The aim of this study was to estimate the basic reproduction number ( R 0 ) of COVID-19 in the early stage of the epidemic and predict the expected number of new cases in Shahroud in Northeastern Iran. The R 0 of COVID-19 was estimated using the serial interval distribution and the number of incidence cases. The 30-day probable incidence and cumulative incidence were predicted using the assumption that daily incidence follows a Poisson distribution determined by daily infectiousness. Data analysis was done using ‘earlyR’ and ‘projections’ packages in R software. The maximum-likelihood value of R 0 was 2.7 (95% confidence interval (CI): 2.1−3.4) for the COVID-19 epidemic in the early 14 days and decreased to 1.13 (95% CI 1.03–1.25) by the end of day 42. The expected average number of new cases in Shahroud was 9.0 ± 3.8 cases/day, which means an estimated total of 271 (95% CI: 178–383) new cases for the period between 02 April to 03 May 2020. By day 67 (27 April), the effective reproduction number ( R t ), which had a descending trend and was around 1, reduced to 0.70. Based on the R t for the last 21 days (days 46–67 of the epidemic), the prediction for 27 April to 26 May is a mean daily cases of 2.9 ± 2.0 with 87 (48–136) new cases. In order to maintain R below 1, we strongly recommend enforcing and continuing the current preventive measures, restricting travel and providing screening tests for a larger proportion of the population.
【저자키워드】 COVID-19, Epidemic, Iran, Reproduction number, projection, incident case, 【초록키워드】 Travel, basic reproduction number, preventive measures, incidence, distribution, early stage, predict, screening test, Poisson distribution, COVID-19 epidemic, Analysis, R software, 95% CI, 95% confidence interval, average, assumption, cumulative, effective, the epidemic, maximum-likelihood, predicted, proportion, reduced, maintain, expected, was done, descending, 【제목키워드】 Novel coronavirus, basic reproduction number, the epidemic,