Search

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 pose 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 two days for fourteen days. Results: In total, 1,371 participants collected 2,029 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

Background Families with children may be at higher risk for influenza infection. Community transmission can suffer from underreporting as testing is often not performed. We studied the epidemiology of influenza in households with school-aged children using home-based sample collection. Methods We conducted a remote household study surveilling respiratory viruses from November 2019-June 2021, in King County, Washington (WA), USA. Households with school-aged children were enrolled, mailed home specimen collection kits, and asked to self-assess for weekly acute respiratory illness (ARI) using remote survey platforms. Participants with ARI symptoms were prompted to complete serial illness surveys and self-collect/parent collect mid-turbinate nasal swabs. Samples were sent to a University of Washington study laboratory for RT-PCR influenza testing. Influenza rates were compared to WA Department of Health (DOH) reporting. Results A total of 1861 ARI events were reported among 992 adults and 869 children in 470 households; 75 influenza cases were detected (36 influenza A and 39 influenza B). The study participant median age was 32 years (0-84), 10 years (1-49) for influenza A, and 11 years (3-49) for influenza B cases. Overall 13% of households had an influenza case, of which 13 (22%) reported >1 case. A total of 81% of participants reported receipt of one dose of the 2019-2020 influenza vaccine, including 91% of influenza A and 90% of influenza B cases, and 84% received the 2020-2021 influenza vaccine. Like WA DOH, we observed a wave of influenza B cases followed by influenza A in 2019-2020. During influenza season 2020-2021, WA DOH reported 9 positive influenza tests and none observed in our study. Commonly, influenza case-patients reported were fever, cough, rhinorrhea, and fatigue. GI symptoms were more common in children than adults. Of the cases, 92% of influenza A and 78% of influenza B occurred in children. Figure 1.Influenza A and B cases from 2019-2021Figure 2A.Reported Symptoms of Influenza A D0-Day of reported onset, D7-7 days after reported illness onset. No participants >49 years were positive for influenza. D0: 30 participants responded and of respondents, 13% D0-Day of reported onset, D7-7 days after reported illness onset. No participants >49 years were positive for influenza. D0: 28 participants responded and of respondents, 4% Conclusion Influenza illness in 2019-2020 was initially influenza B, and subsequently replaced by influenza A. Most cases were in children and adolescents, despite at least one dose of influenza vaccine. Symptoms were widely distributed and similar between influenza A and B. Influenza incidence in our cohort declined to zero with the rise of SARS-CoV-2 cases and widespread mitigation efforts. Disclosures 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.

Background Non-pharmaceutical interventions (NPIs), such as masking and social distancing, can reduce SARS-CoV-2 transmission. Longitudinal behavioral data in individuals with acute respiratory illness (ARI) during the COVID-19 pandemic are limited. We describe changes in adherence to NPIs and the impact of ARIs on work or school in families before and during the COVID-19 pandemic. Methods From November 2019 to June 2021, households with school-aged children in King County, WA, were remotely monitored on a weekly basis for symptoms of respiratory illness. Participants with ARI (cough or ≥2 qualifying symptoms) were asked about illness-related behavior changes (e.g. masking, isolation, hand hygiene, surface cleaning, public transit use) and impacts on school/work 7 days after initial symptom report. Using generalized estimating equations for household clusters, we compared the frequency of behavior changes and school/work impact during 3 time periods: the pre-/early COVID-19 pandemic period (11/14/19-3/22/20), pre-vaccine period (3/23/20-12/10/20), and post-COVID-19 vaccine period (12/11/20-6/19/21). Results Of 1861 participants in 470 households, 695 (37%, from 70% of households) reported 1157 ARIs. Over the 3 time periods, the percent of ill participants who reported staying home (34 vs 34 vs 54%, respectively, P< .001), avoiding contact with others (25 vs 28 vs 45%, P< .001), and masking (3 vs 23 vs 38%, P< .001) increased (Fig 1A). Other illness-related behaviors, including washing hands and disinfecting surfaces, were unchanged over time. The percent of ill participants who worked from home (7 vs 9 vs 3%, P= .02) and missed work due to ARI (13 vs 8 vs 8%, P= .03) decreased over time (Fig 1B). Figure 1A.Participant reported illness-related health behaviors in the past week — Seattle, WA, 2019–2021.Figure 1B.Participant reported illness-related school or work impact in the past week due to illness — Seattle, WA, 2019–2021 Time periods were defined as: Period 1: 11/14/19 – 3/22/20 (pre-/early COVID-19 pandemic), Period 2: 3/23/20 – 12/10/20 (post-Washington State Stay at Home order), and Period 3: 12/11/20 – 6/19/21 (United States Food and Drug Administration Emergency Use Authorization for the Pfizer-BioNTech COVID-19 vaccine for those 16 years and older). Illness was defined per Acute Respiratory Illness (ARI) case definition: cough or two qualifying symptoms (fever, sore throat, runny nose, muscle or body aches, headache, difficulty breathing, fatigue, nausea or vomiting; for participants < 18 years of age, ear pain or drainage, rash, and diarrhea were also qualifying symptoms). Conclusion As the COVID-19 pandemic progressed, households with school-aged children engaged in isolation, social distancing, and masking more frequently in response to ARI. The impact of ARIs on work decreased during the pandemic. Disclosures 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.

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 eight were true positives confirmed by RT‐PCR. The sensitivity and specificity of the home influenza test were 72.7% and 96.2%, respectively. There were eight 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.

BackgroundHouseholds 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.MethodsWe 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.Results124 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.ConclusionsWe 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.SummaryIn 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.

Background Although multiple respiratory viruses circulate in humans, few studies have compared the incidence of different viruses across the life course. We estimated the incidence of outpatient illness due to 12 different viruses during November 2018 through April 2019 in a fully enumerated population. Methods We conducted active surveillance for ambulatory care visits for acute respiratory illness (ARI) among members of Kaiser Permanente Washington (KPWA). Enrolled patients provided respiratory swab specimens which were tested for 12 respiratory viruses using reverse transcription polymerase chain reaction (RT-PCR). We estimated the cumulative incidence of infection due to each virus overall and by age group. Results The KPWA population under surveillance included 202 562 individuals, of whom 2767 (1.4%) were enrolled in the study. Influenza A(H3N2) was the most commonly detected virus, with an overall incidence of 21 medically attended illnesses per 1000 population; the next most common viruses were influenza A(H1N1) (18 per 1000), coronaviruses (13 per 1000), respiratory syncytial virus (RSV, 13 per 1000), and rhinovirus (9 per 1000). RSV was the most common cause of medically attended ARI among children aged 1–4 years; coronaviruses were the most common among adults aged ≥65 years. Conclusions Consistent with other studies focused on single viruses, we found that influenza and RSV were major causes of acute respiratory illness in persons of all ages. In comparison, coronaviruses and rhinovirus were also important pathogens. Prior to the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronaviruses were the second-most common cause of medically attended ARI during the 2018/19 influenza season.

While influenza and other respiratory pathogens cause significant morbidity and mortality, the community-based burden of these infections remains incompletely understood. The development of novel methods to detect respiratory infections is essential for mitigating epidemics and developing pandemic-preparedness infrastructure., While influenza and other respiratory pathogens cause significant morbidity and mortality, the community-based burden of these infections remains incompletely understood. The development of novel methods to detect respiratory infections is essential for mitigating epidemics and developing pandemic-preparedness infrastructure. From October 2019 to March 2020, we conducted a home-based cross-sectional study in the greater Seattle, WA, area, utilizing electronic consent and data collection instruments. Participants received nasal swab collection kits via rapid delivery within 24 hours of self-reporting respiratory symptoms. Samples were returned to the laboratory and were screened for 26 respiratory pathogens and a housekeeping gene. Participant data were recorded via online survey at the time of sample collection and 1 week later. Of the 4,572 consented participants, 4,359 (95.3%) received a home swab kit and 3,648 (83.7%) returned a nasal specimen for respiratory pathogen screening. The 3,638 testable samples had a mean RNase P relative cycle threshold (Crt) value of 19.0 (SD, 3.4), and 1,232 (33.9%) samples had positive results for one or more pathogens, including 645 (17.7%) influenza-positive specimens. Among the testable samples, the median time between shipment of the home swab kit and completion of laboratory testing was 8.0 days (interquartile range [IQR], 7.0 to 14.0). A single adverse event occurred and did not cause long-term effects or require medical attention. Home-based surveillance using online participant enrollment and specimen self-collection is a safe and feasible method for community-level monitoring of influenza and other respiratory pathogens, which can readily be adapted for use during pandemics.

Background Noninfluenza respiratory viruses are responsible for a substantial burden of disease in the United States. Household transmission is thought to contribute significantly to subsequent transmission through the broader community. In the context of the coronavirus disease 2019 (COVID-19) pandemic, contactless surveillance methods are of particular importance. Methods From November 2019 to April 2020, 303 households in the Seattle area were remotely monitored in a prospective longitudinal study for symptoms of respiratory viral illness. Enrolled participants reported weekly symptoms and submitted respiratory samples by mail in the event of an acute respiratory illness (ARI). Specimens were tested for 14 viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), using reverse-transcription polymerase chain reaction. Participants completed all study procedures at home without physical contact with research staff. Results In total, 1171 unique participants in 303 households were monitored for ARI. Of participating households, 128 (42%) included a child aged Conclusions This study highlights the circulation of respiratory viruses within households during the winter months during the emergence of the SARS-CoV-2 pandemic. Contactless methods of recruitment, enrollment, and sample collection were utilized throughout this study and demonstrate the feasibility of home-based, remote monitoring for respiratory infections.

Detection of Covid-19 through a Citywide Surveillance Platform The Seattle Flu study, initiated in 2018, mailed kits for home collection of midnasal swabs to people reporting respiratory symptoms. ...

IntroductionWhile seasonal influenza and other respiratory pathogens cause significant morbidity and mortality each year, the community-based burden of these infections remains incompletely understood. Understanding the prevalence, epidemiology, and transmission dynamics of respiratory pathogen infections among community-dwelling individuals is essential during pandemic and epidemic settings and for developing pandemic-preparedness infrastructure.Methods and AnalysisWe present the protocol for a novel, city-wide home-based cross-sectional study in the Seattle Metropolitan area, utilizing rapid delivery systems for self-collection of a nasal swab and return to the laboratory for respiratory pathogen testing. All participation takes place electronically, including recruitment, consent, and data collection. Within 48 hours of participants self-reporting respiratory symptoms, a nasal swab kit is delivered to the household via a courier service. Demographic and illness characteristics are collected at the time of sample collection and recovery and behavioral information collected one week later. Specimens are tested in the laboratory for multiple respiratory pathogens, and results are available on a public website for participants.Ethics and DisseminationThe study was approved by the University of Washington Institutional Review Board (Protocol #00006181). Results will be disseminated through peer-reviewed publications, talks at conferences, and on the Study Website (www.seattleflu.org).Article SummaryThe findings of this study will inform whether a home-based approach to city-wide respiratory surveillance is possible in epidemic settingsA key strength of this study is that it is conducted across diverse neighborhoods spanning a major metropolitan areaClinical findings may not be generalizable, as they are reliant on self-report (vaccination status, symptoms, healthcare utilization, etc.)