Hands “Cross-Contaminate” Surfaces

Healthy individuals have colonies of good resident bacteria that help fight bad transient bacteria. Without bacteria, humans would not exist. People host many different species of beneficial bacteria on the skin, mucous membranes, feces, body cavities, and under fingernails. This biome rainbow protects us from getting sick.

Before discussing the differences between cross-contamination and cross-contact, we must first address an essential distinction between them: “cross-infection.” Cross-contamination can be followed by cross-infection. A sick person was admitted to a hospital because a cross-infection developed after the patient became infected days earlier.:

• Pushing buttons at an ATM with their fingertips (instead of using knuckles);
• The public restroom hand air dryer blew pathogenic aerosolized droplets off their

hands and into their nostrils, eyes, and mouth;

• They shook the hand of someone who didn’t use soap after using the toilet, or
• Riding in an elevator without a ventilation exhaust fan after a sick person had coughed in the elevator twenty minutes earlier.

Cross-infection does not mean a person will become sick. Still, the determinants of infection taking hold and spreading depend on the health of the resident good bacteria living on the host and the number of harmful transient bacteria, viruses, or fungi that have attached to the host through cross-contamination.

Hepatitis B only needs 10 viruses to make a person sick.

Different Enterobacteriaceae species need more than 100,000 bacteria.

Cross-contamination and cross-contact are often used interchangeably, but these two words have different meanings, even though the process of transference from one surface to another surface is the same. Also, the preventive measures to eliminate the consequences of surface-to-surface contamination are nearly identical.

Cross-contamination usually means that bacteria, viruses, and spores have been transferred from one surface to another surface.

Cross-contact describes the transfer of a food protein from one surface to another surface, such as peanuts or MSG, which means people who are allergic to these foods may react to this contamination.

One main difference between these two terms is in the cooking process. Proper cooking of contaminated foods at precise temperatures can reduce or eliminate foodborne illness caused by bacteria or viruses spread through cross-contamination. Unfortunately, cooking does not eliminate or minimize cross-contact, which transfers an allergen from one food to another that does not contain it.

Hard and soft surfaces include countertops, kitchen appliances, utensils, tablecloths, tabletops, and, of course, the greatest explorer of all time —the human hand.

Another difference that studies reveal:

• Liquid soap can be effective in removing food proteins/pathogens from your hands.
• Alcohol-based sanitizers do not remove food proteins, even though they are effective at removing pathogens.

While cross-contamination may not occur after hand washing or sanitizing, cross-contact can still occur if you’re using hand sanitizer to clean your hands.

People commonly use the term “cross-contact” when describing how food is handled, prepared, and served to the public. Food safety educators use this term to describe how raw meat, seafood, eggs, poultry, and vegetables are handled during the preparation of food served at home or in a restaurant.

“Cross-contamination” describes how any surface contaminated with pathogens transfers them by way of:

• Handshakes;
• Bottoms of shoes/purses/bags/briefcases;
• Coughing and sneezing;
• Petting of dogs, cats, and birds (Salmonella, Escherichia coli 0157); and
• Poor cleaning.

It doesn’t take much imagination to understand that our hands set us apart from other life forms. We can hold, manipulate, examine, and ponder that which we hold in our hands. Almost everything we do will eventually involve our hands.

The CDC reported that in 2008, an estimated 450,000 children globally under the age of five became sick from Rotavirus. (35)

This study, Rotavirus survival on human hands and transfer of infectious virus to animate and nonporous inanimate surfaces, was conducted by Shamim Ansari, Syed Sattar, Susan Springthorpe, Geroge Wells, & Walter Tostowaryk. (36) They sought to determine how long rotaviruses can live on human hands and how easy is it for the hands to transfer this infectious virus to other hands and nonporous inanimate surfaces.

“Contact between a contaminated and a clean hand twenty and sixty minutes after virus inoculation resulted in the transfer of 6.6 percent and 2.8 percent, respectively, of the input infectious virus.”

“These findings indicate the potential vehicular role for human hands in the

spread of rotaviral infections.”

Besides handwashing, the number one thing that individuals can do to help prevent contaminating surfaces and other people is to stop shaking hands. Shaking hands transmits ten times as many bacteria as a fist bump. (37) Bumping fists is better than handshaking, but during a pandemic, the best way to greet someone is by bumping elbows.