Flimsy white sheets shaped like the seat, paper toilet liners can be found in many public bathrooms. Notably, however, while they may provide reassurance to the germaphobic and finicky, toilet seat covers have little else to offer in terms of decreasing your odds of being infected with some pathogen when sitting on the toilet seat.

Once thought to be capable of conducting sexually transmitted diseases (STDs), contrary to popular belief, today scientists know that toilet seats are very poor vehicles for spreading such maladies (like herpes and HIV). This is due to the relative fragility of these viruses outside of a human host, as well as the very effective protective barrier offered by the skin of your backside. (Note, however, that if you have an open cut or other wound on your derriere, it is possible one of these viruses could get through in that scenario.)

Of course, this doesn’t mean that viruses and bacteria aren’t sometimes present on toilet seats, and, in fact, an eight-year old girl once caught gonorrhea (Neisseria gonorrhoeae) from one; however, she didn’t get it by sitting on the seat, she picked it up when she tried to use toilet paper to clean the soiled seat off and got the microbes on her hand.

In addition to a few, short-lived STDs, toilet seats may have germs like E. coli and streptococcus; however, neither of these can typically invade a body through the skin, so the only way they will make you sick is if they get on your hands and you don’t then wash your hands before eating or the like.

Nonetheless, some people have very sensitive skin and seats covered with certain allergy triggers like chemical cleaners, paints, or varnishes may cause contact dermatitis, a condition seat covers would help prevent. In addition, the truly fastidious would find themselves in a difficult position if toilet seat liners weren’t available.  For the biggest germaphobes, toilet paper strategically placed on top of the toilet seat liner may also ease your mind, albeit not actually accomplishing much in terms of disease prevention over what your skin already offers.  Of course, when a toilet containing fecal matter is flushed, it tends to result in microbes and bits of said matter being sprayed about, including landing on that latch handle you touched, exposed bits of toilet paper and, yes, the exposed part of the disposable toilet seat liners…

It could be worse, though. In Ancient Rome, a wet sponge on a stick was often used for wiping.  That may sound very comfortable and appealing until you learn that, after being used, the sponge was placed back in a tub of salt water to await the next person to come along and wipe with it.  Even if the salt content was sufficiently strong to kill off any microbes. Ewww.

If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes, Spotify, Google Play Music, Feed), as well as:

• Toilet Paper wasn’t Commonly Used in the United States Until the Early 20th Century
• How Soap Works To Get Rid of Bacteria
• Why Don’t Americans Use Bidets?
• Why Beans Give You Gas
• Why Don’t Vultures Get Sick When Eating Dead Things?

Bonus Facts:

• In 2013, more than $7 billion in toilet tissue was sold in the United States alone, with three Charmin products, Ultra Soft, Ultra Strong and Basic, comprising more than $2 billion in revenue, alone.
• For 2005, while people in the US spent more than $5 billion on TP, India had the highest total sales with $7.7 billion (US). Of course, India has (literally) about a billion more people than the United States.
• The annual per capita consumption of toilet paper in the United States and Canada is about 50 lbs. This far outpaces use in Europe (about 30 lbs.), Latin America (about 9 lbs.), Asia (about 4 lbs.) and Africa (not quite 1 lb. per person).
• Worldwide, nearly 2.5 billion people have no access to a proper sanitation facility, and just over 1 billion are forced to defecate openly. Nonetheless, services have improved, and since 1990, nearly 2 billion more people have obtained access to improved sanitation.
• Open defecation continues to be a problem globally, and it is on the rise in sub-Saharan Africa. It is a main cause of diarrhea, and together with other diseases caused by poor hygiene and inadequate sanitation, contributes to the deaths of about 1.5 million children each year. Eighty percent of diseases in developing countries are caused by poor sanitation and unsafe water supplies.
• The second most commonly reported “notifiable” disease in the US, gonorrhea rates have been rising of late, and in 2013, more than 300,000 cases of gonorrhea were reported. More prevalent in the South (with a rate of 128.6 cases per 100,000 people), the state with the highest rate of gonorrhea was Louisiana, at 188.4 cases per 100k.
• In addition to being spread through sexual contact, gonorrhea can be passed from a pregnant woman to her baby during childbirth. Its symptoms include, for men a burning sensation when peeing, swelling in the genitals (in a bad way) and a discharge from the penis. For women, symptoms also include painful urination and discharge (from the vagina), as well as abnormal bleeding. Luckily treatments are available, although gonorrhea is one of the bacteria strains that is developing a strong resistance to antibiotics.