parazitit

Parazitit is a term used in some languages to denote a parasite, an organism that lives in or on another organism (the host) from which it derives nutrients, often harming the host. Parasites are diverse and can be categorized by their location as ectoparasites—living on the body surface such as fleas, ticks, and lice—and endoparasites—living inside the body such as intestinal worms and protozoa. They may have simple life cycles or complex ones that involve multiple hosts or vectors.

Parasites influence their hosts through nutrition, tissue damage, immune modulation, and sometimes by transmitting other pathogens. Their effects range from asymptomatic to severe disease. Human parasites include protozoans such as Plasmodium (malaria) and Giardia lamblia; helminths such as Taenia (tapeworms) and Ascaris; and ectoparasites such as lice and mites. Zoonotic parasites can cross species barriers, and some parasites can alter host behavior to improve transmission.

Diagnosis relies on detecting the parasite, its eggs or DNA in clinical samples, serology, or imaging. Treatments include antiparasitic drugs, with regimens chosen by parasite type and disease severity; resistance and toxicity can be concerns. Prevention emphasizes hygiene, safe water and food, vector control, vaccination where available, and public health measures to reduce exposure.

Parasitism is widespread across ecosystems. Studying parasites informs biology, ecology, medicine, and agriculture, and understanding parasite life cycles and host interactions is essential for controlling infectious diseases.