Fig. 1

Proportion of serological populations (seronegative, S -, and seropositive, S +) per total IgG and subclass (IgG1, IgG2, IgG3 and IgG4), stratified by asymptomatic or symptomatic carrier. The sample was classificatied in two populations based on a three-component mixture model (defined as S - = 1; S + = 2, 3) to compare the proportions between carriers per each IgG subclass by Fisher’s exact test. The percentages are indicated within the columns