The Epidemiology of Long Coronavirus Disease in US Adults.

BACKGROUND: We estimated the prevalence of long COVID and impact on daily living among a representative sample of adults in the United States. METHODS: We conducted a population-representative survey, 30 June-2 July 2022, of a random sample of 3042 US adults aged 18 years or older and weighted to the 2020 US population. Using questions developed by the UK's Office of National Statistics, we estimated the prevalence of long COVID, by sociodemographics, adjusting for gender and age. RESULTS: An estimated 7.3% (95% confidence interval: 6.1-8.5%) of all respondents reported long COVID, corresponding to approximately 18 828 696 adults. One-quarter (25.3% [18.2-32.4%]) of respondents with long COVID reported their day-to-day activities were impacted "a lot" and 28.9% had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection more than 12 months ago. The prevalence of long COVID was higher among respondents who were female (adjusted prevalence ratio [aPR]: 1.84 [1.40-2.42]), had comorbidities (aPR: 1.55 [1.19-2.00]), or were not (vs were) boosted (aPR: 1.67 [1.19-2.34]) or not vaccinated (vs boosted) (aPR: 1.41 [1.05-1.91]). CONCLUSIONS: We observed a high burden of long COVID, substantial variability in prevalence of SARS-CoV-2, and risk factors unique from SARS-CoV-2 risk, suggesting areas for future research. Population-based surveys are an important surveillance tool and supplement to ongoing efforts to monitor long COVID.

The prevalence of SARS-CoV-2 infection and long COVID in U.S. adults during the BA.4/BA.5 surge, June-July 2022.

Due to changes in SARS-CoV-2 testing practices, passive case-based surveillance may be an increasingly unreliable indicator for monitoring the burden of SARS-CoV-2, especially during surges. We conducted a cross-sectional survey of a population-representative sample of 3042 U.S. adults between June 30 and July 2, 2022, during the Omicron BA.4/BA.5 surge. Respondents were asked about SARS-CoV-2 testing and outcomes, COVID-like symptoms, contact with cases, and experience with prolonged COVID-19 symptoms following prior infection. We estimated the weighted age and sex-standardized SARS-CoV-2 prevalence, during the 14-day period preceding the interview. We estimated age and gender adjusted prevalence ratios (aPR) for current SARS-CoV-2 infection using a log-binomial regression model. An estimated 17.3% (95% CI 14.9, 19.8) of respondents had SARS-CoV-2 infection during the two-week study period-equating to 44 million cases as compared to 1.8 million per the CDC during the same time period. SARS-CoV-2 prevalence was higher among those 18-24 years old (aPR 2.2, 95% CI 1.8, 2.7) and among non-Hispanic Black (aPR 1.7, 95% CI 1.4,2.2) and Hispanic adults (aPR 2.4, 95% CI 2.0, 2.9). SARS-CoV-2 prevalence was also higher among those with lower income (aPR 1.9, 95% CI 1.5, 2.3), lower education (aPR 3.7 95% CI 3.0,4.7), and those with comorbidities (aPR 1.6, 95% CI 1.4, 2.0). An estimated 21.5% (95% CI 18.2, 24.7) of respondents with a SARS-CoV-2 infection >4 weeks prior reported long COVID symptoms. The inequitable distribution of SARS-CoV-2 prevalence during the BA.4/BA.5 surge will likely drive inequities in the future burden of long COVID.

Estimating the period prevalence of SARS-CoV-2 infection during the Omicron (BA.1) surge in New York City (NYC), January 1-March 16, 2022.

In a population-based survey of NYC adults, we assessed positive SARS-CoV-2 tests (including via exclusive at-home testing) and possible cases among untested respondents. An estimated 27.4% (95%CI: 22.8%-32.0%) or 1.8 million adults (95%CI: 1.6-2.1 million) had SARS-CoV-2 infection between January 1 and March 16, 2022.

The Importance of Incorporating At-Home Testing into SARS-CoV-2 Point Prevalence Estimates: Findings from a U.S. National Cohort, February 2022.

BACKGROUND: Passive case-based surveillance underestimates the true extent of active infections in the population due to undiagnosed and untested cases, the exclusion of probable cases diagnosed point-of-care rapid antigen tests, and/or the exclusive use of at-home rapid tests which are not reported as part of case-based surveillance. The extent in which COVID-19 surveillance may be underestimating the burden of infection is likely due to time-varying factors such as decreased test-seeking behaviors and increased access to and availability of at-home testing. OBJECTIVE: The objective of this study was to estimate the prevalence of SARS-CoV-2 based on different definitions of a case to ascertain the extent to which cases of SARS-CoV-2 may be underestimated by case-based surveillance. METHODS: A survey on COVID-19 exposure, infection, and testing was administered to calculate point prevalence of SARS-CoV-2 among a diverse sample of cohort adults between 8-22 February 2022. Three-point prevalence estimates were calculated among the cohort 1) proportion positives based on PCR and/or rapid antigen tests, 2) proportion positive based on testing exclusively with rapid at-home tests, and 3) proportion of probable undiagnosed cases. Test positivity and prevalence differences across booster status were also examined. RESULTS: Among a cohort of 4328, there were a total of 644 cases. The point prevalence estimate based on PCR and/or rapid antigen tests was 5.5% (95% CI: 4.8% - 6.2%), 3.7% (95% CI: 3.1%- 4.2%) based on at-home rapid tests and 5.7% (95% CI: 5.0% - 6.4%) based on the case definition of a probable case. The total point prevalence across all definitions was 14.9% (95% CI: 13.8% - 16.0%). The percent positivity among PCR and/or rapid tests was 50.2%. No statistically significant differences were observed in prevalence between participants with a COVID-19 booster compared to fully vaccinated and non-boosted participants except among exclusive at-home rapid testers. CONCLUSIONS: Our findings suggest a substantial proportion of cases were missed by case-based surveillance systems during the Omicron BA.1 surge, when at-home testing was common. Point prevalence surveys may be a rapid tool to be used to understand SARS-CoV-2 prevalence and would be especially important during case surges to measure the scope and spread of active infections in the population.

Household factors and the risk of severe COVID-like illness early in the U.S. pandemic.

OBJECTIVE: To investigate the role of children in the home and household crowding as risk factors for severe COVID-19 disease. METHODS: We used interview data from 6,831 U.S. adults screened for the Communities, Households and SARS/CoV-2 Epidemiology (CHASING) COVID Cohort Study in April 2020. RESULTS: In logistic regression models, the adjusted odds ratio [aOR] of hospitalization due to COVID-19 for having (versus not having) children in the home was 10.5 (95% CI:5.7-19.1) among study participants living in multi-unit dwellings and 2.2 (95% CI:1.2-6.5) among those living in single unit dwellings. Among participants living in multi-unit dwellings, the aOR for COVID-19 hospitalization among participants with more than 4 persons in their household (versus 1 person) was 2.5 (95% CI:1.0-6.1), and 0.8 (95% CI:0.15-4.1) among those living in single unit dwellings. CONCLUSION: Early in the US SARS-CoV-2 pandemic, certain household exposures likely increased the risk of both SARS-CoV-2 acquisition and the risk of severe COVID-19 disease.