Strongylida is a taxonomic order within the phylum Nematoda, commonly known as roundworms. It comprises a diverse group of parasitic nematodes that primarily infect mammals, including humans, as well as other vertebrates. The name Strongylida is derived from the Greek word "strongylos," meaning round or cylindrical, which describes the characteristic shape of these worms.
Members of the Strongylida order are characterized by their robust and elongated bodies, tapering towards both ends. They possess a complete digestive system, with a mouth located anteriorly and an anus situated posteriorly. These parasitic worms typically possess a buccal capsule armed with teeth or plates, which aids in their attachment to the host's intestinal walls.
Strongylida species exhibit complex life cycles, involving both direct and indirect modes of transmission. The free-living adults in the environment lay eggs, which, upon ingestion by a suitable host, hatch into infective larvae. The larvae then penetrate the host's intestinal walls, migrate through various organs and tissues, and eventually develop into sexually mature adults, causing an array of diseases and health issues in the host.
Due to their ubiquitous nature and vast array of host species, the Strongylida order has significant medical and veterinary importance. In humans, some Strongylida species, such as the hookworms (Ancylostoma and Necator), can cause significant intestinal diseases, leading to anemia, malnutrition, and impaired physical and cognitive development, particularly in children. In livestock and companion animals, infections by Strongylida nematodes can result in reduced growth, decreased productivity, and general health deterioration. Consequently, the control and prevention of Strongylida infections are of paramount importance in both public health and veterinary medicine.
