Tag Archives: centers for disease control

Shaving your legs to deter ticks

Colin Purrington Photography: Green steps &emdash; girl-with-shaved-legsPeople shave their legs for a variety of reasons: to look younger (artificial neoteny), to look less like men, to show off tattoos, to show off muscle definition, to improve athletic performance (less drag, plus fools brain into thinking you’re going fast), to facilitate post-accident wound cleaning (cyclists), and because shaved legs induces a pleasurable sensory overload (at least to some). But can shaving also protect you from ticks? I became curious this week after watching a tick crawl up my leg (photograph below). I was really surprised to discover that no experiments on this topic have been done, but did succeed in finding three relevant snippets on the internet (two from mountain bikers, one from cross country runner):

“One thing that helps is shaving your legs. Not a foolproof way but I would say it reduces them critters by 80%, maybe more. I noticed that when my wife and I were out and she had none, I had around 14 that day.” source

“As an experiment I shaved my legs before riding point to point at lbl with KRS and a few others. It was tick season. After 40+ miles of riding I had 1 tick on my sock. Along the way KRS pulled OVER 15 ticks. We rode the same route at the same pace. I’ve kept the hair off ever since.”  source

“I’d say its mostly impractical. Although, I know many trail runners (including myself sometimes in the summer) do it to prevent ticks from attaching.” source

But, hey, maybe the anecdotes are just that, and hairy legs actually deter ticks in some way. 

Colin Purrington Photography: Spiders and ticks &emdash; American dog tick (Dermacentor variabilis)

But it makes sense that shaving would deter ticks. The first is obvious: ticks can grip hair, so if you are hairless (and are wearing shorts, skirt, or kilt), they can’t climb as fast (they are headed for your groin, by the way). The second is that you if you have hairless legs you can most likely better feel them crawling up your legs. I.e., all eight of their legs are touching your skin’s sensory array (or all six of their legs if they are larvae). The third is that when you remove all your leg hair you are removing a lot of sensory distractions caused by wind (experiment on swimmers), and thus you can zero in on things crawling on you. Indeed, all of these mechanisms might touch on why we evolved to be relatively hairless in the first place

So about the experiments that need to be done …

An easy way to assess would be to count numbers of ticks on a group of people out for a walk, some of whom shave. But at least in the United States, that would break down to men versus women, and males smell worse than women and thus might attract more ticks, regardless of hirsuteness. And men are usually larger, so there’s the surface area thing that goes against us, too. So it would be far better to recruit a group of hairy-legged women and ask them to shave just one leg, then march around a field known to have ticks. Participants would tie white bandanas around their upper thighs to arrest the ticks before they got too intimate, then count tick numbers. But finding enough women who don’t shave might make the protocol hard to follow (again, at least in the United States). So perhaps using a group of guys would be more feasible. An ideal group might be a men’s college swim team right before the season begins. Just ask the coach to donate their legs for science. Would be an easy publication for a day’s work, and the experiment would be crazy photogenic. Plus great team-building exercise. Would get the college on the evening news I’m sure. 

A simpler design might be to just have a motivated group of people (perhaps students in a field ecology course?) conduct tick races on shaved, unshaved legs. You just need to start them on the ankles and have participants hold still while the ticks make their ascents. That would be equally photogenic and fun, I think. And to get at the perception part, you could have blindfolded participants that would be asked to identify location of ticks crawling up legs (with controls being placement of non-ticks on ankles, perhaps).

The proposed experiments might seem horrific, but just the for record, I once swam around the edges of a small pond just to see how many leeches would attach to me. I recall that my father challenged me, and that we were going to see who could win. I don’t remember who ended up with more. (Yes, that was a nerd x testosterone interaction effect.)

If somebody does go ahead and conducts this experiment — and if the effect is huge (my guess) — the next step would be to alert the folks at the CDC so they could add a shaving recommendation to their tick page. The reaction to that would be entertaining.

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Evidence-based antibiotic usage

Stop prescribing antibioticsIn my ongoing quest to show that “antibiotic” is a word that does more harm than good to public health outreach, I frequently encounter people on the Internet who insist that confusion over antibiotic efficacy is not due, at all, to the word itself.  I value these people’s insight, of course, because their views certainly might be true for the planet they live on. There are probably a lot of habitable planets in the Universe (40 billion just in our galaxy!), and I don’t presume to know what reality is like for those places.

On Earth, however, the belief that antibiotics treat viruses is rampant, generates over-prescription, and is clearly related to the word itself. Here are Exhibit A (from answers.com) and Exhibit B (from Google definitions):

What does antibiotic mean?What is a germ?  Definition from Google.People believe that antibiotics treat viruses because on Earth we regularly use a word’s roots to infer meaning. So for the average person who doesn’t remember any biology from middle school, parsing the meaning of antiviral, antibacterial, antifungal, etc. is easy … as long as he/she knows what anti-, viral, bacterial, and fungal mean.  But that same trick doesn’t work for antibiotic.  And because people don’t realize their inference is incorrect, the misconception becomes forever entrenched in public opinion, and on the internet.  The CDC (and others) waste millions of dollars each year trying to quash the misconception, but such efforts will always fail because the strength of the “antibiotics” misnomer is always truthier to the average Joe than a bunch of patronizing posters on a doctor’s waiting room wall.

[As an aside, misnomers are words (you can probably guess, based on the roots … if you live on Earth) that deliver an incorrect meaning.  “Pencil lead” (two words, of course) is a great example, and there are thousands of parents each year who call their doctors in a panic after Jimmy gets stabbed during math class with a pencil. Or they search the internet for “pencil lead poisoning“.  Luckily, pencil lead is graphite (always has been), a harmless crystal of carbon that is not going to cause Jimmy to be developmentally delayed.]

So how bad a misnomer is “antibiotics”?   How should physicians decide whether to use “antibiotics” or “antibacterials” when discussing treatment of illnesses?  Like any medical question, the decision should be evidence-based.  Here is how to get the evidence (Pew Research Center folks, this means you):

Antibiotic versus antibacterial poll dataResponses for questions #1 and #2 show that approximately 10% and 36% (pdf) of adults are confused about the correct answers, respectively.  That’s a HUGE fraction given the daily importance of bacteria and viruses in our lives and in the news.  Unfortunately, there are no poll data for #3 and #4.  But my guess is that the fraction of incorrect responses for #3 and #4 will be 1% and 5%, respectively.  “Antibacterials” clearly suggests the drug kills bacteria — only people unfamiliar with English might be clueless.  And I’m guessing that 5% of the public think viruses are bacteria (I’ve asked dozens of virologists … and none knew of poll data on classification ignorance).  No matter what the actual numbers, the level of confusion for “antibacterials” is going to be dramatically less than that caused by “antibiotics.”

So if you are a doctor hoping to improve patient understanding and patient care, using “antibacterials” is a no-brainer.  And if you are worried that “antibacterial” is a rare word, stop worrying: it’s from the 1890s (that’s old!) and is found 13,200,000 times on the internet (that’s less than the 23.8 million for “antibiotic”, but still totally respectable).  Don’t wait for the CDC, WHO, AMA, ACP, APA, etc. to recommend the change, because chances are they won’t — they love the word, “antibiotic” (I’ve emailed them all, trust me).  So just tell your colleagues and staff on the floor to get on board.  And then let me know how it goes.

Below are my other posts on the topic, if you need further convincing.  All posts have graphics that you are encouraged to use for your talks on the topic (this week is Antibiotic Awareness Week, after all). Please consider sharing these links with others on Twitter and Facebook if you are on board with my suggestion, and if you can forward to impressionable medical students, you get bonus points.

  1. Curbing the misuse of antibiotics
  2. Antibiotics are antiviral
  3. How doctors can reduce antibiotic demands from patients
  4. Antibiotic Awareness Week poster
  5. Antibiotics work against viruses
  6. How to improve Antibiotic Awareness Week
  7. Seasonal plea for informed antibiotic usage
  8. Antibacterial soap
  9. The Walking Dead need antivirals, not antibacterials (Shopping list for anti-infectives)
  10. Venn guide to pills that kill things

[If you’re curious why I am so interested in this issue, it’s because I witnessed, first-hand, confusion over “antibiotics” when I lectured on antibacterial resistance in my evolution courses at Swarthmore College.  My students were (largely) bright, and were often bound for medical school … yet they frequently made the same incorrect assumptions about efficacy that totally uneducated people make.  Misuse of “antibiotics” became one of my pet peeves.  Because I have a blog, I thought it would be worth a try to effect some change.]

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Antibiotic Awareness Week poster

Ten interesting facts about antibiotics, for Antibiotic Awareness Week (Nov 18 -24, 2013).  Below is an image that can be used for presentations. PDF version for printing: facts-about-antibiotics.pdf.

Antibiotic Awareness Week poster

I’ve tried to craft the above poster with information that is mildly interesting, with the hope that people (people like you?) might pass the link along. There are 100s of posters on the internet … but they seem to be completely ineffective at educating the public (according to an experiment). In my view, the problem is that all of these posters use “antibiotics” instead of the correct term, “antibacterial.” Please see my page, “Curbing the misuse of antibiotics” for details on why antibiotic/antibacterial choice matters for the public, even if it doesn’t matter to you (who probably have a higher degree).

Below are some links that explore some of statements in the PDF above. I’m putting them below the fold because they are probably TMI for 99% of the people who might be interested in the above PDF. If you are that 1%, go crazy.

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Antibacterial soap

Ever wonder why soap companies label their products “antibacterial” instead of “antibiotic”?  OK, probably not.  But this is not just trivia, folks — the explanation can help us address the rather pressing problem of drug-resistant strains of bacteria. So if this post is too boring now, at least consider returning when you are dying in a hospital bed from an untreatable bacterial infection.  It will seem more important then.

colin purrington photography: Blog photos &emdash; antibacterial-soap

So the answer is that I think soap manufacturers have figured out that using “antibacterial” is much clearer than using “antibiotic” — consumers have zero expectation that antibacterial soaps kill fungi, viruses, or protozoans.  That’s because to most people antibiotics have a broad range of action (Google definition; Wikipedia entry).  So soap companies avoid this confusion by specifying “antibacterial,” and their usage has clearly caught on.  As proof, please see the graph below to see how people search for information about such soaps online.  The blue line, which shows the number of people searching Google for “antibacterial soap” is vastly higher than the red line, which shows “antibiotic soap” searches.

Antibiotic soaps on Google Trends

I make the above points not to highlight how great soap companies are, but rather to show pharmaceutical companies, physicians, and health organizations that if they’d adopt “antibacterial” as way to describe antibacterial drugs, the public would fall in line. Currently all these groups love using the word “antibiotic,” and when I’ve suggested to them that they should switch, they respond politely, “You have wasted our valuable time with this crackpot suggestion” (I’m paraphrasing).  They firmly believe the word “antibiotic” is not causing the public confusion.  I think they haven’t really thought about how misnomers work on the brain — they truly do influence people’s perceptions. I also believe that they haven’t searched Google for the definition of “antibiotic”, and that they haven’t looked at the Wikipedia entry (links above).  I fully admit that word “antibiotic” doesn’t confuse microbiologists or physicians, but those people make up a rather small proportion of the world’s population.  The remaining people are justifiably confused about the specificity of “antibiotics,” and that’s why they tend to demand antibacterials from their doctors for viral infections. For example, many people use Google to research specificity of antibiotics; they never search for specificity of antibacterial (see graph in a new window). Getting rid of “antibiotics” should be a no-brainer for anyone concerned with the over-prescription of antibacterials.

So I’m looking for just one medical association, one non-profit, or one pharmaceutical company brave enough to abandon “antibiotic”.  It would be good press, and it would help fight the evolution of drug-resistant bacteria.

Please see, “Curbing the misuse of antibiotics” for further information if you are concerned with evolution of antibacterial-resistant strains of bacteria. My theme, again, is that simply deleting “antibiotic” is an insanely easy thing we could all do.

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How to improve Antibiotic Awareness Week

In case you didn’t get the memo, the CDC’s Get Smart About Antibiotics Week (GSAAW) will be Nov 18th – 24th.  I know this is hugely unexciting to most of you, so you can stop reading now and I won’t be hurt. For others, thanks for visiting.

Get Smart About Antibiotics WeekPerhaps the most important goal of the GSAAW is to reduce the percentage of people who think antibiotics can treat viral infections.  In some surveys, more than half believe that’s the case, and those people are likely to demand antibacterials for their viral illnesses (that’s bad).  So the CDC produces websites, fact sheets, public service announcements, and even sends staffers into the wild to give talks.  Watch this TV spot (YouTube, in a new window) to get a quick taste of the effort.  The initiative spans more than just one week, and no doubt costs tens of millions of dollars each year. And we still have a HUGE problem with public misunderstanding about antibiotics, and a HUGE problem with the evolution of resistant strains.

I have a cheap suggestion for the CDC: replace “antibiotic” with “antibacterial” in all the relevant websites, PDFs, PSAs, and slideshows. Purging “antibiotic” gets rid of a word that actively misinforms patients because it sounds like it’s a wonder drug, capable of killing bacteria AND all other microorganisms, too (viruses, fungi, protozoans, etc). If you Google the definition (like a sick individual might do), you get this view confirmed:

Definition of antibiotic“Antibacterial,” on the other hand, is the perfect word to describe drugs that kill bacteria. And it’s been around with that same definition since 1890 (ish):

Definition of antibacterialIndeed, it’s probably because people know of the word “antibacterial” that makes them assume antibiotic means something else. After all, there is also a word for drugs that kill viruses (antivirals). I’ve tried to be persuasive above, but I realize that most people have an almost innate protectiveness about the word, “antibiotics.”  Most people view the word as vastly better than “antibacterial” and assume that the true problem is just about educating the public about what antibiotics cannot do.  They cling to “antibiotic” even though switching to “antibacterial” is the easiest way to make the public understand.  Ultimately, nobody wants to be the first to make the switch.  So we just need one (1) organization to take the plunge, to show others that the goal of reducing antibacterial abuse trumps people’s fondness for the useless misnomer that is antibiotics.

So if you have influence at the CDC, please ask them to at least explore this word swap. It really would be one of the cheapest improvements they could ever dream up.  Over the years I’ve tried to get them on board with this idea, but the brochures never seem to change.  For example, their 6 Fact Sheets have 192 instances of “antibiotics” (that’s 32 instances per page!), but zero instances of “antibacterial.”  In case there are individuals at the CDC who might actually like to try this swap, they could use some vocal support from people other than me. Especially if you’re important.  So if you can, please send emails to getsmart@cdc.gov.  And if by chance Dr Tom Frieden (CDC Director) follows your tweets, he’s @DrFriedenCDC.

In related news, please also see “Curbing the misuse of antibiotics“.

And have a great Antibiotic Awareness Week!

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