According to the Society for General Microbiology, some bacteria divide every 20 minutes at the right temperatures and with the right nutrients.
A 2016 study of the most contaminated objects in the home also found over 340 different bacteria on 30 different objects.
Not all bacteria are harmful — your body contains plenty of bacteria that don’t make you sick. But some can be found throughout your home and make you sick, including:
- Staphylococcus aureus, or staph
- yeast and mold
- Escherichia coli, or E. coli
- fecal matter
The SARS-CoV-2 virus, the new coronavirus was known for causing the COVID-19 pandemic, can also be found on many of the same surfaces. Symptoms of COVID-19 include shortness of breath, coughing, and fever.
It can spread quickly because it lives for hours or days on certain surfaces.
At March 2020 study looked at how long the new coronavirus could live on the following environments and surfaces:
- in the air: up to 3 hours
- plastic and stainless steel: up to 72 hours
- cardboard: up to 24 hours
- copper: up to 4 hours
The kitchen, where food is stored or prepared, had more bacteria and fecal contamination than other places in the home.
More than 75 percent of dish sponges and rags had Salmonella, E. coli, and fecal matter compared to 9 percent on bathroom faucet handles.
Other kitchen items that need frequent cleaning include:
- cutting boards
- coffee maker
- refrigerator, especially areas in contact with uncooked and unwashed food
- kitchen sink and countertops
Here are some tips for keeping these spots clean:
- Use disinfectant wipes on the faucet, refrigerator surfaces, and countertops.
- Heat damp sponges in the microwave for a minute to kill bacteria.
- Soak sponges in a quart of warm water with half a teaspoon of concentrated bleach.
- Change dish towels a few times a week.
- Wash your hands before and after touching or handling food.
Knobs, Handles, and Switches
Countertops, handles, and light switches are a few less-than-obvious places for germs.
While many people assume that the bathroom doorknob would be the dirtiest, the NSF found other spots that ranked higher with bacteria, including:
- bathroom light switches
- refrigerator handles
- stove knobs
- microwave handles