Seroprevalence of toxocariasis in schoolchildren in Trinidad

Abstract

The seroprevalence of toxocariasis was investigated in 1997/98 in 1009 schoolchildren (aged 5–12 years) throughout Trinidad. Infection, as measured by titre, was found to be high compared to values obtained from children in other countries. Using an excretory-secretory antigen and performing an ELISA test, it was found that 62·3% of children had an IgG antibody titre of ≥ 1: 100, indicating exposure to the parasite, while 27·2% had a titre of ≥ 1: 800, indicating a current or recent infection. Relationships were explored between seroprevalence and host factors including age, sex, school location, and other risk factors including geophagia, thumb-sucking, presence of other gastrointestinal-tract parasitism and pet ownership. There was no significant relationship between age and the presence of current or recent infection ( P = 0·746). Boys were significantly more commonly infected than girls as were the attendees of rural schools versus urban schools ( P < 0·001). The percentage of seropositivity among children varied widely from school to school. Pet ownership and the absence of pipe-borne water in the household were found to be significantly associated with positive serology ( P < 0·05). Clinical symptoms mostly associated with positive serology were eczema, seizures and chronic cough. Recommendations derived from this study include health education in order to increase the public awareness on the transmission of the disease, de-worming all dogs and cats periodically and the curbing of stray dogs and cats. Environmental sanitation measures should include keeping children away from contaminated areas and practising proper hygiene after play.