The circumoval precipitin test in early experimental schistosomiasis japonica.

The time of the appearance of circumoval precipitins by testing weekly blood samples of rabbits infected with light, moderate and heavy doses of cercariae of Schistosoma japonicum as well as their titers were determined. In heavy infections, circumoval precupitins appeared as early as the end of the 4th week or 28th day after cercarial penetration while the appearance of detectable levels in light infections was delayed only up to the 7th week after infection. In view of these observations, the circumoval precipitin test should be used for detection of early schistosomal infection before eggs are demonstrable in the faeces.