Modes of Transmission

Modes of Transmission of Infection

Close contact

Close contact with another person greatly increases the risk of infection.
Most droplets fall to the ground after travelling about 2 meters (6 feet) from the body.
Blood and fluids need to be directly touched for contamination to occur, and airborne pathogens will dissipate to a low concentration after 2 meters unless indoors (where airflow is restricted).
A vector-borne or fecal-oral borne disease does not require the new host to be in close contact with an infected person, but still requires close contact between the new host and the vector, or close contact between safe and contaminated sources.

Surfaces

A contaminated surface can present an infection risk if the pathogen on that surface has a high survivability and the contamination passes from the surface to the new host.
Once the pathogen has passed to the new host, it still needs to enter the body either through the mouth/nose/eyes, or through a break in the skin.

Shared items

Some diseases transfer through shared items. A toothbrush, an infected needle, or a towel can transmit a disease to another person, depending on what the disease is.
Someone with a droplet-borne infection can transfer that infection to another by sharing a toothbrush without properly washing it first. Likewise, infections that affect the skin (athlete’s foot, warts) can be passed through a contaminated towel.

To illustrate how important hand washing is in infection control, we used a Glo Germ Kit to simulate infection staying on hands after washing.

In this demonstration:

3 drops of Glo Germ were placed in the student's hand.
She rubbed the simulated germs from the gel on her hands
She washed her hands vigorously for 30 seconds with soap and water
We used a black light to illustrate where Glo Germ was still located on her hands. The white glowing regions indicate areas where, even after washing her hands, the germs remained

If she was sharing items with others or in close contact with others after this simulated demonstration, she would still have germs on her hands

In this demonstration, Glo Germ Powder was used to simulate how easily surfaces can become contaminated with infection.

Glo Germ powder was placed on the student's hands
She rubbed her hands together
She touched various items in the laundry room
The room was darkened and black light was used to illustrate the contaminated surfaces around the room that she had touched

If she had an infection or bacteria on her hands and it transferred to these various contact locations, the next person to touch those items could find themselves with the bacteria or infection also on their hands.

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