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Mobile microbes: mobile phones are five-star hotels for microbes and spread disease

Mobile phones have become our figurative third hand, so what happens when we don't clean them regularly?

Mobile phones are 5-star hotels for microbes, which instantly negate the gold standard of hand hygiene as a measure of infection control.

According to research we carried out in 2021, 173 bacteria, 8 fungi, 8 protists, 53 bacteriophages, 317 virulence factor genes, and 41 distinct antibiotic-resistant genes live on the surface of community-derived mobile phones. Even higher numbers were found on the hospital-derived mobile phones of healthcare personnel.

Mobile phones are highly-touched microbial contaminated platforms that are used for over 4 hours a day on average. Phones are like 5-star hotels for microbes since:

  1. Phones are microbial niches, touched thousands of times a day by soiled hands, often used in bathrooms and kept in dirty pockets or bags.
  2. Phones are heated, temperature-controlled electronic devices on which microbes thrive.
  3. Saliva droplets are continually shed onto the surfaces of phones during calls, acting as ideally moisturised microbial ‘spas’ or ‘pools’.
  4. People regularly eat while holding their phones, and small pieces of food are often dropped onto the screens, providing a ‘free buffet’ of nutrients for the microbes.
  5. The surfaces of mobile phones can be viewed as a ‘private lounge’ in which horizontal genetic transfers are common, such as the exchange of antibiotic resistance and disease virulence factor genes.

Mobile phones act as ‘third hands’ soiled with microbes

Mobile phones have become our figurative third hand, which is for all intents and purposes ‘attached’ to us, while simultaneously being a heavily contaminated platform that passes microbes to our biological hands. 

The World Health Organisation (WHO) explained that hand hygiene saves millions of lives annually. But mobile phones negate hand washing and are, therefore, jeopardising our health. The extent of its impact on our society is still unknown. This is critical since these soiled phones are used by millions of healthcare workers, food handlers, travellers, teachers, aged care and childcare workers, front-line responders, and more.

Ignaz Semmelweis, who in the 19th Century revolutionised infection control and prevention, is the godfather of handwashing. If he was alive today, his SMS to all of us on the globe would probably be, “Please, clean your third hand as well,” and such a message would, ironically, be ‘viral’. 

Woman spraying mobile phone with disinfectant
Credit: Pexels / Gustavo Fring

Microbes on mobile phones are health risks

In the community phones examined during our research, we were the first to report the presence of protozoa such as Entamoeba histolytica, which is acquired by a faecal-oral route. Several bacteria found on the community-derived mobiles phones we examined were also associated with diseases in humans and included Staphylococcus aureus (Golden staph), Listeria monocytogenes, Bacillus cereus, Acinetobacter baumannii, Pseudomonas aeruginosa, Salmonella enterica, Bordetella pertussis, Campylobacter, Escherichia coli, and Enterococci species. 

Among the 317 virulence factor genes identified, 96% of exacerbated disease genes were linked to the Staphylococcus aureus (Golden staph) bacteria. A total of 41 different types of antibiotic-resistant genes were also found on community-derived mobile phones, suggesting that handheld devices are a real concern to global public health.

As an example, the SARS-CoV-2 virus has been shown to survive on phones for up to 28 days, while bacteria can have a more extended survival time on inanimate objects, with E.coli surviving for between 7 days and 1 year and Golden staph surviving for as little as 1.5 hours and as long as 16 months

This longevity and persistence of microbes to survive on the surfaces of phones raises multiple red flags in global public health arenas for several reasons:

First, our hands are cross-contaminated each time mobile phones are in use. Research has shown that we touch our face more than 20 times an hour and, therefore, microbial transfer from mobile phones to our hands, and from our hands to our face, would inadvertently result in the spread of germs to our body.

The United States Centre for Disease Control and Prevention (CDC) has reported that 80% of all common infections are contracted from our hands. However, people are largely unaware of the self-inoculation of disease-causing germs that occurs when they touch their faces after their fingers have been cross-contaminated by their phone.

Second, microbes survive on inanimate surfaces for hours, days, and even weeks. Modern modes of transportation enable millions of people to travel around the globe each year. The risk of microbial dissemination around the globe may be exacerbated by the mobile phones of billions of travellers entering non-endemic borders without any customs checks or implemented device disinfestation.

In 2020, we hypothesised, in a scoping review, that mobile phones could contribute to SARS-CoV-2 being rapidly spread across the planet through modern transportation systems. Several reports have supported this, noting the presence of the SARS-CoV-2 virus on the phones of COVID-19 patients.

Our research also demonstrated the presence of animal and plant pathogens on phones, raising further public health concerns, since zoonotic pathogens are microbes that could potentially ‘jump’ from animals to humans.

Native flora and fauna in some countries may be impacted since plant and animal microbes on phones can travel across border security without detection by biosecurity authorities.

Border biosecurity authorities, as well as public health authorities, therefore, need to seriously consider the importance of sanitising phones at borders. This may result in saving lives, public health expenditure, and protecting native fauna/flora.

infographic showing how mobile phones are hotels for microorganisms
Infographic on microbes on mobile phones
Credit: Dr Matthew Olsen and Dr Lotti Tajouri

How can we clean our phones?

Given the dynamic and ongoing microbial contamination of mobile phones, the sanitisation of phones must be frequent and akin to hand washing. 

Using chemicals is not ideal, as wipes with chemicals deteriorate parts of the phone such as the oleophobic layer on most smartphones currently on the market. Additionally, frequent use of wipes is an unsustainable and time-consuming method and may possibly also be abrasive to phones. 

Recently, ultraviolet-C-based sanitisers that can safely disinfect phones have been developed. Although many of these ultraviolet-C (UV-C) devices are available, consumers should only purchase the instruments which are robust, safe, certified, and known to be efficient in killing microbes. Furthermore, ensuring compliance with the cleaning of phones is paramount. Evidence suggests that UV-C phone sanitisers that can clean phones in 10-20 seconds are practical for use in all scenarios. 

Common hand hygiene, along with UV-C sanitised phones are achievable and practical (see illustrated infographic). Based on our research, we believe that the deployment of efficient and fast UV-C phone sanitisers in public and private settings is likely to decrease microbial dissemination and infection worldwide and contribute to the reduction of global public health expenditure, in line with the United Nations’ Sustainable Development Goals.

The billions of ‘filthy’ mobile phones globally pose serious risks to public health and biosecurity due to the spread of pathogens. Implementing Ultraviolet-C phone sanitiser devices in all private and public settings is paramount for global infection control and improved community health. 

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Reference

Tajouri, L., Campos, M., Olsen, M., Lohning, A., Jones, P., Moloney, S., Grimwood, K., Ugail, H., Mahboub, B., Alawar, H., McKirdy, S., & Alghafri, R. (2021). The role of mobile phones as a possible pathway for pathogen movement, a cross-sectional microbial analysis. Travel Medicine and Infectious Disease, 43, 102095. https://doi.org/10.1016/j.tmaid.2021.102095

Dr Lotti Tajouri is an Associate Professor at Bond University and Murdoch University in the field of Molecular Genetics and an exclusive member of the Dubai Police Scientific Council. HIs research is associated with autoimmune diseases, Public Health, and Global Biosecurity with over 60 publications in peer-reviewed international scientific journals.

Prof. Rashed Alghafri is the Director of International Centre for Forensic Sciences and Criminology, Chairman of Dubai Police Scientist Council, and an active specialised researcher in Forensic Genetics. He was awarded professorship in Murdoch, the UAE, and Bond universities. He has also successfully completed Development Leadership and National Expert Programs in the UAE organised respectively by the MBRCLD and NEP.

Dr Matthew Olsen is a Bond University PhD graduate whose thesis focuses on unravelling the role of Mobile Phones as vectors for the spread of infectious diseases. He has published numerous articles in international peer-reviewed scientific journals aiming to raise awareness on effective mobile phone sanitisation protocols. His current research focuses on exploring the application of novel UV-C sanitisation technologies in community and healthcare settings.

Professor Simon McKirdy is the Pro Vice Chancellor at Harry Butler Institute and Professor in Biosecurity at Murdoch University. His expertise covers plant biosecurity, corporate leadership, corporate and academic research management, policy development, and the management of biosecurity operations within the government and private sectors. He has a PhD in Plant Pathology from the University of Western Australia. He is currently a Director for Plant Health Australia and the Chairperson of the Western Australian Biosecurity Council that provides advice to the Western Australian government through the Minister for Agriculture.