In community ecology: Parasite-host interactions Parasites and their hosts engage in a similar evolutionary arms race, although in the past parasitologists believed this not to be the case. Instead, parasites were thought to evolve gradually toward reduced antagonism—having a less detrimental effect on their hosts. The degree of… Read More
disease
In disease: Host-parasite relationships In the context of communicable disease, the host-parasite relationship must be considered not only with respect to the individual host-parasite interaction but also in terms of the interrelationship between the host and parasite populations, as well as those of any other host species… Read More
In disease: Prevention …the links connecting the susceptible host with the source of infection. Malaria can be controlled effectively by the elimination of the mosquito vector, and louse-borne typhus in humans can be regulated by disinfestation methods. Similarly, diseases spread in epidemic form through the agency of water or milk are controlled by… Read More
In human disease: Predisposition of the host Up to this point, diseases caused by biotic agents have been considered in terms of the role of the invader. Equally important is the role of the host, the individual who contracts the disease. Any infectious disease is a test between the invader and… Read More
parasitism
In community ecology: Types of parasites …in or on a single host throughout either a stage in their lives or their entire life span, thereby decreasing the survival or reproduction of their hosts. This lifestyle has arisen many times throughout evolution. The most species-rich groups of organisms are parasites, which, in becoming specialized to live off… Read More
plant disease
In plant disease: Classification of plant diseases by causal agent …known to occur on certain hosts in regions, countries, or continents) are valuable in diagnosis. When an apparently new disease is found on a known host, a check into the index for the specific host often leads to identification of the causal agent. It is also possible to classify diseases… Read More
virology
In virus …of finding a susceptible animal host. In 1933 the British investigators Wilson Smith, Christopher H. Andrewes, and Patrick P. Laidlaw were able to transmit influenza to ferrets, and the influenza virus was subsequently adapted to mice. In 1941 the American scientist George K. Hirst found that influenza virus grown in Read More
