Comments on "Preliminary estimation of the basic reproduction number of novel Coronavirus (2019-nCoV) in China, from 2019 to 2020: A data-driven Analysis in the early phase of the outbreak"

Abstract

I have read the original article "Preliminary estimation of the basic reproduction number of novel Coronavirus (2019-nCoV) in China, from 2019 to 2020: A data-driven analysis in the early phase of the outbreak" which is recently published in your esteemed journal "International Journal of Infectious Diseases". Firstly, I would like to congratulate the authors for a successful publication and for making some contributions. The methodology used in the paper for the estimation of the reproduction number strongly assumes that the growth rate is exponential. However, in the Results section, the growth rate and its estimate are missing. The estimation of the reproduction number is likely to change significantly if the hypothetical growth rate differs from the actual growth rate (Wallinga and Lipsitch, 2007Wallinga J. Lipsitch M. How generation intervals shape the relationship between growth rates and reproductive numbers.Proc Biol Sci. 2007; 274: 599-604https://doi.org/10.1098/rspb.2006.3754sCrossref PubMed Scopus (0) Google Scholar). It is too early to say about the pattern of any specific distribution regarding growth rate, new incidence cases and the cumulative number of cases of novel Coronavirus (2019-nCoV). It would be great if authors address this as a limitation of the study and provide more details about the estimation of intrinsic growth rate. Table 1 provides the results (reproduction number estimates) for different folds of reporting rate by using three different serial intervals (SI). Since limited studies are available in detail about SI for novel coronavirus, it is obvious to use the serial interval of MERS and SARS but many studies show wide variation in their serial interval (Lipsitch et al., 2003Lipsitch M. Cohen T. Cooper B. Robins J.M. Ma S. James L. et al.Transmission dynamics and control of severe acute respiratory syndrome.Science. 2003; 300: 1966-1970https://doi.org/10.1126/science.1086616Crossref PubMed Scopus (1075) Google Scholar). The estimates of serial intervals used in the paper are 7.6 ± 3.4 and 8.4 ± 3.8 (in days) respectively for MERS and SARS, hence the coefficient of variation (CV) of SI for MERS and SARS seems higher (44.73% and 45.23% respectively). Due to this variation, it is highly recommended to a perform sensitivity analysis between SI and reproduction number so that variation between SI and reproduction number for novel Coronavirus (2019-nCoV) can be obtained. There is a significant difference between the estimates of reproduction number reported by WHO and the findings of Shi Zhao et al., and this variation could be due to many reasons including the parameters used in the model (SI); this can be also understood by sensitivity analysis (Obadia et al., 2012Obadia T. Haneef R. Boëlle P.Y. The R0 package: a toolbox to estimate reproduction numbers for epidemic outbreaks.BMC Med Informatics Decision Making. 2012; 12: 147https://doi.org/10.1186/1472-6947-12-147Crossref PubMed Scopus (181) Google Scholar). Conflict of interest: No conflict of interest to declare. Funding source: None. Ethical approval: Approval was not required. Preliminary estimation of the basic reproduction number of novel coronavirus (2019-nCoV) in China, from 2019 to 2020: A data-driven analysis in the early phase of the outbreakInternational Journal of Infectious DiseasesVol. 92PreviewThe atypical pneumonia case, caused by a novel coronavirus (2019-nCoV), was first reported and confirmed in Wuhan, China on December 31, 2019 (World Health Organization, 2020a). As of January 26 (17:00 GMT), 2020, there have been 2033 confirmed cases of 2019-nCoV infections in mainland China, including 56 deaths (National Health Commission of the People’s Republic of China, 2020). The 2019-nCoV cases were also reported in Thailand, Japan, Republic of Korea, Hong Kong, Taiwan and the US, and all of these cases were exported from Wuhan; see the World Health Organization (WHO) news release https://www.who.int/csr/don/en/ from January 14–21. Full-Text PDF Open AccessThe basic reproduction number of novel coronavirus (2019-nCoV) estimation based on exponential growth in the early outbreak in China from 2019 to 2020: A reply to DhunganaInternational Journal of Infectious DiseasesVol. 94PreviewThe ongoing outbreak of the novel coronavirus (2019-nCoV) pneumonia in Wuhan, China and other regions remains a major public health concern. We thank Dhungana for comments to our study, Zhao et al. (2020), recently published in the International Journal of Infectious Diseases. The estimates on the basic reproduction number, R0, were carried out early in the outbreak as of January 22, 2020, when the surveillance data and the knowledge of the key epidemiological features of 2019-nCoV were limited. Full-Text PDF Open Access

Topics & Concepts