Presymptomatic transmission of SARS-CoV-2 infection: a secondary analysis using published data

Casey, Mícheál; Griffin, John M.; McAloon, Conor G.; Byrne, Andrew; Madden, Jamie M.; Evoy, David Mc; Collins, Áine B.; Hunt, Kevin; Barber, Ann; Butler, Francis; Lane, Elizabeth A.; O’Brien, Kirsty; Wall, Patrick; Walsh, Kieran; More, Simon J.

doi:10.1136/bmjopen-2020-041240

Cited by 36 publications

(36 citation statements)

References 59 publications

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“…Only primary cases associated with a secondary case are shown. Symptom onset of persons with secondary cases before symptom onset of persons with primary cases was observed in 4 pairs, consistent with previous reports ( 21 , 22 ), and could be caused by presymptomatic transmission ( 23 , 24 ) or variability in self-reported symptom onset date. Household contacts were exposed to persons who had a primary case within household settings.…”

Section: Resultssupporting

confidence: 90%

“…However, further characterization of serial interval, particularly stratified by vaccination status, is warranted. Symptom onset of persons who had secondary cases before symptom onset of persons who had primary cases was observed in a small number of pairs, consistent with previous reports ( 21 , 22 ), and could be caused by presymptomatic transmission ( 23 , 24 ) or variability in self-reported symptom onset date.…”

Section: Discussionsupporting

confidence: 90%

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Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States

Gharpure¹,

Sami²,

Vostok³

et al. 2022

Emerg. Infect. Dis.

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During July 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.617.2 variant infections, including vaccine breakthrough infections, occurred after large public gatherings in Provincetown, Massachusetts, USA, prompting a multistate investigation. Public health departments identified primary and secondary cases by using coronavirus disease surveillance data, case investigations, and contact tracing. A primary case was defined as SARS-CoV-2 detected < 14 days after travel to or residence in Provincetown during July 3–17. A secondary case was defined as SARS-CoV-2 detected < 14 days after close contact with a person who had a primary case but without travel to or residence in Provincetown during July 3–August 10. We identified 1,098 primary cases and 30 secondary cases associated with 26 primary cases among fully and non–fully vaccinated persons. Large gatherings can have widespread effects on SARS-CoV-2 transmission, and fully vaccinated persons should take precautions, such as masking, to prevent SARS-CoV-2 transmission, particularly during substantial or high transmission.

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Section: Resultssupporting

confidence: 90%

Section: Discussionsupporting

confidence: 90%

Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States

Gharpure¹,

Sami²,

Vostok³

et al. 2022

Emerg. Infect. Dis.

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“…In this study, patients with the Delta variant strain had a shorter transmission time before symptom onset (1.4 days) than those with non-Delta strains (2.0 days) by Mann-Whitney U test. In previous studies on the wild-type strain, the transmission time relative to symptom onset varied among countries [17]. Nonetheless, the transmission time relative to symptom onset could be reduced by voluntary quarantine after symptom onset.…”

Section: Discussionmentioning

confidence: 93%

“…Understanding transmission dynamics is also important for the evaluation of an epidemic. Quantifying the transmission potential before symptom onset will inform epidemic progression predictions [17]. In Japan, cases of Delta variant domestic transmission began to be confirmed in the latter half of May 2021 [18].…”

Section: Introductionmentioning

confidence: 99%

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Shorter Incubation Period among Unvaccinated Delta Variant Coronavirus Disease 2019 Patients in Japan

Ogata

Tanaka

Irie

et al. 2022

IJERPH

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Few studies have assessed incubation periods of the severe acute respiratory syndrome coronavirus 2 Delta variant. This study aimed to elucidate the transmission dynamics, especially the incubation period, for the Delta variant compared with non-Delta strains. We studied unvaccinated coronavirus disease 2019 patients with definite single exposure date from August 2020 to September 2021 in Japan. The incubation periods were calculated and compared by Mann–Whitney U test for Delta (with L452R mutation) and non-Delta cases. We estimated mean and percentiles of incubation period by fitting parametric distribution to data in the Bayesian statistical framework. We enrolled 214 patients (121 Delta and 103 non-Delta cases) with one specific date of exposure to the virus. The mean incubation period was 3.7 days and 4.9 days for Delta and non-Delta cases, respectively (p-value = 0.000). When lognormal distributions were fitted, the estimated mean incubation periods were 3.7 (95% credible interval (CI) 3.4–4.0) and 5.0 (95% CI 4.5–5.6) days for Delta and non-Delta cases, respectively. The estimated 97.5th percentile of incubation period was 6.9 (95% CI 5.9–8.0) days and 10.4 (95% CI 8.6–12.7) days for Delta and non–Delta cases, respectively. Unvaccinated Delta variant cases had shorter incubation periods than non–Delta variant cases.

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Modeling and Global Sensitivity Analysis of Strategies to Mitigate Covid-19 Transmission on a Structured College Campus

et al. 2023

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In response to the COVID-19 pandemic, many higher educational institutions moved their courses on-line in hopes of slowing disease spread. The advent of multiple highly-effective vaccines offers the promise of a return to “normal” in-person operations, but it is not clear if—or for how long—campuses should employ non-pharmaceutical interventions such as requiring masks or capping the size of in-person courses. In this study, we develop and fine-tune a model of COVID-19 spread to UC Merced’s student and faculty population. We perform a global sensitivity analysis to consider how both pharmaceutical and non-pharmaceutical interventions impact disease spread. Our work reveals that vaccines alone may not be sufficient to eradicate disease dynamics and that significant contact with an infectious surrounding community will maintain infections on-campus. Our work provides a foundation for higher-education planning allowing campuses to balance the benefits of in-person instruction with the ability to quarantine/isolate infectious individuals.

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Presymptomatic transmission of SARS-CoV-2 infection: a secondary analysis using published data

Cited by 36 publications

References 59 publications

Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States

Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States

Shorter Incubation Period among Unvaccinated Delta Variant Coronavirus Disease 2019 Patients in Japan

Modeling and Global Sensitivity Analysis of Strategies to Mitigate Covid-19 Transmission on a Structured College Campus

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