OBJECTIVES: The number of SARS-CoV-2 infections is underestimated in surveillance data. Various approaches to assess the seroprevalence of antibodies to SARS-CoV-2 have different resource requirements and generalizability. We estimated the seroprevalence of antibodies to SARS-CoV-2 in Denver County, Colorado, via a cluster-sampled community survey. METHODS: We estimated the overall seroprevalence of antibodies to SARS-CoV-2 via a community seroprevalence survey in Denver County in July 2020, described patterns associated with seroprevalence, and compared results with cumulative COVID-19 incidence as reported to the health department during the same period. In addition, we compared seroprevalence as assessed with a temporally and geographically concordant convenience sample of residual clinical specimens from a commercial laboratory. RESULTS: Based on 404 specimens collected through the community survey, 8.0% (95% CI, 3.9%-15.7%) of Denver County residents had antibodies to SARS-CoV-2, an infection rate of about 7 times that of the 1.1% cumulative reported COVID-19 incidence during this period. The estimated infection-to-reported case ratio was highest among children (34.7; 95% CI, 11.1-91.2) and males (10.8; 95% CI, 5.7-19.3). Seroprevalence was highest among males of Black race or Hispanic ethnicity and was associated with previous COVID-19-compatible illness, a previous positive SARS-CoV-2 test result, and close contact with someone who had confirmed SARS-CoV-2 infection. Testing of 1598 residual clinical specimens yielded a seroprevalence of 6.8% (95% CI, 5.0%-9.2%); the difference between the 2 estimates was 1.2 percentage points (95% CI, -3.6 to 12.2 percentage points). CONCLUSIONS: Testing residual clinical specimens provided a similar seroprevalence estimate yet yielded limited insight into the local epidemiology of COVID-19 and might be less representative of the source population than a cluster-sampled community survey. Awareness of the limitations of various sampling strategies is necessary when interpreting findings from seroprevalence assessments.
OBJECTIVES: The number of SARS-CoV-2 infections is underestimated in surveillance data. Various approaches to assess the seroprevalence of antibodies to SARS-CoV-2 have different resource requirements and generalizability. We estimated the seroprevalence of antibodies to SARS-CoV-2 in Denver County, Colorado, via a cluster-sampled community survey. METHODS: We estimated the overall seroprevalence of antibodies to SARS-CoV-2 via a community seroprevalence survey in Denver County in July 2020, described patterns associated with seroprevalence, and compared results with cumulative COVID-19 incidence as reported to the health department during the same period. In addition, we compared seroprevalence as assessed with a temporally and geographically concordant convenience sample of residual clinical specimens from a commercial laboratory. RESULTS: Based on 404 specimens collected through the community survey, 8.0% (95% CI, 3.9%-15.7%) of Denver County residents had antibodies to SARS-CoV-2, an infection rate of about 7 times that of the 1.1% cumulative reported COVID-19 incidence during this period. The estimated infection-to-reported case ratio was highest among children (34.7; 95% CI, 11.1-91.2) and males (10.8; 95% CI, 5.7-19.3). Seroprevalence was highest among males of Black race or Hispanic ethnicity and was associated with previous COVID-19-compatible illness, a previous positive SARS-CoV-2 test result, and close contact with someone who had confirmed SARS-CoV-2 infection. Testing of 1598 residual clinical specimens yielded a seroprevalence of 6.8% (95% CI, 5.0%-9.2%); the difference between the 2 estimates was 1.2 percentage points (95% CI, -3.6 to 12.2 percentage points). CONCLUSIONS: Testing residual clinical specimens provided a similar seroprevalence estimate yet yielded limited insight into the local epidemiology of COVID-19 and might be less representative of the source population than a cluster-sampled community survey. Awareness of the limitations of various sampling strategies is necessary when interpreting findings from seroprevalence assessments.
Authors: Jannae C Parrott; Ariana N Maleki; Valerie E Vassor; Sukhminder Osahan; Yusyin Hsin; Michael Sanderson; Steven Fernandez; Amber Levanon Seligson; Scott Hughes; Jing Wu; Andrea K DeVito; Stephen P LaVoie; Jennifer L Rakeman; L Hannah Gould; Karen A Alroy Journal: J Infect Dis Date: 2021-06-04 Impact factor: 5.226
Authors: Kristina L Bajema; Ryan E Wiegand; Kendra Cuffe; Sadhna V Patel; Ronaldo Iachan; Travis Lim; Adam Lee; Davia Moyse; Fiona P Havers; Lee Harding; Alicia M Fry; Aron J Hall; Kelly Martin; Marjorie Biel; Yangyang Deng; William A Meyer; Mohit Mathur; Tonja Kyle; Adi V Gundlapalli; Natalie J Thornburg; Lyle R Petersen; Chris Edens Journal: JAMA Intern Med Date: 2021-04-01 Impact factor: 21.873
Authors: Kristina L Bajema; F Scott Dahlgren; Travis W Lim; Nicolette Bestul; Holly M Biggs; Jacqueline E Tate; Claudio Owusu; Christine M Szablewski; Cherie Drenzek; Jan Drobeniuc; Vera Semenova; Han Li; Peter Browning; Rita Desai; Monica Epperson; Lily T Jia; Natalie J Thornburg; Chris Edens; Alicia M Fry; Aron J Hall; Jarad Schiffer; Fiona P Havers Journal: Clin Infect Dis Date: 2020-12-10 Impact factor: 9.079
Authors: Hannah Clapham; James Hay; Isobel Routledge; Saki Takahashi; Marc Choisy; Derek Cummings; Bryan Grenfell; C Jessica E Metcalf; Michael Mina; Isabel Rodriguez Barraquer; Henrik Salje; Clarence C Tam Journal: Emerg Infect Dis Date: 2020-06-16 Impact factor: 6.883