Epidemiologic Findings from Case Investigations and Contact Tracing for First 200 Cases of Coronavirus Disease, Santa Clara County, California, USA

Ortiz, Nancy; Villarino, Elsa; Lee, James T.; Bajema, Kristina L.; Ricaldi, Jessica N; Smith, Shanon; Lin, Winston T.; Cortese, Margaret M.; Barskey, Albert E.; Silva, Juliana F. Da; Bonin, Brandon; Rudman, Sarah L.; Han, George; Fischer, Marc; Chai, Shua J.; Cody, Sara H.

doi:10.3201/eid2705.204876

Cited by 2 publications

(2 citation statements)

References 15 publications

(15 reference statements)

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“…Our results indicate that the risk of SARS-CoV-2 transmission was significantly higher between people living in the same household (IRR 2.6 and 12.4) than between people in work (IRR 1.5 and 1.9) or other social (IRR 1.7 and 1.9) situations. These results concur with findings of a contact-tracing study conducted in the United States from January through March 2020 in which 24.5% of known exposures were attributed to a household member and 8.5% within the workplace while 15% were considered travel-related (Ortiz et al, 2021). Similar results were reported in a contact-tracing study conducted in China in which the secondary infection rate was 9-14% when the case was from the same household, 3-8% when it was a work colleague, and 3-5% when it was another social contact (Ng et al, 2021).…”

Section: Discussionsupporting

confidence: 89%

“…The secondary attack rate among train passengers in one study was 0.3% and increased by 0.15% per hour of travel with an infected person, but was as high as 3.5% when seated adjacent to an infected person (Hu et al, 2021). Authors of a contract-tracing study done in early 2020 in the USA reported that 9.5% of cases were exposed due to international travel, with another 5.5% exposed while travelling within the USA (Ortiz et al, 2021). A similar study done in Iceland in March 2020 noted that early cases were largely exposed through international travel while later cases were more often exposed to infected family members (Gudbjartsson et al, 2020).…”

Section: Discussionmentioning

confidence: 97%

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Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year

Coleman

Fischer

Maunder

et al. 2022

Can J Public Health

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Objective To estimate the incidence of SARS-CoV-2 in education workers and the factors associated with infection between March 2020 and July 2021. Methods A prospective cohort study of education workers working ≥8 h per week in Ontario, Canada. Participants self-reported results of tests for SARS-CoV-2 and completed online surveys about demographic information, exposures, and vaccinations against SARS-CoV-2. Participants submitted self-collected dried blood spots. Antibodies to SARS-CoV-2 spike, the receptor binding domain of spike, and nucleocapsid were assessed. Multivariable regression was used to assess risk factors for infection. Results Of 2834 participants, 85% were female, 81% were teaching staff, and 86% had received at least one dose of SARS-CoV-2 vaccine. Of the 1983 who had been tested via a respiratory specimen, 4.9% reported a positive test. Five additional participants had serologic testing suggestive of a previous infection (3.6% overall incidence). In multivariable regression analysis, risk factors for infection included exposure to a SARS-CoV-2 infected adult (adjusted incidence rate ratio (aIRR) 13.6; 95% confidence interval 8.6, 21.3) or child (aIRR 2.3; 1.3, 4.2) in the household, or school student (aIRR 1.9; 1.2, 3.2), or travel outside the province within 14 days of testing (aIRR 6.0; 1.5, 23.6). Conclusion In the first 18 months of the pandemic, education workers had a similar risk of infection with SARS-CoV-2 as other Ontario residents. Practicing protective measures whenever any household member has been exposed to a possible case and at all times when exposed to anyone from outside the home would help reduce the risk of infection.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 97%

Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year

Coleman

Fischer

Maunder

et al. 2022

Can J Public Health

View full text Add to dashboard Cite

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Missing science: A scoping study of COVID-19 epidemiological data in the United States

Bhatia

I²,

Baral

2022

PLoS ONE

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Systematic approaches to epidemiologic data collection are critical for informing pandemic responses, providing information for the targeting and timing of mitigations, for judging the efficacy and efficiency of alternative response strategies, and for conducting real-world impact assessments. Here, we report on a scoping study to assess the completeness of epidemiological data available for COVID-19 pandemic management in the United States, enumerating authoritative US government estimates of parameters of infectious transmission, infection severity, and disease burden and characterizing the extent and scope of US public health affiliated epidemiological investigations published through November 2021. While we found authoritative estimates for most expected transmission and disease severity parameters, some were lacking, and others had significant uncertainties. Moreover, most transmission parameters were not validated domestically or re-assessed over the course of the pandemic. Publicly available disease surveillance measures did grow appreciably in scope and resolution over time; however, their resolution with regards to specific populations and exposure settings remained limited. We identified 283 published epidemiological reports authored by investigators affiliated with U.S. governmental public health entities. Most reported on descriptive studies. Published analytic studies did not appear to fully respond to knowledge gaps or to provide systematic evidence to support, evaluate or tailor community mitigation strategies. The existence of epidemiological data gaps 18 months after the declaration of the COVID-19 pandemic underscores the need for more timely standardization of data collection practices and for anticipatory research priorities and protocols for emerging infectious disease epidemics.

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Epidemiologic Findings from Case Investigations and Contact Tracing for First 200 Cases of Coronavirus Disease, Santa Clara County, California, USA

Cited by 2 publications

References 15 publications

Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year

Study of the epidemiology of COVID-19 in Ontario elementary and secondary school education workers: an interim analysis following the first school year

Missing science: A scoping study of COVID-19 epidemiological data in the United States

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