Shahroud University of Medical Masoume Miri ijhs@shmu.ac.ir mEDRA 202109060609 This dataset was exported with ojs2, version 3.0.0.0.

06 10.22100/ijhs.v7i4.824 https://ijhs.shmu.ac.ir/index.php/ijhs/article/view/824 Abstraction Shahroud University of Medical Sciences mEDRA 01 1-38-824 01 Shahroud University of Medical siences IR 01 1 07 24236594 JD 01 Open Journal Systems (OJS) 7 4 Volume 7, Issue 4: 2021 06 2021 7 1 A01 Fariba Zare 1 Zare 1, Fariba 1- Center for Health Related Social and Behavioral Sciences Research, Shahroud University of Medical Sciences, Shahroud, Iran. 2 A01 Mohammad Hassan Emamian 2 Emamian 2, Mohammad Hassan 2- Ophthalmic Epidemiology Research Center, Shahroud University of Medical Sciences, Shahroud, Iran. 3 A01 Reza Chaman 3 Chaman 3, Reza 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 4 A01 Marzieh Rohani-Rasaf 3 Rohani-Rasaf 3, Marzieh 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 5 A01 Shahrbanoo Goli 3 Goli 3, Shahrbanoo 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 6 A01 Solmaz Talebi 3 Talebi 3, Solmaz 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 7 A01 Ali Hosseinzadeh 3 Hosseinzadeh 3, Ali 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 8 A01 Ahmad Khosravi 1,3* Khosravi 1,3*, Ahmad 1- Center for Health Related Social and Behavioral Sciences Research, Shahroud University of Medical Sciences, Shahroud, Iran, 3- Department of Epidemiology, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran. 01 eng 23 COVID-19;Serial interval;Gamma distribution 01 Type of manuscript: short report Introduction: Serial interval refers to the average time between of the onset of the symptoms of two successive cases. Serial interval distribution can be used for the calculation of the basic reproduction number (R0), transmission rate, and study of an epidemic trend. This study aims to investigate the mean, standard deviation, and distribution of serial interval among the confirmed cases of COVID-19 using a Gamma distribution. Methods: To determine the serial interval, 60 confirmed infected cases of COVID-19 (based on PCR test results) in February 20th-May 20th, 2020 were selected as the cases. For these cases, 37 transmissions occurred. The data of the dates of the occurrence of primary and secondary symptoms were collected by referring to the COVID-19 surveillance system and interviewing the patients Results: The findings showed that the median and mean of the serial interval were 3.0 and 4.5± 3.5 days. The findings showed that the median of the serial interval was 3.0 days (with the inter-quartile range of 2.0-6.0). The mean serial interval was 4.5± 3.5 days (95% confidence interval: 3.1-5.5). Conclusions: Our report showed a shorter period for a serial interval less than the previous reported interval in China. It seems that regarding the shorter serial interval reported in this study, the basic reproduction numbers reported by the first papers published in Iran have been overestimated regarding the serial interval of 7.5 days. Key words: COVID-19, Serial interval, Gamma distribution 20210724 81 01 1-38 89 01 1-38-824-g686