|  | Public Health Safety | Public Health

What Are Tapeworms?

Tapeworms are flatworms forming the class Cestoda. They are parasites that live of cats, dogs and also humans. Tapeworms can use other animals and organisms such as fleas, pigs, goats and sheep as intermediate hosts. When humans or domestic animals consume these meats raw or undercooked, the eggs will become an adult tapeworm. The adult tapeworm attaches itself to the intestines of the host where it lives as a parasite.

  1. Appearance

    • The adult tapeworm can reach several inches and are white in color. Segments form in the adult tapeworm then break off and can be seen in the feces of the host. The segments resemble grains of rice and can be seen near the anus of the host or in the feces. The segments contain eggs that again can infest humans or animals when they get in contact with these eggs and ingest it.

    Feeding

    • The tapeworm attaches itself with hooks or tentacles to the intestines of the host. It absorbs nutrients from the host in this manner. The host can either be a vertebrate animal, such as a dog or cat, or a human. Because it is a parasite it only takes from the host without attributing anything to the host. It has negative effects on the host and typical symptoms are weight loss and nausea. In instances where cysts form in the organs of the host it can become life threatening.

    Types

    • The most common tapeworm in dogs and cats are the Dipylidium Caninum. A tapeworm called Echinococcus is also found in dogs but is less common. The Cipylidium Caninum is normally taken in through fleas that act as intermediate hosts to tapeworms. Echinococcus comes from small rodents and can infest the dog or cat when they eat these rodents. Tapeworms in pork are called Taenia Solium and those in beef are Taenia Saginata.

    Life Cycle of a Tapeworm

    • When flea larvae begin eating tapeworm egg-infected stool, the life cycle of the tapeworm begins. The eggs then hatch into cysticercoids within the flea; each cysticercoid becomes a tapeworm. The mature tapeworm hooks onto the intestines of the host so it can feed off the nutrients being consumed. The segments of the adult tapeworm, in the host's feces, contain eggs that are again consumed by the flea larvae.

    Reproduction

    • Each of the Proglottids (segments) of the tapeworm contains a complete set of male and female reproductive organs. Fertilization normally occurs between two adjacent worms. There are also certain tapeworms that self-fertilize, but it is not as common. These fertilized eggs leave the body of the host in the feces to start the cycle of infestation.

    Hosts

    • While animals such as dogs and cats are normally primary hosts for the tapeworm, humans can also be the hosts. It normally happens in areas where there is fecal contamination in soil or water. In areas where meat and fish are eaten raw or undercooked, tapeworm infestation in humans is also common. If humans ingest the eggs of the tapeworm through fecal contamination, the human becomes an intermediate host and tapeworm infection can become dangerous.

Public Health - Related Articles