Author/Authors :
Azimi, Sara Department of Epidemiology - Student Research Committee - School of Public Health and Safety - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Koohi, Fatemeh Department of Epidemiology - Student Research Committee - School of Public Health and Safety - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Aghaali, Mohammad Department of Epidemiology - School of Health - Qom University of Medical Sciences, Qom, Iran , Nikbakht, Roya Department of Biostatistics - Faculty of Health - Mazandaran University of Medical Sciences, Sari, Iran , Mahdavi, Maryam Obesity Research Center - Research Institute for Endocrine Sciences - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Mokhayeri, Yaser Department of Epidemiology and Biostatistics - School of Public Health and Nutrition - Lorestan University of Medical Sciences, Khorramabad, Iran , Mohammadi, Rasool Department of Epidemiology and Biostatistics - School of Public Health and Nutrition - Lorestan University of Medical Sciences, Khorramabad, Iran , Taherpour, Niloufar Department of Epidemiology - School of Public Health and Safety - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Nakhaeizadeh, Mehran Modeling in Health Research Center - Institute for Futures Studies in Health - Kerman University of Medical Sciences, Kerman, Iran , Khalili, Davood Prevention of Metabolic Disorders Research Center - Research Institute for Endocrine Sciences - Shahid Beheshti University of Medical Sciences, Tehran, Iran , Sharifi, Hamid HIV/STI Surveillance Research Center and WHO Collaborating Center for HIV Surveillance - Institute for Futures Studies in Health - Kerman University of Medical Sciences, Kerman, Iran , Hashemi Nazari, Saeed Prevention of Cardiovascular Disease Research Center - Department of Epidemiology - School of Public Health and Safety - Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abstract :
Background: Estimation of the basic reproduction number of an infectious disease is an important issue for controlling the infection.
Here, we aimed to estimate the basic reproduction number (ܴ0) of COVID-19 in Iran.
Methods: To estimate ܴ0 in Iran and Tehran, the capital, we used 3 different methods: exponential growth rate, maximum likelihood,
and Bayesian time-dependent. Daily number of confirmed cases and serial intervals with a mean of 4.27 days and a standard deviation
of 3.44 days with gamma distribution were used. Sensitivity analysis was performed to show the importance of generation time in
estimating ܴ0.
Results: The epidemic was in its exponential growth 11 days after the beginning of the epidemic (Feb 19, 2020) with doubling time
of 1.74 (CI: 1.58-1.93) days in Iran and 1.83 (CI: 1.39-2.71) in Tehran. Nationwide, the value of ܴ0 from February 19 to 29 using
exponential growth method, maximum likelihood, and Bayesian time-dependent methods was 4.70 (95% CI: 4.23-5.23), 3.90 (95% CI:
3.47- 4.36), and 3.23 (95% CI: 2.94-3.51), respectively. In addition, in Tehran, ܴ0 was 5.14 (95% CI: 4.15-6.37), 4.20 (95% CI: 3.38-
5.14), and 3.94 (95% CI: 3.45-4.40) for exponential growth, maximum likelihood, and Bayesian time-dependent methods, respectively.
Bayesian time dependent methods usually provide less biased estimates. The results of sensitivity analyses demonstrated that changes
in the mean generation time affect estimates of ܴ0.
Conclusion: The estimate of ܴ0 for the COVID-19 ranged from 3.94 to 5.14 in Tehran and from 3.23 to 4.70 in nationwide using
different methods, which were significantly larger than 1, indicating the potential of COVID-19 to cause an outbreak.
