Evidence map›Paper›PMID 36346940›Full record

Observational studyJMIR public health and surveillance2022

The Association Between Clinical Severity and Incubation Period of SARS-CoV-2 Delta Variants: Retrospective Observational Study.

Kai Wang, Zemin Luan, Zihao Guo, Jinjun Ran, Maozai Tian, Shi Zhao

Abstract readObservational Study
In one paragraph

Observational study in JMIR public health and surveillance, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Kai Wang *Department of Medical Engineering and Technology, Xinjiang Medical University, Urumqi, China.ORCID 0000-0002-6224-8453
Zemin Luan *Department of Medical Engineering and Technology, Xinjiang Medical University, Urumqi, China.ORCID 0000-0001-7045-7362
Zihao Guo *JC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China (Hong Kong).ORCID 0000-0001-9002-0483
Jinjun RanSchool of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China.ORCID 0000-0002-2684-6341
Maozai TianDepartment of Medical Engineering and Technology, Xinjiang Medical University, Urumqi, China.ORCID 0000-0002-0515-4477
Shi ZhaoJC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China (Hong Kong).ORCID 0000-0001-8722-6149

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAs of August 25, 2021, Jiangsu province experienced the largest COVID-19 outbreak in eastern China that was seeded by SARS-CoV-2 Delta variants. As one of the key epidemiological parameters characterizing the transmission dynamics of COVID-19, the incubation period plays an essential role in informing public health measures for epidemic control. The incubation period of COVID-19 could vary by different age, sex, disease severity, and study settings. However, the impacts of these factors on the incubation period of Delta variants remains uninvestigated.

objectiveThe objective of this study is to characterize the incubation period of the Delta variant using detailed contact tracing data. The effects of age, sex, and disease severity on the incubation period were investigated by multivariate regression analysis and subgroup analysis.

methodsWe extracted contact tracing data of 353 laboratory-confirmed cases of SARS-CoV-2 Delta variants' infection in Jiangsu province, China, from July to August 2021. The distribution of incubation period of Delta variants was estimated by using likelihood-based approach with adjustment for interval-censored observations. The effects of age, sex, and disease severity on the incubation period were expiated by using multivariate logistic regression model with interval censoring.

resultsThe mean incubation period of the Delta variant was estimated at 6.64 days (95% credible interval: 6.27-7.00). We found that female cases and cases with severe symptoms had relatively longer mean incubation periods than male cases and those with nonsevere symptoms, respectively. One-day increase in the incubation period of Delta variants was associated with a weak decrease in the probability of having severe illness with an adjusted odds ratio of 0.88 (95% credible interval: 0.71-1.07).

conclusionsIn this study, the incubation period was found to vary across different levels of sex, age, and disease severity of COVID-19. These findings provide additional information on the incubation period of Delta variants and highlight the importance of continuing surveillance and monitoring of the epidemiological characteristics of emerging SARS-CoV-2 variants as they evolve.

Indexed as

COVID-19SARS-CoV-2FemaleHumansInfectious Disease Incubation PeriodLikelihood FunctionsMaleRetrospective StudiesChinaclinical severityCOVID-19Delta variantincubation period

Identifiers

PMID36346940
PMCPMC9678331

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.