Vertical transmission; in humans also known as mother-to-child transmission, is the transmission of an infection or other disease from the parental generation of the species to the offspring. Vertical transmission tends to evolve benign symbiosis. It is therefore a critical concept for evolutionary medicine. Because a pathogen's ability to pass from parent to child depends significantly on the hosts' ability to reproduce, pathogens' transmissibility tends to be inversely related with their virulence. In other words, as pathogens become more harmful to and thus decrease the reproduction rate of their host organism, they are less likely to be passed on to the hosts' offspring, since there will be fewer offspring. Although AIDS is sometimes transmitted through perinatal transmission, its virulence can be accounted for by the fact that its primary mode of transmission is not vertical. Moreover, medicine has further decreased the frequency of vertical transmission of AIDS. The incidence of perinatal AIDS cases in the United States has declined as a result of the implementation of recommendations on HIV counselling and voluntary testing practices and the use of zido\aidinc therapy by providers to reduce perinatal HIV transmission. Wikipedia [ - ]

Vertical transmission; in humans also known as mother-to-child transmission, is the transmission... [ + ]