Age and gender distribution of COVID-19 infected cases in Italian population

Abstract Since the SARS-CoV-2 epidemic started, it became clear that the impact of the infection incidence and fatality rate were closely related to the population structure. Our analysis was devoted to the distribution of the infected cases in the Italian population stratified by age and sex in order to define the differences in gender impact of COVID-19 in each age class. Data on infected cases were extracted from the Italian EpiCentro (ISS) web site from March 12 to May 20, 2020. Data were pooled in ten years’ groups. Odds ratio (OR) men versus women was evaluated by the Fisher exact test. Logistic regression was used to investigate the combined effect of age and sex on infection incidence. Statistical analysis, performed by R-Bioconductor, highlights differences in age-dependent susceptibility to infection between men and women. In elderly class (50+ ) generally man result more infected than women, with the exception of the oldest women (90+). In age classes <50 OR was about 1.0, while an intriguing exception is the age group 20-29 in which the ratio was unbalanced in favour of men. This analysis supports a strong influence of biological sex and environmental factors related to age in COVID-19 infection by SARS-Cov-2.