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November 28th, 2009

ICAAC-IDSA — Alone Again (Naturally)

pcvb_con_hallJust received my latest copy of Infectious Disease News, that large glossy review magazine* that arrives approximately monthly in my mailbox.

As usual, I turned right to Dr. Theodore C. Eickhoff’s always-thoughtful editorial, this month entitled “Reflections on the 47th IDSA Meeting.”  He writes:

It was a much more “user-friendly” number of attendees, in contrast to the almost 15,000 people that attended the joint meeting last year. I heard absolutely no one express a desire to have another joint IDSA-ICAAC meeting.

I can see his point — the combined meeting in Washington last year drew over 15,000 participants, and at times was just too gargantuan to manage.

But if I could for a moment be the lone voice arguing for a joint meeting, here’s my pitch:  Last year, tons of people  in ID went to ICAAC-IDSA, even people who rarely go to either meeting.  This year, not so much — which might explain the “somewhat muted and subdued” tone Eickhoff found at IDSA this year in Philadelphia.

Either that or what the Yankees were doing against the Phillies.

(*Don’t call it a “throwaway!”)

November 20th, 2009

Ties Tied to Bugs

matching tie and handkerchiefAre doctors’ neckties causing infections?  That’s the implication of this Wall Street Journal piece:

The list of things to avoid during flu season includes crowded buses, hospitals and handshakes. Consider adding this: your doctor’s necktie. … A 2004 analysis of neckties worn by 42 doctors and medical staffers at the New York Hospital Medical Center of Queens found that nearly half carried bacteria that could cause illnesses such as pneumonia and blood infections. That compared with 10% for ties worn by security guards at the hospital.

This is old news, of course (yet somehow it warranted front page coverage in the WSJ, go figure).  In fact, the British went so far as to ban neckties for doctors entirely in 2006, stating a tie is an “unnecessary piece of clothing.”   (No comments about ascots, however.)

One problem with the cited study in the WSJ is that it does not link the wearing of neckties to actual infections in patients — and I don’t think any study has.  Meaning this:  do the patients of the necktie-wearing docs get more infections than the patients of MDs who dress more casually?

If not, then it’s just another study of this ilk:  “We cultured ________ [fill in the blank of some seemingly innocuous item — computer keyboard, reflex hammer, clock radio], and found evidence of staph and coliform bacteria in XX%.  These results suggest that [insert item] should be sterilized prior to patient care.”

My hunch:  neckties may carry bacteria — see this company’s antimicrobial neckties for vivid proof — but they are not themselves causing nosocomial infections.

But since I could be wrong on this one, should we get rid of neckties in the hospitals and clinics just in case?

November 13th, 2009

Practical H1N1 Management Question

pneumoniaLet’s imagine you’re seeing a case of pneumonia, and you suspect (as is quite reasonable these days) that it is precipitated by H1N1 influenza.

What antibiotics do you choose for an outpatient?

(If someone is sick enough to be admitted — especially to the ICU — I’m assuming the all-guns blazing approach will be adopted.)

Even though some of these pneumonias have been only H1N1, bacterial superinfection can and does occur — most commonly with our old friend S. pneumoniae, somewhat less so with group A strep, S. aureus (including MRSA, of course), and H. influenza.

But since we hardly ever know exactly what species of bacteria we’re dealing with, how can you leave even one of these out?  That MRSA one in particular?

This past week I chose trimethoprim-sulfamethoxazole + high-dose levofloxacin — in addition to the oseltamavir.

Overkill?  These guidelines from Canada would suggest so, but I’m not so sure.  After all, most people with H1N1 do not get pneumonia at all (and hence do not need antibiotics), and not surprisingly this was not a person with a normal immune system.

Should be an interesting winter …

November 7th, 2009

A Career in Infectious Diseases and “The Next Big Thing”

the_visionaryI was working with a medical intern in clinic this past week who is potentially interested in ID. After seeing our 3rd consecutive stable HIV patient, he asked me what I thought the next big challenge would be in our field — especially since HIV treatment has been “solved.”

“Solved” might be stating it a bit strongly — after all, we still have no cure, the drugs aren’t perfect, not everyone can get them, there’s no vaccine,  etc — but he had a point.  Many of the research questions on HIV treatment are now about moving things forward incrementally, and it’s hard to imagine an advance anytime soon along the lines of combination therapy in the mid 1990s, or even the second wave of newer treatments that become available in 2006-8.

So what’s the answer to his question?  I compiled a brief list, shown below in no particular order:

  • Highly drug-resistant bacteria — MRSA, carbapenemase-producing gram negatives, etc.
  • Influenza, obviously, plus other SARS-like respiratory viruses
  • Hepatitis C, though we’ll have to take this back from the hepatologists — I doubt they’ll mind — with nearly a hundred novel treatments in development
  • Infections associated with therapeutic immunosuppression — TNF blockers, other biologics
  • Food safety
  • Device-related infections
  • Novel diagnostics — PCR, other amplification techniques, direct antigen detection methods, etc
  • Finding the next infectious cause of some idiopathic or autoimmune disease — some helicobacter-like discovery regarding Crohn’s, or multiple sclerosis, or sarcoid

(Not on my list are issues specifically related to ID in resource-limited settings, because that’s not what I do.)

I’m sure I’m missing something, but it’s a start.

October 31st, 2009

Would Changing Restrictive HIV Testing Laws Improve Survival?

halloween_imageEmphatically yes — to the tune of >600,000* years of life gained nationwide.  So says a nifty paper being presented at the annual IDSA meeting today by Mike April, under the direction of Rochelle Walensky.

(*Original abstract said 549,437, cited in the link; number at the actual presentation, though, was 609,656.)

Bottom line is that laws that limit HIV testing (such as requiring written consent, ahem) lead to later diagnoses, and hence shorter projected life span for those with HIV.  As always with such models, one could quibble with certain assumptions, but the results remain robust through a wide range of sensitivity analyses.

In fact, the only way that switching to an opt-out testing policy could fail to improve survival is if opt-out discouraged a large group of people from getting tested at all — for which there’s not the slightest bit of evidence whatsoever.

Are you listening Massachusetts?  I think you are .

October 20th, 2009

Well That Was Fast! HIV Vaccine Trial Published

canaryRemember the HIV vaccine trial press release?  The one announcing the first-ever positive result?

Then the backlash, with people questioning how the analyses were done, and reported?

Now, less than a month later, we have the scientific presentation and the paper appear on the same day.

Read all about it here and here.

If you want the view from 10,000 feet (why is that the chosen altitude for that cliche?), here it is:

  • The vaccine strategy combines two vaccine generally thought to be ineffective on their own — canarypox ALVAC-HIV and glycoprotein 120 AIDSVAX B/E — in a “prime and boost” approach
  • Over 16,000 patients are enrolled in Thailand in a placebo-controlled trial
  • The “modified intention-to-treat” analysis, which excludes those who are found to be HIV positive at entry, shows a modest but statistically significant protective effect, reducing the infection rate by about 30%
  • There is a trend towards a protective effect in the intention-to-treat and per protocol analyses
  • In those who were vaccinated and became infected, there was no effect on CD4 cell count or HIV RNA

Numerous questions remain, many of them summarized in this accompanying editorial:  Why did it work when the individual strategies didn’t?  How durable is the protection?  How do the strains causing infection relate to those in the vaccine?  Did the per-protocol analysis fail to show a significant protective effect solely because of a smaller sample size?  Would the vaccine work if tested on higher-risk populations?  What effect will this study have on the ongoing vaccine development effort, both in the lab and in trials?

Answers to some of these questions may be forthcoming.  Regardless, the surprising results of this study serve as a reminder of just how mysterious the immune system remains — despite some incredibly smart people working on it with lots of resources.

Because if you asked the vaccine cognoscenti to vote a little over a year ago on which strategy in clinical trials would end up with a positive result — the “prime and boost” one published today or the adenovirus vector approach —  the latter would have won in a landslide.

October 17th, 2009

Is Chronic Fatigue Syndrome Another Retroviral Disease?

retrovirusHere’s a surprising report in Science:

Studying peripheral blood mononuclear cells (PBMCs) from CFS patients, we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus-related virus (XMRV), in 68 of 101 patients (67%) compared to 8 of 218 (3.7%) healthy controls … These findings raise the possibility that XMRV may be a contributing factor in the pathogenesis of CFS.

I confess, I had never even heard of “xenotropic murine leukemia virus-related virus” (wow that’s a mouthful) before this report, but apparently virologists have been aware of it for some time, due to a possible association with prostate cancer.

The story behind the Whittemore Peterson Institute reporting these findings is almost as interesting as the paper itself.  From their web site:

In September of 2004, a group of dedicated citizens and clinicians proposed the concept of a medical institute for the millions of patients in the US suffering from the disorders known as Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), fibromyalgia and other closely related illnesses. They were concerned by the lack of available doctors to understand and serve the growing numbers of patients with these complex chronic illnesses. 

According to the coverage of the story in the Times, the Institute got its start with a several million dollar donation from Annette and Harvey Whittemore, whose child has been suffering from CFS for over twenty years.  The Times piece goes on to quote Dr. William Reeves from CDC, who sounds quite skeptical about the findings.

“We and others are looking at our own specimens and trying to confirm it,” he said, adding, “If we validate it, great. My expectation is that we will not.”

My take on all this?  Despite our being down this road before on CFS — EBV, HHV-6, candida, enterovirus, parainfluenza, Lyme, to list a few putative causes — without much to show for it scientifically, I’m all for having multiple groups working on trying to find the cause of this awful disorder, even if it seems likely that there is more than one cause.

And judging from some of the pained, angry, and frustrated comments posted here, I’m clearly not alone.

October 12th, 2009

AIDS Vaccine: Maybe not Effective After All

Well, that didn’t take long:

Researchers from the U.S. Army and Thailand announced last month they had found the first vaccine that provided some protection against HIV. But a second analysis of the $105 million study, not disclosed publicly, suggests the results may have been a fluke, according to AIDS scientists who have seen it.

In short, two additional analyses (intention-to-treat and per protocol) do not show a statistically significant protective effect.  In other words, the study subjects who followed the protocol most closely (per protocol) had less protection from the vaccine strategy.

What the …

But even in the original report, the protective effect didn’t seem all that great — statistically significant, yes, but maybe not clinically significant — so when you add how cumbersome this vaccine is to administer (and probably to manufacture), as well as these new findings, the likelihood of this vaccine strategy making its way to clinical use seems vanishingly small.

So what can we still hope from this study?

At best, some understanding of the correlates of protection.  Maybe.

October 5th, 2009

No Baseball Tonight

“Are you writing another funny blog post because there’s no baseball?” asks my son J.

As “funny” is very much in the eye of the beholder, that remains to be seen.  But here are a few things on my mind the last few days:

  • No data supporting N95 over surgical masks for flu.  One huge logistical issue dodged — at least for now.  But Consumer Reports, that darling of objective reporting, seems to think they’re just great. Since “minimax” is the operative strategy for infection control, look for this controversy to go on for a bit.
  • Speaking of flu, I’ve been hearing for weeks (from a certain someone) how chaotic this H1N1 vaccine situation will be in pediatric practices.  And here’s proof.
  • LONG (wow) piece on E. coli O157:H7.  Not unreasonable, given the potential severity of the illness and the tortuous route hamburgers take en route to our kitchens.  (Yuck.)  Did I mention before that this is one of the few ID issues that my wife and I take a hard line on?  Make those burgers well-done, thank you.
  • Hey, did you catch the 10AM agenda in tomorrow’s General Court of the Commonwealth of Massachusetts?  Can’t miss that.
  • Finally, did a throat infection bring down the mighty Tyrannosaurus rex? Perhaps if the dinosaur doc sent a “hold” tube to the lab, they can make the diagnosis retrospectively.

Good luck Tigers/Twins fans!

September 30th, 2009

The Battle for Colonic Microflora

My two favorite newspapers (New York Times and Wall Street Journal — sorry, hometown paper) have just covered opposite ends of a topic on the edges of ID practice — namely, colonic micro-organisms.

Too few?

Too many?

Wrong type?

In the Times, a review of the probiotic debate:

Probiotics are live micro-organisms that work by restoring the balance of intestinal bacteria and raising resistance to harmful germs… So what health problems can probiotics really help? After gathering at a Yale workshop to review the available evidence, a panel of 12 experts concluded that there was strong evidence that several probiotic strains could reduce diarrhea, including that associated with antibiotic use. Several studies have also suggested that certain probiotics may be useful for irritable bowel syndrome.

I suspect the “experts” were gathered specifically because they had interest in this topic, and hence may be predisposed to a favorable review of the data.  Still, there might be something to it, and I’m  crazy about yogurt — full summary of their report here, which was published in 2008.

Far more fringey, however, is the whole “colon cleansing” craze, covered in the WSJ:

The typical American diet of processed foods, pharmaceuticals, stress and lack of exercise is clogging up our lower intestinal tracts, leaving them inflamed and lined with waste—and leaking toxins into the body that cause problems ranging from headaches and chronic fatigue to arthritis and cellulite. All that “stubborn fecal matter” also contributes to bulging bellies and expanding waistlines, cleansing proponents claim.

Eliminating the buildup, either with supplements or laxatives, or by flushing the colon with warm water—a practice known as “hydrotherapy” or “colonics”—can dramatically improve a person’s health and well-being, proponents claim …

Gastroenterologists pooh-pooh [I did not make that up!] many of these claims …

What follows is a very thoughtful review — and a clear debunking — of what seems to be a major form of quackery out there.  For example, here are the claims of one such service:

Colon cleansing benefits intestinal tract problems, absorption, bowel disease, constipation, digestive system, parasites, yeast infection. Helps control blood pressure, restores pH balance, restores proper digestion, reduces bad odors.  Colon cleansing also clears intestinal blockage, relieves bloating, helps purify blood, kills bad bacteria, viruses. These are just of few of the many benefits one can receive by cleaning the intestinal tract.

The problem, of course, is the scientific data backing up these claims are pretty much non-existent.  But hey, it’s just $25 for the “Oxygenated Colon Cleanser,” and $35 for the “Super-Oxygenated.”  FREE SHIPPING!

Ultimately, I think one of the gastroenterologists quoted in the WSJ piece really nails it here:

“There is a degree of obsession that goes along with this,” says Dr. Landzberg… Even “natural” laxatives, such as the plants senna and cascara, can harm the bowel, Dr. Landzberg says, adding, “The public has grown increasingly wary of the side effects of pharmaceuticals. I would like to see people bring that same degree of healthy skepticism to ‘natural’ products.”

Wise words indeed.

HIV Information: Author Paul Sax, M.D.

Paul E. Sax, MD

Contributing Editor

NEJM Journal Watch
Infectious Diseases

Biography | Disclosures | Summaries

Learn more about HIV and ID Observations.