Parasites occur in nearly every population. They often interact in complex ways with other stressors. In some cases, the interaction may lead to a disproportionately negative effect on the host population. In other cases, the stressor may ameliorate the effects of parasitism. Here we illustrate intersections of four types of environmental stressors with infectious diseases. First, pollutants ma...

Many trophically-transmitted parasite larvae actively manipulate their intermediate host behaviour in ways increasing its transmission probabilities to the next host in their life cycle. Only stages infective for the next host alter host behaviour in such a way. Before reaching infectivity, parasite larvae grow into several larval stages in the intermediate host, all being non-infective for the...

The parasitic nematode Angiostrongylus cantonensis is a major cause of eosinophilic meningitis in humans, and has been documented in other incidental hosts such as birds, horses, dogs and non-human primates. It is endemic in Hawaii, and there have been sporadic reports in the southern continental United States. This parasite uses rats as definitive hosts and snails as intermediate hosts. In thi...

Trematode parasites can affect the molluscan hosts serving as first intermediate hosts in their complex life-cycles in manifold ways, but little is known about trematode-induced effects in second intermediate mollusc hosts. In 2 field experiments in 2 habitats and at 2 tidal heights (low and mid intertidal), controlled infection of blue mussels Mytilus edulis serving as second intermediate host...

Several species of invertebrate animals have been reported as intermediate or as paratenic hosts for the rat lungworm, Angiostrongylus cantonensis. Intermediate hosts which have been found naturally infected include: the land snails, Bradybaena stmMaris, Opeas javanicum, Macrochlamys resplendens, Achatina fulica, Pupina complanata, and Subulina octona; the slugs, Deroceras laeve, Vaginalus pleb...

The importance and prevalence of phylogenetic tracking between hosts and dependent organisms caused by co-evolution and shifting between closely related host species have been debated for decades. Most studies of phylogenetic tracking among phytophagous insects and their host plants have been limited to insects feeding on a narrow range of host species. However, narrow host ranges can confound ...

A total of 25 specimens of Cavia porcellus (guinea pig), 5 Dasyprocta agouti (agouti), and 22 Calomys callosus (vesper mice) were inoculated with infective eggs of Lagochilascaris minor. The inoculum was prepared with embryonated eggs and orally administered to each individual animal through an esophagus probe. In parallel, 100 specimens of Felis catus domesticus were individually fed with 55-7...

sarcocystis is a coccidia protozoan develops obligatory in two hosts consisting of the herbivores as an intermediate host (prey) and the carnivores as a host (predator). depend on species, the size of cysts and structure of cyst wall in intermediate hosts are different. the ultrastructure of sarcocystis cysts (sarcocysts) could be a good indication for diagnosis of the parasite species. in the ...