Epidemiological Parameters of COVID-19: Case Series Study

Area of Science:

• Epidemiology
• Infectious Disease Dynamics
• Public Health

Background:

• Estimates of key COVID-19 epidemiological parameters are often unreliable due to small sample sizes or inaccuracies.
• Accurate parameter estimation is crucial for effective pandemic control strategies.

Purpose of the Study:

• To obtain robust estimates of COVID-19 incubation period, serial interval, presymptomatic transmission frequency, and basic reproduction number (R0).
• To provide a larger, more reliable dataset for public health decision-making.

Main Methods:

• Systematic retrieval and screening of 20,658 COVID-19 case reports from China, Japan, and Singapore.
• Inclusion of 9,942 publications from PubMed and CNKI (up to April 8, 2020) containing individual data for parameter estimation.
• Application of gamma distribution models to estimate epidemiological parameters from 1,591 final analysis cases.

Main Results:

• Mean incubation period: 7.04 days (n=687); Mean serial interval: 6.49 days (n=1015).
• Incubation period exceeded 14 days in 5.82% of cases; presymptomatic transmission occurred in 43.58% (n=129/296).
• Basic reproduction number (R0) estimated at 1.85 (95% CI 1.37-2.60).

Conclusions:

• The study provides robust epidemiological parameter estimates for COVID-19.
• Findings support current 14-day quarantine practices but indicate a need for enhanced control measures.
• The prevalence of presymptomatic and asymptomatic transmission underscores the importance of testing, quarantine, and social distancing.