VIRULENCE AND TRANSMISSION OF INFECTIOUS-DISEASES IN HUMANS AND INSECTS - EVOLUTIONARY AND DEMOGRAPHIC PATTERNS

The rate and degree of proliferation of disease organisms determine th eir pathogenicity and the efficiency of their transmission. These trai ts dictate the impact of a disease on individuals as well as populatio ns. Virulence and transmission of diseases are molded by evolutionary forces - pathogens and hosts are each selected to reproduce and persis t. New ideas about the evolution of human diseases also apply to the r elationships between insects and their diseases. Evidence for close as sociations between insects and pathogens include the viral suppression of insect molting hormones and the occurrence of latent virus that ca n be activated by foreign viruses.