Experimental model of congenital syphilis.

Female LSH hamsters infected with Treponema pallidum subsp, endemicum before pregnancy or during early pregnancy transmit a form of syphilis to the fetus that is similar to human congenital syphilis. The offspring develops rhinitis, skin rash, failure to thrive, and hepatosplenomegaly. T. pallidum is detectable in their livers, spleens, and nasal secretions. Immunoglobulin M antibodies are detected in the serum.