BACKGROUND: The clinical and genomic epidemiology of human metapneumovirus (hMPV) infections in community settings is not well understood. METHODS: From 2018 to 2022, individuals with respiratory symptoms were recruited and enrolled from the greater Seattle, Washington community in the United States. Residual clinical specimens from individuals presenting with respiratory symptoms were additionally collected. Specimens were tested for hMPV by reverse-transcription polymerase chain reaction, with whole genome sequencing performed on a subset (209/1002). RESULTS: hMPV positivity was higher among clinical specimens (835/21 539 [3.9%]) compared to community specimens (167/28 348 [0.6%]). Children aged 0-4 years had the highest percent positivity across both clinical and community settings (497/10 213 [4.9%] and 28/1640 [1.7%], respectively). In multivariate analysis, a household income of ≤US$100 000 (adjusted odds ratio [aOR], 1.72 [95% confidence interval {CI}, 1.07-2.85]), and recent international travel (aOR, 6.51 [95% CI, 3.11-12.22]) were associated with hMPV positivity. A subset of 209 of 1002 samples (21%) was sequenced; the distribution of subtypes A2b, A2c, B1, and B2 were similar across both community and clinical settings, with an increase in the proportion of subtype B1 after the start of the pandemic. CONCLUSIONS: Risk factors of testing positive for hMPV in a community setting included lower household income and recent international travel. Co-circulation of hMPV subtypes was observed across community and clinical settings.

Human metapneumovirus (hMPV) is an important cause of respiratory illness. However, information about hMPV incidence, patient characteristics, and symptoms outside hospital settings is limited. During June 2022-March 2024, participants aged 6 months-49 years who were enrolled in the CASCADIA community-based cohort study submitted weekly illness surveys and nasal swabs, and completed follow-up illness surveys. Swabs collected 0-3 days before reporting new or worsening symptoms were tested for hMPV and other respiratory viruses by multiplex polymerase chain reaction. Incidence was analyzed using an exponential survival model. Among 3,549 participants, 306 had symptomatic hMPV infection, representing an average of 7.5 cases per 100 persons per year (95% CI = 6.7-8.4). Incidence was highest during January-March (adjusted hazard ratio [aHR] = 4.3; 95% CI = 3.0-6.0) compared with October-December, and among those aged 2-4 years (aHR = 5.8; 95% CI = 3.8-9.0) compared with those aged ≥40 years. The most frequently reported symptoms were cough (80.4%) and nasal congestion (71.9%). Among 252 (82.4%) participants who completed a post-illness follow-up survey, 68 (27.0%) missed work, school, or child care facility attendance. Together, these findings indicate that hMPV is a common cause of respiratory illness during late winter to spring, particularly among young children, and frequently disrupts daily activities. Understanding hMPV epidemiology can guide surveillance definitions, clinical testing, and prioritization of prevention strategies.

BACKGROUND: In 2021, the Philippines launched the Healthy Hearts demonstration project for delivering hypertension (HTN) services in seven Rural Health Units (RHUs) in District 1 of Iloilo Province, West Visayas Region. This study evaluates the provider time cost and medication cost of delivering these services under three medication procurement scenarios, projecting them to the district and province levels to inform scaling-up efforts. METHODS: A mixed-methods design was used for cost data collection, including key informant interviews (KII), focus group discussions (FGD), and secondary data sources. The HEARTS costing tool was adapted to analyze program costs per patient from the health system perspective. Three scenarios were assessed, depending on the procurement scheme of HTN medications: baseline local government procurement, pooled procurement through the Philippine Pharma Procurement Inc. (PPPI) national pooling mechanism, and private pharmacy outsourcing. We assessed annual provider labor costs and medication costs per patient for each scenario. RESULTS: The average provider cost per patient was considerably lower for patients with controlled HTN than for patients with uncontrolled HTN: USD 5 (range USD 3.4-6.1 across RHUs) vs. USD 32.9 (range USD 28.8-38.4)) due to the need for more frequent follow-up visits for the latter. Average medication costs per patient were estimated at USD 9.1 (range USD 7.2-11.5) using local procurement prices, USD 2.9 (range USD 2.3-3.7) using PPPI pooled procurement prices, and USD 23 (range USD 17.9-30.5) using private pharmacy outsourced prices. The higher medicine costs in the pharmacy outsourcing scenario were partially offset by lower provider costs (an average reduction of USD 1.5 per patient per year) due to reduced on-site dispensing time in this scenario. CONCLUSIONS: The findings from this study indicate two key opportunities for cost savings in HTN management in the Philippines' rural health units system: 1) enhancing the control of HTN, thereby reducing the need for follow-up visits and cutting down on provider time costs, and 2) utilizing pooled medication procurement mechanisms such as through the Philippine Pharma Procurement Inc. Provider time costs can also be partially reduced through outsourcing the dispensing of medications to private pharmacies, although doing so is currently associated with higher medication costs, further underscoring the utility of pooled procurement mechanisms for essential hypertension medicines.

BACKGROUND: Household transmission of respiratory viruses may drive community spread. Few recent studies have examined household respiratory syncytial virus (RSV) transmission in the United States. METHODS: We conducted a prospective community-based cohort study from 1 June 2022 to 31 May 2023. Participants had blood samples collected and completed nasal swabs and surveys at least weekly, irrespective of symptoms. We tested serum for RSV antibody, nasal swabs by quantitative reverse transcription polymerase chain reaction (RT-qPCR), and performed whole genome sequencing. We evaluated secondary RSV transmission and associated risk factors based on a log-linear Poisson regression model. RESULTS: RSV was detected among 310 (10%) participants within 200 (20%) households. Most (94%) index cases were symptomatic. We identified 37 cases of potential secondary transmission within 14 days of a distinct index case (10%, 95% confidence interval [CI]: 7%, 14%); median age of index and secondary cases were 6 (interquartile range [IQR]: 3-10) and 35 (7-41) years, respectively, with 89% (24/27) of index cases aged 6 months to 12 years. Factors associated with increased risk of RSV transmission included index case viral detection ≥1 week and contact age ≤12 years. Of 120 sequenced specimens, the main lineages represented were A.d.5.2 (n = 37) and A.d.1 (n = 30). Sequenced viruses from households with ≥2 RSV infections were similar when occurring within ≤14 days (mean pairwise difference 4 [range 0-13], n = 17 households), compared to those >14 days (137 [37-236], n = 2). CONCLUSIONS: Most RSV household transmission occurs from infants and young children to adults. Viral genome sequencing demonstrated that multiple household infections within a 14-day period are likely due to within-household transmission.

Introduction: COVID-19 surveillance in congregate settings is important to mitigating disease, but the health and economic impact of testing remains unclear. Methods: The authors developed a Markov model to project the cost-utility of COVID-19 testing strategies in homeless shelters from the healthcare payer and societal perspective over 1 year. Model inputs utilized data from residents aged ≥18 years across 23 Seattle shelters from January 1, 2020, to May 31, 2021. No in-shelter surveillance was compared with scenarios of 2 COVID-19 testing strategies implemented monthly: polymerase chain reaction (PCR) testing and rapid antigen testing; scenarios in which only PCR testing was available were also evaluated. The primary health outcome was quality-adjusted life years. Interventions were considered cost-effective if the incremental cost-effectiveness ratio was ≤$150,000 per quality-adjusted life year and dominant if they saved costs and provided health effects. Results: When assuming the availability of both antigen and PCR tests, most rapid antigen testing strategies were cost-effective, whereas PCR testing was dominated by antigen testing. Compared with no in-shelter surveillance, antigen testing increased mean quality-adjusted life years by 0.0009 (0.03% infections averted) at an incremental cost of $97/resident from the healthcare perspective (incremental cost-effectiveness ratio=$112,352/quality-adjusted life year gained) and $8/resident from the societal perspective (incremental cost-effectiveness ratio=$9,627/quality-adjusted life year gained) at 75% vaccination coverage. PCR testing was not cost-effective when antigen testing was available but was cost-effective compared with no surveillance at low vaccination coverage levels (<30% coverage from the healthcare perspective and ≤48% coverage from the societal perspective). Probabilistic sensitivity analysis showed that antigen testing was cost-effective in 62% and 86% of simulations from the healthcare and societal perspectives, respectively. Conclusions: Modeled findings show that COVID-19 testing in shelters can be a cost-effective pandemic response. Antigen testing remained cost-effective at high vaccination levels, whereas PCR testing was most effective at low vaccination levels if antigen testing was not available. © 2024 The Author(s)

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of hospitalization among infants in the United States (US). RSV immunization, in the form of a monoclonal antibody (mAb) for infants and vaccines for pregnant people, may reduce infant RSV risk. METHODS: In April and May 2023, we surveyed adults with children in Oregon and Washington about the likelihood to accept infant mAb and maternal RSV vaccine and RSV awareness. We used multivariable logistic regression to identify predictors of self-reported likelihood of accepting RSV immunization. RESULTS: Among 1082 respondents, 68% and 70% responded they would very likely accept infant mAb or maternal RSV vaccine, respectively. Respondents had lower odds of accepting infant mAb (OR: 0.10, 95% CI: 0.07-0.15) and maternal RSV vaccine (OR: 0.16, 95% CI: 0.12-0.23) if they were somewhat or very concerned about side effects. Respondents had higher odds of accepting infant mAb if they received an influenza vaccination (OR: 3.79, 95% CI: 1.88-7.63). Respondents had higher odds of accepting maternal vaccine if they had an advanced degree (OR: 1.70, 95% CI: 1.06-2.73), had received an influenza vaccination (OR: 3.62, 95% CI: 1.80-7.25), or were aware of RSV before our survey (OR: 2.03, 95% CI: 1.03-4.01). CONCLUSION: Most respondents reported that they would likely accept RSV mAb for their infant or an RSV vaccine during pregnancy. Concerns about side effects lowered the odds of accepting immunization, however, nearly one-half of those concerned about side effects still expressed a high likelihood of accepting either immunization.

BACKGROUND: Institutions of higher education (IHE) have been a focus of SARS-CoV-2 transmission studies but there is limited information on how viral diversity and transmission at IHE changed as the pandemic progressed. METHODS: Here we analyze 3606 viral genomes from unique COVID-19 episodes collected at a public university in Seattle, Washington from September 2020 to September 2022. RESULTS: Across the study period, we found evidence of frequent viral transmission among university affiliates with 60% (n = 2153) of viral genomes from campus specimens genetically identical to at least one other campus specimen. Moreover, viruses from students were observed in transmission clusters at a higher frequency than in the overall dataset while viruses from symptomatic infections were observed in transmission clusters at a lower frequency. Although only a small percentage of community viruses were identified as possible descendants of viruses isolated in university study specimens, phylodynamic modeling suggested a high rate of transmission events from campus into the local community, particularly during the 2021-2022 academic year. CONCLUSIONS: We conclude that viral transmission was common within the university population throughout the study period but that not all university affiliates were equally likely to be involved. In addition, the transmission rate from campus into the surrounding community may have increased during the second year of the study, possibly due to return to in-person instruction.

BACKGROUND: Understanding protection against SARS-CoV-2 infection by vaccine and hybrid immunity is important for informing public health strategies as new variants emerge. METHODS: We analyzed data from three cohort studies spanning September 1, 2022-July 31, 2023, to estimate COVID-19 vaccine effectiveness (VE) against SARS-CoV-2 infection and symptomatic COVID-19 among adults with and without prior infection in the United States. Participants collected weekly nasal swabs, irrespective of symptoms, annual blood draws, and completed periodic surveys, which included vaccination status and prior infection history. Swabs were tested molecularly for SARS-CoV-2. VE was estimated using Cox proportional hazards models for the hazard ratios of infections, adjusting for covariates. VE was calculated considering prior infection and recency of vaccination. RESULTS: Among 3,344 adults, adjusted VE of bivalent vaccine against infection was 37.2% (95% CI: 12.3-55.7%) within 7-59 days of vaccination and 21.1% (95% CI: -0.5-37.1%) within 60-179 days of vaccination compared to participants who were unvaccinated/received an original monovalent vaccine dose ≥180 days prior. Overall, adjusted VE of bivalent vaccine against infection, in conjunction with prior infection, was 62.2% (95% CI: 46.0-74.5%) within 7-179 days of vaccination and 39.4% (95% CI: 12.5-61.6%) ≥180 days compared to naïve participants who were unvaccinated/received a monovalent vaccine dose ≥180 days prior. CONCLUSIONS: Adults with both prior infection and recent vaccination had high protection against infection and symptomatic illness. Recent vaccination alone provided moderate protection.

Globally, abuse of older people (AOP) affects one in six individuals aged 60 years and older every year. Despite the widespread prevalence of AOP, evidence-based interventions for preventing and responding to this issue are insufficient. To address this gap, WHO proposed an initiative to accelerate the development of effective interventions for AOP across all country income levels. In the first phase, the initiative identified 89 promising interventions across a total of 101 evaluations or descriptions, which led to the creation of a public database. Most interventions targeted physical, psychological, and financial abuse and neglect, were implemented in the USA, and focused on victims or potential victims. These interventions were primarily delivered by social workers and nurses, usually in health-care facilities and community centres. Face-to-face delivery was common. Additionally, 28 (28%) of the 101 evaluations used randomised controlled trial designs. The results of this Review can be used to identify interventions that are ready for a rigorous outcome evaluation.

To understand how COVID-19 vaccines impact infection risk in children <5 years, we assessed risk of SARS-CoV-2 infection from Sept 2022-April 2023 in three cohort studies. There was no difference in risk by vaccination status. While vaccines reduce severe disease, they may not reduce SARS-CoV-2 infections in young children.

Congregate homeless shelters are disproportionately affected by infectious disease outbreaks. We describe enterovirus epidemiology across 23 adult and family shelters in King County, Washington, USA, during October 2019-May 2021, by using repeated cross-sectional respiratory illness and environmental surveillance and viral genome sequencing. Among 3,281 participants >3 months of age, we identified coxsackievirus A21 (CVA21) in 39 adult residents (3.0% [95% CI 1.9%-4.8%] detection) across 7 shelters during October 2019-February 2020. We identified enterovirus D68 (EV-D68) in 5 adult residents in 2 shelters during October-November 2019. Of 812 environmental samples, 1 was EV-D68-positive and 5 were CVA21-positive. Other enteroviruses detected among residents, but not in environmental samples, included coxsackievirus A6/A4 in 3 children. No enteroviruses were detected during April 2020-May 2021. Phylogenetically clustered CVA21 and EV-D68 cases occurred in some shelters. Some shelters also hosted multiple CVA21 lineages.

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal pathogen priority list. This systematic review aimed to evaluate the epidemiology and impact of infections caused by Talaromyces marneffei, Coccidioides species, and Paracoccidioides species. PubMed and Web of Sciences databases were searched to identify studies published between 1 January 2011 and 23 February 2021 reporting on mortality, complications and sequelae, antifungal susceptibility, preventability, annual incidence, and trends. Overall, 25, 17, and 6 articles were included for T. marneffei, Coccidioides spp. and Paracoccidioides spp., respectively. Mortality rates were high in those with invasive talaromycosis and paracoccidioidomycosis (up to 21% and 22.7%, respectively). Hospitalization was frequent in those with coccidioidomycosis (up to 84%), and while the duration was short (mean/median 3-7 days), readmission was common (38%). Reduced susceptibility to fluconazole and echinocandins was observed for T. marneffei and Coccidioides spp., whereas >88% of T. marneffei isolates had minimum inhibitory concentration values ≤0.015 μg/ml for itraconazole, posaconazole, and voriconazole. Risk factors for mortality in those with talaromycosis included low CD4 counts (odds ratio 2.90 when CD4 count <200 cells/μl compared with 24.26 when CD4 count <50 cells/μl). Outbreaks of coccidioidomycosis and paracoccidioidomycosis were associated with construction work (relative risk 4.4-210.6 and 5.7-times increase, respectively). In the United States of America, cases of coccidioidomycosis increased between 2014 and 2017 (from 8232 to 14 364/year). National and global surveillance as well as more detailed studies to better define sequelae, risk factors, outcomes, global distribution, and trends are required.

Introduction: Longitudinal data on how acute respiratory illness (ARI) affects behavior, namely school or work participation, and nonpharmaceutical intervention (NPI) usage before and during the COVID-19 pandemic is limited. The authors assessed how ARIs and specific symptoms affected school, work, and health-related behaviors over time. Methods: From November 2019 to June 2021, participating households with children in King County, Washington, were remotely monitored for ARI symptoms weekly. Following ARIs, participants reported illness-related effects on school, work, and NPI use. Using logistic regression with generalized estimating equations, the authors examined associations between symptoms and behaviors. Results: Of 1,861 participants, 581 (31%) from 293 households reported 884 ARIs and completed one-week follow-up surveys. Compared with the prepandemic period, during the period of the pandemic pre–COVID-19 vaccine, ARI-related school (56% vs 10%, p<0.001) absenteeism decreased and masking increased (3% vs 28%, p<0.001). After vaccine authorization in December 2020, more ARIs resulted in masking (3% vs 48%, p<0.001), avoiding contact with non-household members (26% vs 58%, p<0.001), and staying home (37% vs 69%, p<0.001) compared with the prepandemic period. Constitutional symptoms such as fever were associated with work disruptions (OR=1.91; 95% CI=1.06, 3.43), staying home (OR=1.55; 95% CI=1.06, 2.27), and decreased contact with non-household members (OR=1.58; 95% CI=1.05, 2.36). Conclusions: This remote household study permitted uninterrupted tracking of behavioral changes in families with children before and during the COVID-19 pandemic, identifying increased use of some NPIs when ill but no additional illness-associated work or school disruptions. © 2024 The Authors

In response to the growing global burden of fungal infections with uncertain impact, the World Health Organization (WHO) established an Expert Group to identify priority fungal pathogens and establish the WHO Fungal Priority Pathogens List for future research. This systematic review aimed to evaluate the features and global impact of invasive candidiasis caused by Candida tropicalis. PubMed and Web of Science were searched for studies reporting on criteria of mortality, morbidity (defined as hospitalization and disability), drug resistance, preventability, yearly incidence, diagnostics, treatability, and distribution/emergence from 2011 to 2021. Thirty studies, encompassing 436 patients from 25 countries were included in the analysis. All-cause mortality due to invasive C. tropicalis infections was 55%-60%. Resistance rates to fluconazole, itraconazole, voriconazole and posaconazole up to 40%-80% were observed but C. tropicalis isolates showed low resistance rates to the echinocandins (0%-1%), amphotericin B (0%), and flucytosine (0%-4%). Leukaemia (odds ratio (OR) = 4.77) and chronic lung disease (OR = 2.62) were identified as risk factors for invasive infections. Incidence rates highlight the geographic variability and provide valuable context for understanding the global burden of C. tropicalis infections. C. tropicalis candidiasis is associated with high mortality rates and high rates of resistance to triazoles. To address this emerging threat, concerted efforts are needed to develop novel antifungal agents and therapeutic approaches tailored to C. tropicalis infections. Global surveillance studies could better inform the annual incidence rates, distribution and trends and allow informed evaluation of the global impact of C. tropicalis infections.

Recognizing the growing global burden of fungal infections, the World Health Organization established a process to develop a priority list of fungal pathogens (FPPL). In this systematic review, we aimed to evaluate the epidemiology and impact of infections caused by Fusarium spp., Scedosporium spp., and Lomentospora prolificans to inform the first FPPL. PubMed and Web of Sciences databases were searched to identify studies published between January 1, 2011 and February 23, 2021, reporting on mortality, complications and sequelae, antifungal susceptibility, preventability, annual incidence, and trends. Overall, 20, 11, and 9 articles were included for Fusarium spp., Scedosporium spp., and L. prolificans, respectively. Mortality rates were high in those with invasive fusariosis, scedosporiosis, and lomentosporiosis (42.9%-66.7%, 42.4%-46.9%, and 50.0%-71.4%, respectively). Antifungal susceptibility data, based on small isolate numbers, showed high minimum inhibitory concentrations (MIC)/minimum effective concentrations for most currently available antifungal agents. The median/mode MIC for itraconazole and isavuconazole were ≥16 mg/l for all three pathogens. Based on limited data, these fungi are emerging. Invasive fusariosis increased from 0.08 cases/100 000 admissions to 0.22 cases/100 000 admissions over the time periods of 2000-2009 and 2010-2015, respectively, and in lung transplant recipients, Scedosporium spp. and L. prolificans were only detected from 2014 onwards. Global surveillance to better delineate antifungal susceptibility, risk factors, sequelae, and outcomes is required.

Recognizing the growing global burden of fungal infections, the World Health Organization established a process to develop a priority list of fungal pathogens (FPPL). In this systematic review, we aimed to evaluate the epidemiology and impact of invasive infections caused by Aspergillus fumigatus to inform the first FPPL. The pre-specified criteria of mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence were used to search for relevant articles between 1 January 2016 and 10 June 2021. Overall, 49 studies were eligible for inclusion. Azole antifungal susceptibility varied according to geographical regions. Voriconazole susceptibility rates of 22.2% were reported from the Netherlands, whereas in Brazil, Korea, India, China, and the UK, voriconazole susceptibility rates were 76%, 94.7%, 96.9%, 98.6%, and 99.7%, respectively. Cross-resistance was common with 85%, 92.8%, and 100% of voriconazole-resistant A. fumigatus isolates also resistant to itraconazole, posaconazole, and isavuconazole, respectively. The incidence of invasive aspergillosis (IA) in patients with acute leukemia was estimated at 5.84/100 patients. Six-week mortality rates in IA cases ranged from 31% to 36%. Azole resistance and hematological malignancy were poor prognostic factors. Twelve-week mortality rates were significantly higher in voriconazole-resistant than in voriconazole-susceptible IA cases (12/22 [54.5%] vs. 27/88 [30.7%]; P = .035), and hematology patients with IA had significantly higher mortality rates compared with solid-malignancy cases who had IA (65/217 [30%] vs. 14/78 [18%]; P = .04). Carefully designed surveillance studies linking laboratory and clinical data are required to better inform future FPPL.

BACKGROUND: SARS-CoV-2 antigen-detection rapid diagnostic tests (Ag-RDTs) have become widely utilized but longitudinal characterization of their community-based performance remains incompletely understood. METHODS: This prospective longitudinal study at a large public university in Seattle, WA utilized remote enrollment, online surveys, and self-collected nasal swab specimens to evaluate Ag-RDT performance against real-time reverse transcription polymerase chain reaction (rRT-PCR) in the context of SARS-CoV-2 Omicron. Ag-RDT sensitivity and specificity within 1 day of rRT-PCR were evaluated by symptom status throughout the illness episode and Orf1b cycle threshold (Ct). RESULTS: From February to December 2022, 5,757 participants reported 17,572 Ag-RDT results and completed 12,674 rRT-PCR tests, of which 995 (7.9%) were rRT-PCR-positive. Overall sensitivity and specificity were 53.0% (95% CI: 49.6-56.4%) and 98.8% (98.5-99.0%), respectively. Sensitivity was comparatively higher for Ag-RDTs used 1 day after rRT-PCR (69.0%), 4 to 7 days post-symptom onset (70.1%), and Orf1b Ct ≤20 (82.7%). Serial Ag-RDT sensitivity increased with repeat testing ≥2 (68.5%) and ≥4 (75.8%) days after an initial Ag-RDT-negative result. CONCLUSION: Ag-RDT performance varied by clinical characteristics and temporal testing patterns. Our findings support recommendations for serial testing following an initial Ag-RDT-negative result, especially among recently symptomatic persons or those at high-risk for SARS-CoV-2 infection.

BACKGROUND: Early during the COVID-19 pandemic, it was important to better understand transmission dynamics of SARS-CoV-2, the virus that causes COVID-19. Household contacts of infected individuals are particularly at risk for infection, but delays in contact tracing, delays in testing contacts, and isolation and quarantine posed challenges to accurately capturing secondary household cases. METHODS: In this study, 346 households in the Seattle region were provided with respiratory specimen collection kits and remotely monitored using web-based surveys for respiratory illness symptoms weekly between October 1, 2020, and June 20, 2021. Symptomatic participants collected respiratory specimens at symptom onset and mailed specimens to the central laboratory in Seattle. Specimens were tested for SARS-CoV-2 using RT-PCR with whole genome sequencing attempted when positive. SARS-CoV-2-infected individuals were notified, and their household contacts submitted specimens every 2 days for 14 days. RESULTS: In total, 1371 participants collected 2029 specimens that were tested; 16 individuals (1.2%) within 6 households tested positive for SARS-CoV-2 during the study period. Full genome sequences were generated from 11 individuals within 4 households. Very little genetic variation was found among SARS-CoV-2 viruses sequenced from different individuals in the same household, supporting transmission within the household. CONCLUSIONS: This study indicates web-based surveillance of respiratory symptoms, combined with rapid and longitudinal specimen collection and remote contact tracing, provides a viable strategy to monitor households and detect household transmission of SARS-CoV-2. TRIAL REGISTRATION IDENTIFIER: NCT04141930, Date of registration 28/10/2019.

Vaccine effectiveness (VE) studies utilizing the test-negative design are typically conducted in clinical settings, rather than community populations, leading to bias in VE estimates against mild disease and limited information on VE in healthy young adults. In a community-based university population, we utilized data from a large SARS-CoV-2 testing program to estimate relative VE of COVID-19 mRNA vaccine primary series and monovalent booster dose versus primary series only against symptomatic SARS-CoV-2 infection from September 2021 to July 2022. We used the test-negative design and logistic regression implemented via generalized estimating equations adjusted for age, calendar time, prior SARS-CoV-2 infection, and testing frequency (proxy for test-seeking behavior) to estimate relative VE. Analyses included 2,218 test-positive cases (59 % received monovalent booster dose) and 9,615 test-negative controls (62 %) from 9,066 individuals, with median age of 21 years, mostly students (71 %), White (56 %) or Asian (28 %), and with few comorbidities (3 %). More cases (23 %) than controls (6 %) had COVID-19-like illness. Estimated adjusted relative VE of primary series and monovalent booster dose versus primary series only against symptomatic SARS-CoV-2 infection was 40 % (95 % CI: 33-47 %) during the overall analysis period and 46 % (39-52 %) during the period of Omicron circulation. Relative VE was greater for those without versus those with prior SARS-CoV-2 infection (41 %, 34-48 % versus 33 %, 9 %-52 %, P < 0.001). Relative VE was also greater in the six months after receiving a booster dose (41 %, 33-47 %) compared to more than six months (27 %, 8-42 %), but this difference was not statistically significant (P = 0.06). In this relatively young and healthy adult population, an mRNA monovalent booster dose provided increased protection against symptomatic SARS-CoV-2 infection, overall and with the Omicron variant. University testing programs may be utilized for estimating VE in healthy young adults, a population that is not well-represented by routine VE studies.

IMPORTANCE: Bivalent mRNA COVID-19 vaccines were recommended in the US for children and adolescents aged 12 years or older on September 1, 2022, and for children aged 5 to 11 years on October 12, 2022; however, data demonstrating the effectiveness of bivalent COVID-19 vaccines are limited. OBJECTIVE: To assess the effectiveness of bivalent COVID-19 vaccines against SARS-CoV-2 infection and symptomatic COVID-19 among children and adolescents. DESIGN, SETTING, AND PARTICIPANTS: Data for the period September 4, 2022, to January 31, 2023, were combined from 3 prospective US cohort studies (6 sites total) and used to estimate COVID-19 vaccine effectiveness among children and adolescents aged 5 to 17 years. A total of 2959 participants completed periodic surveys (demographics, household characteristics, chronic medical conditions, and COVID-19 symptoms) and submitted weekly self-collected nasal swabs (irrespective of symptoms); participants submitted additional nasal swabs at the onset of any symptoms. EXPOSURE: Vaccination status was captured from the periodic surveys and supplemented with data from state immunization information systems and electronic medical records. MAIN OUTCOME AND MEASURES: Respiratory swabs were tested for the presence of the SARS-CoV-2 virus using reverse transcriptase-polymerase chain reaction. SARS-CoV-2 infection was defined as a positive test regardless of symptoms. Symptomatic COVID-19 was defined as a positive test and 2 or more COVID-19 symptoms within 7 days of specimen collection. Cox proportional hazards models were used to estimate hazard ratios for SARS-CoV-2 infection and symptomatic COVID-19 among participants who received a bivalent COVID-19 vaccine dose vs participants who received no vaccine or monovalent vaccine doses only. Models were adjusted for age, sex, race, ethnicity, underlying health conditions, prior SARS-CoV-2 infection status, geographic site, proportion of circulating variants by site, and local virus prevalence. RESULTS: Of the 2959 participants (47.8% were female; median age, 10.6 years [IQR, 8.0-13.2 years]; 64.6% were non-Hispanic White) included in this analysis, 25.4% received a bivalent COVID-19 vaccine dose. During the study period, 426 participants (14.4%) had laboratory-confirmed SARS-CoV-2 infection. Among these 426 participants, 184 (43.2%) had symptomatic COVID-19, 383 (89.9%) were not vaccinated or had received only monovalent COVID-19 vaccine doses (1.38 SARS-CoV-2 infections per 1000 person-days), and 43 (10.1%) had received a bivalent COVID-19 vaccine dose (0.84 SARS-CoV-2 infections per 1000 person-days). Bivalent vaccine effectiveness against SARS-CoV-2 infection was 54.0% (95% CI, 36.6%-69.1%) and vaccine effectiveness against symptomatic COVID-19 was 49.4% (95% CI, 22.2%-70.7%). The median observation time after vaccination was 276 days (IQR, 142-350 days) for participants who received only monovalent COVID-19 vaccine doses vs 50 days (IQR, 27-74 days) for those who received a bivalent COVID-19 vaccine dose. CONCLUSION AND RELEVANCE: The bivalent COVID-19 vaccines protected children and adolescents against SARS-CoV-2 infection and symptomatic COVID-19. These data demonstrate the benefit of COVID-19 vaccine in children and adolescents. All eligible children and adolescents should remain up to date with recommended COVID-19 vaccinations.

Non-pharmaceutical interventions minimize social contacts, hence the spread of respiratory pathogens such as influenza and SARS-CoV-2. Globally, there is a paucity of social contact data from the workforce. In this study, we quantified two-day contact patterns among USA employees. Contacts were defined as face-to-face conversations, involving physical touch or proximity to another individual and were collected using electronic self-kept diaries. Data were collected over 4 rounds from 2020 to 2021 during the COVID-19 pandemic. Mean (standard deviation) contacts reported by 1456 participants were 2.5 (2.5), 8.2 (7.1), 9.2 (7.1) and 10.1 (9.5) across round 1 (April-June 2020), 2 (November 2020-January 2021), 3 (June-August 2021), and 4 (November-December 2021), respectively. Between round 1 and 2, we report a 3-fold increase in the mean number of contacts reported per participant with no major increases from round 2-4. We then modeled SARS-CoV-2 transmission at home, work, and community settings. The model revealed reduced relative transmission in all settings in round 1. Subsequently, transmission increased at home and in the community but remained exceptionally low in work settings. To accurately parameterize models of infection transmission and control, we need empirical social contact data that capture human mixing behavior across time.

INTRODUCTION: With the licensure of maternal RSV vaccines in Europe and USA, data are needed to better characterize the burden of respiratory syncytial virus (RSV)-associated acute respiratory infections (ARI) in pregnancy. This study aims to determine among pregnant individuals the proportion of ARI testing positive for RSV and RSV incidence rate, RSV-associated hospitalizations, deaths, and perinatal outcomes. METHODS: We conducted a systematic review following PRISMA 2020 guidelines using five databases (Medline, Embase, Global Health, Web of Science and Global Index Medicus) and included additional unpublished data. Pregnant individuals with respiratory infections who had respiratory samples tested for RSV were included. We used a random-effects meta-analysis to generate overall proportions and rate estimates across studies. RESULTS: Eleven studies with pregnant individuals recruited between 2010 and 2022 were identified, most of which recruited pregnant individuals in community, inpatient and outpatient settings. Among 8126 pregnant individuals, the proportion with respiratory infections that tested positive for RSV ranged from 0.9% to 10.7%, with a meta-estimate of 3.4% (95% CI: 1.9; 54). The pooled incidence rate of RSV infection episodes among pregnant individuals was 26.0 (15.8; 36.2) per 1000 person-years. RSV hospitalization rates reported in two studies were 2.4 and 3.0 per 1000 person-years. Of five studies that ascertained RSV-associated deaths among 4708 pregnant individuals, no deaths were reported. Three studies comparing RSV-positive and RSV-negative pregnant individuals found no difference in odds of miscarriage, stillbirth, low birth weight, and small for gestational age. RSV-positive pregnant individuals had higher odds of preterm delivery (odds ratio 3.6 [1.3; 10.3]). CONCLUSION: Data on RSV-associated hospitalization incidence rates are limited but available estimates are lower than those reported in older adults and young children. As countries debate whether to include RSV vaccines in maternal vaccination programs, which are primarily intended to protect infants, this information could be useful in shaping vaccine policy decisions.

BACKGROUND: The epidemiology of respiratory viral infections is complex. How infection with one respiratory virus affects risk of subsequent infection with the same or another respiratory virus is not well described. METHODS: We retrospectively analyzed data from a longitudinal household cohort study from October 2019-June 2021. Enrolled households completed active surveillance for acute respiratory illness (ARI), and participants with ARI self-collected nasal swabs; after April 2020, participants with ARI or laboratory-confirmed SARS-CoV-2 and their household members self-collected nasal swabs. Specimens were tested via multiplex RT-PCR for respiratory viruses. A Cox regression model with a time-dependent covariate examined risk of subsequent detections following a specific primary viral detection. RESULTS: Rhinovirus was the most frequently detected pathogen in study specimens (n=406, 9.5%). Among 51 participants with multiple viral detections, rhinovirus to seasonal coronavirus (8, 14.8%) was the most common viral detection pairing. Relative to no primary detection, there was a 1.03-2.06-fold increase in risk of subsequent virus detection in the 90 days following primary detection; risk varied by primary virus: parainfluenza, rhinovirus, and respiratory syncytial virus were statistically significant. CONCLUSIONS: Primary virus detection was associated with higher risk of subsequent virus detection within the first 90 days after primary detection.

Background Households represent important settings for transmission of influenza and other respiratory viruses. Current influenza diagnosis and treatment relies upon patient visits to healthcare facilities, which may lead to under-diagnosis and treatment delays. This study aimed to assess the feasibility of an at-home approach to influenza diagnosis and treatment via home testing, telehealth care, and rapid antiviral home delivery.Methods We conducted a pilot interventional study of remote influenza diagnosis and treatment in Seattle-area households with children during the 2019-2020 influenza season using pre-positioned nasal swabs and home influenza tests. Home monitoring for respiratory symptoms occurred weekly; if symptoms were reported within 48 hours of onset, participants collected mid-nasal swabs and used a rapid home-based influenza immunoassay. An additional home-collected swab was returned to a laboratory for confirmatory influenza RT-PCR testing. Baloxavir antiviral treatment was prescribed and delivered to symptomatic and age-eligible participants, following a telehealth encounter.Results 124 households comprising 481 individuals self-monitored for respiratory symptoms, with 58 home tests administered. 12 home tests were positive for influenza, of which 8 were true positives confirmed by RT-PCR. The sensitivity and specificity of the home influenza test was 72.7% and 96.2%, respectively. There were 8 home deliveries of baloxavir, with 7 (87.5%) occurring within 3 hours of prescription, and all within 48 hours of symptom onset.Conclusions We demonstrate the feasibility of self-testing combined with rapid home delivery of influenza antiviral treatment. This approach may be an important control strategy for influenza epidemics and pandemics.Summary In this pilot study, 481 individuals self-monitored for respiratory symptoms. Of 58 home tests, 12 were influenza-positive. There were 8 baloxavir home deliveries within 48 hours of illness onset. A home-based approach to influenza diagnosis and treatment could be feasible.Competing Interest StatementH.Y.C. has received research support from GlaxoSmithKline, Novavax, and Sanofi Pasteur; J.A.E. has received research support from AstraZeneca, GlaxoSmithKine, Merck, and Pfizer and served as a consultant for Sanofi Pasteur and Meissa Vaccines. M.L.J. has received research support from Sanofi Pasteur. M.B. receives research support and serves as a consultant for Ansun Biopharma, Gilead Sciences, Janssen, and Vir Biotechnology; and serves as a consultant to GlaxoSmithKline, ReViral, ADMA, Pulmocdie and ModernaClinical TrialNCT04141930Funding StatementThe Seattle Flu Study is funded by Gates Ventures. The funder was not involved in the design of the study, does not have any ownership over the management and conduct of the study, the data, or the rights to publish.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:University of Washington Institutional Review Board (STUDY00008200)All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesData and code used for analyses may be available upon request.

Introduction Influenza epidemics and pandemics cause significant morbidity and mortality. An effective response to a potential pandemic requires the infrastructure to rapidly detect, characterize, and potentially contain new and emerging influenza strains at a population level. The objective of this study is to use data gathered simultaneously from community and hospital sites to develop a model of how influenza enters and spreads in a population.Methods and Analysis Starting in the 2018-19 season, we have been enrolling individuals with acute respiratory illness from community sites throughout the Seattle metropolitan area, including clinics, childcare facilities, Seattle-Tacoma International Airport, workplaces, college campuses, and homeless shelters. At these sites, we collect clinical data and mid-nasal swabs from individuals with at least two acute respiratory symptoms. Additionally, we collect residual nasal swabs and data from individuals who seek care for respiratory symptoms at four regional hospitals. Samples are tested using a multiplex molecular assay, and influenza whole genome sequencing is performed for samples with influenza detected. Geospatial mapping and computational modeling platforms are in development to characterize the regional spread of influenza and other respiratory pathogens.Ethics and Dissemination The study was approved by the University of Washington’s Institutional Review Board. Results will be disseminated through talks at conferences, peer-reviewed publications, and on the study website (www.seattleflu.org).Strengths and limitations of this study- Large-scale multiple-arm study of respiratory illness characterization with collection of samples from individuals in the community as well as in ambulatory care and hospital settings- Integration of sociodemographic, clinical, and geospatial data on a regional level- Multiplex molecular testing for multiple viral and bacterial pathogens and whole genome sequencing of influenza for detailed molecular epidemiologic characterization and transmission mapping- Geographically and socioeconomically diverse sampling of community-based acute respiratory illnessesCompeting Interest StatementAmanda Adler, Elisabeth Brandstetter, Michael Famulare, Chris D. Frazar, Peter D. Han, Reena K. Gulati, James Hadfield, Michael L. Jackson, Anahita Kiavand, Louise E. Kimball, Kirsten Lacombe, Jennifer Logue, Victoria Lyon, Kira L. Newman, Thomas R. Sibley, Jay Shendure, Lea Starita, Monica L. Zigman Suchsland, and Caitlin Wolf declare no competing interests. Helen Y Chu receives research support from Sanofi, Cepheid, and Genentech/Roche and is a consultant for Merck. Janet Englund receives research support to her institution from Astrazeneca, GlaxoSmithKline, Merck, and Novavax and is a consultant for Sanofi Pasteur and Meissa Vaccines.Funding StatementThe Seattle Flu Study is funded through the Brotman Baty Institute. The funder was not involved in the design of the study, does not have any ownership over the management and conduct of the study, the data, or the rights to publishAuthor DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable YesThe data will be accessed only by authorized individuals on the study team. Access to deidentified, aggregated data and analysis code will be publicly available on the study web page (www.seattleflu.org). http://www.seattleflu.org

Estimating prevalence of SARS-CoV-2 antibodies is important to determine disease burden. We tested residual samples from 763 Seattle-area adults for SARS-CoV-2 antibodies. Prevalence rose from 0% to 1.2% between October 2019–April 2020, suggesting a small percentage of this metropolitan-area cohort had been infected with SARS-CoV-2 at that time.Competing Interest StatementHelen Y. Chu receives research support from Cepheid and is a consultant for Merck, Pfizer, the Bill and Melinda Gates Foundation, and Ellume. Michael L. Jackson receives research funding from Sanofi Pasteur. Denise J. McCulloch, James P. Hughes, Sandra Lester, Lisa Mills, Brandi Freeman, Mohammad Ata Ut Rasheed, and Natalie J. Thornburg, declare no competing interests.Funding StatementThis work was supported by the University of Washington Department of Medicine Scholars Award to Helen Chu.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:University of Washington IRBAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThe data analyzed during the current study are available from the corresponding author on reasonable request.

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 1/1/2020 -5/31/2021. 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 time of detection (74%) and detected during routine surveillance (73%). Outbreak testing yielded higher test positivity compared to routine surveillance (2.7% vs. 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. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.

Homeless shelter residents and staff may be at higher risk of SARS-CoV-2 infection. However, | 34 SARS-CoV-2 infection estimates in this population have been reliant on cross-sectional or | 35 outbreak investigation data. We conducted routine surveillance and outbreak testing in 23 | 36 homeless shelters in King County, Washington to estimate the occurrence of laboratory37 confirmed SARS-CoV-2 infection and risk factors during 1/1/2020 -5/31/2021. Symptom surveys | 38 and nasal swabs were collected for SARS-CoV-2 testing by RT-PCR for residents aged ≥3 | 39 months and staff. We collected 12,915 specimens from 2,930 unique participants. We identified | 40 4.74 (95% CI 4.00 – 5.58) SARS-CoV-2 infections per 100 individuals (residents: 4.96, 95% CI | 41 4.12 – 5.91; staff: 3.86, 95% CI 2.43 – 5.79). Most infections were asymptomatic at time of | 42 detection (74%) and detected during routine surveillance (73%). Outbreak testing yielded higher | 43 test positivity compared to routine surveillance (2.7% vs. 0.9%). Among those infected, | 44 residents were less likely to report symptoms than staff. Participants who were vaccinated | 45 against seasonal influenza and were current smokers had lower odds of having an infection | 46 detected. Active surveillance that includes SARS-CoV-2 testing of all persons is essential in | 47 ascertaining the true burden of SARS-CoV-2 infections among residents and staff of congregate | 48 settings.

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.