(NBC NEWS) — The makers of a new test say that you can use a simple swab to find out in 48 hours if any surface is contaminated with the virus that causes COVID-19.

NBC News investigative and consumer correspondent Vicky Nguyen got an exclusive look on TODAY Thursday at a product that could help businesses and schools identify what surfaces may contain SARS-CoV-2, which causes COVID-19, and determine if someone may be shedding the virus in that area.

Health experts say the primary mode of transmission for COVID-19 is through inhaling respiratory droplets from someone who is sick.

Contaminated surfaces are not the main cause of coronavirus spreading, but testing the surfaces could provide more information about whether people infected with COVID-19 have been inside a school or business even if they’re not showing symptoms.

Nguyen used the swabs from the San Francisco-based company Phylagen, which sells them in a 10-pack for $400, and collected samples from around New York City.

She took swabs from frequently-touched surfaces like handrails, elevator buttons and door handles, and tested surfaces in high-traffic areas like a subway station, coffee shop, public restroom and grocery store.

The results, which were returned 48 hours after shipping the samples, found that Florida had by far the highest level of positive results.

Nearly 20% of the samples taken in Miami were positive.

Read more here.