The missing microbial link

It turns out the oily wind that a subway train brings into a subway station carries its own passengers with it: bacteria DNA.

As passengers step into the car and compete for seats, they do so thickly coated with the DNA of millions of microscopic parasites. 

But do not be alarmed. Recent news stories have reassured us that while DNA for bubonic plague can be found in the nooks and crannies of New York City subways, we should not worry a cross-town ride risks the plague any more than asymptomatic patient Craig Spencer spread Ebola.

We should extend the same logic to hospital infection control.

Every few months there is a new article confirming that doctors, nurses and the things they wear and use are not sterile. NOOO! Stethoscopes, ties and our beloved white coats in particular have drawn ample attention for their unsurprising propensity to - gasp! - have bacteria on them. 

This is useful research, and hypothesis forming. Might doctors and nurses contribute to the epidemic of healthcare-associated infection (HAI) via fomites like these?

Absolutely, they could.

But our reactions to this interesting hypothesis have been far from scientific. We have gone from hypothesis to heartfelt belief in five seconds flat.

One second we know stethoscopes and ties and white coats have bacteria on them and the next we conclude that we should do away with the lot of them. Britain's NHS, for instance, famously adopted a "bare below the elbows" stance in 2008, and US infection control mavens have recommended a similar policy recently.

Where's the science? 

We all want to prevent HAI's, and lord knows the physician fashion index would rise by fully 2.5 points if we left our silly white coats at home (excellent logistical points made by an esteemed surgical blogger aside). But before we invest in nationwide changes to attire and clinical practice, we should convert these reasonable hypotheses into real evidence. 

If going bare below the elbows, or skipping neckties, or burning our white coats, really will protect patients, then we should be able to prove it.

Before we draw conclusions, let's do the damn experiment: compare infection rates in comparable patients cared for by providers who do or do not wear neckties, or who do or do not subscribe to a BBE policy, whatever. Bring on the data!

It's not that easy, you say?

I understand. Science is hard. 

If we can't show the intervention works, why invest in it? It is no great challenge to leave our ties at home, but until we base our recommendations in science the hard work of culture change may not be worth it. Why not just make the change? Well - how well is that argument working so far?

Let's be scientists people, lest we get schooled one day that these stories of stethoscope contamination are as alarming as bubonic plague DNA found in the New York City subway.

Was a study about bias - biased?

Sexism is a major problem in the sciences, technology, engineering and medicine, and the first step to fix this problem is awareness.

Yet a new study suggests awareness is exactly what many men lack.

Moss-Racusin et al write in Psychology of Women Quarterly that among 423 respondents in an online forum about articles on sexism in STEM fields, men were more likely to suggest sexism isn't a problem even when confronted with clear evidence to the contrary.

Let that sink in a little.

Men sure are clueless, aren't they. Let's get out the cattle prods. 

BZZT!

Or... maybe not.

A closer reading of the study reveals the way it was conducted could lead to bias. Not bias in the sense of being sexist, but bias in the statistical sense of the word, i.e. that the authors' conclusions may be invalid.

Here's why.

It turns out the authors collected 831 responses from an online forum regarding articles on sexism in STEM fields. We don't know who responded, and how they might differ from those who didn't. Were non-sexist men less likely to opine, leaving the sexist trolls to put the dark side of their humanity on full display? Probably - but we just can't really know because the information is unavailable. 

That's not all. From out of those 831 responses, the authors analyzed data only from the 423 in which the respondent's sex could be inferred from their response. If the respondent said, "As a man, I am aggrieved that women are scientists but there is no evidence of sexism," then their rabidly sexist and clueless response was included in the study. If a man wrote, "Yay women in science - but they face sexism all the time" without indicating his sex, his more enlightened response was thrown out.

That's right: the authors did not systematically evaluate the major variable of interest - respondent sex - in an unbiased way. As a result their analyses were potentially biased to include people who mention their sex when writing about sexism. If, for instance, male sexists are more likely to mention that they are men, then the study conclusions are completely invalid. 

The authors do cop to some of the study limitations, but not this one. They write, regarding study limitations, that the study approach,

necessitated the usage of a non-random, self- selected sample of commenters. ... Commenters were limited to those who had access to the Internet, were sufficiently interested in bias in STEM to read an article on the topic, read one of our three selected articles, and decided to leave a comment. As such, although our sample may be representative of the focal underlying population of individuals who are interested in such issues, as well as read and comment on such articles, these commenters may not be representative of other groups.

True enough. As a man in STEM, I hope they aren't representative of me! 

But more centrally, can the authors really conclude they know how aware men (or even men online) are of sexism in STEM if they do not even know how many of the original 831 respondents are men? (Not to mention the full group of men who read the articles in question in the first place.) Similarly, how can they conclude that men are more likely to be skeptical of sexism in STEM fields if they cannot compare all men's responses to all women's responses.

Short answer: they can't. 

What is sad is that the authors are able to cite a bevy of other articles that DO suggest some men in STEM fields are sexist, and that some men deny that sexism exists. I don't doubt it: I've seen both, and wouldn't argue otherwise. 

Here's a random sampling of anonymized Twitter commentary about the findings:

Reading this I realize that stepping into this issue could leave me with egg on my face or something stinky on my shoe.

I would guess that the lived experience of these and other commentators - like mine, let me emphasize, wait, here are some emphases: like mine - supports the idea that some men in STEM disregard sexism even when it's staring them in the face.

With such preexisting beliefs - realities! - appear to be confirmed by a study like this one, it's easy to turn off our critical thinking skills and trot it out for the world to see. The risk of course is that the clear problems with study structure, platinum-plated as the authors' intentions surely are, come to light, the ensuing discussion can undermine the true message we were trying to convey. 

We should call out and fight sexism in STEM fields. It is pernicious, archaic and it must go. While fighting that noble fight - which we are winning by the way - we should not undermine the effort by basing conclusions on flawed data.

This blog was cross-posted at KevinMD.

Lessons from the 2014 Ebola epidemic

I was honored to have my thoughts included with those of luminaries like Anthony Fauci of the NIH in The Atlantic's year-end review of lessons learned from the 2014 Ebola epidemic. Click here to read the whole article by Julie Beck.

Why we shouldn't say we have a "cure" for HIV until it's really true

The Berlin patient, Timothy Ray Brown, is historically unique - he is the only person ever truly cured of HIV. 

But in recent years scientific journals and the popular press alike have published multiple claims of HIV cures. From the French "functional cure" to the Mississippi baby, we have seen the word "cure" used a lot -- as well as vague synonyms for it like "cleared" and "HIV-free" -- and yet each time we've had to walk the hype back. 

Check out my new post over at The Conversation on why we shouldn't overhype HIV "cures."

Doctors Should Not Deny Ebola Patients CPR

The first time I did CPR, coagulated blood spurted onto my new white coat from a wound in the patient’s chest. Another time a patient’s urine soaked through the knees of my pants as I knelt at his side.

Even in the best of conditions, cardiopulmonary resuscitation (CPR) is a spit-smeared, bloody business that can expose health care workers to all kinds of body fluids. Like all health care workers, I put on gloves and a game face and accept such things as part of patient care.

The 2014 Ebola outbreak changes all that. It is much more dangerous for clinicians to resuscitate patients with Ebola. As a result, should we skip CPR altogether? Bioethicist Joseph Fins of the Weill Medical College of Cornell University recently suggested we should.

I disagree. See my rebuttal at Health Affairs. What do you think?

Top 10 trends in HIV this year

This year we have seen palpable progress in the fight against AIDS, and also some astonishing hucksterism. In celebration of World AIDS Day 2014, here are 10 of the most influential trends in HIV this year. 

1. The cure, and its pretenders. To date only one person has ever been cured of HIV infection: Timothy Ray Brown, a resident of Berlin who received a CCR5-deleted bone marrow transplant while on potent anti-HIV medications. Recently we heard the word "cure" applied frequently but ultimately falsely to the Mississippi baby and some patients given ordinary bone marrow transplants. Everyone but Timothy has relapsed. Next year let's use the "C" word with caution, and for a great book on the search for a cure, try Cured: How the Berlin Patients Defeated HIV and Forever Changed Medical Science by Nat Holt. 

2. A new model for AIDS. As I summarized in the Scientific American, Warner Greene's lab unleashed simultaneous papers in Science and Nature in late 2013 that upend how we understand the pathogenesis of AIDS. Through a stroke of luck reminiscent of the early identification of AZT - in which a promising new drug was already sitting on the shelf as a result of unrelated cancer research - Greene's group even moved a promising new approach to HIV treatment into clinical trials.

3. Better ART. Speaking of antiretroviral therapy (ART), the three-in-one antiretroviral drug Atripla has long been king of the HIV treatment hill. This changed with the late 2013 publication of the SINGLE trial in which a new combination drug (dolutegravir/abacavir/lamivudine) was safer and more effective than Atripla. This - and other similar studies in new HIV treatment options - has driven yet another shift in HIV treatment as patients have more and more ways of living long lives on good HIV medicine. This is cause for celebration, but we should not forget that most people with HIV can't access these treatments for one reason or another.

4. Do we really need all those CD4's? For years doctors have checked CD4 counts with every clinical visit, and patients have grown accustomed to that regular gauge on how they're doing. Yet as life expectancy on antiretroviral therapy gets longer and clinical visits become less frequent, many HIV docs have realized those faithfully-plotted CD4 counts aren't guiding our decisions for patients with suppressed HIV viral loads and strong immune systems. As a result, new guidelines make CD4 count monitoring "optional" for some patients - and I think it should be optional for more. 

5. Hope for hepatitis C. HIV treatment successes weren't the only reason for hope this year. Drug development for hepatitis C has also progressed dizzyingly quickly. Multiple new effective regimens have been released recently, including some with equivalently near-perfect efficacy in people with HIV. Treatment is still complicated, but when the smoke clears and we work out the considerable financial obstacles to widespread treatment, many expect these potent new drugs to put a huge dent in the hepatitis C epidemic.

6. The high potential and personal politics of PrEP. A key recent boon to the fight against AIDS has been the discovery that HIV drugs can safely protect many high risk people from HIV infection. In a huge boon to HIV prevention, pre-exposure prophylaxis (PrEP) has been proven to protect men who have sex with men, heterosexual men and women, and people who inject drugs from HIV. Recent WHO guidelines suggested "All men who have sex with men should have the opportunity to choose PrEP if they feel that it meets their HIV prevention needs" whereas the CDC guidelines recommended PrEP to groups that hew more closely to populations in whom PrEP showed proven protection. Political commentary has been plentiful, and new clarified WHO guidelines are due out soon, so the PrEP conversation is sure to rage on.

7. A shot in the arm for vaccines. Many HIV vaccine candidates have fizzled out in clinical trials, including the much-lauded Merck adenovirus vaccine which may have increased the risk of HIV infection. Fortunately the 2009 Rv144 trial showed a protective HIV vaccine is possible, and subsequent studies showed that certain antibody levels correlated with HIV protection among vaccine recipients. This has fueled a new phase of HIV vaccine research, with many new candidates now in clinical trials built on what we have learned in the past few years.

8. Stagnant funding. For years the United States has been the major funder of the global HIV response. Yet on the heels of the global financial crisis, and a diversification of PEPFAR funds, HIV funding has stagnated and experts fear there is a growing gap between the global HIV need and our ability to address it. Will we look at this year as the beginning of the end of HIV, or the year we started to turn away from the dream of zero HIV?

9. Progress for children. Children are our most precious resource. We have a long way to go, but everybody welcomed the wonderful news from UNICEF that new HIV infections in children have dropped by 40%. Hallelujah! 

10. A PROMISE for pregnant women. There was good news this year for both children and mothers with HIV. This fall, a pivotal clinical trial called PROMISE was closed early when it showed that full antiretroviral therapy is better for new mothers with HIV. It also surprised many of us by showing a dark horse regimen was best. The ethics of the trial were hotly contested, as I wrote recently in Health Affairs, but ultimately the results of the PROMISE study will help drive global HIV policy in the right direction for years to come.

2014 was a great year for HIV. We saw real progress, we made startling new discoveries, and the HIV community remains as vibrant as ever. Would you have chosen the same top 10 trends in HIV for 2014?

Is a clinical trial of therapy for mothers with HIV unethical?

A global health controversy erupted this summer when the prominent scientific journal Nature ran an article entitled “HIV trial attacked.” Within, commentators squared off over whether a huge ongoing study provides suboptimal and thus unethical treatment options to mothers with HIV in the developing world.

To read more, see my new post at Health Affairs.

How Hospitals Are Getting Safer for American Children

I could tell I was being watched as I walked into the neonatal intensive care unit.

I took off my white coat, folded my stethoscope in a pocket, and hung the coat in a closet. In a nearby sink I washed my hands for a full minute, scrubbing between each finger before drying my hands.

I approached a high-tech isolette and leaned in to examine my patient, the pink baby within.

A voice stopped me: “Doctor!”

There were footsteps behind me. I pulled back and thought, what did I miss? I retraced each step. Coat. Stethoscope. Hands.

The desk clerk pointed a finger. “Your ring, doctor. You forgot to take off your wedding ring.”

She was right. I rolled my eyes, pocketed my ring, washed again, and went back to my little patient.

Small interactions like these make hospitals safer for children by reducing rates of hospital-acquired infections. Now a new article shows exactly how much safer.

To read more, click on my story over at The Atlantic.

Are sugar daddies to blame for HIV in Africa?

Messaging about the prevention of HIV transmission is the ultimate act of cross-cultural communication. In our haste to save lives, it can be easy to make blunders.

Recently, a cross-cultural assumption about African sexual practices that was the focus of prevention messaging has been called into question. That assumption has to do with intergenerational sex, and on closer scrutiny we are reminded about how important it is to be modest in the face of cross-cultural communications.  

Read more in my new post at Scientific American guest blogs.

Is HIV superinfection unhealthy?

People who contract HIV once can contract it again, often through the same risk behaviors that led to the initial infection. A long-standing question has been whether getting infected with a second strain of HIV leads to more rapid HIV disease progression than infection with a single strain.

To this point, a 24-year-old man who has sex with men recently asked me, "Doc, I already rang the bell, why do I care if I get HIV again?"

My answer is at TheBodyPro.