Dynamic of cercarial production of Schistosoma mansoni in Biomphalaria alexandrina.

The susceptibility of B. alexandrina to infection with S. mansoni miracidia varies due to biological & ecological parameters. In case of snail infection in less than 4 or 5 months productivity doubled between 1 and 2 miracidium, but with more than 2 miracidia with practically no increase in productivity. In more than 5 months, there no was discernible difference in productivity between monomiracidial and polymiracidial infections. The production of cercariae was characterized by very irregular daily emissions and by the alternation of periods of high and low emissions, which gave rise to a production rhythm.

Toxoplasma antibodies in normal and complicated pregnancy.

A total of 70 women with complicated pregnancy and 20 ones with normal pregnancy were selected. They were all RH positive and free from syphilis, brucellosis and malignany. Both groups were subjected to detection of anti-Toxoplasma antibodies levels by the indirect haemagglutination tests (IHAT-IgG) and by ELISA (IgG and IgM). The results showed that all controls (normal pregnancy) were IHA-IgG and ELISA-IgM negative. However, two of the controls (10%) were ELISA. IgG positive. As to the women with complicated pregnancy 68/70 or 97.1% were IHAT positive. When using ELISA, 57/70 or 81.4% were IgG positive and 42/70 or 60% were IgM positive. The results revealed a significant difference between the complicated cases and controls. The diagnosis of abortion, stillbirth, premature labour, or neonatal death due to Toxoplasma infection needs careful and laborious evaluation. The use of ELISA (IgG & IgM) is a must, as it is more sensitive and specific than IHAT.