Variations of the prevalence of IgG and IgM antibodies to Toxocara in Trinidadian school children - abstract

ABSTRACT

Toxocara involvement in ocular lesions was suspected following the high frequency of IgG antibodies in serum samples of patients attending the Eye Clinic at the General Hospital, Port-of-Spain. Also, a high prevalence of IgG antibodies to Toxocara was found in 5-9 year-old children in certain Caribbean islands. Fifty children, aged 6-15 years with equal numbers of boys and girls, were randomly selected from 5 schools in rural South and Central Trinidad. A stool sample (examined for parasites) and a 5ml blood sample were obtained from each student. Serum from 17 patients with ocular symptoms and from 39 patients with other symptoms were also examined. Serum IgG and IgM antibodies (to Toxocara) were determined by ELISA method. Fifty children from one school were given a thorough eye examination. The prevalence of antibodies seemed to increase with age, from 54 per cent in 5-7 year olds to 87 per cent in 12-13 year olds for IgG, and from 56 per cent to 61-63 per cent for IgM antibodies. IgG antibodies to Toxocara were more prevalent in males than females, but there was no positive correlation with reported geophagia or association with domestic pets. There was a higher prevalence of IgGs (88 per cent) in sera from patients with ocular lesions than in those without such lesions (39 per cent, p<0.01). Results suggest the need for a comprehensive study of toxocariasis in childhood in Trinidad and Tobago (AU)