NEONATAL SEROLOGIC SCREENING AND EARLY TREATMENT FOR CONGENITAL TOXOPLASMA-GONDII INFECTION

Background. Most infants with congenital Toxoplasma gondii infection h ave no symptoms at birth, but many will have retinal disease or neurol ogic abnormalities later in life. Early detection and treatment of con genital toxoplasmosis may reduce these sequelae. Methods. In Massachus etts since January 1986, and in New Hampshire since July 1988, newborn s have been screened for intrauterine infection with T. gondii by mean s of an IgM capture immunoassay of blood specimens routinely collected for screening for metabolic disorders. Congenital infection is confir med by assays for specific IgG and IgM antibodies in serum from infant s and their mothers. For this study, infants with serologic evidence o f infection underwent extensive clinical evaluation and received one y ear of treatment. Results. Through June 1992, 100 of 635,000 infants t ested had positive screening tests. Congenital infection was confirmed in 52 infants, 50 of whom were identified only through neonatal scree ning and not through initial clinical examination. However, after the serologic results became available, more detailed examinations reveale d abnormalities of either the central nervous system or the retina in 19 of 48 infants evaluated (40 percent). After treatment, only 1 of 46 children had a neurologic deficit (hemiplegia attributable to a cereb ral lesion present at birth). Thirty-nine treated children had follow- up ophthalmologic examinations when one to six years old; four (10 per cent) had eye lesions that may have developed postnatally (a macular l esion in one child and minor retinal scars in three). Conclusions. Rou tine neonatal screening for toxoplasmosis identifies congenital infect ions that are subclinical, and early treatment may reduce the severe l ong-term sequelae.