A team of researchers from Sweden, Germany and China found that the average reproduction number (R0) for the COVID-19 coronavirus was 3.28, which exceeds the Organization’s estimates. World Health Organization (WHO) from 1.4 to 2.5.
This scanning electron microscope image shows the COVID-19 (yellow) virus, also known as 2019-nCoV and SARS-CoV-2, isolated from a patient in the United States, emerging from the surface of the cells (pink) grown in the laboratory.
R0 is an indication of the transmissibility of a virus, which represents the average number of new infections generated by an infectious person in a completely naive population.
For R0 greater than one, the number of infected people is likely to increase, and for R0 it is likely that less than one transmission will be extinguished.
The basic reproduction number is a central concept in the epidemiology of infectious diseases, which indicates the risk of an infectious agent in relation to the spread of an epidemic.
The WHO estimates that the coronavirus COVID-19 has an R0 of between 1.4 and 2.5.
“Our review shows that the coronavirus is at least as transmissible as the SARS virus,” said Professor Joacim Rocklöv, a researcher at the University of Umeå, Sweden.
“And that says a lot about the seriousness of the situation.”
Professor Rocklöv and his colleagues identified 12 recent studies that have estimated the basic reproductive number of COVID-19 in China and abroad.
“The studies consisted of estimates of the growth rate based on the cases observed in the Chinese population and statistical and mathematical methods,” they said.
“The first studies on the coronavirus indicated a relatively low transmissibility.”
“Subsequently, transmissibility increased rapidly to stabilize between 2-3 in the most recent studies.”
The number of replicates in the studies increased to an average of 3.28 and a median of 2.79, which is significantly higher than the WHO estimate of 1.4-2.5.
“When we look at the development of the COVID-19 epidemic, reality seems to match or even overcome the greatest epidemic growth in our calculations,” said Professor Rocklöv.
“Despite all the response and control activities, the coronavirus has already spread much more than SARS.”
The synthesis document was published in the Journal of Travel Medicine.