Archive for category Public Health

Something old, something new…

Unless you’ve been living under a rock (and even if you have) you can’t help but have noticed the headlines about all the viruses we’re seeing lately. Measles in Ohio – the largest outbreak in the US since 1996. Polio in Syria and Iraq – a resurgence of a once eradicated virus as war leads to a breakdown in the vaccination efforts. MERS – a second case reported in the US of a “new” zoonotic infection from the Middle-East.

There was a whole session devoted to these “emerging” infections at the recent Pediatric Academic Societies meeting in Vancouver. There are many lessons that we can take away from these events. Firstly, that the well-fought victories we have won against vaccine-preventable infections are actually more of a fragile truce. Given enough of a susceptible population many of these viruses are ready to recur. Measles is an obvious example: probably the most infectious disease known to man, and a plane ride away from ongoing outbreaks in Europe and Africa. One of the most embarrassing exports from my homeland of England has to be the disgraced Andrew Wakefield (I won’t do him the honor of calling him a “doctor”) who pedaled fabricated data to support his efforts to sell a “safe” measles vaccine to a fearful British public. But what about polio? For the first time in years we have seen a significant increase in cases worldwide, as the safety of those administering the vaccinations has been threatened by war. Even as India can now claim itself Polio-free for the first time, I’m starting to wonder if and when we might expect our first case of imported polio to the US from the northern African countries or the Middle East, as the vaccine delayers and refusers leave us with an increasingly vulnerable population.

Secondly, that the pathogens just keep on coming! The Middle Eastern Respiratory Syndrome virus is a coronavirus, only the sixth known to infect humans. It is entirely distinct from the SARS coronavirus, and we’re still trying to piece together exactly how humans are catching and spreading it. Thankfully human-to-human transmission seems to be inefficient, which is just as well as asymptomatic infection seems to be rare, and the mortality rate is about 40%! It’s just as well it has absolutely nothing in common with a virus that causes the common cold that could mean its transmission might become easier…oh, wait….never mind….

The third lesson I took away from the PAS meeting was just how adept we have become at chasing these infections down. Modern sequencing technologies allow us to send patient specimens from an outbreak of an unknown infection, and within a few days we can have a full-length genome sequence and a phylogenetic tree of its nearest and dearest. MERS was isolated in good old fashioned virus culture by a doctor in Saudi Arabia, then confirmed through collaborative efforts in the UK and Netherlands, and reported publicly through global mailing lists prior to publication. Infectious Disease doctors and epidemiologists are recognizing the ease of global spread of infection, especially novel infections, and the need to work together if we are to stay ahead of them.

But it’s not just exotic imports we have to worry about. The epidemiology of infections in the Americas is changing too. Florida has already become a place where Dengue fever can be picked up without the need for a passport, and as our climate changes that may change too. I saw three cases of imported Dengue in Connecticut last year, and all we need is the Aedes aegypti mosquito to set up shop here and our imported cases can become local! (Chronic Dengue in Connecticut, anyone?)

Just about the only positive thing to come out all of this, is that it’s pretty much guaranteed that my job will stay interesting for years to come.

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MRSA’s everywhere – ignore the MRSA

Ermahgerd! It’s MIRZAH!

MRSA, affectionately pronounced “mur-sah”, and the abbreviation for “methicillin resistant staphylococcus aureus”, has become the epidemic of our time.

Everyone thinks they know what it is. Few actually have a good handle on what it really means, especially with kids.

MRSA was first described back in good old Blighty in the 1960’s, not long after the drug methicillin was released in an attempt to combat the rise in penicillin-resistant staphylococcus aureus. In the modern era methicillin is no longer available, due to kidney toxicities that are much less in the current selection of anti-staph penicillins (nafcillin and oxacillin), but the MRSA tag remains in use.

In practical, and literal terms, it simply means that the organism in question is resistant to that particular antibiotic. Well, whoopdedoo. Lets just pick another. Except you can’t. The way in which staph becomes resistant to methicillin is through the production of an altered protein that renders the bug resistant to EVERY antibiotic in that entire FAMILY of antibiotics. Penicillin? Gone. Cephalosporins? Gone. Beta-lactamase inhibitors? Useless. Carbapenems? Fat chance.

So you go to another class – quinolones, aminoglycosides, tetracyclines, sulfonamides – but none of them are especially active against staph and…wait for it….MRSA is often resistant to these drugs too.

The first place in which MRSA was discovered was in healthcare settings – long-term care facilities and hospitals. The overuse and abuse of antibiotics selected for strains of bacteria that had acquired all sorts of resistance genes. In fact, the gene for hospital-acquired MRSA is a multi-segment behemoth that carries with it all sorts of additional genes, so the whole lot are inherited together. MRSA infections were associated with severe, invasive disease and death, usually in adults already weakened by other diseases. Due to delays in starting the right treatment, and being forced to use second-line, less effective drugs like vancomycin, MRSA infections add to hospital stays and healthcare costs. Like to the tune of $60,000 apiece.

Just as the world was getting used to dealing with MRSA in hospitals, we started hearing about it in the community. People were showing up with skin abscesses, boils and other infections that were, in about half of cases, growing out MRSA. Worse, they didn’t seem to have any link to the typical risk factors of diabetes, renal failure, cancer, prolonged hospital stay etc. And even more scarily, this was being seen in kids.

But they’re different from the old hospital-acquired MRSA cases. The community MRSA gene cassette is far smaller, lacking the resistance genes of the hospital MRSA. We have a small, but reliable list of antibiotics to use to treat it. Invasive disease is unusual, skin infections are the norm. I have not, yet, seen a real hospital-acquired strain of MRSA in a child. I have seen a few kids pick up MRSA while in the hospital, but it’s always been the “community” strain brought in by visitors, family or other patients.

Diagram of MRSA gene cassettes – hospital (top, types I thru III) versus community (bottom, types IV thru VI)

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Right now, I see a steady stream of kids with MRSA in my clinic and in the hospital. By far the vast majority are recurrent skin infections, often bouncing around various family members. Parents, reading up on MRSA online are understandably freaked out. Friends and relatives shun their kids, for fear of picking it up. Furnishings and furniture are steam-cleaned and thrown out, course after course of an antibiotic is given to treat each infection, but they never seem to go away. Even pets end up getting “swabbed” and tested in the lab, and yes, some are sent on their way as the presumed culprit.

None of this matters.

The truth of the matter is, while MRSA does indeed cause a good chunk of these kind of infections, it’s not got the hold on it. Just as many regular, sensitive staph (MSSA) cause these things. Fully one third of the population carries staph aureus on them – and clearly one third of the population is not suffering from recurrent skin infections. Carrying staph doesn’t mean you’ll get infections. And, annoyingly, you can test negative for staph from a swab (typically done from the nose) and still have infections elsewhere, such as the armpit, legs, or buttocks. We’re exposed to staph everywhere, all the time – and we mostly don’t even know it. That’s if we don’t have it already.

The reason why the skin infections keep happening is due to an entirely separate set of genes, related to immune evasion and skin invasion, which although more common in MRSA are also in some MSSA. (They are, interestingly, mostly absent in the hospital MRSA strains.) The way to get rid of it, if the levels are high enough for these infections to keep happening, is simply to decolonize the skin. That can be done with chlorhexidine washes and bactroban nasal ointment (a two week protocol), but you also have to prevent re-colonization, a more difficult proposition. Bathroom surfaces need to be bleached, towels washed daily (paper towels for hand washing) and EVERYONE in the household needs to have this done. There’s no point focusing on little Johnny with his butt abscesses if mommy and daddy, who are carriers, give him a hug and spread it back.

I never promise that with this approach staph will go away entirely. What we do know is that, if everything is done at once, you CAN eradicate staph at least temporarily from the skin. What we also know is that a third of the population carries staph….so wait long enough and you’ll get it again. I hope to merely reduce the frequency of outbreaks.

In my experience…this seems to work. Except in situations where kids have severe eczema or other skin issues, or where they’re not following EVERY step of the plan, I generally don’t see these kids back again.

So that’s prevention – what about cure? How should we treat these kinds of infections when they do show up? One drug that has seen a resurgence of late is bactrim – trimethoprim-sulfamethoxazole. A combination drug that is designed to inhibit the bacteria’s use of a chemical called folate which is a key component of DNA creation. It sounds good on paper, stop the bacteria from growing and it’ll die. In the lab, staph is often 99% sensitive or more (good odds when your risk of resistance to other staph drugs is around 50%!). The trouble is, in an abscess there is pus. And pus is basically dead and dying cells and bacteria. That’s a lot of DNA hanging around. Using bactrim in that setting is a lot like telling a farmer he can’t grow any more food, but putting him in a grocery store. He ain’t gonna starve any time soon. Bactrim also ignores the risk of strep, which are the other cause of skin infections and which are inherently resistant to bactrim. As such, deliberately targeting MRSA with this kind of approach actually results in MORE treatment failures than using a simple staph drug like cephalexin, even though that shouldn’t work with MRSA! You WILL get treatment failures with cephalexin too of course, and some with the other drugs like clindamycin, doxycycline etc. But it’s as if one should ignore the MRSA when planning your treatment. Drain abscesses (you usually don’t even need antibiotics if you do that) and then use a regular “skin infection” drug to minimize side effects and maximize your chances of success. These days we have NO ideal drug for empiric therapy of skin infections – but we certainly do worse if we panic about MRSA and try to tackle that first. Weird.

Of course sick patients are a different matter – even though the risk of severe invasive disease is low, the consequences are dire. You should ALWAYS cover a very sick patient with vancomycin or other MRSA drug until you know what you’re dealing with.

So I don’t panic about MRSA. I see it all the time. It’s annoying. It’s rarely dangerous. I know that if you focus on it to the detriment of the regular staph and strep you do worse. If someone is a carrier or has an active infection, good hand washing and covering any draining sites is enough to keep it at bay. No need to decontaminate entire schools just because a kid has been found to have MRSA. No need to put everyone on vancomycin if they’re not sick. And if they ARE sick, please don’t use vancomycin by itself, cos its a crappy drug and we only use it because we have to. Don’t bother swabbing just to check for carriage – positive results aren’t worth acting on unless the patient is sick (or, perhaps, due for surgery soon…that’s a whole other issue), and negative results are useless if the patient is actively infected. Deal with the infections, attempt decolonization, move on. Repeat if necessary.

MRSA – it’s a pain in the butt. And not just for the patients.

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How safe vaccines led to the resurgence of pertussis

For those who haven’t been under a rock recently, several parts of the US have seen a surge in pertussis cases. Much of this has been (fairly) blamed on anti-vaccination efforts to reduce herd immunity and the cocooning of vulnerable infants. But that’s not the whole story.

Interestingly enough, it’s now clear that the DTaP vaccine (diphtheria, tetanus, acellular pertussis) doesn’t provide long-lasting immunity. We had some clues with this as an awareness grew of pertussis in older teens and adults, fueled in part by vastly improved testing for pertussis (PCR versus ‘cough plates’ for culture) and a recognition that pertussis in older kids and adults didn’t look like the classic ‘whopping cough’ that youngsters got.

A booster dose of pertussis vaccine was recommended, included as part of the tetanus booster (the new Tdap vaccines). Recent outbreaks seemed to focus on the group of kids aged 10-11 years of age – when vaccine immunity was waning, but just before their Tdap booster – but the recent outbreak in Washington State has involved even 13-14 year olds, who did get their booster!

The question then should be – why does the NEW vaccine work LESS well? The answer is because it is SAFER.

The old DTP vaccine began to get a bad reputation for neurologic disease – in fact a contraindication still exists to withhold pertussis-containing vaccines in kids who develop neurologic issues after pertussis vaccination, even though the vaccine is different. The old DTP contain literally thousands of antigens, based as it was on a relatively impure cocktail of cell culture fragments that contained the pertussis bacteria. It caused a fair amount of immune reaction, and clearly was linked to febrile seizures.

Several high-profile cases of apparently neurologically damaged children (leading to the formation of some of the early modern anti-vaccine movement) pushed the vaccine manufacturers to create a cleaner vaccine, an ‘acellular’ pertussis vaccine, which is why we have DTP and DTaP. DTaP doesn’t have the same link of febrile seizures and no link to any neurologic issues (interestingly, as detailed in Paul Offit’s book on the history of antivaccine junk science, neither do any of the original DTP kids…it was all a big screwup). Tdap is even less immunogenic as it has slower concentration of antigens – you can tell this because it has a small “p” instead of a big “P”. True story.

The trouble of course is that by having a less inflammatory response, with far fewer antigens, the protection is less. The original DTP vaccine contained more antigens than the ENTIRE modern vaccine schedule does, several times over. Any statement about ‘too many too soon’ is pure bunk – our kids are exposed to fewer vaccine antigens in their entire schedule that we were in one vaccine.

This story highlights several points – firstly, contrary to antivax propaganda, not only are there mechanisms in place to detect and respond to potential vaccine side effects but there are CHANGES made to the vaccines in an attempt to keep people safe. (Probably the only positive thing to come out of the antivax movement is the establishment of the Vaccine Adverse Event Reporting System, VAERS). Secondly, there are compromises to be made – more effective sometimes also means more side effects, so if you want to lower one you may end up lowering the other.

There is also data from Europe that as the vaccine strains of pertussis wane, there is strain replacement with potentially more virulent strains. So although we are seeing fewer cases, those cases we do see may be more serious (this finding hasn’t yet held true for the US…as far as I know).

Of course the antivax brigade have twisted the story yet again “Whooping Cough Epidemic Caused by Virulent New Pertussis Strain—And It’s the Result of Vaccine” shouted one headline. While technically true it doesn’t really go into the real explanation of WHY…even more impressive, but entirely unsurprisingly to me, the actual article the antivax site uses to support their claim starts with the words “Before childhood vaccination was introduced in the 1940s, pertussis was a major cause of infant death world- wide. Widespread vaccination of children succeeded in reducing illness and death.” which not only proves how disingenuous antivax proponents are, but how stupid they are. The first rule of selective quotation is to use sources that support your argument.

Sadly, those who believe antivax propaganda are not usually stupid – if anything they tend to be more educated than average, and well read. They just read the wrong things. Not everyone can go to medical school after all.

Then again, even that isn’t foolproof. One of the original antivax “Expert” witnesses from the UK trials that showed the DTP link with neurologic illness to be wrong went on to further his infamy with AIDS denialism.

Much of the details on the stories of the DTP and DTaP history are in Paul Offit’s book – Deadly Choices, which I highly recommend. In it he not only details how antivax proponents twist science and the facts to suit their case, but also how they nearly brought down the entire US vaccine industry through irresponsible and indefensible litigation. The vaccine WORKS to reduce serious illness from pertussis and undoubtedly saves lives. It’s not perfect, no one has ever said a vaccine was perfect – at least, not unless they were trying to make a point that it wasn’t…

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Gardasil hysteria plays into hands of pediatricians

20110813-221604.jpgCartoon by Ben Lansing – from Age of Autism website

Stories like this one at anti vaccine sites are unfortunately typical in their misinformation and use of hyperbole and sound bites rather than informing the reader in a non-biased manner. What I found amusing is that the specific approach used in this article actually plays into the hands of pediatricians…

Let’s ignore the rhetoric of the “dangerous” HPV vaccine (it is not) or the claim that it has caused “as many as twelve deaths in the US alone” (it has not) and focus on the headline of the piece.

“California mulls giving 12-year-olds STD vaccine Gardasil without parental consent”

While being technically correct that Gardasil does indeed protect against a sexually transmitted virus, the implications here are clear – anything involving 12 years olds and STDs is immoral, and anything where the parents have no say is unethical. Putting the two together is an order of magnitude worse!

Far from implying that 12 year olds are “sexual animals” (their words, not mine) the simple fact is that the 11-12 year old well-child visit is a perfect time to address many aspects of preventative care before the child becomes a teenager. This is why the vaccine is recommended at 11 years even though it is approved down to 9 years of age. Updating the vaccines at that visit is a no-brainer. With any luck the kids are NOT YET “sexual animals”, because ideally you want to protect them before that happens. Getting the HPV shots started 6 months before a teen’s “big night” is, I’m sure, not something they have on the calendar…and having taken care of my share of teenage mothers I can vouch for the fact that planning their sexual activity is clearly not something they are very good at at all.

Sexual health for teens includes proper counseling, education, and access to contraception. Abstinence is the most obvious way to avoid STDs and unwanted pregnancies, but abstinence-only education is associated with HIGHER rates of pregnancy and SIMILAR rates of STDs than more well-rounded education! Over half of abstinence “pledgers” will still go on to have pre-marital sex, the same rate as teens who don’t pledge abstinence (80% in fact denied ever having pledged in the first place…) While there may be an initial delay in the first sexual episode, after that the lack of proper education really does these people a disservice (if they are delaying sex, but their STD rates are similar, then someone is playing catch-up!) Not giving them a vaccine that, if all three shots are given on time, protects against 70% of cervical cancer is simply wrong.

The second part is whether or not parents have a say. In general, parents operate under the assumption that they are responsible for the health and well-being of their child until they are an adult. They get to call the shots (pardon the pun) and have access to all the information. Sadly, as some discover, that simply isn’t true. Parents do have the responsibility to take care of their kids, but if they fail to do so then the authorities can step in and take over that responsibility – most obviously in cases of child abuse or neglect. Effectively the State acts as if it is responsible for the welfare of children and merely delegates that responsibility to the kids’ parents or legal guardians – a delegation they can revoke if need be. But a lesser known area where parents lose their right to control their kid’s healthcare is sexual health.

It is clear that in order for teens to feel safe about coming forward to ask for help with sexual health issues, this MUST be done under strict confidentiality. Having a requirement that parents provide consent to treat (as is needed for every other situation except life-threatening emergencies) is a barrier to effective safe treatment of teens sexual health issues. The laws vary by State but in many places minors are allowed access to confidential sexual healthcare.

Ironically perhaps, by trying to demonize Gardasil as a way in which the medical establishment is sexualizing the youth of today, and labeling it explicitly as a sexual health vaccine, antivax groups are automatically putting it outside the remit of parental oversight. In the same way as a sexually active teen can (and should) get advice, contraception or treatment for STDs without fear of their parents knowing about it, I see no reason why they shouldn’t be allowed to ask for a sexual health vaccine under the same existing laws.

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Vaccines, choice, and training rabbits

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Just for a moment I’m going to take the view that vaccines are, you know, safe and effective. Sure, there are known side effects, mostly mild short-lived things like injection-site reactions or fever, but Bad Things do happen (e.g. Vaccine Associated Paralytic Polio from the live oral polio vaccine). On balance though it is clear that the benefits of vaccination to society as a whole outweigh the risks to society as a whole. Their success is measured in what we DON’T see – the 20,000 HiB cases a year, the 80-90% drop in pneumococcal disease from vaccine strains, the congenital rubella cases that every medical student knows how to spot (“Blueberry Muffin” baby, cataracts, persistent ductus arteriosus) but will likely never see in their professional lifetime. Safety monitoring is there, as imperfect as it is, which is why for example we don’t have oral polio vaccine in the US any more, and why the first rotavirus vaccine was pulled from the market.

So if we were to take a purely logical view on the matter, vaccination is a no-brainer. For many Docs this is why they get so irate about vaccine refusers. We learn about the diseases and the successes, and find it hard to fathom how you could come to any different conclusion. But clearly people do. There are unfounded fears about “too many too soon”, or aluminum adjuvants that add less exposure than breastmilk, or the fraudulent claim of autism causation that ended up being a scam for one Doc (the infamous Andrew Wakefield) to sell his own measles vaccine. Some parents are simply worried based on a previous bad reaction (I know I was, based on the way my eldest acted after his 2 month shots). Others have a genuine religious belief about medical interventions, and vaccination is just one aspect of that.

So then we run up against the problem of how to deal with this issue. As a general rule of thumb, it is accepted that a patient has the right to refuse aspects of their healthcare. There are very few exceptions to that rule, usually in the interests of others in society – forced hospitalization of mentally ill people who pose a threat to themselves or others, or cases of medical neglect where the State assumes responsibility for the medical decisions of a child when the parent puts them at risk, or Directly Observed Therapy for TB, where optimal treatment is paramount and doses should not be skipped. Things like that.

But vaccines are put into a different category. Why? I think the biggest, most obvious difference is that we’re not talking about treatment of someone with a disease, where inaction has obvious consequences, but rather an intervention to a typically healthy individual. In fact, moderate illness (enough to require hospitalization) is one reason to consider delaying vaccination, as the immunization might not work as well. As such, even though the results of inaction can be severe, resulting in death or disability, and inaction certainly has an impact on others in society, there is a natural reluctance to literally force vaccination upon people. Instead, there are more insidious ways to encourage vaccination through school mandates etc. Vaccines are not mandatory, you just have to get them. (If you can understand that, let me know, as that was how a non-mandatory examination was explained to us in medical school…)

As one approach, I am going to use the analogy of rabbits. Above you can see Princess Lulu Merryweather, an Old English Mini-Lop who was with us for over 8 years before succumbing to a pasteurella abscess. Lulu was a house rabbit and was pretty much housetrained. She knew a basic list of commands and would poop in her cage. The training of a bunny is interesting – as a prey animal they do not respond well to the typical training one might use with a predator animal such as a dog or cat. They are more like a horse, and respond best to coercion rather than discipline. In fact, an effective way to get them to do what you want is to embarrass them. This is difficult to do. It generally involves stamping your foot, turning your back on them, but trying to make eye contact so you know that they know that you are displeased. If you’ve ever had a bunny and told them off for something, you’ve probably seen them do this to you. There were several occasions when, as a kitten, she would pee on the couch and we would both end up stamping and back-turning on each other as I would tell her not to do that, and she would try to tell me not to shoo her off the couch. It was her couch, after all. (Did I mention the “Princess” part was added later? It was more a description than a title…)

So, since the decision not to vaccinate is often based more on emotion than logic, it seems reasonable that for some people (not all of course) an emotional approach will work better than a logical one. Human beings are hard-wired to fear bad things from an action (to vaccinate) more than from inaction (not vaccinating), even though a decision to do nothing is still technically a decision, and fear after all is an emotion. I wonder then if pressure from society, an explicit message that says that unvaccinated kids are an unacceptable risk to others would work. Peer pressure. At the moment we have an attitude of tolerance on the whole – barely more than a raised eyebrow, more often a nod of understanding. There may be pressure from the Docs and schools who are trying to protect society from itself, but there needs to be a grass-roots movement among the parents in my opinion.

I’m not entirely sure yet how exactly to go about doing this. I don’t agree with literally holding a parent back while we forcibly inject their child – since after all we do live in an age where many of the preventable diseases are at very low levels, and that goes against every fiber of my “patient-centered” being. I would much rather have informed decision-making – I just realize that for many their mind is made up no matter what facts I lay out and what misconceptions I correct. What I would like to see is an attitude of personal responsibility to temper the push for personal freedoms. Parents should WANT to vaccinate. Currently most fall into the “I don’t care” or the “I don’t want to” camps. That kind of paradigm shift may be slow coming, and I’m open for suggestions on how that might occur. We can’t use a stick, we need to use the carrot.

And maybe some foot-stomping.

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