Sex/Gender Differences in Infectious Diseases

The immune response to infectious pathogens varies between men and women. Women exhibit a higher ability to recognize pathogens, recruit more innate immune cells, and mount stronger adaptive immune responses than men. Pathogens tend to be detected earlier in women than in men. Low estradiol concentrations promote Th1-type immune responses and cell-mediated immunity, while high estradiol concentrations encourage Th2-type responses and humoral immunity. Both progesterone and testosterone exhibit a wide range of anti-inflammatory effects and inhibit innate immune responses. In women, heightened immune responses are induced through the involvement of various genes related to the X chromosome, which influences the severity of infections. Men are generally more susceptible to infections from certain bacteria and parasites than women, although clinical and epidemiological differences exist depending on the causative pathogen. It is challenging to interpret all the mechanisms of infectious disease outbreaks solely based on sex differences caused by hormonal and chromosomal disparities. The impact of gender, taking into account social sensitivity, should also be considered.