How is the iceberg of COVID-19? Results from a rapid literature review

Given the various reports of the clinical spectrum of the disease, the aim of the present study was to determine possible scenarios of Coronavirus 2019 (COVID-19) iceberg using published articles.

The present study was a rapid review of all international databases, including PubMed (Medline), Scopus, Web of Sciences, Embase, and Cochrane Library from January 1 to October 30, 2020.

In this review, 7 scenarios were considered for COVID-19 iceberg, in which the range of fatality percentage was estimated to be 0.5% to 7%, the range of asymptomatic cases 1% to 88.6%, the range of cases with mild symptoms 8% to 78%, no symptoms 1 % to 90 %, the range of intensive care unit (ICU) admission was 0.5% to 14.2%, and finally the intubation percentage was estimated to be 0.2% to 12.2%. The Scenarios Diamond Princess Cruise Ship and Iceland are closer to the reality of the clinical spectrum of COVID-19 around the world, which represent 0.6% and 0.5% of deaths, 0.7% and 1% of intubations, 2.5% and 9.7% of ICU admissions, 1.1% and 6% of hospitalizations, 15% and 31% of cases with mild symptoms, and finally 56.9% and 75% of asymptomatic cases of COVID-19, respectively, which should now be considered as the basis of the clinical knowledge of the disease. 

Understanding the clinical spectrum and natural knowledge of the disease and paying attention to asymptomatic or mild-symptom cases can help to make better decisions and develop more effective interventions to control COVID-19.