Respiratory Viral Infections from 2015 to 2022 in the HIVE Cohort of American Households: Incidence, illness characteristics, and seasonality.

BACKGROUND: Viral respiratory illnesses are the most common acute illnesses experienced and generally follow a predicted pattern over time. The SARS-CoV-2 pandemic interrupted that pattern. METHODS: The HIVE (Household Influenza Vaccine Evaluation) study was established in 2010 to follow a cohort of Southeast Michigan households over time. Initially focused on influenza, surveillance was expanded to include other major respiratory pathogens, and, starting in 2015, the population was followed year-round. Symptoms of acute illness were reported, and respiratory specimens were collected and tested to identify viral infections. Based on the known population being followed, virus-specific incidence was calculated. RESULTS: From 2015 to 2022, 1755 participants were followed in HIVE for 7785 person-years with 7833 illnesses documented. Before the pandemic, rhinovirus (RV) and common cold human coronaviruses (HCoVs) were the viruses most frequently identified, and incidence decreased with increasing age. Type A influenza was next but with comparable incidence by age. Parainfluenza and respiratory syncytial viruses were less frequent overall, followed by human metapneumoviruses. Incidence was highest in young children, but infections were frequently documented in all age groups. Seasonality followed patterns established decades ago. The SARS-CoV-2 pandemic disrupted these patterns, except for RV and, to a lesser extent, HCoVs. In the first two years of the pandemic, RV incidence far exceeded that of SARS-CoV-2. CONCLUSION: Longitudinal cohort studies are important in comparing the incidence, seasonality, and characteristics of different respiratory viral infections. Studies documented the differential effect of the pandemic on the incidence of respiratory viruses in addition to SARS-CoV-2.

Respiratory virus circulation during the first year of the COVID-19 pandemic in the Household Influenza Vaccine Evaluation (HIVE) cohort.

Background: The annual reappearance of respiratory viruses has been recognized for decades. COVID-19 mitigation measures taken during the pandemic were targeted at respiratory transmission and broadly impacted the burden of acute respiratory illnesses (ARIs). Methods: We used the longitudinal Household Influenza Vaccine Evaluation (HIVE) cohort in southeast Michigan to characterize the circulation of respiratory viruses from March 1, 2020, to June 30, 2021, using RT-PCR of respiratory specimens collected at illness onset. Participants were surveyed twice during the study period, and SARS-CoV-2 antibodies were measured in serum by electrochemiluminescence immunoassay. Incidence rates of ARI reports and virus detections were compared between the study period and a preceding pre-pandemic period of similar duration. Results: Overall, 437 participants reported a total of 772 ARIs; 42.6% had respiratory viruses detected. Rhinoviruses were the most frequent virus, but seasonal coronaviruses, excluding SARS-CoV-2, were also common. Illness reports and percent positivity were lowest from May to August 2020, when mitigation measures were most stringent. Seropositivity for SARS-CoV-2 was 5.3% in summer 2020 and increased to 11.3% in spring 2021. The incidence rate of total reported ARIs for the study period was 50% lower (95% CI: 0.5, 0.6; p < 0.001) than the incidence rate from a pre-pandemic comparison period (March 1, 2016, to June 30, 2017). Conclusions: The burden of ARI in the HIVE cohort during the COVID-19 pandemic fluctuated, with declines occurring concurrently with the widespread use of public health measures. Rhinovirus and seasonal coronaviruses continued to circulate even when influenza and SARS-CoV-2 circulation was low.

Respiratory Virus Circulation during the First Year of the COVID-19 Pandemic in the Household Influenza Vaccine Evaluation (HIVE) Cohort.

Background: The annual reappearance of respiratory viruses has been recognized for decades. The onset of the COVID-19 pandemic altered typical respiratory virus transmission patterns. COVID-19 mitigation measures taken during the pandemic were targeted at SARS-CoV-2 respiratory transmission and thus broadly impacted the burden of acute respiratory illnesses (ARIs), in general. Methods: We used the longitudinal Household Influenza Vaccine Evaluation (HIVE) cohort of households in southeast Michigan to characterize mitigation strategy adherence, respiratory illness burden, and the circulation of 15 respiratory viruses during the COVID-19 pandemic determined by RT-PCR of respiratory specimens collected at illness onset. Study participants were surveyed twice during the study period (March 1, 2020, to June 30, 2021), and serologic specimens were collected for antibody measurement by electrochemiluminescence immunoassay. Incidence rates of ARI reports and virus detections were calculated and compared using incidence rate ratios for the study period and a pre-pandemic period of similar length. Results: Overall, 437 participants reported a total of 772 ARIs and 329 specimens (42.6%) had respiratory viruses detected. Rhinoviruses were the most frequently detected organism, but seasonal coronaviruses-excluding SARS-CoV-2-were also common. Illness reports and percent positivity were lowest from May to August 2020, when mitigation measures were most stringent. Study participants were more adherent to mitigation measures in the first survey compared with the second survey. Supplemental serology surveillance identified 5.3% seropositivity for SARS-CoV-2 in summer 2020; 3.0% between fall 2020 and winter 2021; and 11.3% in spring 2021. Compared to a pre-pandemic period of similar length, the incidence rate of total reported ARIs for the study period was 50% lower (95% CI: 0.5, 0.6; p<0.001) than the incidence rate from March 1, 2016, to June 30, 2017. Conclusions: The burden of ARI in the HIVE cohort during the COVID-19 pandemic fluctuated, with declines occurring concurrently with the widespread use of public health measures. It is notable, however, that rhinovirus and seasonal coronaviruses continued to circulate even as influenza and SARS-CoV-2 circulation was low.

A WORKLOAD SELECTION PROCEDURE FOR THE ÅSTRAND-RYHMING TEST FOR WOMEN.

UNLABELLED: The Åstrand-Ryhming Submaximal Bicycle Test is an accurate and widely used test to estimate maximal oxygen consumption. This test requires a participant to maintain a workload over a 6-min. PERIOD: The issue facing many employing this protocol is the identification of an appropriate workload for the cycling regimen. The present study is designed to identify a method for determining an appropriate workload for female participants. A prior study designed a workload selection procedure specifically for men; however, the selection procedure designed for women in this study was better able to elicit a final heart rate (average of minutes five and six) between 165-170 bpm compared to the original Åstrand-Ryhming procedure.