Placental and oral delivery of Schistosoma mansoni antigen from infected mothers to their newborns and children.

A 63-kD Schistosoma mansoni antigen was detected in 149 (86%) of 174 umbilical cord blood sera from infected women at delivery. Specific IgG antibodies to this antigen were also detected in 80% of cord blood sera. The 63-kD antigen showed the same molecular mass by Western blotting when isolated from cord blood, maternal blood, breast milk, and urine from women infected with S. mansoni. This antigen was detected in the urine of 25 infants born to infected mothers and followed for 18-24 months after delivery. It was also detected in some infants up to 21 days after parturition and then disappeared at 28 days, demonstrating the influence of breast-feeding on persistence of antigen in infants born to infected women. Thus, exposure to Schistosoma antigens and maternal antibodies to this organism may influence the developing immune responses to natural infection or vaccination of children born in endemic areas.