Vectors and Disease Virulence

This Element is an excerpt from Germs, Genes, & Civilization: How Epidemics Shaped Who We Are Today (9780137019960) by David P. Clark. Available in print and digital formats.

The crucial role of vectors in disease virulence-and the best place to focus disease prevention efforts.

If a germ hitches a ride between victims via mosquito, it matters little that the first victim is too sick to move. This may even work to the germ's advantage. Mosquitoes can suck blood without the victim swatting them. Diseases carried between people by some other agency have little motivation to evolve mildness toward humans. The best way to control them is to kill the vectors, interrupting transmission.

David P. Clark is Professor in the Microbiology Department at Southern Illinois University. He has published 70+ articles in scientific journals and is author of several college textbooks, including Brock Biology of Microorganisms, now in its 12th edition; Molecular Biology Made Simple and Fun, now in its 3rd edition; Molecular Biology: Understanding the Genetic Revolution; and Biotechnology: Applying the Genetic Revolution. Clark earned his Ph.D. from Bristol University in 1977. His research has focused on antibiotic resistance and the genetics and regulation of bacterial fermentation.