ArticleInternational journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases2022
Contact tracing period and epidemiological characteristics of an outbreak of the SARS-CoV-2 Delta variant in Guangzhou.
Article in International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 3 of them syntheses that pooled it.
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Who cites it
8 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Impact of disease severity, age, sex, comorbidity, and vaccination on secondary attack rates of SARS-CoV-2: a global systematic review and meta-analysis.BMC infectious diseases · 2025Pooled it
- Assessing changes in incubation period, serial interval, and generation time of SARS-CoV-2 variants of concern: a systematic review and meta-analysis.BMC medicine · 2023Pooled it
- Household Secondary Attack Rates of SARS-CoV-2 by Variant and Vaccination Status: An Updated Systematic Review and Meta-analysis.JAMA network open · 2022Pooled it
- The public health impact of COVID-19 variants of concern on the effectiveness of contact tracing in Vermont, United States.Scientific reports · 2024Article
- Optimizing the detection of emerging infections using mobility-based spatial sampling.International journal of applied earth observation and geoinformation : ITC journal · 2024Article
- Review: The Landscape of Antiviral Therapy for COVID-19 in the Era of Widespread Population Immunity and Omicron-Lineage Viruses.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2024Review
- SARS-CoV-2 Quarantine Mandated by Contact Tracing: Burden and Infection Rate Among Close Contacts in Zurich, Switzerland, 2020-2021.International journal of public health · 2024Article
- Association Between Population-Level Factors and Household Secondary Attack Rate of SARS-CoV-2: A Systematic Review and Meta-analysis.Open forum infectious diseases · 2023Article
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Authors and funding
12 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesAn outbreak of the SARS-CoV-2 Delta variant occurred in Guangzhou in 2021. This study aimed to identify the transmission dynamics and epidemiological characteristics of the Delta variant outbreak to formulate an effective prevention strategy.
methodsA total of 13102 close contacts and 69 index cases were collected. The incubation period, serial interval, and time interval from the exposure of close contacts to the symptom onset of cases were estimated. Transmission risks based on the exposure time and various characteristics were also assessed.
resultsThe mean time from exposure to symptom onset among non-household presymptomatic transmission was 3.83 ± 2.29 days, the incubation period was 5 days, and the serial interval was 3 days. The secondary attack rate was high within 4 days before onset and 4-10 days after symptom onset. Compared with other contact types, household contact had a higher transmission risk. The transmission risk increased with the number and frequency of contact with index cases. Cycle threshold (Ct) values were associated with lower transmission risk (adjusted odds ratio [OR] 0.93 [95% CI 0.88-0.99] for ORF 1ab gene; adjusted OR 0.91 [95% CI 0.86-0.97] for N gene).
conclusionThe contact tracing period may need to be extended to 4 days before symptom onset. The low Ct value of index cases, the high number and frequency of contact with index cases, and household contacts were associated with a higher transmission risk of SARS-CoV-2 Delta.
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