Wednesday, July 24, 2013

Is a woman's purse really more contaminated than a toilet seat?

I've been wondering ever since this revelation splashed across the Internet.

Like most of these groundbreaking discoveries, this one got plenty of media attention. Despite the numerous articles mentioning the purse-toilet seat connection study and its sponsor, the Initial Washroom Hygiene Solutions company, I wasn't able to locate the full text or even an abstract of the investigation itself.

What I have pieced together from several different reports and the company's press release is that 25 handbags were examined and 100 objects were swabbed.

It seems that only one in five of the purses had excessive contamination.

And here's more interesting stuff from the press release: "Initial Washroom Hygiene, one of the UK’s leading hygiene and washroom services companies, today unveiled research showing that the handles of women’s handbags are home to more bacteria than the average toilet flush." [emphasis added]

So the contamination was with the handles of the bag and the comparison was to a toilet flush, not the toilet seat, which was the focus of many headlines. For example, this is what New York's CBS News outlet said, "Study: Handbags May Have More Bacteria Than A Toilet Seat." 

Or here's video from Slate which compares handbag contamination to both a toilet seat and a toilet (exact area of comparison not stated).

Let's talk about some problems.

The study was small. It was sponsored by a maker of hygiene products. How does one measure the amount of bacteria in a toilet flush? Wouldn't that depend on what was in the toilet bowl at the time? How many flushes were analyzed? The reporting was somewhat crappy since a flush was somehow conflated with a seat.

Finally, the press release was dated August 5, 2012. Why did this suddenly become news almost a year later?

It is possible that a woman's purse is more contaminated than a toilet flush, a toilet seat or even a toilet, but this "study" doesn't prove anything. It simply serves to confuse lay people.

It is one of a new genre of studies that apparent consider the toilet seat as the "gold standard" for contamination.

Here are some items that have been allegedly found to contain more bacteria that a toilet seat: cell phones, barbecues, desktops, kitchen sponges, light switches, computer keyboards, money, motel bedspreads, ATM keypads, office telephones, restaurant menus, grocery carts, steering wheels, gym equipment, and kitchen faucet handles.

As far as I know, disease transmission has not been linked to the handles or any other part of a woman's purse or any of the other objects said to be more contaminated than a toilet seat.

Come to think of it, what about disease transmission from a toilet seat?  Although a recent study linked over 9000 penile crush injuries over an 8-year period to falling toilet seats, there is no evidence that you can catch any infectious disease from a toilet seat.

Here's a quote from a WebMD article on the subject: "To my knowledge, no one has ever acquired an STD on the toilet seat—unless they were having sex on the toilet seat!" said Abigail Salyers, PhD, president of the American Society for Microbiology.

So can we please stop comparing things to toilet seats?

What we should be comparing things to is shower heads. See "Did Your Morning Shower Spray You With Bacteria?"


Anonymous said...

I believe in UK parlance the "flush" refers to the lever you press on the toilet to activate the flush.

Skeptical Scalpel said...

Thank you very much. That nuance was lost on me as well as the people who reported the story. It makes a lot more sense now.

Here we would call it a "handle."

Still, it's not the same as the toilet seat.

CholeraJoe said...

I'm certain Dr. Salyer is correct but almost everyone has a friend of a friend, a cousin, or knew someone who got (insert STD) from a toilet seat. I laugh at the elaborate precautions people take in public restrooms, custom seat covers, half a roll of toilet paper, then walk out without washing their hands adequately, or at all.

Skeptical Scalpel said...

Joe, thank for the comments. On target as usual.

legal doc said...

As a medical student many many years ago, I rotated through the then called VD Clinic. A young man came in and said to the consultant that he had "caught a cold in his penis from a toilet seat". The wry statement was "Well until they both either cough or sneeze you get penicillin"

ehdoublujay said...

Toilet seats: the gold standard for bacteria--wait, what?

Old Rockin' Dave said...

An ID doctor I knew was occasionally asked if it was possible to contract an STD on a toilet seat. She invariably answered, "Yes, but only if you're not alone."

Skeptical Scalpel said...

I agree.

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