INTEGBI 114 Lecture Notes - Lecture 3: Armadillidiidae, Semen, Vertically Transmitted Infection
Document Summary
Lecture #3: major types of transmission pathways, vertical transmission between generations from parent to offspring, horizontal transmission within one generation between unrelated individuals. Vertical transmission pathways: female to offspring most common, types, cytoplasmic, trans-placental, perinatal (during birth) or in plants and animals, adhesion to egg or seed surface, postnatal (during lactation) or close contact of mother and offspring. Quantitative aspects of vertical transmission: vertical transmitted diseases are not sustained unless transmission is 100, there are always trade-offs: evolution of increased transmission by one pathway may reduce transmission by another pathway. For a vertically pathogen to persist it must: either have an additional horizontal transmission mode, or increase the reproductive success of its host relative to uninfected individuals, however this, by definition, makes a pathogen a mutualist. Example endosymbiotic bacterium wolbachia often acts as a reproductive pathogen. Xi. useful words in human related transmission: formites objects on which diseases are transmitted.
