Estimation of the basic reproduction number, average incubation time, asymptomatic infection rate, and case fatality rate for COVID-19: Meta-analysis and sensitivity analysis

Abstract

The coronavirus disease 2019 has been found to be caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, comprehensive knowledge of COVID-19 remains incomplete and many important features are still unknown. This manuscripts conduct a meta-analysis and a sensitivity study to answer the questions: What is the basic reproduction number? How long is the incubation time of the disease on average? What portion of infections are asymptomatic? And ultimately, what is the case fatality rate? Our studies estimate the basic reproduction number to be 3.15 with the 95% interval (2.41, 3.90), the average incubation time to be 5.08 days with the 95% confidence interval (4.77, 5.39) (in day), the asymptomatic infection rate to be 46% with the 95% confidence interval (18.48%, 73.60%), and the case fatality rate to be 2.72% with 95% confidence interval (1.29%, 4.16%) where asymptomatic infections are accounted for.

Face Masks Against COVID-19: An Evidence Review

“…Randomised control trial evidence that investigated the impact of masks on household transmission during influenza epidemics indicate potential benefit, although we should be careful of assuming these results will transfer to SARS-CoV-2. In particular, influenza has an R0 (the basic reproduction number) of 1.4 (21) whereas SARS-CoV-2 has an R0 of 2.4 or more (22). Suess et al conducted an RCT (23) that suggests household transmission of influenza can be reduced by the use of non-pharmaceutical interventions, namely the use of face masks and intensified hand hygiene, when implemented early and used diligently.…”

“…In this section we look at models that have attempted to estimate the possible magnitude of such an effect. The basic reproduction number R0 is estimated to be in the range 2.4-3.9 (22).…”

“…This characteristic differentiates SARS-CoV-2 (COVID-19) from SARS-CoV, as replication is activated early in the upper respiratory tract (51). A study of temporal dynamics inferred that infectiousness started from 2.3 days before symptom onset and peaked at 0.7 days before symptom onset (22).…”

COVID-19 projections for reopening Connecticut

“…However, these data may not provide timely insight into the current and future dynamics of COVID-19 transmission. Because viral testing of asymptomatic individuals is not yet widespread, symptomatic individuals at least 4-5 days from infection may constitute the majority who seek testing [16][17][18][19][20][21][22], and COVID-19 case counts or positive test proportion may be poor surrogate measures of current infection prevalence. Hospitalization may not occur until more than 2 or 3 weeks following infection, and death may not occur for weeks after that [17,[23][24][25][26][27].…”

A Syndromic Surveillance Tool to Detect Anomalous Clusters of COVID-19 Symptoms in the United States

“…These metrics might be nevertheless highly informative if it is assumed that all infected individuals seek medical attention and are thus incorporated into the case statistics. These metrics, however, do not consider the population that is infected but is completely asymptomatic (40%-50% in many studies), 5 or those who prefer not to seek medical care despite having symptoms. Furthermore, when hospitalizations do occur, they often happen days after contracting the disease, when symptoms begin to manifest or worsen.…”