Disease can occur when microbes included in normal bacteria flora enter a sterile area of the body such as the brain or muscle. This is considered an endogenous infection. A prime example of this is when the residential bacterium E. coli of the GI tract enters the urinary tract.

Endogenous factors are the characteristics of the place itself or factors which have originated internally. They are the local place factors and include location, topography, physical geography, land use, built environment and infrastructure, demographic and economic characteristics.

Endogenous factors are internal influences on the identity of a place. In contrast, exogenous factors are external influences on the identity of a place. These include the changing nature of farming, migration, young people leaving to work or study, and flows of investment.

Originating from outside the organism

No matter the germ, there are six points at which the chain can be broken and a germ can be stopped from infecting another person. The six links include: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.

Abstract. A dental health care worker (DHCW) has an obligation to prevent the spread of health care associated infections. Adhering to proper hand hygiene procedures, selecting appropriate hand hygiene products and the use of gloves are all important elements of infection control.

Break the chain by cleaning your hands frequently, staying up to date on your vaccines (including the flu shot), covering coughs and sneezes and staying home when sick, following the rules for standard and contact isolation, using personal protective equipment the right way, cleaning and disinfecting the environment.

Description: The chain of infection has 3 main parts. A reservoir such as a human and an agent such as an amoeba. The mode of transmission can include direct contact, droplets, a vector such as a mosquito, a vehicle such as food, or the airborne route.

The transmission of microorganisms can be divided into the following five main routes: direct contact, fomites, aerosol (airborne), oral (ingestion), and vectorborne. Some microorganisms can be transmitted by more than one route.

Direct contact infections spread when disease-causing microorganisms pass from the infected person to the healthy person via direct physical contact with blood or body fluids. Examples of direct contact are touching, kissing, sexual contact, contact with oral secretions, or contact with body lesions.