The CDC states that the death-dealing virus that causes COVID-19 spreads predominantly from person to person (P>P). A deeper dive into assessing this transmission route — and its presence in the food industry — may help sharpen intervention tactics.

This assessment starts with a look at an infected person’s cough, sneeze, singing and talking, all giving rise to a discharge of particles from the mouth or nose. Where the term “person” is used, it refers to the internal system of a person where a pathogen either has entered or is given entry.

Heavy particles quickly fall to the floor or any surface in between people. Lighter aerosolized ones remain airborne for up to three hours or more. A room’s air filtration system can be effective in trapping these contaminants. The wearing of masks is a critical intervention. Physical distancing is also a meaningful transmission-preventive action.

If that infected person’s cough or sneeze is self-covered with his or her bare hand instead of the crook of an elbow, it becomes one of those surfaces between the mouth/nose and the floor. Here handwashing or hand sanitizing is the obvious intervention of choice. If that hand were gloved, the glove would need to be changed, with a handwash before donning the new gloves. The better intervention is prevention by catching that cough or sneeze in one’s elbow.

Person-to-person, person-to-surface-to-person & person-to-surface-to-hand-to-person

It can get pretty complicated.

What is the dominant vector transmitting Coronavirus from one person to another? Is it the air we breathe or the hand that moves the virus from a long list of surfaces (fomites) to the nose, eyes or mouth? The CDC recently released an advisory that indicated the aerosolized form was the primary route of transmission. These particles can cause infection when “inhaled into the nose, mouth, airways, and lungs.” “This is thought to be the main way the virus spreads.” 

Three days latter this news was withdrawn with this notice: “CDC is currently updating its recommendations regarding airborne transmission of SARS-CoV-2 (the virus that causes COVID-19),”  “Once this process has been completed, the update language will be posted.” The current guidance makes no mention of aerosol transmission.

Person-to-surface-to-person (P>S>P) is a legitimate route for the coronavirus to move from one person to another with the surface (fomites) acting as a bridge or a “bus terminal” where the virus awaits a touch, a touch from a living host, needed to sustain its biological activity. This pathogen path is probably reported as a person-to-person transmission. The receiving person is most likely going to self-contaminate by transferring the coronavirus from the hand to the nose, eyes or mouth, completing the trip from Person-To-Surface-To-Hand-To-Person, P>S>H>P. The mouth route is contested by some scientists who say that stomach acids will kill the virus.

The P>S>P route is mostly a P>S>H>P transmission and clearly calls for frequent hand washing or sanitizing as it is all but impossible to keep surfaces TouchReady® clean between re-contaminations. Coronavirus can live on stainless steel and plastics for 2 to 3 days. How often is any high-touch surface touched — like the refrigerator, microwave, bed table or rails? Yes, these surfaces should be cleaned frequently but handwashing or hand sanitizing are the better controls.

A handshake transfer of the virus is an intermediate stage of the more circuitous Person-To-Person trip One’s hand is either contaminated by a self-fielded cough or sneeze or touching a contaminated surface. The handshake moves the pathogen to the next hand where it harmlessly resides until it is moved to the nose, eyes or an open cut or scratch.

Studies have also shown that restroom surfaces could spread this virus as they do with norovirus. According to the CDC, vomiting and diarrhea are both considered symptoms of COVID-19 in some patients. These conditions raise the risk for restroom surfaces. This area is not known to be a major contributing factor in the spread of the virus, however.

Healthcare kitchens and restaurants in general may want to consider their potential exposure to legal actions if a cluster of COVID-19 infections are traced back to foodservice where the legal principle of strict liability may apply. While COVID-19 is not considered a foodborne illness, its contraction in a dining environment may well bring strict liability into play. There is precedent for this in the Chipotle norovirus outbreaks and subsequent litigation. 

(To sign up for a free subscription to Food Safety News, click here.)