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Posts Tagged Infectious disease

Update on the Zika Virus

zika-virus-mosquitoA new word has been added to the public’s vocabulary – the Zika virus. It seems we have one more infectious agent to worry about. Here are the facts as we currently understand them regarding the recent Zika epidemic, and also some rumors and conspiracy theories that need debunking.

Zika virus

The Zika virus (of the viral family Flaviviridae, an Arthropod-Borne or arbovirus) is spread through Aedes mosquito bites, the same mosquitoes that also spread dengue fever, West Nile, and yellow fever. The infections themselves are usually mild, causing fever, rash, joint pain, and conjunctivitis. Many of those infected (about 80%) may even have a subclinical infection, meaning they do not notice any symptoms.

According to the World Health Organization:

Zika virus is diagnosed through PCR (polymerase chain reaction) and virus isolation from blood samples. Diagnosis by serology can be difficult as the virus can cross-react with other flaviviruses such as dengue, West Nile and yellow fever.

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Posted in: Public Health, Vaccines

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Lyme Testing

The little burrowing bacteria that bores into your pores to cause Lyme disease, EEEEEWWW!!!

The little burrowing bacteria that bores into your pores to cause Lyme disease, EEEEEWWW!!! Darkfield 400x microscopy image of the 10-25µm long Borrelia burgdorferi spirochaete which causes Lyme disease (1993). Provided by the CDC’s Public Health Image Library (PHIL #6631) via the Wikimedia Commons

I hate those oh hell moments. I was up way too late last night, but who can pass up the opportunity to see Patti Smith playing Horses (and more) for the 40th anniversary of the album. Only 44? Behind the Eagles? No way. I would nudge it up a few more spaces. Hard to believe I was 18 when that album came out. Horses is one of the few albums that made the transition from vinyl to CD. It was a tremendous show, and at 69 Patt performs with the energy and passion of a 29 year old. And she sure can spit. I had the evening off, so food and drinks at Swine until well past midnight. First time my wife and I closed a bar. I am too old for this.

But as I was blearily drinking my a.m. coffee on a dreary PDX morning, I opened the browser to SBM and there was a post by Jann. Oh hell. That means I have a post due tomorrow and I had lost track of the time over the holidays. I thought my next post was next Friday. Oh. Hell. So unlike most posts which I write over a week, this one was done in about 4 hours. And I am sure it will show.

How do you diagnose an infection?

Not always so simple. You always start with a history and, for infectious diseases, an exposure history is paramount. People get what they are exposed to, so you want to know travel, animals, diet, water, sex etc. If you have ridden a horse to have sex in an Indian lake while drinking raw milk (not really an unusual history in my practice; people do the darndest things) you have exposure risks for a variety of infections. If you have not left the Willamette Valley it is unlikely that the cause of the illness is malaria, although you always have to consider that the infection came to the patient rather than the other way around. (more…)

Posted in: Basic Science, Diagnostic tests & procedures, Lyme, Science and Medicine

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No, Purell Does Not Breed Super-Anything

Pictured:  Mechanism of pumpy doom, or savior to us all?  Neither!

Pictured: Superbug spawner, or savior to us all? Neither!

Recently, I was sitting in a meeting and reached for the dispenser of Purell hand sanitizer sitting on the conference room table. A colleague of mine gave a small, rueful shake of her head to the person on her other side. Apparently I had erred. I asked what was the matter, and got a brief answer to the effect of “because superbugs.” We exchanged nothing more about it; the interaction was over before the alcohol had dried from my hands.

I wouldn’t have thought anything of such an interaction with anyone else, but my colleague is a PhD student in immunology, six years older and more schooled than I, doing her doctoral research in a lab run by a physician-scientist — a specialist in infectious disease, no less. A touch ironic.

And so I noticed a need for some mythbusting: alcohol-based hand sanitizers do not breed resistant bacteria. (more…)

Posted in: Epidemiology, Evolution, Public Health, Science and Medicine

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SCAM Cell Therapies

Surprisingly, the best youth is in the chump.

Pictured: Stem cells.  Surprisingly, the best youth is in the chump.

Injecting animal cells into humans for therapeutic reasons has a long history. The most infamous was John Brinkley who injected goat testicles into 16,000 men in the 1920s and 30s to treat impotence. Harriet wrote a review of Charlatan: America’s Most Dangerous Huckster, the Man Who Pursued Him, and the Age of Flimflam, which covers the topic. I wonder who would get the title today. Chopra…Gesundheit.

I had thought this therapy was consigned to the sharps container of history. Of course not. No SCAM ever fades away.

As part of my ID reading I came across the headline “Q Fever Outbreak Among Travelers to Germany Who Received Live Cell Therapy — United States and Canada, 2014.”

It surpasses the classic “Notes from the Field: Campylobacter jejuni Infections Associated with Sheep Castration — Wyoming, 2011” for foolishness, where:

…men reported having used their teeth to castrate some of the lambs.

Really. A most curious way to acquire Campylobacter. But at least the castrators were doing practical, albeit eeewwwwwwww, work. And there is an alternative to teeth, including the Burdizzo Emasculatone, which is:

an elegant little tool especially suited to crushing the spermatic cords of a variety of male mammals. It really helps to make a neat job of what would otherwise be an unpleasantly messy endeavor, and the Burdizzo achieves the goal of bloodless castration admirably.

But I digress and leave to the commenters to make completely inappropriate remarks. Only the SCAM universe can be odder than infectious diseases. (more…)

Posted in: Homeopathy, Humor

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More Lyme ‘Guidelines’

The black-legged tick responsible for spreading the bacteria that causes Lyme disease

The black-legged tick responsible for spreading the bacteria that causes Lyme disease

I noted with understanding that the Doubtful News can’t take it anymore. The relentless tsunami sewage slurry of pseudo-science (who says I can’t alliterate?) has worn her down. She is:

currently experiencing a phase in which I can’t seem to bring myself to promote another ridiculous story in the media about a haunted location, scary sounds from the sky, or the latest outrage fueled by ancient superstition. You might call that… jaded. It’s been over four years now of nearly daily effort to keep track of the weird world of woo. It can wear one down when virtually or literally the same thing appears and reappears over and over as if it hasn’t already been passed around a million times.

I sympathize. I have had a touch of SCAM ennui of late. It is a bit due to the repetitiveness of the SCAMs. I still find the variations on the theme of pseudo-sciences curious. It is like infectious diseases where every case has unique and subtle diversity so no two SCAMs are the same. But there are almost 4,000 clinical trials on acupuncture and I would wager that they all have several of the same half-dozen fatal errors. It is like hand hygiene at work. We have known for, oh what, 160 years, that hand hygiene prevents the spread of disease but people still can’t do it right. We know how to do a good clinical trial but the SCAMsters just can’t seem to figure it out.

The ennui is not the seeming futility of the endeavor. I have always been comfortable with futility, secure, as an example, in the knowledge that someday I will be consumed by the bacteria I spent a career killing. Unless, of course, they get me cremated right away. I keep looking for a motto for the SfSBM; I am attracted to “Sisyphus had it easy.” (more…)

Posted in: Guidelines, Lyme, Politics and Regulation, Quality Improvement

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Lyme Testimony

The black-legged tick, responsible for spreading Borrelia burgdorgeri, the bacteria that causes Lyme disease

The black-legged tick, responsible for spreading Borrelia burgdorgeri, the bacteria that causes Lyme disease

As the saying goes, when you do not have the facts, argue the law. This tried and (?) true approach was successful in New York where a law was passed protecting those who are, shall we say, creative in treating patients with Lyme and ‘chronic’ Lyme.

The bill protects those from investigation of misconduct:

based solely on treatment that is not universally accepted by the medical profession.

The major bone of contention has been extended courses of IV antibiotics for ‘chronic’ Lyme, but there are a wide variety of treatments that may be used by so called “Lyme literate” doctors.

The number of therapies divorced from reality that are offered to Lyme patients is remarkable. I do not know if chronic Lyme patients have greater use of pseudo-medical therapies than other pseudo-diagnoses, but I am impressed by the offerings in a recent review:

Results. More than 30 alternative treatments were identified, which fell into several broad categories: these included oxygen and reactive oxygen therapy; energy and radiation-based therapies; nutritional therapy; chelation and heavy metal therapy; and biological and pharmacological therapies ranging from certain medications without recognized therapeutic effects on Borrelia burgdorgeri to stem cell transplantation. Review of the medical literature did not substantiate efficacy or, in most cases, any rationale for the advertised treatments.

Conclusions. Providers of alternative therapies commonly target patients who believe they have Lyme disease. The efficacy of these unconventional treatments for Lyme disease is not supported by scientific evidence, and in many cases they are potentially harmful.

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Posted in: Lyme, Politics and Regulation, Science and Medicine

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Lyme: Two Worlds Compared and Contrasted

The Lyme tick

The western black-legged tick, carrier of the Borrelia burgdorferi bacteria which causes Lyme disease.

The practice of infectious disease (ID) is both easy and difficult. If you read my ID blog on Medscape you are aware of my trials and tribulations in diagnosing and treating infections.

ID is easy since, at least in theory, diseases have patterns and an infecting organism has a predictable epidemiology and life cycle. So if you can recognize the pattern and relate it to the life cycle and exposure history, you can often make a diagnosis before the cultures come back.

My favorite story is the time I was asked to see a young girl with endocarditis. The history was she had a week of fevers, headache and myalgia that went away for five days, returned for a week, went away for five days and returned yet again.

So I asked her “How was your vacation at Black Butte?”

The look of astonishment on her face as she asked how I knew she had been to Black Butte was so satisfying. (more…)

Posted in: Legal, Naturopathy, Politics and Regulation, Public Health, Science and Medicine

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Conspiracy theories and Ebola virus transmission

Yesterday, I spiffed up a post that some of you might have seen, describing how a particular medical conspiracy theory has dire consequences in terms of promoting non-science-based medical policy. Specifically, I referred to how the myth that there are all sorts of “cures” for deadly and even terminal diseases that are being kept from you by an overweening fascistic FDA’s insistence on its approval process is an important driving force behind ill-advised “right to try” legislation that’s passed in four states and likely to pass in Arizona by referendum tomorrow. I’m not exaggerating, either. If you have the stomach to delve into the deeper, darker recesses of alternative medicine and conspiracy theory websites, you’ll find words far worse than that used to describe the FDA, such as this little gem from everyone’s favorite über-quack Mike Adams basically portraying the FDA as Adolf Hitler. Even more “mainstream” advocates, such as Reason.com’s Ronald Bailey and Nick Gillespie, are not above using a version of this myth stripped of the worst of its conspiracy mongering for public consumption, claiming that the FDA is killing you.

Unfortunately, this sort of medical conspiracy theory is very common. Like all conspiracy theories, medical conspiracy theories tend to involve “someone” hiding something from the public. I like to refer to this as the fallacy of “secret knowledge.” That “someone” hiding the “secret knowledge” is usually the government, big pharma, or other ill-defined nefarious forces. The “secret knowledge” being hidden comes invariably in one of two flavors. Either “they” are hiding cures for all sorts of diseases that conventional medicine can’t cure, or “they” are hiding evidence of harm due to something in medicine. Although examples of the former are common, such as the “hidden cure for cancer,” it is examples of the latter that seem to be even more common, in particular the myth that vaccines cause autism and all sorts of diseases and conditions, that genetically modified organisms (GMOs) are dangerous, or that radiation from cell phones causes cancer. In these latter examples, invariably the motivation is either financial (big pharma profits), ideological (control, although descriptions of how hiding this knowledge results in control are often sketchy at best), or even some seriously out there claims, such as the sometimes invoked story about how mass vaccination programs are about “population control” or even “depopulation.” Either way, “The Truth” needs to be hidden from the population, lest they panic and revolt.
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Posted in: Basic Science, Clinical Trials, Public Health

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Salk’s swansong: renaissance of the injected polio vaccine

Picture a lab scientist. White coat, pensive expression, microscope in hand. Glasses, perhaps. The person you have in mind (providing you are willing to humour a stereotype or two) may have a striking resemblance to Jonas Salk, the archetypal laboratory researcher, born in New York City on Wednesday 28th October 1914 — one hundred years ago today.

The name will be familiar to many. As creator of the inactivated polio vaccine (or IPV), Salk is cemented firmly into the annals of medical history. When his vaccine hit the shelves in 1955, the annual epidemics of poliomyelitis represented a fierce insult to postwar American civility: one particularly devastating bout in 1952 caused over 20,000 cases of paralysis and more than 3,000 deaths, mostly among children. The arrival of IPV was greeted with nationwide celebrations, and Salk was praised as a worker of miracles.

Jonas Salk at the University of Pittsburgh where he developed the first polio vaccine.

Jonas Salk at the University of Pittsburgh where he developed the first polio vaccine.

IPV has been in demand ever since, and its use in several countries has been sufficient to get rid of polio. Until recently, however, Salk’s injected vaccine has largely played second fiddle in eradication efforts. When the Global Polio Eradication Initiative was launched in 1988, it favoured an alternative formulation, Albert Sabin’s oral polio vaccine (OPV), as its weapon of choice.

But the spotlight may be shifting. With the eradication programme preparing for what is hoped to be a final onslaught, IPV is poised to take centre stage once more. Indeed, the World Health Organization recently recommended that all countries introduce at least one dose of Salk’s vaccine into routine immunisation by the end of 2015.

Why is IPV so important to polio eradication plans? What does the injected vaccine offer that the oral one does not? The centenary of Salk’s birth offers a fitting occasion to consider these issues.

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Posted in: History, Public Health, Vaccines

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Lemons and Lyme: Bogus tests and dangerous treatments of the Lyme-literati

Tick

It’s that time of year when every day I can expect to see at least one patient with a concern about Lyme disease. In Lyme-endemic regions such as Western Massachusetts, where I practice pediatrics, summer brings a steady stream of children to my office with either the classic Lyme rash (erythema chronicum migrans, or ECM), an embedded tick, a history of a tick bite, or non-specific signs or symptoms that may or may not be due to Lyme disease. Sometimes the diagnosis is relatively straightforward. A child is brought in after a parent has pulled off an engorged deer tick, and there is a classic, enlarging ECM rash at the site of the bite. More often the presentation is less clear, requiring detective work and science-based reasoning to make an informed decision and a diagnostic and therapeutic plan based on the best available evidence. Depending on the story, the plan may include immediate treatment without any testing (as in the straightforward case described above), immediate testing without treatment pending test results, or waiting as we watch and see how a rash progresses before doing anything. An example of this latter course of action would be when a patient comes in with a pink swelling at the site of a new tick bite. In this case, it may not be clear if the swelling is a Lyme rash or simply a local reaction to the bite, a much more common occurrence. The classic ECM rash (an enlarging, red, circular, bull’s-eye rash at or near a tick bite) typically develops 1-2 weeks after a tick bite, but can occur anywhere from 3-30 days later. It then expands and darkens over another 1-3 weeks before fading. This classic rash is not the most common rash of Lyme disease, however, as it occurs in only about 30% of cases. Instead, the rash may be uniformly pink or red (or even darker in the center) without the target-like appearance, or may be a linear rash, expanding outward from the tick bite site. In the case of a patient who comes in with a vague, pink swelling within a day few days of a tick bite, we will typically wait and see what happens to the rash. If it is a local reaction, it will likely resolve within another few days. With Lyme disease, the rash will continue to enlarge and declare itself as an ECM rash. Another unclear and not uncommon situation is when a patient comes in with non-specific symptoms such as fatigue, musculoskeletal pains, and headache. If warranted by the history and the physical exam, we may in this case order Lyme testing. This may not give us an answer even if the patient has Lyme disease, because results are often negative in the first few weeks of the disease. In this case, if symptoms persist or evolve, we will repeat the testing in another few weeks at which point true Lyme disease will test positive and can then be treated. The good news is that the treatment of Lyme disease, particularly in the early, localized phase of the disease, is extremely safe and effective with a 14-day course of antibiotics. The testing is also relatively straightforward, with very good sensitivity and specificity when performed correctly. And this is where the bad news comes… (more…)

Posted in: Diagnostic tests & procedures, Science and Medicine

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