However, it is around 10 months that have already been gone since the first infection of the coronavirus in December 2019 and all countries have been imposed several prevention measures. For instance, they reported a summary estimate of the basic reproductive number without considering the net reproductive number and the time-dependent reproductive number. However, of the three studies that have been provided summary reproductive number so far were limited in several areas and did little to settle these disagreements. To settle these disagreements on the reported reproductive number and know the current situation of infection, a summary estimate of the reproductive number is important. For instance, the basic reproductive number is used when an infected person can mix randomly to non-infected persons (i.e., no control intervention was applied), whereas, the net and time-dependent reproductive number are used when control interventions were applied. Of the three reproductive numbers estimated, namely the basic reproductive number ( R 0), net reproductive number ( R e), and time dependent reproductive number ( R t), are applicable for different purposes. Another important source of variation of the estimated reproductive number was the type of reproductive numbers considered. Other reported sources of variations of the reported reproductive number were the country for which the reproductive number was estimated and its stages of infection and preventive measures applied.
However, they were not consistent in terms of their measurement procedures and methods used, therefore, the estimated reproductive number was quite different. There are various researches in the country level that have been reported the reproductive number of coronavirus.
Moreover, it also helps to develop an effective epidemiological mathematical model considering possible transmission ways, such as, droplets and direct contacts with coronavirus infected patients (COVID-19), which are important to know the risk population and the appropriate epidemiologic parameters. These are important to reduce new infections through designing effective control measures such as social distancing and to know the expected duration of keeping control measures. Knowing the accurate reproductive number of coronavirus, defined as the capability of transmission per primary infected person to the secondarily infected persons, is significant for various reasons, including to assess epidemic transmissibility and to predict the future trend of spreading. Reducing new infections, therefore, needs further comprehensive preventive measures. However, the new infections are rising exponentially, in all ages and sexes, irrespective of the countries. Given no treatments or vaccines available for this virus, countries are now imposing numerous non-medical measures to reduce further infections, which include restricting people's movements, banned international and local travels, quarantine, and isolation. Consequently, the World Health Organization (WHO) has declared it as pandemic and suggested countries to take aggressive measures to reduce new infections. More than 29.5 million population have been infected so far worldwide, of which more than 933,720 are died. We also reported significant heterogeneity of the type of reproductive number- a high-value reported if it was the time-dependent reproductive number.Ĭoronavirus (SARS-COV-2) is now a global concern that speared out to 213 countries or territories as of September 15, 2020. The higher reproductive number was reported if it was estimated by using the Markov Chain Monte Carlo method (MCMC) method and the Epidemic curve model. The highest reproductive number was reported for the Diamond Princess Cruise Ship in Japan (14.8). Our sub-group analysis was found the significant variations of reproductive number across the country for which it was estimated, method and model that were used to estimate the reproductive number, number of case that was considered to estimate the reproductive number, and the type of reproductive number that was estimated. We found evidence of very high heterogeneity (99.5%) of the reproductive number reported in the included studies. The estimated summary reproductive number was 2.87 (95% CI, 2.39–3.44). Total of 42 studies included in this review whereas 29 of them were included in the meta-analysis.