If you've been wondering what to blame for the coronavirus' rapid spread, there's a good chance you're looking at it right now.
Scientists say our phones are "five-star hotels with premium heated spas, free buffet for microbes to thrive on" which should be washed as often as we wash our hands.
"You can wash your hands as many times as you like - and you should - but if you then touch a contaminated phone you are contaminating yourself all over again," said Australian molecular geneticist Lotti Tajouri.
He led a team which reviewed 56 prior studies on phone contamination, and concluded at the very least, our "third hand" should be cleaned at least once a day - preferably with the kind of hand sanitiser that's been in short supply lately, or devices which blast them with UV rays.
Phones are ideal breeding grounds for microbes, he said.
"They have temperature control, we keep them in our pockets, we are addicted to them. We talk into them and deposit droplets that can be full of viruses, bacteria - you name it. We eat with them, so we give nutrients to micro-organisms. And nobody - absolutely nobody - washes or decontaminates their phone."
In addition, while border control officers can ask questions and even check for symptoms of disease, they typically aren't in the habit of taking swabs from our phones away for testing - making them an ideal "Trojan horse" for bringing the virus in, Dr Tajouri claims.
SARS-CoV-2, the virus behind COVID-19, eventually dies if it can't infect a new host. But research earlier this year found it can survive three or four days on plastic and glass surfaces. Soap, strong UV light and sanitisers of at least 70 percent alcohol are effective killers when used correctly.
But who bothers to sanitise their phone? As Dr Tajouri said, nobody. And with the average Kiwi spending 18 hours a week scrolling away, there are plenty of opportunities to swoop up nasties and deposit them in places where others can pick them up.
The research was carried out before the pandemic began, but Dr Tajouri said it could be a clue as to how millions of people got infected so quickly, considering it's not clear if the virus can be transmitted through the air.
"The extraordinarily fast contagion that has scientists puzzled might reside within these mobile phones spreading COVID-19 everywhere at ultra-speed. After all, they’re everywhere, travelling the world in planes, cruise ships and trains," he said.
"Let's take that hypothesis seriously. If we clean our phones daily and this makes a difference then we might with this little action curve down the COVID-19 epidemic and save lives."
There have been 228,000 confirmed deaths from COVID-19, with 3.2 million confirmed infections - both counts, especially the latter, likely to be underestimates.
The latest research was published in journal Travel Medicine and Infectious Disease.