Search results
Results from the WOW.Com Content Network
These can be categorized into three groups; cestodes, nematodes and trematodes. Examples include: Acanthocephala; Ascariasis (roundworms) Cestoda (tapeworms) including: Taenia saginata (human beef tapeworm), Taenia solium (human pork tapeworm), Diphyllobothrium latum (fish tapeworm) and Echinococcosis (hydatid tapeworm)
Cestodes are parasites of vertebrates, with each species infecting a single definitive host or group of closely related host species. All but amphilinids and gyrocotylids (which burrow through the gut or body wall to reach the coelom [ 6 ] ) are intestinal, though some life cycle stages rest in muscle or other tissues.
Adult trematodes lay smaller numbers of eggs compared to cestodes or nematodes. However, the egg develops into a miracidia from which thousands of cercariae , or swimming larvae, develop. This means that one egg may produce thousands of adult worms. [ 15 ]
About 90% of nematodes reside in the top 15 cm (6") of soil. Nematodes do not decompose organic matter, but, instead, are parasitic and free-living organisms that feed on living material. Nematodes can effectively regulate bacterial population and community composition—they may eat up to 5,000 bacteria per minute.
There are 18,000 [1] to 24,000 [2] known species of trematodes, divided into two subclasses — the Aspidogastrea and the Digenea. Aspidogastrea is the smaller subclass, comprising 61 species. These flukes mainly infect bivalves and bony fishes. [3] Digenea — which comprise the majority of trematodes — are found in certain mollusks and ...
Other internal parasites are found living inside fish gills, include encysted adult didymozoid trematodes, [15] a few trichosomoidid nematodes of the genus Huffmanela, including Huffmanela ossicola which lives within the gill bone, [16] and the encysted parasitic turbellarian Paravortex. [17]
The review showed that the most useful finding is an increase in the level of pain [likelihood ratio (LR) range, 11–20] makes infection much more likely, but the absence of pain (negative likelihood ratio range, 0.64–0.88) does not rule out infection (summary LR 0.64–0.88).
In 2014–15, the WHO estimated that approximately 2 billion people were infected with soil-transmitted helminthiases, [6] 249 million with schistosomiasis, [60] 56 million people with food-borne trematodiasis, [61] 120 million with lymphatic filariasis, [62] 37 million people with onchocerciasis, [63] and 1 million people with echinococcosis. [64]