The prevalence and persistence of antibodies against cytomegalovirus (CMV), herpes simplex virus types 1 (HSV1) and 2 (HSV2), Helicobacter pylori and Chlamydia pneumoniae were determined in Alaskan Eskimos. The study included 610 individuals (mean age 43 +/- 15 years; 45% males) participating in the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. Archived serum samples and those collected during the GOCADAN study were analysed for antibodies against the above pathogens by ELISA. The current prevalence of antibody seropositivity was 94% to CMV, 90% to HSV1, 38% to HSV2, 80% to H. pylori, and 42% to C. pneumoniae. The persistence of antibodies (in both archived and current samples) against CMV, HSV1 and H. pylori was high (83%, 84% and 67%, respectively) compared with those against HSV2 (26%) and C. pneumoniae (29%). Moreover, the seroconversion rates to these organisms were low. Most individuals acquired CMV, HSV1 and H. pylori antibodies by the age of 24 years (94%, 90% and 72%, respectively), and >50% carried HSV2 and C. pneumoniae antibodies by the age of 45 years. There were gender differences in antibody seropositivity rates. Over 70% of individuals had antibodies to at least three of the five pathogens tested. The study demonstrated the high prevalence and lifelong persistence of multiple antibodies, suggesting chronic infections among Alaskan Eskimos.