Egg polymorphism of Schistosoma bovis

A study of the egg morphology of Schistosoma bovis from Sudan and Spain revealed some differences in the size and shape of eggs depending on the method of their sampling. The size of eggs (especially the length) tended to increase in the following order: those recovered from the worm uterus smaller than those recovered from the liver and from the faeces of mice for both strains. The shape of eggs from the host faeces (the typical ones) and from the distal portion of the worm uterus for both strains tended to be homogeneous whereas those from the host liver were more heterogeneous. A comparison between the eggs of the two strains showed a great similarity in spite of their distant geographical origins; only the length of the eggs collected from the distal part of the worm uterus and those from the host faeces showed a significant difference at a 99% confidence limit.