Or How infection is caused The Chain of Infection Or How infection is caused

Recap! Infections are caused by the entry of a micro-organism Bacteria, viruses, fungi Infection may be acute or chronic Infection may be localised or systemic Normal flora & transient flora

The Chain of Infection Identifies: The micro-organism The reservoir Portals of exit Methods of transmission Portals of entry Hosts

The Micro-organism Disease causing organisms include Bacteria Viruses Fungi

Reservoir This refers to anywhere an infectious organism can survive, grow or multiply Includes: Plants Animals Soil Water Medical equipment

Reservoir The human body is the most common reservoir! Carrier A person who carries and can spread disease

Portals of exit The way the infectious organism leaves the body Body fluids including blood Coughing Sneezing

Methods of transmission Four methods Contact Direct – person to person Indirect – person to object Droplet – e.g. sneeze Airborne – longer distance & greater time Ingestion – contaminated food or water Vector – via living creatures or insects

Portals of entry Respiratory tract Ears and eyes Gastro-intestinal Genito-urinary tract Broken skin

Hosts Barriers are compromised e.g. broken skin Imunocompromised Level of susceptibility depends on Age: Infants & elderly at greater risk Nutritional status Stress Environment Pre-existing conditions

Finally… Mrs Price