Chain of Infection

• The chain of infection consists of six links: pathogen, reservoir, place of exit, method of transmission, port of entry, and susceptible host.
• The pathogen is the cause of the disease.
• The reservoir is the place for a pathogen to live and grow.
• The place of exit is where pathogens escape the reservoir.
• The method of transmission is a way to get to a new host.
• The port of entry is where pathogens enter a new host.
• The susceptible host is one that has little (if any) resistance to the pathogen and thus, lacks the ability to fight them off.
• Carriers are those who carry germ, but show no signs or symptoms; they can spread disease, but often do so unknowingly.
• All six links need to be connected in order for a disease to be transmitted.
• If even one link is broken, an infection will not occur.
• Killing the pathogen stops it from spreading.
• Preventing contact with an infected source prevents the pathogen from escaping.
• Preventing the pathogen's escape prevents the disease from spreading.
• Preventing transmission by not giving pathogens a means to travel can stop the spread.
• Blocking the ports prevents pathogens from entering a new host, thus preventing infection.
• Resistant hosts are those that have made smart choices about their health and developed a strong immune system, enabling their bodies to fight off pathogens without ever feeling sick.