# Infection
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**Infection** is a [[disease]] that results from the presence of a [[pathogen]] in or on someone's body. The best way to prevent infection is to maintain [[asepsis]], especially in a hospital setting where there is a risk of acquiring an [[healthcare associated infection|HAI]]. These can be very dangerous, which is why it is a huge focus for [[nursing|nursing]].
An infection is caused when there is a colonization, but not all colonizations are necessarily considered infections. This is true of our [[normal microbiota|normal flora]], such as [[Escherichia coli|E. coli]] when it is in our intestines (where it lives).
A **fomite** is an object or material that is likely to carry infection, such as clothes, utensiles or furniture.
## Cycle of Infection
The **cycle** or **chain of infection** is a series of events that need to take place in order for an infection to happen.
1. **Infectious agent**: Although there is no real "start" to a cycle, in order for there to be an infection, first there must be the agent that causes it.
2. **Reservoir**: The [[epidemiology#Disease Reservoirs|disease reservoir]] is where the organism lives and multiplies.
3. **Portal of Exit**: This is where the organism from the reservoir can leave it.
4. **Means of Transmission**: This is how the organism gets from the reservor to the new host.
5. **Portal of Entry**: This is how the organism can get into the new host.
6. **Suseptible Host**: Pathogens can only infect someone if there is someone there to infect.
![[chain of infection.png]]
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