An ongoing dialogue on HIV/AIDS, infectious diseases,
May 3rd, 2009
H1N1! Didn’t You Used to Be Swine Flu?
At the end of last week, “swine flu” became “H1N1”. The CDC web site explains why:
This virus was originally referred to as “swine flu” because laboratory testing showed that many of the genes in this new virus were very similar to influenza viruses that normally occur in pigs in North America. But further study has shown that this new virus is very different from what normally circulates in North American pigs. It has two genes from flu viruses that normally circulate in pigs in Europe and Asia and avian genes and human genes. Scientists call this a “quadruple reassortant” virus.
(Note the URL: http://cdc.gov/h1n1flu/swineflu_you.htm. Hmmm.)
Meanwhile, H1N1 (I’ll get used to it) is off the front page of the newspaper, at least the ones around these parts. A sign we’re in the clear, or just our short attention span?
I think you know the answer.
Still, for some very well-reasoned reassurance, I’ve been referring my non-medical friends and family to this excellent summary in the Wall Street Journal by Peter Palese from Mount Sinai. A key point:
Although the swine virus currently circulating in humans is different from the 1976 virus, it is most likely not more virulent than the other seasonal strains we have experienced over the past several years. It lacks an important molecular signature (the protein PB1-F2) which was present in the 1918 virus and in the highly lethal H5N1 chicken virus.
Of course no one really knows what is going to happen — other virulence properties might be present, next year’s seasonal outbreak could be worse, etc — but it’s welcome to hear some balanced views in the mainstream media along with all the hoopla.
April 29th, 2009
Swine Flu Treatment Guidelines — For Now
The swine flu situation is so dynamic that what I wrote earlier this week now seems hopelessly dated — except that from the perspective of a clinical ID doctor, it still feels eerily similar to the anthrax and SARS outbreaks.
But related to that post — specifically the use of antivirals — these interim guidelines for use of antivirals in suspected cases of swine flu were posted this afternoon on the CDC site. They make good sense.
Note the strategic use of the word “interim”. What are the odds they are unchanged during the next week? 1 in a 1000?
April 26th, 2009
Swine Flu Curbsides: Anthrax, SARS Redux?
In my email in-box yesterday AM from a primary care doc:
A patient of mine, 40 year old woman totally healthy, is going to Cancun on Tuesday for a conference. She’ll be there for 6 days.
I know there are no cases of swine flu in Cancun yet, and the situation is evolving, but here’s my question: what should she do (besides the obvious stuff like handwashing, etc)?? Bring tamiflu?? A mask?? Should she cancel her trip???? [N.B., actual punctuation retained for effect]
Ah, memories of the anthrax attacks and SARS, when an ID threat hits the headlines and people understandably want to know what they can do to protect themselves.
So they turn to their primary care providers, who then turn to us.
And in these situations, there’s the official response to such a question, which as we all know is sometimes different from the practical response — and I define the latter being what would you do for you or your family.
So not only did I say that it would be reasonable to bring some osteltamivir (Tamiflu), I even thought it wouldn’t be crazy to consider a prophylactic strategy — though the fact that she’s totally healthy made me favor the former approach.
And I wonder how many ID docs out there purchased some ciprofloxacin back in 2001, even though we were told not to.
April 20th, 2009
Another HIV Pharmaceutical Partnership
GlaxoSmithKline and Pfizer have created an alliance for HIV drug development.
Since there is only one collaborative effort in the HIV treatment area — the colossally-successful “Atripla” between Gilead and BMS — I had thought this kind of arrangement was fairly rare in the drug biz, but according to this interesting take, apparently not.
Perhaps not surprisingly, GSK is a lot more invested in this effort than Pfizer (85/15% split). Great quote:
The structure looks like GSK has a lot more involved than Pfizer, though, so one of the things to watch will be how much effort Pfizer really puts into the new venture. Lip service is just as common a currency in the drug companies as it is anywhere else, and converts at the same exchange rates.
Regardless, it’s nice to see that there is an HIV drug development pipeline still out there, and hence hope for patients with HIV resistance to all currently available drugs. Good table of the combined GSK/Pfizer investigational agents here.
April 18th, 2009
Ceftriaxone and Calcium — OK Again in Adults!
As every house officer, hospitalist, intensivist, and ID doc knows, ceftriaxone and calcium have been contraindicated since 2007 due to fears of a potentially fatal precipitation of the two that led to the death of 5 neonates.
Pediatricians are fond of saying “kids are not small adults” (I should know), and if that’s true, it’s even more so that “neonates are not really really tiny adults.”
So it’s not surprising that follow-up in vitro studies have shown that this is unlikely to be a problem when the drugs are administered sequentially. It’s also not surrising since no case of this fatal ceftriaxone/calcium precipitation had ever occurred in adults, even though ceftriaxone has been one of the most commonly-given antibiotics on the planet for decades.
But now we can give them to the same patient again, so long as the person is older than 28 days, and ceftriaxone and calcium are administered sequentially.
Hooray.
April 11th, 2009
Another Drug Linked to PML — Law Firms Waiting for Your Call
The psoriasis drug Raptiva (efalizumab) has been linked to progressive multifocal leukoencephalopathy:
On Oct. 16, 2008, FDA updated the FDA-approved labeling for Raptiva to warn of the risk of life-threatening infections, including PML. On Feb. 19, 2009, the FDA issued a Public Health Advisory informing patients and prescribers of the risk of PML in patients taking Raptiva, after receiving reports of four patients with PML, three of whom died.
When I was a fellow, Bob Rubin emphatically taught us that there’s no such thing as a free lunch when it comes to immunosuppression. I think of this each time one of these newer agents is linked with a severe infectious complication.
But while I was getting some background information on the drug, I came upon this ugly site — and there are others like it already. They can join sites like this one and this one for nataluzimab (Tysabri), the multiple sclerosis drug also linked to PML. These legal firms pounce on drug withdrawals like hungry dogs waiting for table scraps to fall on the floor.
April 6th, 2009
Delayed Opening Day Videos, and More
Some random HIV/ID issues while awaiting a delayed opening day here in cold, rainy Boston:
- If you enjoy video highlights, check out these of HIV making its way from T cell to T cell. If you’re short on time, #’s 9-12 are particularly amazing. Still, I don’t imagine that this video will make it to Youtube anytime soon:
Transfer of an entire synaptic button to the CD4+ target cell. Image is an overlay of brightfield image and green fluorescence in a maximum intensity projection of the acquired stack.
(Hat tip to J Li for the link.)
- NA-ACCORD lands, to be published in print April 30th. After a major study has been presented at a meeting twice, discussed extensively and digested, I sometimes wonder, what is the impact of actual publication? Here I’d suggest reading the fine print, as the published paper does differ in some major ways from what was presented last year at ICAAC and this year at CROI: the beneficial effect of starting earlier (with CD4 > 500) was even greater than reported earlier, but the groups who did start early differed (significantly) from those who deferred. The study’s impact on clinical practice? We’ll see, but I suspect it will be substantial given the other data supporting earlier treatment.
- Bats have an image problem. A mysterious illness — white nose syndrome — is decimating the bat population, and no one cares. Why am I not surprised? Money quote:
To a public raised on vampire movies, bats are loathsome, frightening creatures – blind, flying rodents that all carry rabies, suck human blood, and get impossibly tangled in long hair.
(They said it, not me.) Turns out that to garner support for animals, “cuteness rules” — which means that causes for polar bears (global warming) and toucans (rain forests) get much more sympathy (and $$$) than bats.
- But I love pistachio nuts! Oh well.
March 31st, 2009
Infectious Disease in the ICU: Help Please? Part II
In Part I of this topic, I commented on the ironic sameness of ICU Infectious Diseases — that incredibly sick, complex patients entered the ICU with vastly different problems, then over time, seemed to converge, presenting similar kinds of clinical issues and management challenges for the ID doc.
Or, as a visiting medical student said to me, “My ICU attending said that every patient in the ICU should be on vanc/Zosyn.”
Which brings up the issue of empiric antibiotics. On the one hand, there’s the hard-line view that we should only be giving antibiotics for clinically or microbiologically confirmed infections. All antibiotics have side effects, they select for ever more-resistant flora, and may diminish the accuracy of our diagnostic tests. In one commentary on this issue, the author wrote:
The indiscriminate use of antibiotics substantially contributes to the “spiraling empiricism” that characterizes contemporary medical therapy… Broad spectrum systemic antibiotics have become the specific treatment of fever. When I was a medical student, the medical residents taught that cephalothin was the “antipyretic of choice” …
–snip–
The decision to withhold or discontinue antibiotics, however, necessitates an extensive and compulsive physical examination and personal review of all the pertinent evidence (gram stains, urinalysis, radiographs, laboratory values). Critical historical data should be confirmed. Patients must be turned and wounds undressed. Less exhaustive evaluation is inadequate.
Yes, well…. but this view, less elegantly stated, risks sounding like ivory tower medicine at its worst, and brings to mind the sad truth that withholding antibiotics is one of the few things an ID doctor can do to sound macho.
Critically-ill patients with fever should receive some sort of empiric broad-spectrum coverage, at least initially. As one of our fellows just asked me, once the diagnostic evaluation has been done, what else can we offer them? We’ve all been in that uncomfortable position of suggesting that antibiotics be withheld or stopped, then have that critically-ill patient later develop a life-threatening bacterial infection.
Sure, it may have happened anyway — these are highly susceptible hosts, after all — but it just feels worse when it’s done without antibiotics on board. Let’s hope our diagnostic studies in these patients can improve, because absent better testing, I’m afraid we’re going to be stuck with lots of “spiraling empiricism.”