The accompanying editorial by Brad Spellberg is also well worth reading, and locates the cloud in this silver lining: even after the intervention, over one-third of the patients were receiving broad spectrum gram negative active agents and almost half were still receiving broad spectrum anaerobic coverage. And yes, the investigators did exclude those patients who had complicating features (e.g. diabetes, recurrence, fasciitis, etc.) that may have justified such broad spectrum therapy. So even though the intervention was a partial success, challenges to optimizing therapy for SSTI remain.
Monday, February 28, 2011
Saturday, February 26, 2011
Friday, February 25, 2011
Thursday, February 24, 2011
Here's another video of him addressing a non-medical audience on evidence-based medicine. If only I could be this entertaining when I lecture!
Ben Goldacre Talks Bad Science from PopTech on Vimeo.
Wednesday, February 23, 2011
And the joys of caring will not be replaced
What has been must never end
And with the strength we have won't be erased
When the truths of love are planted firm, they won't be hard to find
And the words of love I speak to you will echo in my mind
I believe when I fall in love with you
It will be forever
I believe when I fall in love this time
It will be forever
A group from the Georgia Institute of Technology recently developed a gadget they claim can separate lower respiratory from upper respiratory aerosols. The report can be found here, in the Journal of Medical Devices.
Tuesday, February 22, 2011
For the subset of subjects for whom an organism was isolated from the initial wound culture and susceptibility data were known (183), 2% (2 of 111) of those who received an antibiotic with in vitro activity against the isolate versus 10% (7 of 72) of those who received an inactive antibiotic had worsened by the 48-to-72– hour visit (P=0.02).
|Source: Doonesbury by Gary Trudeau|
"[T]here are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know."
Sunday, February 20, 2011
Saturday, February 19, 2011
Investigators at Denver Health performed a randomized, controlled trial to assess the degree of bacterial colonization and contamination by MRSA on work clothes. The participants were 100 physicians (residents and attendings) on the internal medicine service who were randomized to wear either their personal white coat (subjects were not given prior notification to avoid laundering for the purpose of the study) or a freshly laundered short-sleeved uniform. After eight hours at work, the coats and uniforms were cultured at designated sites using RODAC plates.
The main findings of the study were:
- No difference in overall bacterial counts between the white coats and the uniforms
- No difference in MRSA contamination (16% for white coats vs. 20% for uniforms, p=0.6)
- What is the prevalence of MRSA infection and colonization among internal medicine service patients at this hospital?
- Does the hospital have a MRSA active detection and isolation program for MRSA?
- Are patients with MRSA placed in contact precautions? If so, what is the compliance with contact precautions?
- Are the white coats hospital issued (thereby implying a uniform fabric) or purchased by physicians (implying various types of fabric) and of what type of fabric were the uniforms constructed? Previous studies have shown that duration of contamination by important pathogens can vary with the type of fabric.
Friday, February 18, 2011
Monday, February 14, 2011
Now, the Rhode Island group has examined the impact of CHG bathing on general wards as well. Using a quasi-experimental study design, the investigators performed daily soap and water bathing of all patients on four general medical wards for one year, and then used daily CHG bathing for the next year (13 months, actually). The composite rate of MRSA and VRE healthcare associated infections (HAIs) was reduced by 64% during the intervention period. Interestingly, nearly the entire difference in infection rates was accounted for by UTIs (10 in the pre- vs. 2 in the post-intervention period). Nosocomial bloodstream infection rates were exactly the same pre and post (5 MRSA and 1 VRE BSI during each time period). Clostridium difficile incidence was unchanged over the time course of the study, serving as a nonequivalent dependent variable (to assess for confounders that might be associated with a general decline in HAI rates).
Given the quasi-experimental design, small size (few HAI events), lack of a concurrent control group, etc., these data require confirmation from a larger controlled trial. I also think the study would be more persuasive if the effect was seen across all body sites, rather than UTI alone. Enough of this unromantic nitpicking—go out and buy your valentine a big bottle of CHG!
Wednesday, February 9, 2011
Finally, the WHO has announced a confirmed H5N1 related death in a 5-year old Cambodian girl. This is the first reported mortality due to avain flu since early 2010. The girl had been exposed to sick poultry during the 7-days prior to disease onset. The influenza clock keeps ticking.
Monday, February 7, 2011
|Influenza virus, A/Hong Kong/1/68|
The Guardian reports of an influenza vaccine breakthrough out of Oxford University. The new vaccine, developed by Dr Sarah Gilbert's team, targets proteins inside the flu virus that are common across all strains. The two proteins, Nucleoprotein and matrix protein 1, are more than 90% conserved across all influenza A strains and less liable to change over time.
In their initial human trial of 11 healthy vaccinated people and 11 non-vaccinated people, they exposed them to what I think is A/Wisconsin/67/2005 (H3N2). Fewer vaccinated people got the flu and vaccinated people had more T-cells and more activated T-cells. We will have to wait a bit for more details, since they have just submitted the paper for publication. Interesting that the Guardian is reporting this before a a medical journal. Given how dysfunctional the peer-review process is these days (STAR-ICU trial anyone?), I don't blame them for communicating the results in this time-efficient manner.
You can read about the initial vaccine creation and phase 1 safety trial of the Modified Vaccinia virus Ankara vector encoding nucleoprotein and matrix protein 1 in the January 1st CID.
Guardian article by Alok Jha
Berthoud et al Clin Infect Dis, January 1, 2011
"Over this decade, we believe unbelievable progress can be made, in both inventing new vaccines and making sure they get out to all the children who need them. We could cut the number of children who die every year from about 9 million to half of that, if we have success on it. We have to do three things in parallel: Eradicate the few that fit that profile -- ringworm and polio; get the coverage up for the vaccines we have; and then invent the vaccines -- and we only need about six or seven more -- and then you would have all the tools to reduce childhood death, reduce population growth, and everything -- the stability, the environment -- benefits from that."
My favorite quote (the counterfactual): "In fact, it is so simple, people often forget what a big deal this is. The 2 million people that would have died from smallpox now don't think, 'Wow, I'm alive today because of vaccinations,' but that's the case."
It will be interesting to see if this effort can lead to 6 or 7 new vaccines. A key one would be an influenza vaccine that targets a conserved region of the virus, which would eliminate the need for costly annual vaccinations. I think we will also need a similar effort to identify new antibacterials before too long.
Full transcript and video of Bill Gates interview (CNN.com)
Sunday, February 6, 2011
Link: NY Times story 2/5/2011
|Photo: New York Times|
Saturday, February 5, 2011
Friday, February 4, 2011
Why? Fidaxomicin is more active against C. difficile (bactericidal rather than bacteriostatic), has a longer post-antibiotic effect, and is slightly narrower in spectrum than vancomycin. So it probably kills C. difficile better, for longer, and without as much disruption of the rest of the colonic flora. Further studies will be needed to investigate this further, and to determine why this effect is not seen with the NAP1/BI strain.
The accompanying editorial by Dr. Herbert DuPont is well worth reading, and raises questions about whether our initial therapy for C. difficile is too short in duration (in this study, 10 day treatment courses were used), and whether we’ll eventually be using a combination of antibiotics and immunotherapy to effectively treat and prevent C. difficile recurrences. That is, if stool transplants haven’t become the treatment of choice by then.
*This drug is made by Optimer Pharmaceuticals, and all of the authors have listed disclosures at the end of the article—three of the authors are Optimer employees
Wednesday, February 2, 2011
|The new "didn't wash hands!"|
This approach worries me. It's punitive and adversarial, and in the end, may damage the trusting relationship between hospital epidemiology and healthcare workers that I think is needed for effective infection control. Other hospitals have had successes in improving hand hygiene compliance without resorting to such extreme measures. It's really quite rare for a healthcare worker to refuse to wash when confonted, and offenders can still be held accountable. It makes me wonder how bad hand hygiene compliance must have been to drive this approach.
Well, I sure hope this strategy works, since I shudder to think what could be next. Public stocks? Caning? Finger amputations?
Oh, one last question: who gets the money?
Tuesday, February 1, 2011
The authors found a reduction in contaminated cultures from 1.1% to 0.6% (OR 0.57, p 0.009) with sterile gloves.
It's worth pointing out that cultures drawn through lines were excluded, as were cultures obtained in the Emergency Department (an area of high contamination rates in some hospitals), pediatrics wards and surgical wards. In addition, povidone-iodine was used as the skin disinfectant.
When I was a resident, all blood cultures were drawn by housestaff and I proudly recall that I never had a contaminated blood culture (and I did wear sterile gloves). But we had a vested interest in avoiding contaminants, as it would mean drawing more cultures and potentially extending the patient's hospital stay, all of which meant more work for us.
If these questions intrigue you, you’ll be interested in a Pfizer-pfunded four-center performance improvement initiative that included education around the ATS-IDSA pneumonia guidelines and a prospective assessment of outcomes. As the authors report in Lancet Infectious Diseases this week, patients who received “guideline compliant” empiric therapy were more likely to be dead at 28 days than were those who received “guideline non-compliant” therapy.
Before you submit your resignations to IDSA and ATS, you should know that there were plenty of problems with this observational study—most of them are well-summarized in an accompanying editorial. The failure of the authors to consider appropriate de-escalation of therapy in their determination of guideline compliance is an especially big problem, given that antibiotic overuse has been linked to increased mortality in the ICU.