Recent research in the United States has concluded that after just one week of use, pillowcases and sheets contain between 3m and 5m colony-forming units (CFU) of bacteria per square inch (2.5cm) – meaning it contains 17 000 times more bacteria than a toilet seat.
In the study, conducted by Amerisleep, volunteers were asked to swab their bedding for four weeks without washing them.
The most common bacteria found were gram-negative rods, which commonly cause pneumonia and other infections.
Bacilli – bacteria that usually cause food poisoning – were also found on the bedding, reports News24.
The team also compared dirty pillowcases to other germ-infested objects:
- A pillowcase washed two weeks ago has 332 times more bacteria than a tap handle.
- A pillowcase washed three weeks ago has 405 times more bacteria than a kitchen sink.
- And a pillow washed four weeks ago has 39 times more bacteria than a pet bowl.
What about sheets?
- A sheet washed one week ago contains 24 631 times more bacteria than a bathroom doorknob.
- A sheet washed two weeks ago has 302 times more bacteria than a pet toy.
- A sheet washed three weeks ago has 280 times more bacteria than a coffee reservoir.
And a sheet washed four weeks back has 5.4 times more bacteria than a toothbrush holder.
Amerisleep article – Bacteria in your bed (Open access)
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Popular misconceptions about ‘good bacteria’ and ‘good hygiene’
Exposure to sunlight kills bacteria living in dust
Energy-saver washing machines may fail to eradicate pathogens