Key Point

• Thorough cleaning habits can prevent pathogens from being passed between clients and massage therapists by various modes of transmission. 

How does a “cootie” get from one host to another? That’s a key question in infection control, and it has a lot of influence on the choices massage therapists must make about hygienic practices. Pathogens, which can include bacteria, viruses, fungi, or parasites, can travel from one location to another in a variety of ways; these are called modes of transmission. The four avenues relevant for massage therapy practice are airborne transmission, direct contact, droplet transmission, and indirect contact—but there are distinctions within these.

Essential Vocabulary

First, let’s look at a bit of vocabulary. These are terms everyone who takes responsibility for a clean workspace should know.

Reservoir—A reservoir for infection is an animal or environment in which pathogens can stay alive, mature, replicate, and evolve until they have access to a new host. Mosquitoes are reservoirs for the virus that causes dengue fever. Deer ticks are reservoirs for the bacteria that cause Lyme disease. The ticks and mosquitoes are unaffected, but the humans they bite are susceptible hosts and can become extremely ill. Reservoirs can also be environments—incorrectly canned food can be a reservoir for botulism and a poorly cleaned windowsill can be a reservoir for fungi.

Host—A host is a target organism for infection. When it is invaded, a host develops signs and symptoms. This is what differentiates hosts from reservoirs. Humans are the only known hosts for varicella zoster virus, the causative agent of chickenpox and shingles. 

Fomite—A fomite is an inanimate object where pathogens may linger until they gain access to a new host. A hot stone contaminated with Staphylococcus aureus (commonly known as staph) is an example of a possible fomite. A massage table, or even a  bottle of lubricant that is not cleaned between sessions, could be a fomite, allowing the transfer of pathogens from one client to another. 

Vector—A vector is a living transmitter of disease-causing microorganisms from one host to another. The vector may be a reservoir, like the ticks that cause Lyme disease, or it may be another host that also has signs and symptoms. If a human picks up ringworm from a kitten, the kitten is a vector for the fungus.

Portal of entry—While some pathogens can set up an infection on intact skin (e.g., the fungi that cause ringworm), other pathogens require a breach in the skin to gain entry, like having an infected hangnail or access to mucus membranes via the eyes, nose, and mouth. These access points are portals of entry. The blisters that form between the toes of a person with athlete’s foot are excellent portals of entry for more serious infectious agents.

Modes of Transmission

Now that we have this vocabulary, let’s talk about modes
of transmission. 

Airborne Transmission

Airborne pathogens are typically expelled in tiny, aerosolized droplets that are so small they can float on dust particles in the air. They can be spread directly from one infected person to another by way of mucus membranes, when Person A sneezes and Person B, who is standing close by, inhales. But they can also be spread indirectly, as when Person A sneezes and Person B enters the room several hours later and inhales. COVID-19 is a virus that is aerosolized by the infected person and may spread long distances through the air to reach others.

Direct Contact Transmission

Direct contact transmission of pathogens occurs when no intermediary is needed for a pathogen to move from one host to another; it occurs through direct physical contact or shared blood flow. Some infections can be passed from a pregnant person to their fetus—this is direct contact transmission. Other common infections that are transmitted via touch include conjunctivitis, impetigo, and sexually transmitted infections. The key factor here is transmission via contact from one person to another.

Droplet Transmission

Droplet transmission is similar to airborne transmission, but the droplets are much larger and tend to fall to surfaces faster than we see with airborne pathogens. If infected Person A sneezes and Person B, who is standing nearby, gets some droplets on their eyes, nose, or mouth, this is droplet transmission. However, the amount of distance between hosts must be smaller than with airborne infections, and droplets carrying infectious agents are likely to fall onto other surfaces, opening the door to indirect transmission.

Indirect Contact Transmission

Also called fomite transmission, indirect contact transmission happens when a pathogen lingers on an object and is then transferred to a portal of entry on a new host. Think about everyday things that might harbor pathogens: computer keyboards, door handles, light switches, and massage equipment. This is why we must be conscientious about cleaning surfaces, our tools, and our hands for every client.

The Ones You Really Need to Know

This is not a completely comprehensive list of modes of infectious transmission. We haven’t discussed ingestion (taking in pathogens through contaminated food or water) or zoonosis (the passage of infection from a nonhuman host to a human), but we covered the forms that are most likely to occur in a massage therapy setting and that MTs need to understand most fully.