Postnatal challenge infections of congenitally Schistosoma japonicum-infected piglets

The aim of the present study was to assess the effect of a congenital Schis tosoma japonicum infection on the establishment, fecundity, and pathogenici ty of a postnatal challenge infection. Five prenatally S. japonicum-infecte d piglets received a challenge infection (prenatal + challenge group), 5 pr enatally infected piglets were followed without challenge (prenatal group), and 10 piglets, born by unexposed sows. served as challenge controls (chal lenge control group). Challenge infections were given 8 wk after the piglet s were born (14 wk after the primary infection of the sows), and the study lasted another 11 wk. Variables included worm burden, tissue egg count. and liver pathology. Worm establishment and tissue egg count were comparable i n the prenatal + challenge group and in the challenge control group, both e xceeding at a statistically significant level those in the prenatal group. No difference in worm fecundity (eggs/female worms/g tissue) was seen betwe en the 3 groups. Liver pathology (i.e., portal and septal fibrosis) was mor e severe in the challenge control group compared to the other groups. A con genital S. japonicum infection in piglets thus affected neither establishme nt nor fecundity of a postnatal challenge infection. In spite of this. the challenge infection gave rise to much less liver pathology than the similar ly sized challenge control infection.