Which helminthic infection is primarily caused by a cestode?

The primary helminthic infection caused by a cestode is indeed a tapeworm infection. Cestodes, commonly known as tapeworms, are flat, ribbon-like worms that inhabit the intestines of their hosts, where they absorb nutrients through their skin. These organisms are characterized by their segmented bodies, called proglottids, which can multiply and detach to produce more worms.

Tapeworm infections can arise from consuming undercooked or contaminated meat or fish that contain the larval form of the tapeworm. The presence of these parasites can lead to various gastrointestinal issues, though some infections can be asymptomatic. Treatment typically involves the use of specific anthelmintic agents that target cestodes to eliminate them from the host's body.

In contrast, the other choices refer to different groups of helminths: hookworms are nematodes (roundworms) that cause anemia and protein deficiency, roundworms (also nematodes) are associated with a variety of infections, and flukes belong to the class Trematoda, which are also distinct from cestodes. Understanding these classifications is key when identifying the specific types of helminthic infections.