Acanthamoeba castellanii: high antibody prevalence in racially and ethnically diverse populations.

Acanthamoeba is an opportunistic protozoan pathogen that can produce keratitis and rare but fatal encephalitis. In the present study, we examined secretory IgA antibody to Acanthamoeba castellanii of the T4 genotype in mucosal secretions from 114 individuals of 37 countries, inhabitants and/or visitors, aged 16-65 years in London, UK. Acanthamoeba antibody prevalence rate was more than 85%, without any significant differences between males (86.2%) and females (89.2%). Some epidemiological factors contributing to the high prevalence of antibody to Acanthamoeba in surveyed population are discussed further.