We investigate the evolution of virulence of pathogens that reduce their hosts' fitness primarily by affecting host fecundity. We show that, under many conditions, such sterilizing pathogens evolve high rather than intermediate levels of virulence, and this pushes the pathogen population and sometimes the host population toward extinction. We also show that spatial population structure can reve...

Title ON THE ECOLOGY AND DISTRIBUTION OF ECHINOCOCCUS SPP.(CESTODA : TAENIIDAE), AND CHARACTERISTICS OF THEIR DEVELOPMENT IN THE INTERMEDIATE HOST : II. COMPARATIVE STUDIES ON THE DEVELOPMENT OF LARVAL E. MULTILOCULARIS LEUCKART, 1863,IN THE INTERMEDIATE HOST Author(s) OHBAYASHI, Masashi; RAUSCH, Robert L.; FAY, Francis H. Citation Japanese Journal of Veterinary Research, 19(supplement): 1-53 I...

there are many freshwater snails involved in the life cycle of parasitic flukes. some of these animals, such as bulinus spp and lymnaea spp are very important in public health and veterinary medicine. for example, bulinus trucatus and lymnaeid snails transmit human bilharziosis and zoonotic fascioliosis, respectively. for this reason most freshwater bodies of northern iran, were searched for po...

linguatula serrata is a tongue-shaped parasite that infects carnivores or insectivorous reptile as final host and herbivores as intermediate ones. during necropsy of a 1.5-year-old female stray cat, a few white and fine nodules were observed on the diaphragmatic lobes of the lung. in histopathological examination, the nodules contained a turned spinosum parasite with cuticular spines and in par...

Host-parasite interactions in the E. multilocularis-intermediate host model depend on a subtle balance between cellular immunity, which is responsible for host's resistance towards the metacestode, the larval stage of the parasite, and tolerance induction and maintenance. The pathological features of alveolar echinococcosis. the disease caused by E. multilocularis, are related both to parasitic...

The typical multi-host life cycle of many parasites, although conferring several advantages, presents the parasites with a highly hazardous transmission route. As a consequence, parasites have evolved various adaptations increasing their chances of transmission between the different hosts of the life cycle. Some trematode species like the opecoelid Coitocaecum parvum have adopted a more drastic...

BACKGROUND The construction and operation of small multipurpose dams in Africa have a history of altering the transmission of water-based diseases, including schistosomiasis. The current study was designed to investigate the abundance and dynamics of schistosomiasis intermediate host snails and Schistosoma infections in humans during the construction and the first years of operation of a small ...

Each transmission event in complex, multi-host life cycles create obstacles selecting for adaptations by trematodes. One such adaptation is life cycle abbreviation through progenesis, in which the trematode precociously matures and reproduces within the second intermediate host. Progenesis eliminates the need for the definitive host and increases the chance of life cycle completion. However, pr...