The possibility of transplacental transmission of experimental schistosomiasis.

Congenital transmission of Schistosoma mansoni and S. haematobium in mice was studied by experimentally infecting pregnant mice on day three, or nine or 14 of gestation. None of the pups born to mothers infected in early or mid-pregnancy were infected. However, several pregnancies ended in abortion ranging between 10%-40%. On the other hand, eight out of 35 pups born to mice infected with S. mansoni and five out of 30 pups born to mice infected with S. haematobium in late pregnancy were found to harbour schistosomes with granulomas recovered in their livers and intestines. These findings show that congenital infection of mice with S. mansoni and S. haematobium could occur when pregnant mice were infected during late pregnancy. This may have important implications not only for mice, but also for other mammalian hosts of schistosomes, including man.

Detection of Trichinella pseudospiralis antigen in the parenteral phase in experimentally infected mice.

Antigen distribution of T. pseudospiralis in muscles was studied at 10 days, 2,3 and 5 weeks post infection. Immunocytolocalization of antigen in the muscle was performed by peroxidase antiperoxidase (PAP) and immunogold silver staining techniques. Weak positive reaction of the stichosome and the cuticle was observed at 10 days post-infection which increased to attain its highest level in the fully infective stage larvae 3 and 5 weeks post infection. The intensity of staining reaction in the cytoplasm and nucleoplasm of infected host cell and surrounding tissue was highest at 5 weeks p.i. The small nuclei of the host cells and the inflammatory cells were unstained.

Detection of Trichinella pseudospiralis antigen in the enteral phase in experimentally infected mice.

The distribution of T. pseudospiralis antigen in tissue sections of the intestine of infected mice was studied at different intervals (10, 21, 35 hours and 10 days post-infection (P.I.). Immunocytolocalization of antigen in the intestine was done by peroxidase antiperoxidase staining technique. Positive staining reaction of the enterocytes was noted in all durations examined. The mononuclear cells of the lamina propria were positively stained at 10 hrs P.I. while patchy staining of muscularis mucosa was observed at 10 days P.I. The present study revealed intense staining reaction in the stichosome and the cuticle of 10 hrs-old larvae L1, the intensity of the reaction decreased throughout the worm development, until it almost disappeared at 10 days P.I. The gut lining and its occupying substance were positive throughout the enteral phase. Intense staining reaction of the hypodermal cells was observed in L2, L3 and adult stage worm. The genital primordium was weakly stained in the larval stages while the male and female reproductive systems were moderately stained at the adult stage.