Incidence of congenital toxoplasmosis among live births in a tertiary center in Southern Brazil.

Abstract

Toxoplasmosis affects approximately one-third of the global population. Despite the high seroprevalence in Brazil, contemporary data on the incidence and clinical spectrum of congenital toxoplasmosis (CT) in tertiary-care settings remain limited. Few studies have specifically addressed the incidence of symptomatic CT, limiting the identification of risk factors, preventive strategies, and optimal patient management, particularly in the context of recent healthcare disruptions and environmental changes. This study aims to determine the incidence of exposure to gestational toxoplasmosis and CT among live births in a tertiary center in Southern Brazil, and to identify factors associated with vertical transmission and disease manifestations. We conducted a retrospective cohort study of newborns exposed to gestational toxoplasmosis between 2015 and 2024 at a tertiary referral center. Clinical, laboratory, and imaging data were extracted from medical records. Statistical analyses included Chi-square and Student's t-test, with significance set at P < .05. Among 222 exposed infants, 18 developed CT, corresponding to an incidence of 6.2 per 10 000 live births. A marked increase in incidence was observed in recent years, peaking in 2024, coinciding with major regional flooding events. Positive neonatal IgM serology was present in 10 cases (55.6%). Neurological abnormalities on brain imaging were identified in 59% of infected infants, ocular lesions in 39%, and auditory impairment in 5.6%. Late gestational seroconversion and suboptimal prenatal care were associated with infection. This study provides contemporary, real-world epidemiological data from a tertiary referral center in Southern Brazil, highlighting temporal trends potentially linked to environmental and healthcare disruptions, as well as persistent gaps in prenatal screening and treatment. These findings underscore the need for improved prenatal care strategies and surveillance systems to reduce the burden of CT.