key: cord-0772424-e7vy12n5 authors: Ahmadi, Ali; Kheiril, Soleiman; Mohammadian-Hafshejani, Abdollah; Raeisi, Hadi; Mosavi, Masoumeh; Sharifi, Hamid title: The accuracy of “Preliminary estimation of the novel coronavirus disease (COVID-19) cases in Iran: A modelling analysis based on overseas cases and air travel data” date: 2020-04-30 journal: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases DOI: 10.1016/j.ijid.2020.04.071 sha: e4ea7f6fdae4192577164b7933d4b397385a1412 doc_id: 772424 cord_uid: e7vy12n5 nan J o u r n a l P r e -p r o o f Third, the mean incubation period for COVID-19 was 5.2 days (4.1-7 days) , and the basic reproductive number (R 0 ) was reported 2.2 (95% CI: 1.4 to 3.9) (4) . In another study, the mean incubation period was ranges from 0-24 days with mean of 6.4 days and it is not easy to approve all or some of the five detected cases were infected inside Iran or they were Iranian (5). Fourth, the estimated number of infected people is dependent on some valid assumptions: the date of the epidemic onset, precise method, basic reproductive number and robust assumptions (6) . The authors did not clearly define these assumptions. The reason for using each of the parameters is not explained. There are no suitable references for the method used in the study. For example, they used the ABC news for their claims (7). Fifth, the authors only selected three countries (United Arab Emirates, Lebanon, and Oman), in which the reported cases were defined. So, it is likely that the probability of positive instances of COVID-19 will be highly biased. It is necessary for the authors to consider all international flights from Iran during the mentioned period. Therefore, the estimated probability of positive cases of Iran could overestimate the number of infected cases. In brief, we think the method used in this modeling is not robust, and the estimated number could overestimate the number of infections in Iran by 25 February. We should use modeling studies for a better view of the epidemic, especially when direct observation is not as practical as the iceberg pattern of the infection. But if we do not use them with a critical eye for their limitations and some subjective assumption, the results could be misleading the response. There are some concerns about the burden of the COVID-19 epidemic in Iran. By April 6, 2020, 58,266 confirmed cases were detected in Iran with the highest burden of the infection in the East Mediterranean countries. Rapid reporting of cases of COVID-19 in Iran may be attributed to transparency in the reporting, strength of Iran's health system, the importance of discovering high-risk hotspots, and the role of chance that can affect the rate of transmission and cause the faster discovery of the epidemic in a specific region (3) and all of them not considering in modeling by Zhuang et al. Preliminary estimation of the novel coronavirus disease (COVID-19) cases in Iran: A modelling analysis based on overseas cases and air travel data Population and Housing Censuses, Selected Findings of the 2016 National Population and Housing Census Is reporting many cases of COVID-19 in Iran due to strength or weakness of Iran's health system? Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia Defining the Epidemiology of Covid-19 -Studies Needed Nowcasting and forecasting the potential domestic and international spread of the 2019-nCoV outbreak originating in Wuhan, China: a modelling study Iran says 'tens of thousands' may get tested for coronavirus An evaluation version of novaPDF was used to create this PDF file. Purchase a license to generate PDF files without this notice The authors have no conflict of interest. An evaluation version of novaPDF was used to create this PDF file. Purchase a license to generate PDF files without this notice.