ABSTRACT
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. 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. (Figure Presented).
ABSTRACT
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), prevaccine 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 theCOVID-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.
ABSTRACT
Background. Human parainfluenza viruses (HPIV) cause respiratory illness in individuals of all ages. However, HPIV epidemiology data in people experiencing homelessness (PEH) are limited. Methods. We analyzed cross-sectional data from a clinical trial and SARS-CoV-2 surveillance study in 23 homeless shelters in King County, Washington from October 2019-May 2021. Questionnaires and nasal swab specimens were obtained from eligible participants at enrollment. Between October 2019-March 31, 2020, participants included those aged > 3 months with acute respiratory illness. Monthly shelter surveillance was also conducted where participants were recruited regardless of symptoms. With the community spread of SARS-CoV-2, the study design transitioned from a clinical trial to a SARS-CoV-2 surveillance study which expanded enrollment eligibility to include participants with or without symptoms from April 1, 2020, onward. Participants were not followed longitudinally but were permitted to enroll multiple times during the study period. Specimens were tested for HPIV 1-4 and other respiratory viruses using RT-PCR. Results. Among 14,464 specimens, 32 were HPIV-positive from 29 participants (median age 9 years, range 0.3-64 years;45% female;28% Black;10% with chronic conditions) of which 59% were children. Family shelters had the highest percentage of HPIV infections (Table). HPIV was detected every month before the community spread of SARS-CoV-2. All HPIV-positive samples in May 2021 came from a single family shelter (Figure). Only 67% of HPIV-positive participants had symptoms with runny nose, cough and sore throat the most commonly reported. HPIV codetection with other respiratory viruses occurred in 19% of HPIV-positive specimens;Rhinovirus co-detection (16%) was the most common. Human Parainfluenza Encounters by Shelter Type Before and After April 1, 2020 Human Parainfluenza Positive Samples by Shelter Type Among Unique Participants Conclusion. HPIV affected PEH of all ages with most cases in shelters with children. Coinciding with community-wide SARS-CoV-2 mitigation efforts, the number of HPIV infections were reduced. However, a cluster of HPIV infections still occurred within one family shelter. Shelter-specific public health measures including nonpharmaceutical interventions used during the COVID-19 pandemic may reduce HPIV infections among residents.