Congenital toxoplasmosis: Auditory and language outcomes in early diagnosed and treated children

Abstract

AIMS: To describe the auditory and language outcomes of children with early diagnosis and treatment for congenital toxoplasmosis. METHODS: A cross-sectional study included all children diagnosed with congenital toxoplasmosis, through the Minas Gerais State Neonatal Screening Program, from September 2006 to March 2007. All children received early treatment, initiated before the age of 2.5 months, and were periodically assisted by a team of specialists including pediatricians, ophthalmologists and speechlanguage therapists and audiologists. Hearing function was evaluated with the following procedures: tympanometry, transient evoked otoacoustic emissions, distortion product otoacoustic emissions, behavioral observation audiometry, and brainstem auditory evoked potentials. Hearing function and sensitivity was estimated and audiological results were classified as normal, conductive hearing loss, sensory-neural hearing loss and central dysfunction. Language performance was assessed and classified as normal or abnormal, according to test results. The following variables were studied: audiological results, neurological and ophthalmological conditions, language performance and presence of risk indicator for hearing loss other than congenital toxoplasmosis. Univariate analysis was conducted using the chi-square or Fisher´s Exact test. RESULTS: From September 2006 to March 2007, 106 children were diagnosed with congenital toxoplasmosis through the neonatal screening program, and were included in the study. Data analysis showed normal hearing in 60 children (56.6%), while 13 children (12.3%) had conductive hearing loss, four children (3.8%) had sensory-neural hearing loss and 29 children (27.4%) presented central hearing dysfunction. There was association between hearing problems and language deficits. The comparison between children with additional risks for hearing loss other than toxoplasmosis and children who only presented toxoplasmosis as a risk factor showed no differences. This finding suggests that audiological problems were due to congenital toxoplasmosis alone. CONCLUSIONS: Even with early diagnosis and treatment, a high prevalence of hearing problems and language delays was observed in children with congenital toxoplasmosis.