Differences between males and females in infectious diseases notifications in the EU/EEA, 2012 to 2021

Background: There are differences between males and females for most diseases both for exposure and course of illness, including outcome. These differences can be related to biological sex or gender i.e. sociocultural factors that may impact exposure and healthcare access. Aim: We aimed to quantify differences between males and females in infectious disease notifications in Europe and identify countries with these differences significantly different from the European Union and European Economic Area (EU/EEA) average. Methods: Notifiable infectious disease surveillance data are reported by EU/EEA countries to ECDC. We retrieved surveillance data for 2012-2021. Using a cut-off median of annual disability-adjusted life years above 1 per 100,000 population, we included 16 infectious diseases. We calculated median male proportion and interquartile range by disease, year, country and age group and used boxplots to identify outliers. Results: For campylobacteriosis, acute hepatitis B, Legionnaires' disease, malaria and HIV and AIDS, all countries had male proportion above 50%. Most countries had a male proportion below 50% for pertussis (25/28 countries), STEC infection (21/28 countries) and Chlamydia trachomatis infection (16/24 countries). Chlamydia trachomatis infection and listeriosis showed the greatest dispersion of male proportion across age groups. Most outliers were countries reporting few cases. Conclusion: We observed important differences in male proportion across infectious disease notifications in EU/EEA countries. For some diseases with high male proportions in all countries, such as HIV and hepatitis B, behaviours play a role in disease transmission. Screening offered to specific populations may explain differences across countries for example for C. trachomatis infection.