Ocular Findings in Infants with Congenital Toxoplasmosis Following a Toxoplasmosis Outbreak.

Abstract Purpose We investigated the prevalence of ocular abnormalities in infants vertically exposed to Toxoplasma gondii infection during an outbreak in Santa Maria City, Brazil. Design Consecutive case series. Participants A total of 187 infants were included in this study. Methods The infants were recruited from January 2018 to November 2019. All mothers were screened for syphilis and human immunodeficiency virus before delivery. Toxoplasmosis infection was confirmed in all mothers and infants based on the presence of serum anti-T. gondii immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies. All infants underwent an ophthalmologic examination; ocular abnormalities were documented using a wide-field digital imaging system. Neonatal cranial sonography and/or head computed tomography were performed in 181 infants, and the cerebrospinal fluid (CSF) was screened for anti-T. gondii IgG and IgM antibodies in 159 infants. Peripheral blood samples from nine infants and their mothers were analyzed for the presence of T. gondii DNA by real-time polymerase chain reaction. Main Outcomes Measures Ocular abnormalities associated with congenital toxoplasmosis. Results A total of 187 infants were examined. Twenty-nine infants (15.5%) had congenital toxoplasmosis, of whom 19 (10.2%) infants had ocular abnormalities, including retinochoroiditis in 29 of 38 (76.3%) eyes, optic nerve abnormalities in five (13.2%) eyes, microphthalmia in one (2.6%) eye, and cataract in two (5.3%) eyes. Bilateral retinal choroidal lesions were found in 10 of 19 (52.6%) infants. Nine eyes of six infants had active lesions, with retinal choroidal cellular infiltrates at the first examination. Thirteen (7.2%) of 181 infants screened presented with cerebral calcifications. Eighty-three percent of the screened infants were positive for anti-T. gondii IgG and negative for IgM antibodies in the CSF. Congenital toxoplasmosis was higher in mothers infected during the third pregnancy trimester, and maternal treatment during pregnancy was not associated with a lower rate of congenital toxoplasmosis. Conclusions High prevalence rates of clinical manifestations were observed in infants with congenital toxoplasmosis after a waterborne toxoplasmosis outbreak, the largest yet described. Cerebral calcifications were higher in infants with ocular abnormalities and maternal infection during the third pregnancy trimester was associated with a higher rate of congenital toxoplasmosis independent of maternal treatment.