Seroprevalence of anti Toxoplasma gondii IgG antibodies in subjects in Qatar. A. By age class. The number of subject in each age class in the order as shown on the abscissa (from age class <1 through to age class >45) was 338, 29, 63, 419, 539 and 148 respectively. The total sample size was 1625. B. By region of origin. The number of subjects of each ethnic origin was as follows Arabian Peninsula = 630, Africa = 304, Eastern Mediterranean = 180 and Asia = 511. C. By age class and region of origin.