Letter to the Editor: Coronavirus Disease 2019 (COVID-19), Infectivity, and the Incubation Period

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J Prev Med Public Health. 2020;53(2):70-70
Publication date (electronic) : 2020 March 31
doi : https://doi.org/10.3961/jpmph.20.065
1Sanitation 1 Medical Academic Center, Bangkok, Thailand
2Department of Community Medicine, Dr DY Patil University, Pune, India
3Department of Tropical Medicine, Hainan Medical University, Haikou, China
Corresponding author: Beuy Joob, PhD Sanitation 1 Medical Academic Center, Bangkok 10150, Thailand E-mail: beuyjoob@hotmail.com

Dear Editor,

We read with great interest the recent publication entitled “A Chinese case of coronavirus disease 2019 (COVID-19) did not show infectivity during the incubation period: based on an epidemiological survey” [1]. Bae concluded that “the epidemiological findings support the claim that the COVID-19 virus does not have infectivity during the incubation period [1].” In fact, a pathogen should not have infectivity during the incubation period or development of disease. However, the exact incubation period of COVID-19 is still unknown. In a recent report by Linton et al. [2], the incubation range was estimated as between 2 days and 14 days with 95% confidence. Exceptional cases might occur with an unusually short or long incubation period. Nevertheless, the reliability of history-taking should also be addressed. How the author was able to confirm the reliability of the patient’s self-reported history is an interesting issue for further discussion. In our country, Thailand, it is not uncommon for patients to disguise their clinical history, which can cause delays in the diagnosis of COVID-19 and exacerbate the local transmission of the disease.



The authors have no conflicts of interest associated with the material presented in this paper.


1. Bae JM. A Chinese case of novel coronavirus 2019 (COVID-19) did not show infectivity during the incubation period: based on an epidemiological survey. J Prev Med Public Health 2020;53(2):67–69.
2. Linton NM, Kobayashi T, Yang Y, Hayashi K, Akhmetzhanov AR, Jung SM, et al. Incubation period and other epidemiological characteristics of 2019 novel coronavirus infections with right truncation: a statistical analysis of publicly available case data. J Clin Med 2020;9(2):E538.

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