In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen such as a parasite or microbe, to another living organism. Agents regarded as vectors are mostly blood-sucking insects such as mosquitoes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected the stomach tissue of a mosquito.
A mosquito shortly after obtaining blood from a human (note the droplet of blood plasma being expelled as the mosquito squeezes out excess water). Mosquitos are a vector for several diseases, including malaria.
The deer tick, a vector for Lyme disease pathogens
This figure shows how the Flavivirus is carried by mosquitos in the West Nile virus and Dengue fever. The mosquito would be considered a disease vector.
Public health agencies educate people about many different disease vectors. This artwork, at the London School of Hygiene and Tropical Medicine, shows 10 different animal vectors.
In biology, a pathogen, in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.
A photomicrograph of a stool that has shigella dysentery. These bacteria typically cause foodborne illness.
Magnified 100× and stained. This photomicrograph of the brain tissue shows the presence of the prominent spongiotic changes in the cortex, with the loss of neurons in a case of a variant of Creutzfeldt-Jakob disease (vCJD)
Two pinworms next to a ruler, measuring 6 millimeters in length
Brown rot fungal disease on an apple. Brown rot typically target a variety of top-fruits.
