SEROLOGICAL AND EPIDEMIOLOGICAL SCREENING TO ESTIMATE CONGENITAL Toxoplasma gondii INFECTION IN GUAYAQUIL, ECUADOR

Abstract

Serological testing, by indirect haemagglutination and ELISA was performed in 4 age groups: 0 to <5, 5 to <10, 10 to <15 and 15 to <20 years old, to find prevalence and quinquennial incidence. An interview to assess risk factors was performed. The statistical analysis was performed for independent variables and bivariate correlations to calculate the odds ratio. The total number of observations was 578: 285 male and 292 female (1 not determined) and median age was 9.7. An increase in the prevalence was related to age, reaching 60.2% in the group between 15 and 20 years
old, when compared to the same age group in 1989 (78.3%) showing an 18% decrease. Several hypotheses to explain this decrease were proposed. There is a steep increase at the age of 10. The statistical analysis does not demonstrate a direct correlation with any of the risk factors consigned in the interview, with the exception of exposure to young felines (kittens). The risk for acquiring congenital toxoplasmosis was estimated as 1.8 per thousand (18 per ten thousand), hence 106 cases are expected per year, with 69 (65%) of them being asymptomatic, and 37 with different degrees of severity: 17 with mild, 11 severe and 9 with death at birth. Each year there would be 28 newborns with evident lesions and additionally an undetermined number of cases with late onset lesions within the initially asymptomatic group (65%), with unknown socioeconomic impact.