Helminti

Helminti, also known as helminths, are parasitic worms that inhabit vertebrate hosts, including humans. In medical and veterinary contexts they are typically grouped into three main phyla: nematoda (roundworms), cestoda (tapeworms), and trematoda (flukes). They vary considerably in size, from millimeters to several meters, and have complex life cycles that may require one or more intermediate hosts.

Most helminths have a direct life cycle, with infectious stages transmitted between hosts through contaminated food or water. Others require intermediate hosts or vectors. Transmission can occur by ingestion of eggs or larvae, skin penetration by larvae, or via bites of vectors such as mosquitoes. Infections may be asymptomatic or cause a range of symptoms, including abdominal pain, diarrhea, anemia, eosinophilia, and organ damage depending on the species and burden.

Diagnosis relies on laboratory methods such as microscopic examination of stool for parasite eggs, serology, or molecular tests; imaging and clinical signs can support complex infections. Treatment uses specific anthelmintic drugs; common agents include albendazole, mebendazole, praziquantel, and ivermectin, chosen according to the parasite species and local resistance patterns.

Prevention focuses on sanitation, safe water and food handling, wearing footwear to prevent skin-penetrating infections, and public health measures like periodic deworming campaigns in at-risk populations. Helmint infections are a major public health concern in many tropical and subtropical regions and remain a focus of parasitology and neglected tropical disease programs.