Culture of Schistosoma haematobium in vivo and in vitro.

The maximum rate of development of Schistosoma haematobium in the hamster was determined by examination of the most advanced worms recovered at short intervals throughout the course of development. In culture S. haematobium developed at the same rate as in the hamster up to day 31 when pairing first occurs and male worms produce some spermatozoa. In vitro males formed some spermatozoa but pairing did not take place and, probably for this reason, females did not complete sexual maturation as occurs in the host between days 57-65. Somatic growth continued in vitro and at 70 days male worms had achieved almost the same length as in the hamster at this time. The culture medium, previously used for S. mansoni, consisted of equal volumes of serum and Earle's balanced saline with a final concentration of 0.25% lactalbumin hydrolysate, 100 units/ml penicillin, 100 mug/ml streptomycin and 1% rbc. The best culture results were obtained with one particular human serum; seven other human sera gave a wide range of growth support. The samples of baboon, rhesus monkey or foetal calf sera tested provided little or no growth support but prolonged survival was possible in all the sera.