Helmintos

Helmintos, or helminths, are parasitic worms that infect humans and other animals. The major groups affecting people are nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes).

Most helminths have complex life cycles that may involve one or more intermediate hosts and environmental stages. Transmission occurs by ingesting eggs or larvae, by skin penetration, or by vectors, depending on the species. Adult worms inhabit the intestine, liver, blood vessels, or tissues and can cause a broad range of symptoms.

Public health significance is high in regions with limited sanitation. Soil-transmitted helminths such as Ascaris lumbricoides, Trichuris trichiura, and hookworms affect hundreds of millions, especially children. Schistosomiasis, caused by Schistosoma species, is a major tropical disease. Chronic infections can impair growth, cognitive development, and quality of life.

Diagnosis relies on stool examination for eggs or larvae, as well as serology, molecular tests, or imaging for certain infections. Treatments are often effective with anthelmintics such as albendazole or mebendazole for nematodes, and praziquantel for cestodes and trematodes. Prevention focuses on sanitation, safe water, food hygiene, and, in endemic areas, periodic deworming programs.

In research, helminthology classifies species by morphology and genetics and studies life cycles, transmission, and control strategies, including vaccine development and resistance monitoring.