Years ago, when I first started down this path of educating on the use of disinfectants for infection prevention I had lunch with a veteran ICP. We were sitting across from each other (less than 1 meter apart) over soup and salads chatting about transmission of various pathogens. Being a bit naïve, I asked her about the importance of a TB claim on products as I had received several inquiries pertaining to products that carried TB claims for use in populations with high TB prevalence. Let me tell you, I got schooled on Airborne Transmission that day!
The ICP put down her spoon, looked at me and shook her head….you know the kind of shake you get when someone can’t believe you’ve just said something really, really dumb? As my ICP friend went on to explain airborne transmission occurs when bacteria or viruses travel on dust particles or on small respiratory droplets that may become aerosolized when people sneeze, cough, laugh, or exhale. They hang in the air much like invisible smoke. They can travel on air currents over considerable distances. With airborne transmission, direct contact with someone who is infected is not necessary to become ill. The amount of exposure necessary varies from disease to disease. With chickenpox, a child could easily catch it from another aisle in a supermarket. With tuberculosis, closer contact and less air circulation are often needed.
She said “Let me put it to you this way. If I had TB, coughed up a “phlegm-ball”, spit it in your soup and you ate it….you would not catch TB. The ONLY way you can catch TB is to breathe in enough of the air particles I have exhaled that are carrying TB. Diseases such as TB that are only transmitted by inhalation of infectious particles carried in the air are not transmitted by touching surfaces or “eating” someone’s phlegm.”
As I learned that day, while some organisms such as Chickenpox can be spread by both contact with the open lesions and via air, there are a number of organisms such as TB that are solely transmitted by air. The best way to avoid airborne infections is to be in a different room from the person who is ill, with a closed door in between. If you need to be in the same room, wearing a mask such as an N95 respirator will help for a brief exposure. Cleaning and disinfecting surfaces in the patient room is still an important part of infection control to keep down the bio-burden levels, but for organisms that are solely transmitted by air, cleaning and disinfection of surfaces does help in stopping or preventing transmission. Cough etiquette - covering the mouth or nose when coughing or sneezing also decreases droplet spread to some degree as such patients with suspected infections caused by pathogens that are spread by airborne transmission should be given a mask to wear until they can be isolated or if being transported.
I love soup, but even 8 years later, whenever I eat chicken noodle soup, I still recall the story my ICP friend told me and hope no one has spit in my soup! I know I won’t get TB, but who knows what else I could pick up!