Parasite

Parasite the parasite is a unique organism that lives in or on another species. The animal they depend upon is called ‘host’. Parasites benefit from the host by the shelter, locomotion, nutrients, etc. The most common parasite people encounter is an ectoparasite known as head lice (Pediculus humanus). Common endoparasites among children are pinworms (Enterobius vermicularis), large roundworms (Ascaris lumbricoides), etc. Parasitism is a common phenomenon in the animal world that includes groups like protozoan (e.g., malaria), annelids (eg, leeches), arthropods (eg, barnacles, insects, mites and ticks), helminths (eg, flukes, tapeworms), nematodes (eg, roundworms), fishes (eg, hagfishes, sucker fishes, etc.), birds (eg, Cuckoos reproductive strategy), mammals (eg, vampire bats), etc. The host could be of four major types viz. definitive host where parasite do sexual reproduction (eg, human host for filaria, hookworms; mosquito host in malaria), intermediate hosts where asexual multiplication or larval states occurs (eg, human host for Plasmodium, tapeworms, etc.); paratenic host usually helps larval parasite to get proper hosts (ie., fish for tapeworm transfer), reservoir host like a dog is such host for hydatic diseases and accidental host that harbor temporary.

The sources of infection are contaminated soil or water, food, and vectors that bear parasites. Ectoparasites only inhabit the body surface of the hosts. Mites, ticks, and lice in domestic’s animals can harbor pathogens for public health risks. Sharks, rays, and marine megafauna are often parasites by sucker fishes. This help in locomotion and moving to new feeding or breeding grounds for sucker fishes. In the darkest deep sea, tiny male angler fish is attached to the females to help in spawning during reproduction season. Whales are parasites upon barnacles. The hagfishes feed upon fish-host blood during their parasitic phases. Mosquito, lice, bed bugs, mites, and leeches are the ectoparasites that feed upon host blood. A parasite that lives within the body of the host is called endoparasites. Most worms like nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes) are endoparasitic and live upon a wide range of species. Good hygiene and cleanliness are the preventive measures for ectoparasites. Medicare can be provided for endoparasite treatment. [Md. Niamul Naser]