Friend of barfblog, and frequent contributor (and modeler extraordinaire), Don Schaffner writes,
I’m always interested in the way microbiology is perceived in the popular culture. When peer reviewed research articles get wide pick up, I’m especially interested. This happened recently with an article on kitchen sponges. Rob Mancini has already blogged about this right here on barfblog, but I’d like to share my thoughts and perspectives.
The fact the kitchen sponges can be massively contaminated by high levels of microorganisms is not news. This has been shown repeatedly in the peer reviewed literature.
What was apparently new in this latest article was the application of “454–pyrosequencing of 16S rRNA genes and fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH–CLSM)”. And I get it. Molecular-based methods are all the rage, and the ability to visualize the presence of microorganisms is very important.
But we shouldn’t lose sight of the fact that experimental design, and proper experimental controls are important no matter what sort of science you’re doing. When I dug a little deeper into the above article I was shocked to learn that all of their conclusions were based on a sample of 14 sponges. That’s right, 14 sponges. Furthermore, the authors make claims that “sponge sanitation methods appear not sufficient to efectively reduce the bacterial load in kitchen sponges”. How did they know this? Well when they were collecting those 14 sponges they asked the sponge owners “to specify whether they regularly apply special measures to clean their sponge. The procedures mentioned were: heating in a microwave and rinsing with hot, soapy water”. Of the 14 sponges collected, in five cases the sponge owners reported applying special measures, although the authors do not which of the five used microwaving and which used rinsing with hot, soapy water.
What’s my take away message from this? By all means, go out there and use the hot new technology. But please don’t forget that sample size is very important, and while surveying people for their opinion about what they do might be convenient, it’s no substitute for actually investigating. And if I had to predict the effect of washing sponges with hot soapy water? Probably no different than washing in cold soapy water.
And if anybody out there has access to “454–pyrosequencing of 16S rRNA genes and fluorescence in situ hybridization coupled with confocal laser scanning microscopy (FISH–CLSM)“ and wants to collaborate, I am available.
The show begins with a discussion of Ben’s recent travels. From there the discussion moves on to obligatory talk about beverages, Canadian and Philadelphia accents, Apple, and other podcasts. The food safety talk begins in earnest with the discussion about what is meant by the words ‘risk assessment’. From there the discussion turns to ‘food safety programs’, restaurant inspections and what customers might want to know, the humor of David Lloyd, and then back to meat safety and proper thermometer use. The show ends with The Onions humorous take on handwashing water temperature. The After Dark contains the usual nonsense including talk about music videos.
I didn’t know Don Schaffner, food safety guru and pop sensation at Rutgers University, was a Brittney Spears fan.
But he writes, whoops, I did it again, putting publication of peer-reviewed research ahead of press release.
We had an article published in the Journal Food of Protection earlier this week. While this current research is no five second rule, I thought it might garner some press interest, so I worked with colleagues at my university to put together a press release. I do enjoy talking to the media as part of my job, and it’s especially fun when it’s my own research.
(That’s why I became a professor, because I was bored talking about other people’s research and wanted to talk about my own — dp)
I thought I would take a little bit of time and share with barfblog.com readers about the process, because you folks are into this too.
An early draft of the press release had the title “Cool Water as Effective as Hot for Killing Germs”. This led to a conversation with my colleague in media relations who explained that using the word “killing” in the headline would lead to many more hits on Google (the modern-day equivalent of “if it bleeds, it leads”). I had to explain, that while I know all about search engine optimization (SEO), I could not in good conscience tell a scientific fib. Handwashing, for the most part does not kill germs, it simply removes them from your hands, and allows them to be washed down the drain.
Which brings me to antibacterial soaps – which seem to kill germs. This particular research article did look at the question of antibacterial soaps, and basically led to the same conclusion as our other on the issue: antibacterial soaps do work better than plain soaps when it comes to reducing bacterial counts on the hands, probably because there is some actual bacterial killing going on. For a variety of reasons, antibacterial soaps tend to work people up into a lather (pun intended… who says scientists have to be serious?). I had one journalist tell me [no link for you, sleazy British Tabloid] that they had already come to the conclusion that antibacterial soaps don’t work, and could I just say that. No, I explained I could not just say that, because that’s not what our research found. Instead, we found a highly significant difference (p= 0.0003) between hand washes with an antibacterial soap, and with a similarly formulated plain soap. In this particular study the difference was small, about 0.3 log. I know many readers of this blog are comfortable and thinking on the log scale, but for you non-microbiologists, 0.3 log corresponds to about a 50% greater reduction. Now 50% sounds like a lot to a non-microbiologist, but when you’re doing food microbiology, sometimes the data themselves can vary by 0.5 logs, or almost 70%. So what we ended up saying in the manuscript was, while highly significant, the difference was “within the range of error for microbiological data (i.e., a clinically insignificant difference).” I wish I’d said that a bit more forcefully in the manuscript, but sometimes we have to make compromises in peer review. The bottom line? I believe that antibacterial soap works better than plain soap in reducing bacteria on your hands. We reach this conclusion in our meta-analysis on the subject, and even this relatively small difference can have a profound effect on public health, at least if you believe our risk assessment manuscript on the subject.
I wanted to stress in the press release, and what I’ve been leading with during my media interviews, is that wash water temperature makes no difference, at least in the range that we studied (~ 60°F to 100°F). Our data show that there was no significant difference, no matter what temperature was used in the hand wash. Water temperature has along an interesting history in the FDA model food code. It used to be that the code specified a specific water temperature for washing the hands. It turns out that that temperature was based on the temperature at which bacon grease liquefies. The current code says that hands must be washed in warm water. Elsewhere in the current code it specifies that a hand wash sink must be capable of dispensing water at 100°F, hence our reason for doing the research. One point that I’ve been stressing in the media interviews is that it’s all about comfort. We want people to be comfortable when their washing their hands, and so my advice is use whatever water is most comfortable for you. It remains to be seen whether we will be able to change what’s in the code. Check back in 2018 after the next Conference for Food Protection
We looked at several other factors in this research as well. We investigated the volume of soap used: 0.5 mL, one mL and two mL, and we found no difference between these volumes of soap. Of course this doesn’t mean you can use as little soap as you want, my recommendation is to use at least 0.5 mL. Using more than this doesn’t seem to make a difference. This is also consistent with what we found in our [meta-analysis](https://www.ncbi.nlm.nih.gov/pubmed/22054188).
In a recent paper published in Food Protection Trends, my PhD student Dane Jensen (who was also the lead author on this handwashing study), and I published an analysis of recommendations on handwashing signs. Dane had a hand (pun intended, see above) in several of the handwashing research manuscripts coming out of my lab in recent years. What we found in the FPT handwashing signage research was that handwashing recommendations were all over the place. So we decided to study lather time in this current manuscript. For purposes of our research we defined lather time as the time from when the soap is applied, until the water rinse begins. We studied five, 10, 20, and 40 second lather times. We only saw a statistically significant difference between lather times of five and 20 seconds. The recommendation I would draw from this finding, is to lather for at least 10 seconds. Lathering for more than 10 seconds does not appear to offer any additional benefit.
One of the questions that seems to come up again and again in media interviews on this topic is “who funded the research”. While I understand the motivation for the question, it’s starting to get under my skin (okay okay, I’ll stop with the puns). The question seems to imply that somehow if I take money from the industry, my results are not to be trusted. I strongly resent the implication. It’s damn difficult to get grants these days, and I don’t think it’s going to get any easier until something changes in Washington. We funded this research using discretionary money, but I’m proud that we did it in collaboration with our co-authors from GOJO. They were instrumental in helping us think about our experimental design, plus they gave us free soap. They are also really smart and hard-working scientists, who really sweat the details.
Is this the last word on handwashing? I doubt it. We’ve got at least one more paper from Dane’s dissertation in the pipeline, and I’ve still got more ideas. If anyone reading this believes that industry funded research is somehow tainted, and you’ve got $250,000, please get in touch.
That’s the background and shows just how much good scientists sweat the details, whereas any hack can make a claim, spread it on the Internet, supported by no data, just interpretation.
I’ve got a modest 70 peer-reviewed papers, book chapters and a book, but when I had a big lab with the money flowing, I got bored. That’s just me.
Surprisingly I still get cited in peer-reviewed journals a few times a week, so I know I’ve got a body of work that people go to.
Thee scandals of pay-for-publication journals are a smear on the scientific community, but until someone comes up with a better system, peer-review largely works.
I’ve kept my mouth shut for years while papers got written, reviewed and published.
No PR before publication.
Those who do are attention-seeking assholes and another smear on the profession.
Washing our hands can keep us from spreading germs and getting sick. But a new Rutgers-New Brunswick study found that cool water removes the same amount of harmful bacteria as hot.
“People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us that the temperature of the water used didn’t matter,” said Donald Schaffner, distinguished professor and extension specialist in food science.
In the Rutgers study, published in the June issue of the Journal of Food Protection, high levels of a harmless bacteria were put on the hands of 21 participants multiple times over a six-month period before they were asked to wash their hands in 60-degree, 79-degree or 100-degree water temperatures using 0.5 ml, 1 ml or 2 ml volumes of soap.
“This study may have significant implications towards water energy, since using cold water saves more energy than warm or hot water,” said Schaffner. “Also we learned even washing for 10 seconds significantly removed bacteria from the hands.”
While the study indicates that there is no difference between the amount of soap used, more work needs to be done to understand exactly how much and what type of soap is needed to remove harmful microbes from hands, said co-author Jim Arbogast, vice president of Hygiene Sciences and Public Health Advancements for GOJO. “This is important because the biggest public health need is to increase handwashing or hand sanitizing by foodservice workers and the public before eating, preparing food and after using the restroom,” Arbogast said.
These findings are significant, particularly to the restaurant and food industry, because the U.S. Food and Drug Administration issues guidelines, every four years, to states. Those guidelines currently recommend that plumbing systems at food establishments and restaurants deliver water at 100 degrees Fahrenheit for handwashing.
Schaffner said the issue of water temperature has been debated for a number of years without enough science to back-up any recommendation to change the policy guidelines or provide proof that water temperature makes a difference in hand hygiene. Many states, in fact, interpret the FDA guidelines as a requirement that water temperature for handwashing must be 100 degrees, he said.
The FDA is scheduled to hold a conference in 2018 to discuss the existing code and any modifications that should be made and Schaffner would like to see the water temperature policy revised at that time.
“I think this study indicates that there should be a policy change,” said Schaffner. “Instead of having a temperature requirement, the policy should only say that comfortable or warm water needs to be delivered. We are wasting energy to heat water to a level that is not necessary.”
Don and Ben talked big concerts, Flaming Lips (the band, not the anatomy) obscure Canadian bands covering Neil Young and then got into some food safety stuff like the particulars of deer antler tea, with some deer penis sprinkled in. The discussion went to the rules around home-based food businesses and how risk-based decisions are made in regulatory choices. The episode finished with some listener feedback on washing produce and mold and whether food employees at Blue Apron (and like mail-order businesses) should have local health department food handler training.
In this episode, Don and Ben talk about life hacks and things that might not be life hacks; Gwyneth Paltrow, cookbooks and Ben’s recent media experiences (and the perils of emailing while sitting on the toilet). Also in this episode the guys breakdown STEC in soy nut butter and Dixie Dew’s FDA 483 form plus a bonus on ROP cheeses.
This episode opens with an interesting discovery about the messages app then quickly veers into popular culture, and almost as quickly back to food safety. Food safety talk on rice and Bacillus cereus is followed by a discussion of the Salmonella in truffle oil outbreak at Fig & Olive restaurants. The discussion then turns to recalls and when to go public. A recent Listeria recall linked to cheese made from pasteurized milk leads to talk about raw milk, followed by a brief segue into North Carolina life, and then on to a recent Lysol ad, and the five second rule. The show wraps up with a discussion of recipe safety, followed by what Ben thinks might be the best after dark ever.
Don and Ben talk I.M. Healthy’s soy nut butter-linked E. coli O157 outbreak; social responsibility and food safety; and produce washing. The guys also discuss the particulars of goalie screening and Salmonella sticking around in the environment for months. Bonus: urinals.
Continuing the purple themed image run, Don and Ben talk lifehacks, what to call fizzy beverages, other junk food, good TV, junk science, challenges that small food processors encounter and food fraud (with a bonus of press release before publication).
This episode has you covered from the top of your head to the tips of your lucky socks. Ben and Don dig into some 1980’s culture and shoot forward into the food on the future, and then back again. It’s a food (and pet) safety grab bag covering pineapple safety, hand sizes and hand sanitizers, safe raw cookie dough, rats, turtles, milk from camels, microgreens and toilet history.
Some Rutgers University students had a nasty gastrointestinal illness last week that is likely norovirus, according to the Daily Targum. Don and I talked about this outbreak on the podcast today. Rutgers has a few things working for them: the semester is over (leaving lots of time to clean and sanitize; and less places for the virus to be transmitted), and Schaffner is there providing some technical advice.
At least 35 students are complaining of feeling sick after a suspected virus broke out on campus around Dec. 7.
Many of these students, who claim to have eaten in the Livingston and Brower Dining Halls, believe they are suffering from food poisoning. But University Sanitarian John Nason said he does not think this is a food-borne illness.
“The virus is people-to-people. We don’t believe it’s food-borne,” he said. “Most people are getting sick 90 minutes to two hours after eating, which doesn’t make sense. Most people who get sick after eating think it’s food poisoning.”
He said the onset time of 90 minutes to two hours does not equivocate to a food-borne virus, considering viruses such as E. coli and salmonella have an onset time of about six to 48 hours.
Managing a norovirus outbreak is a bit tricky, here are a couple of infosheets we’ve used/developed over the years that might be of use.