(1/n) We gathered and analysed genetic and epidemiological data related to the #COVID19 outbreak in #Iran to gauge its size in late Feb - early Mar and estimate the likely start of transmissions. I will summarise some of our key findings in this thread. Will be ~8 tweets. https://twitter.com/medrxivpreprint/status/1253260939710935041

We have been following the outbreak since the first two reported deaths in #Qom on 19 Feb. In less than a week, cases started popping up in almost every province in the country. Since 23 Mar, #Iran has only released nationwide numbers.

We just found out (not yet included in the preprint) that reports from #Tehran university hospitals indicate the first COVID-19 death took place on 10 Feb followed by 6 more deaths up to 19 Feb before 2 deaths in #Qom were officially announced.
source: http://nihr.tums.ac.ir/ 

One of the first alarming signs for us was that the case fatality ratio in <60 age-groups is 10-20 times higher than those from China and several other countries across Europe (not shown) suggesting possibly high levels of under-reporting in those age-groups.

We used 19 full-genome sequences from cases with a travel to Iran + the first full-genome from inside Iran (all made available by @GISAID) and estimated the TMRCA of sequences back to 21 Jan (95% HPD: 5 Dec - 14 Feb) with a doubling time of about 3 days (95% HPD: 1.68 - 16.27).

Based on known exported cases to OM, KU, LB, and China we estimate the outbreak size on 25 Feb and 6 Mar. Extrapolating back, we find the outbreak likely started ~15 Jan -- more than a month earlier than the announced deaths in Qom. @bbcpersian @IranIntl_En @RadioFarda_Eng

Using the epi model developed by @richardneher's group, to analyse the burden on hospitals and over the next few months. Based on current interventions, we predict a new wave is likely going to hit Iran in the next 1-2 months.
for info about the model see: https://covid19-scenarios.org/ 

We also investigated possible manipulation of numbers using Benford’s law but found no conclusive evidence for it.

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