There’s a Seinfeld episode in which Jerry sees the owner of a restaurant leave the restroom without washing his hands – return to the kitchen and then proceed to make Jerry’s pizza, with a horrified Jerry watching from his seat. It’s classic Seinfeld – and as it turns out, classic male behavior.

Researchers at the London School of Hygiene & Tropical Medicine recently discovered that women are twice as likely as men to wash their hands with soap and water after using the toilet. To get this information, the scientists attached sensor devices to soap dispensers placed in public bathrooms. The post-toilet washing habits of 250,000 men and women then got recorded. While 64 percent of the women did use soap, only 32 percent of the men bothered.

Translated, this means that two out of three men have potty hands, which are far more likely to spread disease. But women still aren’t a sure bet for handshaking (or pizza making), given that one out of three foregoes cleansing. Study director Dr. Val Curtis said, “We are really puzzled about this and can’t really explain it.” Yet, she says, “Some of the men that were included in the study were only urinating. That’s probably why they think they don’t need to wash their hands even if they should.”

To test what might inspire bathroom-goers to use soap and water, the researchers posted flashing signs in bathrooms. The signs worked for men only when the message had dramatic flair. Whereas women responded to signs saying things like “Water doesn’t kill germs, soap does,” men needed to be hit over the head with “manly messages” like, “Soap it off or eat it later.”

Dr. Curtis says that invoking disgust worked particularly well in encouraging recalcitrant men to improve their hygiene habits, although men, it appears, don’t get disgusted easily. But the most effective tactic for both men and women was shaming them. When flashing signs saying, “Is the person next to you washing with soap?” were placed above the sinks, 11 percent more women washed and 12 percent more men. “If they think other people are watching them, then they are more likely to wash hands,” Curtis said. Study co-director, Dr. Judah Gaby added, “It was interesting to see that, for men, the more people there were in the toilet, the more likely they were to wash their hands with soap.”

In a separate study of about 3000 men and 3000 women back in 2007, men and women were interviewed about their bathroom habits by telephone and then observed. While 89 percent of the men claimed to wash their hands every time they used a public bathroom in the interviews, only 66 percent actually did so. The women also showed a discrepancy, with 96 percent claiming on the phone that they always washed, but only 88 percent actually doing so. Since these results make it appear that far more people wash after using the toilet than the current study by Dr. Curtis reveals, we can conclude that either:

1. Men wash their hands more regularly than Dr. Curtis’ study found, but they lie like Pinocchio, while women do wash more than men, plus they lie less.
2. Men wash only with water (the 2007 study didn’t differentiate types of washing, whereas in the 2009 study, washing with soap was necessary).
3. People washed more frequently back in 2007.

In fact, research does indicate that hand-washing has declined, in spite of all the public awareness campaigns. And that’s in spite of the fact that, according to the study’s authors, washing hands with soap is the single most cost-effective intervention for the worldwide control of disease.

“It could save more than a million lives a year from diarrheal diseases, and prevent respiratory infections — the biggest causes of child mortality in developing countries,” they wrote. According to Unicef, washing with soap and water could reduce the spread of diarrheal diseases by over 40% and respiratory infections by 30%.

Before you get all steamed up about your neighbors having sloppy hand hygiene, consider that hygiene among healthcare workers apparently isn’t any better than among men and women in the general public. In fact, experts contend that the two million cases of hospital-related infections contracted each year and the 90,000 resulting deaths could be drastically reduced or eliminated if only nurses, doctors, and other health professionals made friends with soap and water.

The situation in hospitals is so drastic, in fact, that a company called HyGreen has developed a sensor that discerns if healthcare workers have dirty hands. The workers all must wear badges that light up only after proper hand-washing. The CTO of HyGreen, Richard Melker, says, “If you look at the hospitals in the United States and all the health care workers, hand hygiene adherence in the best of the hospitals is around 50 percent.” When you think about it, that’s less than the public in general!!

Which goes to show that knowing better doesn’t guarantee acting smart. Considering that so much attention has been given to the possible terror of a swine flu pandemic in the media, one would think that all of us would wash up after using the loo. Do we really need to wear HyGreen badges of shame like Hester Prynne in the Scarlet Letter before we take the time to use soap and water?

:hc