Parazii

Parazii, or parasites, are organisms that rely on another living being—the host—for nutrients, shelter, and reproduction, often to the host’s detriment. They include protozoa, helminths (worms), and ectoparasites such as mites, fleas, and lice. Parasites may live inside the host (endoparasites) or on its surface (ectoparasites).

Life cycles vary: some have direct life cycles with a single host; others require multiple hosts or vectors. Transmission routes include ingestion of contaminated food or water, contact with contaminated surfaces, skin penetration, or bites from vectors like mosquitoes, ticks, or flies. Hosts can be humans or animals, and parasites can affect one or several organ systems.

Clinical impact depends on the species and infection burden. Infections can be asymptomatic or cause symptoms ranging from digestive disturbances to chronic anemia, malnutrition, organ damage, or immune modulation. Diagnosis relies on microscopy of blood, stool, or tissues; antigen or antibody tests; culture; and molecular methods such as PCR.

Treatment uses antiparasitic medications targeted to the specific organism. Common drugs include albendazole and mebendazole for nematodes, praziquantel for many flatworms, metronidazole for certain protozoa, and ivermectin for selected nematodes. Supportive care may be needed in heavy infections. Prevention emphasizes safe water and food handling, sanitation and hygiene, vector control, and, where available, vaccination.

Parasitic infections have substantial global health significance, particularly in low-resource settings. Effective control relies on integrated approaches combining treatment, prevention, surveillance, and public education.