LitCovid-sentences  

PMC:7110798 / 1923-12897 JSONTXT 12 Projects

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Id Subject Object Predicate Lexical cue
T24 0-12 Sentence denotes Introduction
T25 13-190 Sentence denotes The 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).
T26 191-396 Sentence denotes 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).
T27 397-658 Sentence denotes 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.
T28 659-689 Sentence denotes The outbreak is still ongoing.
T29 690-774 Sentence denotes A recently published preprint by Imai et al. estimated that a total of 1723 (95% CI:
T30 775-886 Sentence denotes 427-4471) cases of 2019-nCoV infections in Wuhan had onset of symptoms by January 12, 2020 (Imai et al., 2020).
T31 887-1067 Sentence denotes The likelihood of travel related risks of disease spreading is suggested by Bogoch et al. (2020), which indicates the potentials of regional and global spread (Leung et al., 2020).
T32 1068-1213 Sentence denotes To the best of our knowledge, there is no existing peer-reviewed literature quantifying the transmissibility of 2019-nCoV as of January 22, 2020.
T33 1214-1377 Sentence denotes In this study, we estimated the transmissibility of 2019-nCoV via the basic reproduction number, R 0, based on the limited data in the early phase of the outbreak.
T34 1379-1386 Sentence denotes Methods
T35 1387-1647 Sentence denotes We obtained the number of 2019-nCoV cases time series data in mainland China released by Wuhan Municipal Health Commission, China and National Health Commission of China from January 10 to January 24, 2020 from (Wuhan Municipal Health Commission, China, 2020).
T36 1648-1826 Sentence denotes All cases were laboratory confirmed following the case definition by the National Health Commission of China (National Health Commission of the People’s Republic of China, 2020).
T37 1827-1927 Sentence denotes Although the date of submission of this study is January 26, we choose to use data up to January 24.
T38 1928-2121 Sentence denotes Note that the data of the most recent few days contain a number of infections that were infected outside Wuhan due to travel, and thus this part of the infections is excluded from the analysis.
T39 2122-2285 Sentence denotes Although there were cases confirmed on or before January 16, the official diagnostic protocol was released by WHO on January 17 (World Health Organization, 2020b).
T40 2286-2456 Sentence denotes To adjust the impact of this event, we considered a time-varying reporting rate that follows a linear increasing trend, motivated by the previous study (Wu et al., 2010).
T41 2457-2580 Sentence denotes We assumed that the reporting rate, r(t), started increasing on January 17, and stopped at the maximal level on January 21.
T42 2581-2765 Sentence denotes The reporting rate increase corresponds to accounts for the announcement on improving the 2019-nCoV surveillance of the Hubei provincial government (Hubei provincial government, 2020).
T43 2766-3084 Sentence denotes The length of the reporting increasing part roughly equals the average of the incubation periods of two other well-known coronavirus diseases, i.e., the Middle East Respiratory Syndrome (MERS) and the Severe Acute Respiratory Syndrome (SARS), i.e., 5 days (Bauch et al., 2005, Lin et al., 2018, Donnelly et al., 2003).
T44 3085-3234 Sentence denotes Denoting the daily reported number of new cases by c(t) for the t-th day, then the adjusted cumulative number of cases, C(t), is C(t)=∑τ=0tc(τ)/r(τ).
T45 3235-3397 Sentence denotes Instead of finding the exact value of r(t), we calculated the fold change in r(t) that is defined by the ratio of r on January 10 over that on January 24 minus 1.
T46 3398-3549 Sentence denotes We illustrated six scenarios with 0- (no change), 0.5-, 1-, 2-, 4- and 8-fold increase in reporting rate, see Figure 1 (a), (c), (e), (g), (i) and (k).
T47 3550-3673 Sentence denotes Figure 1 The scenarios of the change in the reporting rate (top panels) and the exponential growth fitting (bottom panels).
T48 3674-3775 Sentence denotes The top panels, i.e., (a), (c), (e), (g), (i) and (k), show the assumed change in the reporting rate.
T49 3776-3999 Sentence denotes The bottom panels, i.e., (b), (d), (f), (h), (j) and (l), show the reported (or observed, green circles), adjusted (blue dots) and fitted (blue curve) number of 2019-nCoV infections, and the blue dashed lines are the 95%CI.
T50 4000-4167 Sentence denotes The vertical grey line represents the date of January 16, 2020, after which the official diagnostic protocol was released by the WHO (World Health Organization, 2020).
T51 4168-4244 Sentence denotes Panels (a) and (b) show the scenarios that the reporting rate was unchanged.
T52 4245-4329 Sentence denotes Panels (c) and (d) show the scenarios that the reporting rate increased by 0.5-fold.
T53 4330-4412 Sentence denotes Panels (e) and (f) show the scenarios that the reporting rate increased by 1-fold.
T54 4413-4495 Sentence denotes Panels (g) and (h) show the scenarios that the reporting rate increased by 2-fold.
T55 4496-4578 Sentence denotes Panels (i) and (j) show the scenarios that the reporting rate increased by 4-fold.
T56 4579-4661 Sentence denotes Panels (k) and (l) show the scenarios that the reporting rate increased by 8-fold.
T57 4662-4795 Sentence denotes Following previous studies (Zhao et al., 2019, de Silva et al., 2009), we modelled the epidemic curve obeying the exponential growth.
T58 4796-4892 Sentence denotes The nonlinear least square (NLS) framework is adopted for data fitting and parameter estimation.
T59 4893-5092 Sentence denotes The intrinsic growth rate (γ) of the exponential growth was estimated, and the basic reproduction number could be obtained by R 0 = 1/M(−γ) with 100% susceptibility for 2019-nCoV at this early stage.
T60 5093-5338 Sentence denotes The function M(∙) is the Laplace transform, i.e., the moment generating function, of the probability distribution for the serial interval (SI) of the disease (Zhao et al., 2019, Wallinga and Lipsitch, 2007), denoted by h(k) and k is the mean SI.
T61 5339-5492 Sentence denotes Since the transmission chain of 2019-nCoV remains unclear, we adopted the SI information from SARS and MERS, which share a similar pathogen as 2019-nCoV.
T62 5493-5775 Sentence denotes We modelled h(k) as Gamma distributions with a mean of 7.6 days and standard deviation (SD) of 3.4 days for MERS (Assiri et al., 2013), and mean of 8.4 days and SD of 3.8 days for SARS (Lipsitch et al., 2003) as well as their average, see the row heads in Table 1 for each scenario.
T63 5776-5876 Sentence denotes Table 1 The summary table of the estimated basic reproduction number, R0, under different scenarios.
T64 5877-5937 Sentence denotes The estimated R0 is shown as in the ‘median (95%CI)’ format.
T65 5938-6153 Sentence denotes The ‘reporting rate increased’ indicates the number of fold increase in the reporting rate from January 17, when WHO released the official diagnostic protocol (World Health Organization, 2020b), to January 20, 2020.
T66 6154-6191 Sentence denotes Reporting rate increased Estimated R0
T67 6192-6267 Sentence denotes Same as MERS SI 7.6 ± 3.4 SI in average 8.0 ± 3.6 Same as SARS SI 8.4 ± 3.8
T68 6268-6330 Sentence denotes (unchanged) 5.31 (3.99–6.96) 5.71 (4.24–7.54) 6.11 (4.51–8.16)
T69 6331-6390 Sentence denotes 0.5-fold 4.52 (3.49–5.76) 4.82 (3.69–6.20) 5.14 (3.90–6.67)
T70 6391-6448 Sentence denotes 1-fold 4.01 (3.17–5.02) 4.26 (3.34–5.38) 4.53 (3.51–5.76)
T71 6449-6506 Sentence denotes 2-fold 3.38 (2.75–4.12) 3.58 (2.89–4.39) 3.77 (3.02–4.67)
T72 6507-6564 Sentence denotes 4-fold 2.73 (2.31–3.22) 2.86 (2.40–3.39) 3.00 (2.50–3.58)
T73 6565-6622 Sentence denotes 8-fold 2.16 (1.90–2.45) 2.24 (1.96–2.55) 2.32 (2.02–2.66)
T74 6623-6750 Sentence denotes Note: ‘SI’ is serial interval. ‘MERS’ is Middle East Respiratory Syndrome, and ‘SARS’ is the Severe Acute Respiratory Syndrome.
T75 6752-6774 Sentence denotes Results and discussion
T76 6775-6867 Sentence denotes The exponential growth fitting results are shown in Figure 1(b), (d), (f), (h), (j) and (l).
T77 6868-7070 Sentence denotes The coefficient of determination, R-squared, ranges from 0.91 to 0.92 for all reporting rate changing scenarios, which implies that the early outbreak data were largely following the exponential growth.
T78 7071-7133 Sentence denotes In Table 1, we estimated that the R 0 ranges from 2.24 (95%CI:
T79 7134-7160 Sentence denotes 1.96-2.55) to 5.71 (95%CI:
T80 7161-7239 Sentence denotes 4.24-7.54) associated with an 8-fold to 0-fold increase in the reporting rate.
T81 7240-7353 Sentence denotes All R 0 estimates are significantly larger than 1, which indicates the potential of 2019-nCoV to cause outbreaks.
T82 7354-7548 Sentence denotes Since the official diagnostic protocol was released by WHO on January 17 (World Health Organization, 2020b), an increase in the diagnosis and reporting of 2019-nCoV infections probably occurred.
T83 7549-7730 Sentence denotes Thereafter, the daily number of newly reported cases started increasing around January 17, see Figure 1, which implies that more infections were likely being diagnosed and recorded.
T84 7731-7923 Sentence denotes We suggested that changes in reporting might exist, and thus it should be considered in the estimation, i.e., 8-, 4- and 2-fold changes are more likely than no change in the reporting efforts.
T85 7924-8137 Sentence denotes Although six scenarios about the reporting rate were explored in this study, the real situation is difficult to determine given limited data and (almost) equivalent model fitting performance in terms of R-squared.
T86 8138-8233 Sentence denotes However, with increasing reporting rate, we found the mean R 0 is likely to be between 2 and 3.
T87 8234-8353 Sentence denotes Our analysis and estimation of R 0 rely on the accuracy of the SI of 2019-nCoV, which remains unknown as of January 25.
T88 8354-8444 Sentence denotes In this work, we employed the SIs of SARS and MERS as approximations to that of 2019-nCoV.
T89 8445-8682 Sentence denotes The determination of SI requires knowledge of the chain of disease transmission that needs a sufficient number of patient samples and periods of time for follow-up (Cowling et al., 2009), and thus this is unlikely to be achieved shortly.
T90 8683-8839 Sentence denotes However, using SIs of SARS and MERS as approximation could provide an insight to the transmission potential of 2019-nCoV at the early stage of the outbreak.
T91 8840-9110 Sentence denotes We reported that the mean R 0 of 2019-nCoV is likely to be from 2.24 (8-fold) to 3.58 (2-fold), and it is largely in the range of those of SARS, i.e., 2-5 (Bauch et al., 2005, Lipsitch et al., 2003, Wallinga and Teunis, 2004), and MERS, i.e., 2.7-3.9 (Lin et al., 2018).
T92 9111-9307 Sentence denotes We note that WHO reported the basic reproduction number for the human-to-human (direct) transmission ranged from 1.4 to 2.5 (World Health Organization, 2020b), which is marginally lower than ours.
T93 9308-9525 Sentence denotes However, many of the existing online preprints estimate the mean R 0 ranging from 2 to 5 (Imai et al., 2020, Riou and Althaus, 2020, Read et al., 2020, Shen et al., 2020), which is largely consistent with our results.
T94 9527-9537 Sentence denotes Conclusion
T95 9538-9602 Sentence denotes We estimated the mean R 0 of 2019-nCoV ranging from 2.24 (95%CI:
T96 9603-9629 Sentence denotes 1.96-2.55) to 3.58 (95%CI:
T97 9630-9835 Sentence denotes 2.89-4.39) if the reporting effort has been increased by a factor of between 8- and 2-fold, respectively, after the diagnostic protocol released on January 17, 2020 and many medical supplies reached Wuhan.
T98 9837-9879 Sentence denotes Ethics approval and consent to participate
T99 9880-9942 Sentence denotes The ethical approval or individual consent was not applicable.
T100 9944-9978 Sentence denotes Availability of data and materials
T101 9979-10044 Sentence denotes All data and materials used in this work were publicly available.
T102 10046-10069 Sentence denotes Consent for publication
T103 10070-10085 Sentence denotes Not applicable.
T104 10087-10094 Sentence denotes Funding
T105 10095-10218 Sentence denotes DH was supported by General Research Fund (Grant Number 15205119) of the Research Grants Council (RGC) of Hong Kong, China.
T106 10219-10430 Sentence denotes WW was supported by National Natural Science Foundation of China (Grant Number 61672013) and Huaian Key Laboratory for Infectious Diseases Control and Prevention (Grant Number HAP201704), Huaian, Jiangsu, China.
T107 10432-10442 Sentence denotes Disclaimer
T108 10443-10687 Sentence denotes The funding agencies had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.
T109 10689-10710 Sentence denotes Conflict of interests
T110 10711-10754 Sentence denotes The authors declare no competing interests.
T111 10756-10777 Sentence denotes Authors contributions
T112 10778-10974 Sentence denotes All authors conceived the study, carried out the analysis, discussed the results, drafted the first manuscript, critically read and revised the manuscript, and gave final approval for publication.