Routes of Transmission

HOW ARE INFECTIOUS DISEASES SPREAD? 

Pathogens can easily spread, causing outbreaks of an illness. A person may be exposed by contact with another person, from insect or animal bites, from consuming contaminated food or water, or simply by contacting the pathogen in the environment. 
The different ways diseases spread are called routes of transmission. Some pathogens have multiple routes of transmission. The primary means include:
 
Direct contact: (A susceptible person physically contacts an infected person and transfers the organism; for example, by kissing, by sexual contact, or by touching open wounds/sores, etc.) 

Indirect contact: Transmission occurs when an individual touches a contaminated surface and then becomes infected by touching his or her mouth, eyes, or nose.

Airborne: Transmission occurs through droplets or aerosols. With aerosols, the organism gets into the air and is breathed in by another person (breathing in a contaminant or organism is called inhalation). Droplets containing infectious agents are generated when an infected person coughs, sneezes, or speaks. Transmission occurs when droplets come into contact with a person’s eyes, nose, or mouth. 

Vector-borne: Carried by another species; “vector” usually refers to an insect, and transmission occurs via a bite from the vector. 

Non-contact vehicle transmission: Infection spreads from a contaminated source to the individual. Often, the contaminant is ingested (enters through the mouth). Pathogens may be found on food or in water. 

Bloodborne: Bloodborne pathogens are encountered via contact with an infected person’s blood or other body fluids. Diseases from these pathogens are often transmitted by contaminated needle sticks. 

Any of these means of transmission can happen in the workplace. The risk of becoming ill from an infectious disease depends on the opportunity for exposure, incubation period for the disease, the virulence of the disease, and the overall health or susceptibility of the person who is exposed.