The Chain of Infection

http://chainofinfection.org

Chain of infection

http://chainofinfection.org

The "chain of infection" is the name of the model that describes the way how infections spread through a population. This chain of infection is made up by six different elements. All these elements need to be present and linked to each other in order for an infection to be able to spread. Because of the fact that they need to be linked, it is called the chain of infection.

Chain of infection diagram

http://chainofinfection.org

Chain of infection - elementsInfectious agentThis infectious, or etiologic, agent is any microorganism that is capable of producing an infection.ReservoirThis is the place where the microorganism resides. It can be a food or water source, but it can also have a human source such as feces and respiratory secretionsPortal of exitIn order for an etiologic agent to establish an infection, the microorganism needs to leave the reservoir. In humans this portal of exit can be the nose, mouth, urethral meatus, open wounds, vagina, or rectum.Mode of transmissionThis is the method of transfer by which the organism moves or is carried over to another host. Direct transmission involves direct contact between the infectious person and the susceptible host. Indirect transmission involves an intermediate means that caries the infectious agent to the hostFor example the hands of the health care worker may carry bacteria from one person to another (direct transmission) or the bacteria might be left behind on a doorknob and are picked up later by the susceptible host (indirect transmission)Portal of entryThe portal of entry is the place where the microorganism can enter the host. Portals include body orifices, mucus membranes, or breaks in the skin. Portals also result from tubes placed in body cavities, such as urinary catheters, or from punctures produced by invasive procedures such as intravenous fluid replacement.Susceptible hostA person who cannot resist a microorganism invading the body, multiplying, and resulting in infection. The host is susceptible to the disease, lacking immunity or physical resistance to overcome the invasion by the pathogenic microorganism.

http://chainofinfection.org

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http://chainofinfection.org

http://chainofinfection.org