NAAT remains the testing method of choice for diagnosing SARS-CoV-2 infection. However, when timely molecular testing is not readily available or is logistically infeasible, Ag testing helps identify individuals with SARS-CoV-2 infection. Data were insufficient to make a recommendation about the utility of Ag testing to guide release of patients with COVID-19 from isolation. The overall quality of available evidence supporting use of Ag testing was graded as very low to moderate.

Results from a test-and-treat study for influenza among residents of homeless shelters in King County, WA: A stepped-wedge cluster-randomized trial

BACKGROUND

Persons experiencing homelessness face increased risk of influenza as overcrowding in congregate shelters can facilitate influenza virus spread. Data regarding on-site influenza testing and antiviral treatment within homeless shelters remain limited.

METHODS

We conducted a cluster-randomized stepped-wedge trial of point-of-care molecular influenza testing coupled with antiviral treatment with baloxavir or oseltamivir in residents of 14 homeless shelters in Seattle, WA, USA. Residents ≥3 months with cough or ≥2 acute respiratory illness (ARI) symptoms and onset <7 days were eligible. In control periods, mid-nasal swabs were tested for influenza by reverse transcription polymerase chain reaction (RT-PCR). The intervention period included on-site rapid molecular influenza testing and antiviral treatment for influenza-positives if symptom onset was <48 h. The primary endpoint was monthly influenza virus infections in the control versus intervention periods. Influenza whole genome sequencing was performed to assess transmission and antiviral resistance.

RESULTS

During 11/15/2019-4/30/2020 and 11/2/2020-4/30/2021, 1283 ARI encounters from 668 participants were observed. Influenza virus was detected in 51 (4%) specimens using RT-PCR (A = 14; B = 37); 21 influenza virus infections were detected from 269 (8%) intervention-eligible encounters by rapid molecular testing and received antiviral treatment. Thirty-seven percent of ARI-participant encounters reported symptom onset < 48 h. The intervention had no effect on influenza virus transmission (adjusted relative risk 1.73, 95% confidence interval [CI] 0.50-6.00). Of 23 influenza genomes, 86% of A(H1N1)pdm09 and 81% of B/Victoria sequences were closely related.

CONCLUSION

Our findings suggest feasibility of influenza test-and-treat strategies in shelters. Additional studies would help discern an intervention effect during periods of increased influenza activity.

Severe acute respiratory syndrome coronavirus 2 seroprevalence and longitudinal antibody response following natural infection in pregnancy: A prospective cohort study

BACKGROUND

Antenatal care provides unique opportunities to assess severe acute respiratory syndrome coronavirus 2 seroprevalence and antibody response duration after natural infection detected during pregnancy; transplacental antibody transfer may inform peripartum and neonatal protection. We estimated seroprevalence and durability of antibodies from natural infection (anti-nucleocapsid immunoglobulin G) among pregnant people, and evaluated transplacental transfer efficiency.

OBJECTIVE AND DESIGN

We conducted a cross-sectional study to measure severe acute respiratory syndrome coronavirus 2 seroprevalence, and a prospective cohort study to longitudinally measure anti-nucleocapsid immunoglobulin G responses and transplacental transfer of maternally derived anti-nucleocapsid antibodies.

METHODS

We screened pregnant people for the seroprevalence study between 9 December 2020 and 19 June 2021 for anti-nucleocapsid immunoglobulin G in Seattle, Washington. We enrolled anti-nucleocapsid immunoglobulin G positive people from the seroprevalence study or identified through medical records with positive reverse transcription polymerase chain reaction or antigen positive results in a prospective cohort between 9 December 2020 and 9 August 2022.

RESULTS

In the cross-sectional study (N = 1284), 5% (N = 65) tested severe acute respiratory syndrome coronavirus 2 anti-nucleocapsid immunoglobulin G positive, including 39 (60%) without prior positive reverse transcription polymerase chain reaction results and 42 (65%) without symptoms. In the prospective cohort study (N = 107 total; N = 65 from the seroprevalence study), 86 (N = 80%) had anti-nucleocapsid immunoglobulin G positive results during pregnancy. Among 63 participants with delivery samples and prior anti-nucleocapsid positive results, 29 (46%) were anti-nucleocapsid immunoglobulin G negative by delivery. Of 34 remaining anti-nucleocapsid immunoglobulin G positive at delivery with paired cord blood, 19 (56%) had efficient transplacental anti-nucleocapsid immunoglobulin G antibody transfer. Median time from first anti-nucleocapsid immunoglobulin G positive to below positive antibody threshold was 19 weeks and did not differ by prior positive reverse transcription polymerase chain reaction status.

CONCLUSIONS

Maternally derived severe acute respiratory syndrome coronavirus 2 antibodies to natural infection may wane before delivery. Vaccines are recommended for pregnant persons to reduce severe illness and confer protection to infants.

2196. Frequencies of Adenovirus Types in U.S. Children with Acute Respiratory Illness, 2016–2019

Background

Adenovirus (AdV) is a common cause of acute respiratory illness (ARI). Multiple respiratory AdV types have been identified in humans, but it remains unclear which are the most common in U.S. children with ARI.

Methods

We conducted a multicenter, prospective viral surveillance study at seven U.S. children’s hospitals, the New Vaccine Surveillance Network, during 12/1/16–11/30/19, prior to the COVID-19 pandemic. Children < 18 years of age seen in the emergency department or hospitalized with fever and/or respiratory symptoms were enrolled, and mid-turbinate nasal +/- throat swabs were tested using multiplex respiratory pathogen assays or real time polymerase chain reaction (PCR) test for AdV, respiratory syncytial virus (RSV), human metapneumovirus, rhinovirus/enterovirus (RV), influenza, parainfluenza viruses, and endemic coronaviruses. AdV-positive specimens were subsequently typed using single-plex qPCR assays targeting sequences in the hexon gene specific for types 1-7, 11, 14, 16 and 21. Demographics, clinical characteristics, and outcomes were compared between AdV types.

Results

Of 29,381 enrolled children, 2,106 (7.2%) tested positive for AdV. The distribution of types among the 1,330 (63.2%) successfully typed specimens were as follows: 31.7% AdV-2, 28.9% AdV-1, 15.3% AdV-3, 7.9% AdV-5, 5.9% AdV-7, 1.4% AdV-4, 1.2% AdV-6, 0.5% AdV-14, 0.2% AdV-21, 0.1% AdV-11, and 7.0% ≥1 AdV type. Most children with AdV-1 or AdV-2 detection were < 5 years of age (Figure 1a). Demographic and clinical characteristics varied by AdV types, including age, race/ethnicity, smoke exposure, daycare/school attendance, and hospitalization (Table 1). Co-detection with other viruses was common among all AdV types, with RV and RSV being the most frequently co-detected (Figure 1b). Fever and cough were the most common symptoms for all AdV types (Figure 2). Children with AdV-7 detected as single pathogen had higher odds of hospitalization (adjusted odds ratio 6.34 [95% CI: 3.10, 12.95], p= 0.027).

Conclusion

AdV-2 and AdV-1 were the most frequently detected AdV types among children over the 3-year study period. Notable clinical heterogeneity of the AdV types warrants further surveillance studies to identify AdV types that could be targeted for pediatric vaccine development.

Disclosures

Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, F(AAM), BioFire: Grant/Research Support|Luminex: Grant/Research Support John Williams, MD, GlaxoSmithKline: Advisor/Consultant|Quidel: Advisor/Consultant Mary A. Staat, MD, MPH, Centers for Disease Control and Prevention: Grant/Research Support|Cepheid: Grant/Research Support|National Institute of Health: Grant/Research Support|Uptodate: Royalties Christopher J Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric news: Honoraria|Pfizer: Grant/Research Support Mary E. Moffatt, M.D., Becton and Dickinson and Company: Stocks/Bonds|Biogen: Stocks/Bonds|Coloplast B: Stocks/Bonds|Express Scripts: Stocks/Bonds|Novo Nordisk A/S Spons ADR: Stocks/Bonds|Novo Nordisk A/S-B: Stocks/Bonds|Steris PLC: Stocks/Bonds|Stryker Corp: Stocks/Bonds|Thermo Fisher Scientific: Stocks/Bonds Geoffrey A. Weinberg, MD, Merck & Co.: Honoraria|Merck & Co.: Honoraria for composing and reviewing textbook chapters, Merck Manual of Therapeutics Janet A. Englund, MD, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Natasha B. Halasa, MD, Quidel: Grant/Research Support|Quidel: equipment donation|Sanofi: Grant/Research Support|Sanofi: HAI testing and vaccine donation.

1591. The Impact of Pretransplant Respiratory Virus Infection in Pediatric Hematopoietic Cell Transplant Recipients

Background

Respiratory virus infections (RVIs) in adult hematopoietic cell transplant (HCT) candidates have been shown to impact posttransplant outcomes; however, there are few studies in pediatric patients. We sought to evaluate the role of specific viruses and the location of viral infection on post HCT outcomes.

Methods

We evaluated allogeneic pediatric HCT recipients receiving myeloablative conditioning from 3/2010–3/2018. All patients had a multiplex PCR for RVIs prior to HCT, regardless of symptoms. Delaying HCT was recommended when feasible for RSV, parainfluenza, metapneumovirus, adenovirus, and influenza, but not routinely for human rhinovirus (HRV) and endemic coronaviruses. We utilized Cox proportional hazards models to evaluate progression to lower respiratory disease (LRD) post HCT and linear regression models to evaluated days alive and out of hospital (DAOH) by 100 days post HCT.

Results

Of 310 allogeneic HCT recipients receiving myeloablative conditioning, 133 (43%) were positive for a RVI before HCT. Baseline characteristics were notable for differences for age, recipient CMV serostatus, and delayed HCT (Table 1). The most common RVI was HRV (97, 73%) and 81 (61%) patients were symptomatic at the time of detection. Most patients had a URI (92%) and 11 patients had LRD (3 proven, 8 possible). In univariate analysis, HRV as virus type was associated with fewer DAOH and preHCT URI as location of viral infection (with and without symptoms) trended towards fewer DAOH (Figure 1a). When adjusted for age, preHCT lymphocyte count, cell source, and conditioning regimen, both HRV and preHCT URI showed a trend towards fewer DAOH, but no significant association was found (Figure 1b,c). Twenty patients progressed to LRD after HCT with the same preHCT RVI; no factors, including delay of transplant, were associated with reduced progression to LRD.

(A) Univariable linear regression for DAOH, (B) Multivariable linear regression for DAOH by viral type, (C) Multivariable linear regression for DAOH by viral location and symptom composite.

Conclusion

In this single center study, HRV as virus type and URI as location of viral infection before myeloablative allogeneic HCT were associated with increased hospitalization after HCT, but not in multivariate models. Larger multicenter studies are needed to provide timely evaluation and adequate statistical power to definitively determine role of URI versus LRD and the impact of transplant delay and treatment strategies.

Disclosures

Yae-Jean Kim, MD, PhD, Janssen: Grant/Research Support|Korean Society of Pediatric Infectious Diseases: Grant/Research Support|Ministry of Trade, Industry and Energy: Grant/Research Support|MSD: Grant/Research Support chikara Ogimi, MD, Horiba: payment for a lecture Michael J. Boeckh, MD PhD, Allovir: Advisor/Consultant|Amazon: Grant/Research Support|Ansun Biopharma: Grant/Research Support|EvrysBio: Advisor/Consultant|Gates Ventures: Grant/Research Support|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|Helocyte: Advisor/Consultant|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Kyorin Pharmaceuticals: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|Vir Biotechnology: Advisor/Consultant|Vir Biotechnology: Grant/Research Support Janet A. Englund, MD, Astra Zeneca: Advisor/Consultant|Astra Zeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccine: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|SanofiPasteur: Advisor/Consultant Alpana Waghmare, MD, Allovir: Grant/Research Support|Ansun Biopharma: Grant/Research Support|Devarra Therapeutics: DSMB|Kyorin Pharmaceutical: Advisor/Consultant|Pfizer: Grant/Research Support|Vir/GSK: Grant/Research Support.

1456. Environmental and Nasal Pathogen Surveillance in Seattle Area Homeless Shelters

Background

The need for community surveillance of respiratory viruses in high-risk settings such as homeless shelters has been underscored by the COVID-19 pandemic. Here, we show that sampling high-touch surfaces is a low-cost, minimally intensive means of community respiratory virus surveillance.

Methods

Environmental samples were collected weekly from adult and family homeless shelters in King County, WA from November 2019 – April 2020. At times when residents were present, a 10cm2 area of selected high-touch surfaces were swabbed and bioaerosol samples were collected in high-traffic areas. Surfaces included entrance and restroom doorknobs, counters, and surfaces unique to each shelter. Study staff collected mid-turbinate swabs from shelter resident participants aged &gt; 3 months with symptoms of acute respiratory illness (ARI). All samples were tested by RT-PCR for 27 viruses. From January 1, 2020 onward, samples were also tested for SARS-CoV-2.

Results

A total of 788 environmental swabs, 1509 nasal swabs, and 98 bioaerosol samples from 6 adult and 3 family shelters were tested. Adenovirus (109 positive swabs, 13.8% of tested swabs), rhinovirus (107, 13.6%) and human bocavirus (62, 7.9%) were the most frequently detected viruses in surface swabs. Rhinovirus (160, 10.6%), human coronaviruses (79, 5.24%) and influenza B (43, 2.85%) were the most detected in nasal swabs. All viruses detected in nasal swabs were found in surface swabs. Of 9 surfaces, exterior bathroom doorknobs were the physical location with the highest number of pathogens detected. SARS-CoV-2 was first detected in surface swabs on 3/20/20, and in nasal swabs on 3/10/20. Bioaerosol samples detected virus in a low percentage of samples relative to surface and nasal swabs. Table 1Count and period prevalence of environmental viral detection by shelter type, November 18, 2019 - April 10, 2020.Figure 1Number of viral pathogens detected from environmental swabs, disaggregated by shelter type.Figure 2Bar graphs comparing prevalence of respiratory pathogen detection in mid-turbinate nasal swabs and environmental swabs/bioaerosol samples by epidemiologic week, November 18, 2019 - April 30, 2020.

Conclusion

Respiratory viruses detected through environmental sampling in homeless shelters were similar to the viruses detected from ARI episodes in study participants. Environmental surface sampling presents a plausible, minimally invasive method of surveillance for both endemic and emerging respiratory pathogens, as evidenced by the detection of SARS-CoV-2 during the early stages of the pandemic. Further research could focus on sampling public locations for broader community surveillance and culturing viruses found on these surfaces.

Disclosures

Michael J. Boeckh, MD PhD, Allovir: Advisor/Consultant|Amazon: Grant/Research Support|Ansun Biopharma: Grant/Research Support|EvrysBio: Advisor/Consultant|Gates Ventures: Grant/Research Support|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|Helocyte: Advisor/Consultant|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Kyorin Pharmaceuticals: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|Vir Biotechnology: Advisor/Consultant|Vir Biotechnology: Grant/Research Support Janet A. Englund, MD, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Helen Y. Chu, MD, MPH, Cepheid: Reagents|Ellume: Advisor/Consultant|Gates Ventures: Grant/Research Support|Merck: Advisor/Consultant|Pfizer: Advisor/Consultant.

2167. Use and Timing of Antiviral Therapy for Influenza in Hospitalized U.S. Children, 2016–2020

Background

According to the 2018 Infectious Diseases Society of America (IDSA) clinical practice guidelines and Centers for Disease Control and Prevention (CDC) guidance, clinicians should start antiviral treatment as soon as possible for children who are hospitalized with suspected or confirmed influenza. We assessed the use of influenza-specific antiviral therapy in children hospitalized with symptoms of acute respiratory illness and laboratory-confirmed influenza.

Methods

We conducted active, population-based surveillance of children hospitalized with fever and/or respiratory symptoms (12/01/2016–02/28/2020) at the seven U.S. medical centers that comprise the CDC New Vaccine Surveillance Network. We excluded children who did not undergo clinical testing (by rapid antigen testing or nucleic acid amplification test [NAAT]) or research testing (by NAAT) for influenza, those who presented out of influenza season (site- and season-specific), and those whose date of antiviral therapy or whether antiviral therapy was given was unknown. We assessed the use of influenza-specific antiviral therapy in this cohort and defined timely antiviral therapy as administration within 2 days of hospitalization.

Results

Of 11,275 eligible children, 1,149 (10.2%) tested positive for influenza by clinical and/or research assays (Table 1). Overall, 154 influenza cases (13.4%) were detected by clinical testing only, 428 (37.2%) by research testing only, and 567 (49.3%) by both. During their influenza-associated hospitalization, 620 children (54.0%) received influenza-specific antivirals, and therapy was timely in 572 cases (92.3%). Of those who tested positive clinically, 445/721 (61.7%) received timely antiviral therapy, 38 (5.3%) received delayed antiviral therapy, and 238 (33.0%) received no antiviral therapy. Oseltamivir was the antiviral used in all treated cases. The distribution of antiviral-treated cases varied by race and Hispanic origin and study site, but not by age at presentation or influenza season (Figure 1). Table 1

Demographic characteristics of 1,149 children with influenza enrolled in the New Vaccine Surveillance Network over four influenza seasons between December 1, 2016, and February 28, 2020. Figure 1Proportions of children with influenza enrolled in the New Vaccine Surveillance Network who received timely, delayed, or no antiviral therapy by age at presentation, race and Hispanic origin, study site, and influenza season (N=1,149).

Conclusion

Although antiviral therapy is recommended for all influenza-associated hospitalizations in children, antiviral prescribing remains suboptimal. Further studies would help identify and address barriers to antiviral therapy in children with influenza.

Disclosures

John Williams, MD, GlaxoSmithKline: Advisor/Consultant|Quidel: Advisor/Consultant Janet A. Englund, MD, AstraZeneca: Advisor/Consultant|AstraZeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccines: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Advisor/Consultant Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, F(AAM), BioFire: Grant/Research Support|Luminex: Grant/Research Support Mary A. Staat, MD, MPH, Centers for Disease Control and Prevention: Grant/Research Support|Cepheid: Grant/Research Support|National Institute of Health: Grant/Research Support|Uptodate: Royalties Geoffrey A. Weinberg, MD, Merck & Co.: Honoraria|Merck & Co.: Honoraria for composing and reviewing textbook chapters, Merck Manual of Therapeutics Flor M. Munoz, MD, MSc, Gilead: Grant/Research Support|Moderna: DSMB|Pfizer: DSMB Christopher J Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric news: Honoraria|Pfizer: Grant/Research Support Natasha B. Halasa, MD, Quidel: Grant/Research Support|Quidel: equipment donation|Sanofi: Grant/Research Support|Sanofi: HAI testing and vaccine donation.

880. Molecular Subtyping and Macrolide-Resistance Determination of Mycoplasma pneumoniae from Children Enrolled in New Vaccine Surveillance Network in the United States during 2015 to 2020

Background

Mycoplasma pneumoniae (MP), a common pediatric pneumonia pathogen, has 2 subtypes based on P1 adhesin gene variation. Macrolide-resistant MP (MRMP), seen since 2000 in many countries, has been subtype associated. Limited U.S. pediatric data exist on MP subtype or MRMP frequency and their clinical importance.

Methods

During 2015–2020, mid-turbinate nasal swab (MTNS) specimens and/or throat swabs were collected from children with acute respiratory illness (ARI) enrolled in emergency department (ED) or outpatient and inpatient settings at 4 CDC-funded New Vaccine Surveillance Network sites (Cincinnati, Seattle, Houston, and Kansas City). Specimens were tested for MP and common respiratory viruses by singleplex or multiplex polymerase chain reaction assay (PCR). P1-subtyping for MP positive specimens used multiplex TaqMan real-time PCR while MR was assessed by real time PCR with melt curve analysis (Lightmix®, TIBMolbiol). Select demographic/clinical data were analyzed by P1 subtype (P1–1 vs. P1–2).

Results

Of 208 MTNS specimens from 208 children (median age 5.5 years), 110 (53%) were P1–1, 89 (43%) P1–2, and 9 (4%) untypeable. Of 199 typeable specimens, 111 (56%) came from inpatients while 88 (44%) came from ED/outpatients.Overall MRMP prevalence during 2015–2020 was low (3/208,1.4%); all MRMP (Houston: 1 each in 2016–2017 and 2019–2020, Seattle: 1 in 2018–2019) were P1–1. Differences in P1–2 vs. P1–1 proportions were significant in 2 years: P1–2 dominated in 2015–2016; P1-1 in 2019–2020 (Figure 1). Common clinical symptoms for 199 MP-positive patients were fever (84%, mean 102.5±1.5oF), shortness of breath (82%), wheezing (67%), and cough (60%). Clinical manifestations, hospitalization, and antibiotic use did not differ in P1-1 vs. P1-2 patients. Antibiotics were used in 59/199 (30%) patients overall; amoxicillin was most frequent (48/199, 24%), followed by cefdinir (9/199, 5%) and azithromycin (5/199, 3%).

Conclusion

MP subtypes co-circulated during 2015–2020; P1-2 dominated in 2015–2016, P1-1 in 2018–2019. Signs/symptoms were similar for P1-1 and P1-2. MRMP detection was uncommon among our pediatric subjects. Ongoing surveillance is important to assess potential changes in MR prevalence and temporal subtype variation.

Disclosures

Christopher J Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric news: Honoraria|Pfizer: Grant/Research Support Brian R. Lee, PhD, MPH, CDC: Grant/Research Support|Merck: Grant/Research Support Mary E. Moffatt, M.D., Becton and Dickinson and Company: Stocks/Bonds|Biogen: Stocks/Bonds|Coloplast B: Stocks/Bonds|Express Scripts: Stocks/Bonds|Novo Nordisk A/S Spons ADR: Stocks/Bonds|Novo Nordisk A/S-B: Stocks/Bonds|Steris PLC: Stocks/Bonds|Stryker Corp: Stocks/Bonds|Thermo Fisher Scientific: Stocks/Bonds Janet A. Englund, MD, Astra Zeneca: Advisor/Consultant|Astra Zeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccine: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|SanofiPasteur: Advisor/Consultant.