5 Germs You Really Can Get From a Toilet

There are an estimated 50 bacteria per square inch on a toilet seat, but that’s nothing compared to many items in your home. ©tarasov_vl/iStock/Thinkstock

Maybe you hover over the seat, or maybe you'd rather make a paper nest to protect yourself. Regardless of your choice of protection, you're not alone when avoiding the public seat. As many as 50 percent of women in the U.S. won't sit on a toilet seat in a public bathroom [source: ABC News]. Are we overreacting, or is there really a reason to assure our "assets" remain safe against what may be lurking on the toilet seat? We're talking about that which you can't see, not the mess the last user left behind.

Generally, you'll find about 50 bacteria per square inch on a toilet seat -- that's the average. While that may sound gross, there are definitely things around your house that are less clean in comparison. Your kitchen sponge, for instance, has about 10 million bacteria per square inch. That's 200,000 times dirtier than the toilet seat, and makes it pretty much the filthiest thing in your house [source: Pritchard]. Your cutting board, too, is a bacteria breeding ground, as are all your doorknobs. But that doesn't mean the toilet seat is off the hook.

Let's talk first about what everyone assumes you'll catch from visiting a public toilet. Sexually transmitted bacteria (such as chlamydia) and viruses (such as genital herpes) are passed along by skin-to-skin contact. Since those microbes die pretty much as soon as they hit the cold toilet seat, you can breathe a sigh of relief. It's so unlikely to catch an STI from a toilet that we're not going to mention it again. But there are a few infections that you really can pick up from an unsanitary porcelain throne, though the odds are still pretty low. But if you're at the right place (sitting on a toilet seat) at the right time (when the seat's contaminated with feces) it could happen (if you don't wash and dry your hands thoroughly).

E. coli
E. coli bacteria at high magnification. These guys are a normal part of human bacterial flora, but some strains produce a toxin that causes intestinal distress. © Photo Quest Ltd/Science Photo Library/Corbis

E.coli (Escherichia coli) is fecal-borne bacteria, and when you're talking about toilets, you're in the right neighborhood for contamination. E. coli is a bacteria that's normally found in our intestines, and if you're accidentally exposed to it -- usually from contaminated water or food, but it's been known to cling to nonporous surfaces, too -- you could be struck down with diarrhea (sometimes bloody), abdominal cramping and vomiting.

Gastrointestinal viruses such as norovirus (which is the bane of many a cruise ship crew and passenger), also cause stomach distress, and similar to E. coli, they are easily transmitted from person to person. Norovirus has been found contaminating nonporous surfaces, including toilet seats, for as long as two weeks (and that's despite those surfaces having been cleaned) [source: Said et al].

Shigella Bacteria
White blood cells with trapped Shigella bacteria © Dr. Volker Brinkmann/Visuals Unlimited/Corbis

Shigella bacteria passes very easily among people, especially when you forget to wash your hands (or if you're among the 95 percent of people who don't correctly wash their hands). These bacterium causes shigellosis, but you're probably more likely to recognize one of its trademark infections: dysentery. Shigellosis causes infectious, severe diarrhea, abdominal cramping and other gastrointestinal distress that may last for about a week (although some types, such as dysentery, are known to be nasty enough to cause epidemics). And while the bacteria are most infectious during the diarrhea phase of the condition, they remains willing and able to infect you for weeks after their host is feeling better.

Shigella infections, similar to E. coli, happen when an infected person's feces contaminates a surface -- and, yes, those surfaces include toilets, toilet handles and toilet seats. You can also become infected if you consume contaminated food or water handled by an infected person who hasn't practiced good hygiene. Not to scare you, but about 14,000 cases are reported in the U.S. every year [source: CDC].

The best way to keep a toilet and its seat free of shigella bacteria is to clean it with bleach. Otherwise, keep the bacteria at bay by washing your hands, and if you just don't trust that toilet seat, wipe it down with a disinfectant or antibacterial wipe before you sit.

Streptococcus bacteria, pictured here at high magnification, is estimated to be on almost half of all toilet seats. © Tina Carvalho/Visuals Unlimited/Corbis

Streptococcus is a common bacteria that's usually found in your throat, and if you've ever had strep throat or bronchial pneumonia you've had some experience with it. Streptococci can also cause contagious skin infections, including impetigo (a rash that most often affects pre-school kids and babies). It can also cause an invasive, serious skin infection called necrotizing fasciitis (also known as "flesh-eating" bacteria). And here's the worst news: About 39 percent of toilet seats harbor this nasty bug [source: Shoemaker].

So, are we really talking about flesh-eating bacteria lying in wait on a public toilet seat? While it's possible you could contract such an infection from a shared seat, it's highly unlikely. Only about 1 percent of adults carry the strep bacteria on their skin or in their throat, and it's estimated that you're more likely -- at least 50 percent more likely -- to be struck by lightning this year than to develop such an infection [source: Paediactrics & Child Health].

Methicillin-resistant Staphylococcus aureus is persistent -- it can live up to two months on a nonporous surface. © SEBASTIAN KAULITZKI/Science Photo Library/Corbis

Staph (Staphylococcus) likes to hang around, and it can contaminate a nonporous surface for longer than you may expect. Methicillin-resistant Staphylococcus aureus (MRSA), for example, can live on a toilet seat -- and any nonporous part of a toilet -- for more than two months. And it only takes as few as three seconds for it to transmit from a seat to your skin [source: Clinical Infectious Diseases]. However, despite the bad news about its longevity, the truth about staph on toilet seats is this: You're more likely to expose yourself to it by using your cell phone than you are by sitting on toilet seat. More than half of all our phones carry the bacteria [source: Cohen].

Still not convinced that the toilet's safe? Then here's what you need to do: Skip those paper seat covers and carry antiseptic alcohol wipes with you. Wipe the seat before you sit. It's the only effective way to be sure you've killed staph, as well as other bacteria that may cause boils or skin infections.

Influenza (and the Common Cold)
Ah, influenza -- that old chestnut. While it can live on toilet seats, it can also live on almost any other surface you touch. The bathroom needn’t be the scapegoat. © Fuse/Thinkstock

Influenza and other viruses can live for as many as two or three days on nonporous surfaces, including your phone, the remote control and (no surprise) the toilet seat -- and some of these viral strains may live even longer. Bird flu, for example, can live for weeks, just waiting for you to have a seat [source: Wood, et al]. The common cold, on the other hand (or would that be the other cheek?), isn't that much of a threat. You could still catch a cold from the toilet seat, but rhinovirus usually survives less than a day on hard surfaces [source: Winther].

The trick with the cold and flu is not to touch your eyes, nose or mouth after you've touched the toilet seat (or a doorknob, or your office keyboard, etc.). It's easily transmitted through mucous membranes. We shouldn't have to remind you, but always wash your hands after using the bathroom.


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Author's Note: 5 Diseases You Really Can Get From a Toilet

It's undeniably gross when you discover the person who visited the public bathroom before you had, ahem, bad aim, but the seat isn't the filthiest thing about a toilet. Actually, that's probably the flusher. Think about it; how often do you flush with your foot instead of your hand? Right.

Related Articles

More Great Links


  • ABC News. "Myth: Toilet Seats Are the Dirtiest Thing in the Bathroom." October 14, 2005. (May 15, 2014) http://abcnews.go.com/2020/Health/story?id=1213831
  • Borchgrevink, Carl P.; Cha, Jae Min; and Sung Hyun Kim. "Eww! Only 5 percent of us wash hands correctly." Michigan State University School of Hospitality Business. June 10, 2013. (May 15, 2014) http://www.eurekalert.org/pub_releases/2013-06/msu-eo5061013.php
  • Centers for Disease Control and Prevention (CDC) - National Center for Emerging and Zoonotic Infectious Diseases. "Shigellosis: General Information." May 14, 2013. (May 15, 2014) http://www.cdc.gov/nczved/divisions/dfbmd/diseases/shigellosis/
  • Centers for Disease Control and Prevention (CDC) - National Center for Immunization and Respiratory Diseases. "Necrotizing Fasciitis: A Rare Disease, Especially for the Healthy." June 28, 2013. (May 15, 2014) http://www.cdc.gov/features/necrotizingfasciitis/
  • Cocoon. "Determining the Effectiveness of Antimicrobial, Antibacterial, Antifungal Protection in Cocoon Bioshield Membrane." (May 15, 2014) http://www.cocoon.net.au/Cocoon%20Biodefence.pdf
  • Cohen, Hiyaguha. "Dangers In The Bathroom." Baseline of Health Foundation. Oct. 27, 2012. (May 15, 2014) http://jonbarron.org/article/dangers-bathroom#.U3KmFvldVbw
  • Dugdale, David C. "Avian Influenza." The New York Times. Feb. 4, 2013. (May 15, 2014) http://www.nytimes.com/health/guides/disease/avian-influenza/overview.html
  • East Cambridgeshire District Council. "Your Questions Answered: Shigella." (May 15, 2014) http://www.eastcambs.gov.uk/sites/default/files/Shigella.pdf
  • Fox, Maggie. "Swine Flu Deaths Show This Flu Is Difference--Experts." Clinical infectious Diseases. Vol. 49, no. 10. Pages i-ii. Sept. 15, 2009. (May 15, 2014) http://cid.oxfordjournals.org/content/49/10/i.full
  • Giannini, Mary Anne; Nance, Donna; and Jonathan A. McCullers. "Are toilet seats a vector for transmission of methicillin-resistant Staphylococcus aureus?" American Journal of Infection Control. Vol. 37, no. 6. Pages 505-506. August 2009. (May 15, 2014) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2965062/
  • Hygiene Council. (May 15, 2014) http://www.hygienecouncil.org/explore/hygiene-hotspots-home.aspx
  • Litchfield District Council - Health Protection Team. "'Bugs' Information Leaflet On: Dysentery (Shigella)." October 2002. (May 15, 2014). http://www.lichfielddc.gov.uk/download/downloads/id/360/dysentery-bugs0leaflet.pdf
  • Mayo Clinic. "E. coli." July 28, 2011. (May 15, 2014) http://www.mayoclinic.org/diseases-conditions/e-coli/basics/definition/con-20032105
  • Paediatrics & Child Health."Invasive strep infections and 'the flesh-eating disease'." Vol. 4, no. 1. Pages 77-78. Jan-Feb. 1999. (May 15, 2014) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2828232/
  • Perl, Trish M.; and Cynthia L. Sears. "Gastrointestinal Flu: Norovirus in health Care and Long-term Care Facilities." Clinical Infectious Diseases. Vol. 47, no. 9. Pages 1202-1208. 2008. (May 15, 2014) http://cid.oxfordjournals.org/content/47/9/1202.long
  • Pritchard, Charlotte. "Is the toilet seat really the dirtiest place in the home?" BBC News. Nov. 16, 2012. (May 15, 2014) http://www.bbc.com/news/magazine-20324304
  • Roufos, Anna. "Germ and Bacteria Hot-Spots: 12 Things You Should Know." Fitness. January 2006. (May 15, 2014) http://www.fitnessmagazine.com/fitness/printableStory.jsp?storyid=/templatedata/fitness/story/data/1135881081453.xml
  • Shaw, Gina. "Bathroom Germs You Really Can Catch." WebMD. Nov. 16, 2011. (May 15, 2014) http://www.webmd.com/parenting/d2n-stopping-germs-12/bathroom-germs
  • Shoemaker, Dawn. "Who Is Really At Risk In Public Restrooms?" Cleaning & Maintenance Management Online. Oct. 4, 2013 (May 15, 2014) http://www.cmmonline.com/articles/231958-who-is-really-at-risk-in-public-restrooms
  • WebMD. "What Can You Catch in Restrooms?" (May 15, 2014) http://www.webmd.com/balance/features/what-can-you-catch-in-restrooms
  • Winther, B; McCue, K; Ashe, K; Rubino, JR; and JO Hendley. "Environmental contamination with rhinovirus and transfer to fingers of healthy individuals by daily life activity." Journal of Medical Virology. October 2007. Vol. 79, no. 10. Pages 1606-1610. (May 15, 2014) http://www.ncbi.nlm.nih.gov/pubmed/17705174?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=1
  • Wood, Joseph P., et al. "Environmental Persistence of a Highly Pathogenic Avian Influenza (H5N1) Virus." Environmental Science and Technology. Sept. 3, 2010. (May 20, 2014) http://pubs.acs.org/doi/abs/10.1021/es1016153