Sex Hormones and Bacterial Infections

Epidemiological and experimental data suggest the association of gender and sex with susceptibility and severity of infectious diseases (Moss, 2005). Gender and sex likely affect viral and parasitic infectious diseases (Morales-Montor et al., 2004; Fish, 2008; Snider et al., 2009). Here we will review the effect of gender and sex on bacterial infectious diseases (sepsis, mycobacterial diseases and Q fever). We will differentiate gender and sex by considering that gender refers to differences determined by cultural and societal factors and sex refers to the biological differences between males and females (Fish, 2008). Indeed, variables such as poverty, occupational status and marital status affect differently men and women in different countries (Theobald et al., 2006), leading to different risks of exposition to infectious pathogens and accesses to efficient treatment. This is illustrated by the decreased prevalence of tuberculosis in industrialized countries associated with socioeconomic changes including reduced malnutrition and overcrowding, improved sanitary conditions in the workplaces before the use of chemotherapy (Davies et al., 1999). Sex-based differences in the susceptibility to pathogens include what is due to chromosome effect and sex hormones. Thus, it is critical to delineate the respective roles of gender and sex on bacterial infections. The present review focuses on four features of the association between sex and bacterial infections with a special attention for bacterial sepsis, mycobacterial infections and Coxiella burnetii infection.