P arasites that live in intimate contact with the immune system of their hosts require specialized adaptations to survive in such exposed environments. Once adapted to these demanding environments, it seems such parasites could not easily switch to distantly related hosts [1], and, thus, would be good candidates to diversify congruently with their hosts, i.e., cospeciation. One of the best-know...

It is well known that geographic strains of MATERIALS AND METHODS schistosomes vary in infectivity for their host snails2 6 . l Z z 2 . This is of importance not only for Snail Strains. the introduction of schistosomes into previously uninfected areas, but because of the potential for the spread of drug resistant strains of worms. B. glabrata, an albino strain of Puerto Rican origin, has been m...

The proportion of ail cancers represented by urinary bladder cancer varies greatly wi thin Africa and the Middle East, and the ratio of male to female frequency of occurrence is nearly as variable (Parkin, 1986). ln Egyt, the proportion of bladder cancers among aIl cancers in men is twce that in Zambia, four times that in Zimbabwe and 10 times that in Algeria. Very few formai assessments of the...

Praziquantel (PZQ) is effectively the only drug currently available for treatment and control of schistosomiasis, a disease affecting hundreds of millions of people worldwide. Many anthelmintics, likely including PZQ, target ion channels, membrane protein complexes essential for normal functioning of the neuromusculature and other tissues. Despite this fact, only a few classes of parasitic helm...

This paper gives an overview of the recent progress made in the use and application of geographical information systems (GIS) and remotely sensed (RS) satellite sensor data for the epidemiology and control of schistosomiasis in sub-Saharan Africa. Details are given of the use of GIS to collate, map and analyse available parasitological data. The use of RS data to understand better the broad sca...

Draft genome sequences for Schistosoma japonicum and Schistosoma mansoni are now available. The schistosome genome encodes approximately 13,000 protein encoding genes for which the function of only a small minority is understood. The new genes represent potential intervention targets. Molecular tools are needed to determine the importance of these new genes. There is a role for transgenesis in ...

The teguments of adult Schistosoma mattheei from cattle and buffalo, S. hippopotami from hippopotamus and S. margrebowiei from lechwe were examined by means of scanning electron microscopy for cells possibly engaged in immunological action. Leukocytes were observed on the teguments of the schistosomes from all 4 host species. Although certain of these cells seemed to be fused to the surface mem...