In early March of 2020 everything changed. Scientists, healthcare workers, teachers, retailers, restaurateurs, and our entire society scrambled for answers and the proper interventions to protect and care for family, friends, and co-workers. Debates ensued about universal mask wearing, what kind of masks are effective, the primary routes of transmission of the virus, what agents can or should be used to kill the virus…a mountain of questions and opinions flooded the news, science discourse, and nearly every conversation in America.
One recommendation, the single most important preventative measure agreed upon unilaterally was: wash your hands.
Hand washing with simple soap and water is universally recognized as a most vital process in any infection prevention directive. As we continue to wrestle with the COVID-19 pandemic in 2021 and prepare ourselves for future combat against mutant strains, as well as a plethora of existing and emerging multi-drug resistant organisms, the question is: is hand washing enough?
In the case of COVID-19, the answer is clear: hand washing is not enough. We must also wear masks as a barrier to the airborne virus. Pathogens infect us in a variety of ways, they access our bodies through the air (airborne), what we eat (foodborne), an open wound or intravenous route (bloodborne). They may be contracted from another person (direct) or an object’s surface (indirect). Each of these transmission routes, as well as the pathogens that take advantage of them, have different mitigation strategies. While hand washing is an important infection prevention strategy regardless of the pathogen or the transmission route, more is needed.
In particular, the body of research surrounding the risk assessment of infections contracted indirectly from the objects we touch is lacking. There continues to be a blind spot in research, clinical guidance, and knowledge among the general population that undermines hand washing mitigation strategies each and every moment: the cell phone. Nearly all Americans own a cell phone; over 96% of us[ii]. We are a society that spends over 5 hours a day on our phones checking them an average of 63 – 150 times3. The cell phone, as well as many other mobile devices, are now essentially an extension of the hand.
It has been well researched, that cell phones carry more and deadlier[iii] [iv] germs than a toilet seat[v]. If you wash your hands and pick up your phone, there is an enormous chance you have just re-contaminated your hand[vi]. These organisms transfer to and from phones and hands[vii] and subsequently into our bodies to cause infections[viii]. However, most of the research studies regarding pathogen self-inoculation via a fomite[ix] [x] were conducted outside of the context of the extensive use of handheld devices.
This white paper reiterates the importance of hand washing, highlights important research regarding pathogen transfer, and strongly advocates for the redefining of the term Hand Hygiene (as a superset of hand washing) to incorporate phone disinfection, because hand washing is simply not enough.
Why do we bother washing our hands?
Infection prevention professionals battle invisible foes on the front line 24 hours a day. They truly are heroes. Infection prevention’s first hero was the Hungarian Physician, Ignaz Semmelweis, who, in 1847, proposed that hand washing be a standard practice for all physicians. He discovered a drastic reduction of infections and death among his patients when hand hygiene was performed. The scientific establishment at the time was not convinced. In the very same hospital where he practiced, hand hygiene was not used. Subsequently, three times as many women died during childbirth. In his practice, by instituting hand washing, he brought the mortality rate to below 1%. Even as patients labeled him the ‘savior of mothers’, the cause and effect were not accepted as reason enough to implement hand washing. Years after his death of course, hand washing is universally accepted as mandatory in clinical settings today[xi].
Hand washing breaks the chain of pathogen transfer from hands to other people, other fomites, food, and most importantly, to oneself with bacteria and viruses we pickup with our hands. Self-inoculation is an unconscious act. A study conducted during the H1N1 pandemic showed that we touch our faces nearly 23 times per hour[xii]. If a pathogen can persist on a surface, even if it is primarily transmitted through the air, it can be transferred from our hands into our bodies most often through the eyes, nose, mouth, and even our ears. Even though we are aware that we need to wash our hands and not touch our face, we are still human and will still self-inoculate through face-touching.
Today, we all wash our hands to remove bacteria and other pathogens that have contaminated our hands from the things we touch. We are newly reminded by our battle with COVID of how important this is. In hospitals, however, hand washing is front and center due to the immunosuppressed nature of patients and the constant barrage of pathogens clinicians are exposed to. In this context, hand washing reduces the possibility of transmitting pathogens to and from the facility and, potentially, out into the community. Hospital acquired infections (HAIs), infections contracted from the hospital environment, cause nearly 1 million infections and 100,000 deaths per year. Those numbers are staggering both monetarily as well as the human toll they leave behind. Hospital hand hygiene protocols and the staff that perform them are saving lives every day by keeping those numbers, as staggering as they are, to a lower level than they would surely be without hand washing. These numbers seem minuscule compared to the havoc caused by the COVID-19 pandemic. At the time of writing this paper – the infection population in the US alone is over 34 million cases with a death toll of over 613,000 people[xiii] and we have learned that preventive measures are effective at reducing the spread, even in a pandemic[xiv].
When hospitals increase their cleaning and disinfection behavior of high touch surfaces infection rates drop[xv]. The World Health Organization cites several studies showing dramatic reduction of incidence of multi-drug resistant organisms (MDRO) when hand hygiene protocols are implemented. In one study, less than half of medical staff in a hospital were washing their hands, when they achieved 95% compliance by introducing hand washing protocols, they reduced infections by nearly 9%. On the monetary side, they concluded that for every $1 spent on Hand Hygiene protocol implementation, approximately $23 can be saved in the cost of care required had those patients become infected[xvi].
In addition, many studies have shown a reduction of infections by increasing proper and frequent disinfection of the patient environment – bed rails, bathrooms, and all surfaces touched by patients and staff[xvii]. Cleaning (removing) and disinfecting (killing) pathogens on high touch surfaces reduce the opportunity for those pathogens to transfer to our hands and bodies. In fact, the greatest risk to a patient in becoming infected in a hospital is who occupied the room before them and the pathogens they left behind[xviii].
What is a fomite?
fo·mite | \ ˈfō-ˌmīt
plural fomites\ ˈfō-ˌmīts; ˈfä-mə-ˌtēz , ˈfō-
Definition of fomite: an object (such as a dish, doorknob, or article of clothing) that may be contaminated with infectious agents (such as bacteria or viruses) and serve in their transmission.
Nearly everything we touch is a fomite. Fomites harbor bacteria, viruses, and other pathogens. Fomites are contaminated by human hands transferring them from themselves, another person they touched, or another fomite they were contaminated by when they touched it. Fomites are also contaminated by airborne germs released by infected people from their breath, sneezing, and coughing. In fact, fomites harbor many of the deadly MDROs plaguing hospitals, the community, and even in the home[xix]. Hand washing is often the sole barrier preventing these pathogens from infecting ourselves or others. Clinicians wash their hands before and after each patient encounter, medical procedure, and the use of medical devices…and we all wash our hands regularly before eating, using the restroom, but not necessarily after touching every fomite. It may, in fact, be impossible for handwashing to overcome recontamination with every fomite.
What lingers on your phone?
All handheld mobile devices are fomites. The cell phone of course, is a fomite we carry and touch all day long. As stated earlier, our cell phones are dirtier than a toilet seat5. They harbor roughly 25,000 germs per square inch[xx]. Across several studies investigating the contamination level of cell phones, 50% – 70% of all phones sampled confirmed the presence of pathogens3 4, many of which are multi-drug resistant organisms (MDROs). Table 1 lists a few of the most common MDROs found on cell phones across numerous studies.
If it turned out that our hands were contaminated by any of these germs, in order to avoid transferring them to our food, our bodies, our friends, or other fomites, washing our hands properly could break the chain of transmission. This is true of course only if we do not recontaminate them again picking up the phone after our hands are washed.
Clarity, and consistency in guidance is essential. In all the language above, the CDC recommends washing your hands as a preventive measure. The CDC does recommend attending to some fomites when it comes to certain organisms, medical devices and foodborne routes of transmission. For example, they suggest to, “Thoroughly wash hands, counters,cutting boards, and utensils after they touch raw meat” to mitigate Escherichia coli contamination yet they do not call out specific fomites or surface disinfection for MRSA. However, and more importantly, the CDC fails to acknowledge or provide language or specific infection prevention guidance for the most prevalent fomite; the one with the greatest opportunity for recontaminating a hand: the cell phone.
The scientific literature is clear – pathogens, including MDROs, live on our phones providing a reservoir of pathogens with the potential to recontaminate hands and the surrounding environment. Hospitals are beginning to see evidence of this threat. In one study, nearly 50% of cell phones used in a hospital operating room were contaminated with MRSA. The problem does not end there, however. Clinicians, patients, vendors and others take their cell phones home with them along with any pathogens they may harbor. In a survelance survey from 2013, researchers found pathogen transmission from the hospital to the community via a parent’s cell phone visiting their infant in the NICU. The problem goes beyond what happens in hospitals of course. In the community setting, where we now battle a pandemic, studies have shown that over 62% of student’s phones sampled in schools also found pathogens[xxi].
Depending on the species, organisms that inhabit inanimate surfaces can linger for hours to several months if left untouched by disinfection. Below is a list of clinically relevant bacteria and how long they can survive on non-porous fomites[xxii]. The range of survivability among these bacteria is vast—from 1.5 hours to 4.2 years.
Surfaces are a Reservoir for Pathogen Transfer
A 1995 study showed the MRSA contamination in a nurse’s home to be equivalent to that found in the hospital environment[xxiii]. Microbiologists compared the genetic profiles of MRSA obtained from infected patients to MRSA isolated on keyboards in the nurses’ home and found them indistinguishable, suggesting a pattern of environmental contamination that extends beyond a patient’s room.14 In 2002[xxiv], researchers compared the genetic footprint of organisms found on patients, clinicians, and their cell phones to determine the paths of pathogens across fomites.
These studies demonstrate that surfaces frequently touched by healthcare workers serve as reservoirs for pathogen transfer even beyond the walls of a hospital.
In 2013, researchers studied the transfer efficiency of various microbes, including MRSA, from fomite-to-fingers, (e.g. how often do you pick up a pathogen when you touch a fomite). While the study displayed variability between pathogens, surface type, and room humidity, the researchers found that not only does MRSA transfer from an object to hands, but it does so greater than 50% of the time10.
Both in and out of clinical environments, researchers have concluded time and again that pathogen transfer to and from fomites does occur and is a potential cause of infection[xxv] [xxvi]. Some have even suggested strict restrictions on mobile device use may be necessary. Those suggestions, however, are clearly impractical. Most studies suggest that new strategies for preventing pathogen transmission are required3.
COVID-19: can you get it from your phone?
It is generally accepted that COVID-19’s primary route of transmission is via an airborne droplet expelled by an infected individual and inhaled by another, susceptible person. It is unclear, however, as to what percentage of infections are caused via indirect contact vs. direct or airborne contact. It is not unclear, however, that the two most important interventions are wearing a mask and washing your hands. While it may be unclear as to how many have contracted COVID-19 from a surface, several studies and mathematical models conducted have suggested that indirect transmission from surfaces in some settings, may even be the predominant route for many viruses considered to be ‘airborne’, including influenza[xxviii] [xxix] [xxx].
Research conducted during the pandemic included attempts to determine the survivability of coronavirus on various types of surfaces. Medical researchers identified the virus surviving for at least 17 days on a cruise ship[xxxi], while another study published survival at 28 days[xxxii]. Aside from these broad range of findings, the crisis yielded a variety of false and confusing information[xxxiii] as researchers worked iteratively and rapidly to gain insight. This was science in real-time. As more research became available, the following studies[xxxiv] [xxxv] seemed to convergence on a 4 – 9 day window where coronavirus can survive depending on the type of surface:
To further complicate things, variants of the coronavirus have different half lives[xxxvi] on a surface, suggesting risk models may differ not only across pathogens but with each variant. Clearly, the longer a pathogen can survive, the more opportunity it has to transfer.
As stated, mathematical models suggest significant risk of contracting respiratory infections from viruses like COVID-19 via surfaces in certain environments[xxxvii] [xxxviii]. These models are a great start to identifying the potential risk of contracting infections from known pathogens as well as the risk of epidemic and pandemic escalation from new pathogens. However, these models are also extremely limited in the context of assessing risk because they suffer the same blind spot we highlight in this paper – they do not model the unique risk complexity of pathogen transfer from a cell phone, the most ubiquitous fomite there is. The phone is not the same as the fomites used in many risk modeling studies, such as countertops or a medical device button[xxxix]. Holding a phone in your hand, all day, everyday, is not that same as touching any other surface. Cell phones have a repeating (every time you grab your phone) and greater opportunity (the entire palm of your hand vs. a single finger’s touch) for pathogen transfer than other surfaces. Self-inoculation occurs often when we touch our face[xl]; bringing our phones to our face naturally encourages that and adds touching it with a fomite to the risk profile. Our mathematical models and the guidance from the scientific community should reflect these behavioral characteristics.
These models need to utilize assumptions that reflect the reality of our modern real-world risk. Researchers know and note the limited understanding of indirect fomite transmission in many papers addressing surface disinfection31. Clearly more must be done. The experience of COVID unfolding in such a rapid time frame, reflects the urgency a pandemic-inducing pathogen can create. It took 10 years for cell phones to become the number 1 tool used by 96% of people in the US2. It only took a few months for the entire planet to be brought to its knees by an invisible microorganism. If we are going to leverage mathematical models to predict risk, the inputs to the model need to discern and classify surfaces to reflect how we live with them in our hands, and denote the dynamic characteristics of risk associated with rapid changes to longevity on a surface from mutated strains.
Why not just wipe down my phone with chemical wipes?
You can and should but not for the reason you may think.
Cleaning and disinfecting are two different things. Cleaning, as defined earlier, is the removal of dirt and grime from a surface. Disinfecting, however, is the killing of microorganisms. You can actually clean a surface without effectively disinfecting it. Similarly, you can fully disinfect a surface without actually cleaning it.[xli]
Utilizing a disinfecting wipe, requires a human to do it and do it properly. Any repetitive task, especially voluntary ones, contain the performance variability of the user and is subject to the limitations of the person performing the task. Human factors research[xlii], along with numerous clinical studies, show us that the efficiency of a manual task is always negatively impacted by human inconsistency[xliii] [xliv]. Wiping down a fomite, as evidenced by cleaning studies[xlv], show that it is hard to insure complete coverage of a surface.
To further complicate matters, chemical disinfectants require what is called a “contact time” in order to be effective. Every chemical disinfectant has a unique contact time reflected on the label. The contact time is how long a surface must remain wet in order to achieve proper pathogen kill. Contact times can range from 1 – 10 minutes depending on the chemical.
Most chemicals however, dry before their contact time[xlvi]. This means that to achieve the prescribed contact time of a chemical that dries before the contact time has been met, would require the user to apply the chemical more than once. True mitigation strategies must ask the question is this process a realistic expectation?
Another challenge to disinfection efforts with chemicals is that not all chemicals kill all pathogens. Each chemical has a battery of organisms it is capable of killing, each with their own complication. Bleach for instance, must be used to kill C. difficile but bleach is very harsh and corrosive on the body, not safe for use on all surfaces and environments and can be very dangerous if mixed with other chemicals.
The best infection prevention practice for a fomite is to first clean the surface and subsequently kill any organisms left. Knowing that the cleaning/disinfecting process is limited and riddled with obstacles, leaves hospitals and the communities they serve in need of a technology that prioritizes killing of organisms without user variability.
Regardless of the magnitude of the threat of contracting COVID-19 indirectly from a phone, the coronavirus pandemic is a wakeup call. We must not forget, that COVID is not our only threat. We need to be prepared. We must look beyond even the current crisis to implement processes that address both current and future pathogenic threats.
Hand Hygiene is defined as a method of substantially reducing pathogens on the hands. Given that our phones harbor deadly pathogens and they can re-contaminate our hands, hand washing is clearly not enough to achieve true hand hygiene. Hand Hygiene needs a new definition that include technologies to achieve that definition. Hand Hygiene is in essence a superset of hand washing. In order to truly and substantially reduce pathogens on the hands, it must include phone disinfection. A new gold standard – one that can utilize rapid disinfection technology to take user variability out of the equation and increase hand washing compliance is needed to truly yield a lower level of overall risk.
Dr. Semmelweis paved the way but it wasn’t until 1980 that the American Hospital Association began to recognize and instill hand washing and 1995 before hand washing guidelines recommended antimicrobial soap or waterless antiseptic agents[xlvii]. It would be helpful for CDC and other clinical guidance to include the fact that deadly pathogens live on our phones and see hand washing and phone disinfection as two distinct processes that must come together to achieve effective hand hygiene. The theoretical mathematical models currently used to assess the risk of a pathogen, need to accurately model modern day fomite use along with the dynamic characteristics of linger-ability that can change with new pathogenetic threats and every subsequent variant thereof. Many pathogens cause infection through cross-contamination of hands from fomites. The phone is a unique type of fomite, a roaming-high-touch surface, a ‘super-fomite’ like no other we have ever integrated into our lives. We must disinfect our phones and other handheld devices as part of a new definition of Hand Hygiene that goes beyond hand washing. We simply need a new gold standard.
[i] Coronavirus covid19 cases number US Americans by day
[ii] Pew Research – Fact Sheet – mobile
[iii] Presence of Multidrug-Resistant Bacteria on Mobile Phones of Healthcare Workers
[iv] Study of bacterial flora associated with mobile phones of healthcare workers and non-healthcare workers
[v] Why your cellphone has more germs than a toilet
[vi] Transfer Efficiency of Bacteria and Viruses from Porous and Nonporous Fomites to Fingers
[vii] Spread and prevention of some common viral infections in community facilities and domestic homes
[viii] Face touching: A frequent habit that has implications for hand hygiene
[ix] The effectiveness of hand hygiene procedures in reducing the risks of infections in home and community settings
[x] Preventing Transmission of Pandemic Influenza and Other Viral Respiratory Diseases
[xi] CDC Comprehensive Hospital Preparedness Checklist
[xii] Face touching: A frequent habit that has implications for hand hygiene
[xiii] Worldometers Coronavirus Cases
[xiv] Impact of Masks, Hand Hygiene, and Soc Distancing on Influenza, Enterovirus, and All-Cause Pneumonia During Coronavirus Pandemic
[xv] Evidence of hand hygiene to reduce transmission and infections by multidrug resistant organisms in health-care settings
[xvi] Effectiveness and limitations of hand hygiene promotion on decreasing healthcare-associated infections
[xvii] Does improving surface cleaning and disinfection reduce health care-associated infections?
[xviii] The Role Played by Contaminated Surfaces in the Transmission of Nosocomial Pathogens
[xix] Surveillance Study of Bacterial Contamination of the Parent’s Cell Phone in the NICU
[xx] FOMITES IN INFECTIOUS DISEASE TRANSMISSION
[xxi] Isolation and Identification of Bacterial Pathogen from Mobile Phones
[xxii] How long do nosocomial pathogens persist on inanimate surfaces?
[xxiii] Refractory methicillin-resistant Staphylococcus aureus carriage associated with contamination of the home environment
[xxiv] Cell Phones and Acinetobacter Transmission
[xxv] Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens
[xxvi] Spread and prevention of some common viral infections in community facilities and domestic homes
[xxvii] Transmission of SARS and MERS coronaviruses and influenza virus in healthcare settings
[xxviii] Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease
[xxix] Transmission of influenza A in human beings
[xxx] Informing Optimal Environmental Influenza Interventions: How the Host, Agent, and Environment Alter Dominant Routes of Transmission
[xxxi] Public Health Responses to COVID-19 Outbreaks on Cruise Ships — Worldwide, February–March 2020
[xxxii] The effect of temperature on persistence of SARS‑CoV‑2 on common surfaces
[xxxiii] The 13 Most Outrageous Covid-19 Myths and Misconceptions
[xxxiv] Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents
[xxxv] SARS-CoV-2 Survival on Surfaces and the Effect of UV-C Light
[xxxvi] Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents
[xxxvii] Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens
[xxxviii] Risk for Fomite-Mediated Transmission of SARS-CoV-2 in Child Daycares, Schools, Nursing Homes, and Offices
[xxxix] Community Transmission of SARS-CoV‑2 by Surfaces: Risks and Risk Reduction Strategies
[xl] Face touching: A frequent habit that has implications for hand hygiene
[xlii] Using a human factors engineering approach to improve patient room cleaning and disinfection
[xliii] Investigation of Cell Phones as a Potential Source of Bacterial Contamination in the Operating Room
[xliv] Comparative effectiveness of rapid-cycle ultraviolet decontamination to chemical decontamination on high touch communication devices
[xlv] Evaluating hygienic cleaning in health care settings: what you do not know can harm your patients
[xlvi] Premature Evaporation: Is your disinfectant fulfilling your every desire?
[xlvii] WHO Guidelines on Hand Hygiene in Health Care: First Global Patient Safety Challenge Clean Care Is Safer Care.