Seroprevalence of anti-Helicobacter pylori and anti-CagA antibodies among healthy children according to age, sex, ABO blood groups and Rh status in south-east of Iran.

Background/aims: The aim of this study was to evaluate the seroprevalence of anti-Helicobacter pylori (H. pylori) and anticytotoxin associated antigen A (CagA) antibodies in healthy children and to investigate the relation with age, sex, ABO blood groups and Rh status. Methods: Serum samples from 386 children (187 males, 199 females), aged 1-15 years, were tested for the presence of antibody to H. pylori and its virulence factor (CagA) by use of ELISA. ABO blood grouping was also done by hemagglutination test. Results: The overall seroprevalence of H. pylori infection was 46.6%. The prevalence of anti-H. pylori antibody was significantly (p<0.05) higher in males (51.9%) compared to females (41.7%). The prevalence of anti-CagA antibody in infected children was 72.8%. Although the prevalence of anti-CagA antibody was higher in males (78.4%) compared to females (66.3%), the difference was not statistically significant (p=0.07). In age subgroups of 1-5 years, 6-10 years and 11-15 years, the prevalence of anti-H. pylori was 37.6%, 46.9% and 54.9% and in infected children, the prevalence and the mean titer of anti-CagA antibody were 63.8%, 75.94 Uarb/ml; 75%, children acquire H. pylori infection. Anti-CagA common in the children. The seroprevalences of and anti-CagA antibodies were higher in males with age. However, the mean titer of anti-CagA decreased with increasing age. ABO blood groups influence the prevalence of H. pylori infection, especially gender..