A latitudinal gradient study of common anti-infectious agent antibody prevalence in Italy and Colombia.

BACKGROUND Infectious agents are important in the pathogenesis of autoimmune disease since they are a major part of the environmental trigger of autoimmunity. A negative relationship between latitude and infectious disease species richness has been suggested. OBJECTIVES To examine whether their prevalence differs in two latitudinally different populations. METHODS The prevalence of infections with Toxoplasma gondii, rubella virus, cytomegalovirus, Epstein-Barr virus and Treponema pallidum was compared between subjects from Italy and Colombia. RESULTS We found high titers of antibodies against four of five microorganisms tested, Toxoplasma gondii (50.8%), rubella virus (German measles) (75%), cytomegalovirus (86.3%), Epstein-Barr virus (83.3%) and Treponema pallidum (6.3%) in completely healthy individuals from a tropical country (Colombia) and a European country (Italy). Differences between two groups of volunteers were noted regarding two infectious agents. The prevalence of immunoglobulin G anti-rubella antibodies was significantly higher among Italian subjects (85% vs. 67.9%, P = 0.002), whereas antibodies against CMV were less prevalent among Italian as compared to Colombian subjects (77% vs. 92.9%, P < 0.001). CONCLUSIONS These differences might also result in a different tendency towards development of autoimmune diseases associated with these infectious agents in different populations.