There is widespread agreement that one should wash its hands after going to the washroom. However, a large fraction of the population does not wash their hands. These types of signs became fairly common

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I understand that lots of pathogens transmit through hands, whether it is through hand shacking or door knobs. However, it is unclear to me whether our hands carry significantly more pathogens after going to the washroom than before that.

Is the advice Wash you hands after going to the washroom useful because...

  • our hands are filthier after going to the washroom?
  • it is just a good way for someone to not forget to wash its hands 5-8 times a day?
  • 1
    I hope this gets some attention because it's actually an excellent question.
    – Carey Gregory
    Sep 3, 2016 at 1:21

1 Answer 1


Hands play a major role especially in the transmission of blood-borne, fecal, and respiratory tract viruses.

Hand washing after use of bathroom aims at preventing the transmission of pathogens, which rely on faecal-oral transmission, such as rotavirus, noroviruses, enteroviruses in some cases hepatitis A virus (1). It prevents those pathogens from reaching the kitchen for example where it could lead to subsequent ingestion.

Recently a systematic review (2) identified a total of 2881 unique publications addressing this question.

Interestingly, this study found a varying prevalence of hand-washing after contact with extcreta:

We estimate that 19% of people worldwide wash their hands with soap after contact with excreta. The regional mean prevalence of handwashing with soap ranges between 13% and 17% in low- and middle-income regions, and between 42% and 49% in high-income regions

However, the authors reported a 40% reduction in the risk of diarrhoea from the promotion of handwashing with soap (RR 0.60, 95% CI 0.53–0.68) suggesting that hand-washing impact on faecal oral transmission and reduces risk of diarrhoea.


  1. Kampf G, Kramer A. Epidemiologic Background of Hand Hygiene and Evaluation of the Most Important Agents for Scrubs and Rubs. Clinical Microbiology Reviews. 2004;17(4):863-893.

  2. Freeman et al. Systematic review: Hygiene and health: systematic review of handwashing practices worldwide and update of health effects. Tropical Medicine and international health. Volume 19, Issue 8. August 2014. Pages 906–916

  • What happens when someone goes to the bathroom and doesn't touch excreta or perhaps even any waste product? I'm reminded of the old joke about the biologist who, at university, learned to follow standard hygienic practices, the chemist who learned to be thorough (washes his hands for 20 minutes before and 20 minutes after using the bathroom), and the engineer who learned not to pee all over his hands (and therefore sees no added value in hand washing). For example, do pathogens lie in wait on toilet seats and then proactively leap 2 or 3 meters onto the hands of people passing by? Sep 25, 2017 at 21:02

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