vectorparasite

A vector parasite is a parasite that relies on a separate organism, a vector, to reach its vertebrate hosts and often to complete part of its life cycle. In vector-borne systems, the parasite spends developmental stages inside the vector and is transmitted to a new host when the vector takes a bite. Vectors are typically arthropods such as mosquitoes, ticks, sandflies, blackflies, lice, or fleas.

Prominent examples include Plasmodium species, which cause malaria and are transmitted by Anopheles mosquitoes; Leishmania species transmitted by sandflies; Trypanosoma brucei and Trypanosoma cruzi transmitted by tsetse flies and triatomine bugs, respectively; Babesia species transmitted by ticks or sometimes mosquitoes; Onchocerca volvulus transmitted by Simulium blackflies; and filarial nematodes such as Wuchereria bancrofti and Brugia spp., transmitted by various mosquitoes. Dirofilaria immitis (heartworm) is another well-known vector parasite, transmitted by mosquitoes in many regions. Theileria species in livestock are transmitted by ticks and can cause serious diseases.

Biology and transmission are shaped by interactions among the parasite, the vector, and the vertebrate host. Parasites may undergo sexual or asexual development within the vector, and transmission often depends on vector competence, density, feeding behavior, and environmental conditions. Some parasites exhibit transstadial or transovarial transmission in vectors, influencing persistence and spread.

The concept is central to public health and veterinary medicine. Control strategies include reducing vector populations (insecticides, environmental management), protecting hosts (bed nets, repellents, screen protection), interrupting transmission (targeting reservoir hosts), and improving diagnostics and surveillance. The term “vector parasite” emphasizes the dependence on a vector rather than a strict taxonomic grouping.