Tests were performed for the determination of IgM levels (by simple radial immunodiffusion) and antibodies for syphilis (FTA-ABS-IgG and IgM, VDRL and Wassermann (W)) and toxoplasmosis (indirect immunofluorescence IgG (IFI-IgG) and IgM (IFI-IgM)) in 408 new-borns (NB) sera at the University Hospital of the Faculty of Medicine of Ribeirão Preto, USP, selected at random from July 1 to October 9, 1981. Only 3 NB showed greater than normal values of IgM levels in serum, but no clinical or laboratory diagnosis of congenital syphilis or toxoplasmosis was made for them. Two hundred and 91 infants (71.3%) were IFI-IgG positive for toxoplasmosis and none IFI-IgM, before or after chromatography. No clinical diagnosis of congenital toxoplasmosis was made during the period studied. The rheumatoid factor (RF) was determined in order to exclude false-positive results for antibodies of the IgM class. All possible false-negative sera to IFI-IgM and IFI-IgG positive for toxoplasmosis were treated by gel chromatography. Only one positive serum for RF was treated with heat-aggregated gamma-globulin before being tested for the presence of IgM antibodies. Sevem percent of the NB (28) were positive to at least one of the tests for syphilis. FTA-ABS-IgG was positive in 89.3% of them, VDRL in 67.8% and W in 60.7%. Only one serum sample was positive for FTA-ABS-IgM. The concordance of positivity between FTA-ABS-IgG and VDRL was 60.7%; 53.6% between FTA-ABS-IgG and W and 60% between VDRL and W. The syphilis-positive sera were compared with the data in the medical records of the respective NB and their mothers. It was shown that among the 28 NB with positive tests for syphilis only 5 3.5 % of them were detected at birth, 3.6% had negative serology and no data were available for 42.9%. Clinical and/or serological follow-up disclosed that 2 NB evolved with signs of congenital syphilis, 2 were suspected to have syphilis, and were treated but control serology ruled out this possibility, and no data were available for 24. A new screening strategy for this disease and the introduction of the FTA-ABS-IgG test for a more extensive selection of congenital syphilis is suggested.
Syphilis, congenital; Toxoplasmosis, congenital; Wasserman reaction; Fluorescent antibody technic; Gell diffusion test; IgG; IgM
