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. 2022 Jul 27:10:905020.
doi: 10.3389/fpubh.2022.905020. eCollection 2022.

Incubation period of wild type of SARS-CoV-2 infections by age, gender, and epidemic periods

Chiara Achangwa  1 , Huikyung Park  1 , Sukhyun Ryu  1   2
Affiliations

Incubation period of wild type of SARS-CoV-2 infections by age, gender, and epidemic periods

Chiara Achangwa et al. Front Public Health. .

Abstract

Background: The incubation period of the coronavirus disease 2019 (COVID-19) is estimated to vary by demographic factors and the COVID-19 epidemic periods.

Objective: This study examined the incubation period of the wild type of SARS-CoV-2 infections by the different age groups, gender, and epidemic periods in South Korea.

Methods: We collected COVID-19 patient data from the Korean public health authorities and estimated the incubation period by fitting three different distributions, including log-normal, gamma, and Weibull distributions, after stratification by gender and age groups. To identify any temporal impact on the incubation period, we divided the study period into two different epidemic periods (Period-1: 19 January-19 April 2020 and Period-2: 20 April-16 October 2020), and assessed for any differences.

Results: We identified the log-normal as the best-fit model. The estimated median incubation period was 4.6 (95% CI: 3.9-4.9) days, and the 95th percentile was 11.7 (95% CI: 10.2-12.2) days. We found that the incubation period did not differ significantly between males and females (p = 0.42), age groups (p = 0.60), and the two different epidemic periods (p = 0.77).

Conclusions: The incubation period of wild type of SARS-CoV-2 infection during the COVID-19 pandemic 2020, in South Korea, does not likely differ by age group, gender and epidemic period.

Keywords: COVID-19; Korea; SARS-CoV-2; incubation period; log-normal distribution; quarantine.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Distribution of the COVID-19 incubation period after stratification by gender, age group, and epidemic period (Period-1: 19 January−19 April 2020 and Period-2: 20 April−16 October 2020) for the confirmed cases using the log-normal distribution model. (A) Estimated median incubation period after stratification by gender: male (median: 4.9 days); female (median: 4.6 days). (B) Estimated median incubation period after stratification by age: young adults (median: 4.8 days), middle-aged adults (median: 5.0 days), older adults (median: 4.3 days). (C) Estimated median incubation period after stratification by epidemic period: Period-1 (median: 4.8 days), and Period-2 (median: 4.4 days).
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