Disease transmission

Disease transmission is the way that an infectious disease or pathogen is "passed on" or "communicated" from one individual to another in a population of humans, or in groups of other animals. Disease can be transmitted in two ways:


 * Horizontal disease transmission – from one individual to another in the same generation (piers in the same age group). Horizontal transmission can occur by either direct contact (licking, touching, biting), or indirect contact (vectors or fomites that allow the transmission of disease without physical contact).


 * Vertical disease transmission – passing a disease causing agent vertically from parent to offspring. Typically the mother transmits the disease by means of bodily fluid, and sometimes breast milk.