COVID-19 transmission risk factors

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Dynamics

Background:

• The early phase of the COVID-19 pandemic exhibited exponential growth in cases globally.
• Understanding transmission dynamics is crucial for effective public health interventions.

Purpose of the Study:

• To identify and analyze risk factors correlated with the initial transmission growth rate of COVID-19 across various countries.
• To explore potential common interpretations of these risk factors through statistical analysis.

Main Methods:

• Analysis of exponential growth phase of COVID-19 cases in 126 countries, fitting data for 12 days post-30 cases.
• Linear correlation analysis between growth rate exponents and various demographic, environmental, and behavioral variables.
• Principal Component Analysis (PCA) to identify independent combinations of correlated risk factors.

Main Results:

• High-confidence correlations found with low temperature, older population ratio, life expectancy, international tourism, early epidemic start date, physical greeting habits, lung cancer, male obesity, urbanization, general cancer prevalence, alcohol consumption, smoking, and UV index.
• Significant correlations also observed with blood types (RH-, A+, B+), low Vitamin D, CO2/SO emissions, type-1 diabetes in children, and low BCG vaccination coverage.
• PCA identified greeting habits, urbanization, epidemic start date, international tourists, temperature, lung cancer, smoking, and male obesity as key independent factors.

Conclusions:

• Multiple factors significantly influence early COVID-19 transmission rates.
• Urbanization, international travel, and specific lifestyle/health factors are critical drivers of rapid spread.
• Further investigation into potential GDP-per capita bias in testing intensity is warranted.