The Impact of Control Measures and Holiday Seasons on Incidence andMortality Rate of COVID-19 in Iran

Background: preventive measures on the covid-19 pandemic is an effective way to control itsspread. we aimed to investigate the effect of control measures and holiday seasons on theincidence and mortality rate of covid-19 in iran.study design: an observational study.methods: the daily data of confirmed new cases and deaths in iran were taken from the johnshopkins university covid-19 database. we calculated weekly data from 19 feb to 6 oct 2020. toestimate the impact of control measures and holiday seasons on the incidence rate of new casesand deaths, an autoregressive hidden markov model (arhmm) with two hidden states fitted thedata. the hidden states of the fitted model can distinguish the peak period from the non-peakperiod.results: the control measures with a delay of one-week and two-week had a decreasing effect onthe new cases in the peak and non-peak periods, respectively (p=0.005). the holiday season witha two-week delay increased the total number of new cases in the peak periods (p=0.031). thepeak period for the occurrence of covid-19 was estimated at 3 weeks. in the peak period ofmortality, the control measures with a three-week delay decreased the covid-19 mortality(p=0.010). the expected duration of staying in the peak period of mortality was around 6 weeks.conclusions: when an increasing trend was seen in the country, the control measures coulddecline the incidence and mortality related to covid-19. implementation of official restrictions onholiday seasons could prevent an upward trend of incidence for covid-19 during the peak period.