Germs on travellers' phones present a biosecurity risk

Knowledge and ideas circulate freely at international conferences — but so do germs carried from abroad on mobile phones.

That’s according to a new study led by Bond University and published in Infection, Disease & Health, which saw researchers swab 20 mobile phones from local and international attendees at the World Organization of Family Doctors (WONCA) World Conference in 2023. The samples underwent DNA analysis that revealed 2204 microbes on the devices, including 882 bacteria, 1229 viruses, 88 fungi and five single-celled protists.

Among the microbes present on the surface of the mobile phones were antibiotic-resistant bacteria including Staphylococcus aureus, known for causing infections in hospitals, and Pantoea stewartii, which affects crops and can also cause septicaemia in rare native Australian parrots.

A fungus detected on one phone, Fusarium solani, is meanwhile similar to Fusarium euwallaceae which is associated with the polyphagous shot hole borer, first found in Australia three years ago and spreading in Western Australia. The borers have a symbiotic relationship with the fungi and can kill a tree in two years, raising fears that native forests and agricultural crops could be wiped out in Australia.

“The study demonstrates large numbers of microbes are being introduced to Australia via the microbial-contaminated mobile phones of travellers, posing potential threats to local ecosystems, agriculture and public health,” said lead author Dr Lotti Tajouri, who has previously produced research supporting a theory that the international portability of mobile phones may have hastened the spread of COVID-19 between countries.

“Take only the presence of antibiotic-resistant bacteria on the phones of international travellers. This raises concerns about the rapid spread of infections and resistance genes with modern transport.

“This surely can complicate efforts to control and treat infectious diseases and contribute to the global issue of antimicrobial resistance.”

By extrapolating the results of the study out to account for 6.8 million arrivals into Australia between January and October 2023, the authors estimate 749.2 million microbes may have been introduced to Australia in 2022 via mobile phones.

“Not all these microbes are harmful of course, but the odds that pathogenic microbes may have found a potential pathway of entry into Australia is high with millions of visitors,” Tajouri said.

According to Tajouri, the data builds a case that international travellers’ phones should be decontaminated upon arrival to Australia, in addition to existing biosecurity measures.

“Mobile phones act as contaminated mobile petri dishes, yet they are crossing borders without scrutiny,” he said.

“Protecting our biodiversity and reducing the spread of superbugs is critical not only for the economy but for our national security.”

Image credit: iStock.com/vege