Vector Borne Disease Triangle

For a specific disease to be spread, all of the stars have to somehow align. The host, pathogen, and environment/vector all have to interact at the same time. The vector-borne disease triangle illustrates that without one corner, the transmission of the disease would not be possible. This triangle includes hosts, environments/vectors, and pathogens. Hosts are often humans, dogs, or monkeys and are fed on by a vector. Vectors usually include mosquitos, fleas, ticks, mites, and many more. The last part of the triangle is pathogens, these consist of viruses, bacteria, fungus, filarial worms, and protozoa. For a disease to be contracted, there also has to be a pathogen to effect the vector. Many things effect the ability for a disease to be spread. The pathogen has to find a suitable vector, the vector then has to have the correct environment and has to locate a host for a blood meal. Although it seems almost impossible for all of this to align perfectly, diseases caused by insects are a main epidemic in global public health.
The conditions that effect the vitality of vectors include nutrients, a host, temperature, weather, and more. A vector that is able to carry a specific pathogen, such as a mosquito, may not be around in the winter to catch the pathogen to spread it onto a new host. In addition, a pathogen has to come into contact with a suitable vector, and have the ability to survive and mature in that vector. Although there are many blood sucking insects, many are not suitable vectors specific diseases. As an example, the aedes aegypti mosquito transmits Zika, but all other insects are not known to transmit this disease. Lastly, the insect’s ability to find a host depends on the density and availability to find a host. If a mosquito cannot find a host for a blood meal, the pathogen will remain in the