Immune response to Campylobacter jejuni in a rural community in Thailand.

We studied the prevalence of antibodies to Campylobacter jejuni in serum from healthy Thai villagers by using enzyme-linked immunosorbent assays with C. jejuni surface proteins as antigens. Levels of C. jejuni-specific IgA rose progressively through life, IgG peaked in the second year of life and then fell, and IgM peaked during late childhood and the teenage years. These findings confirm results observed in Bangladeshi children, and they suggest there is intense early exposure and continued exposure through life. The ratio of C. jejuni-specific IgA to total IgA was constant in all age groups while the ratio of specific IgG and IgM followed the same age-related pattern as the levels of antibody to C. jejuni. The age-related discordance between the C. jejuni-specific IgA and IgG levels observed in this and the previous study are at present unexplained.