This summer a Salmonella outbreak traced to contaminated eggs has sickened over 1,000 people and led to the recall of over 500 million eggs.

Eggs are particularly susceptible to Salmonella contamination.  The outsides of egg shells can be contaminated by bacteria if they come into contact with chicken droppings or with dirt.  That’s why you should discard cracked or dirty eggs.  The shell itself is fairly resistant to bacteria, but if the chicken is infected with Salmonella then the eggs it produces will contain Salmonella also, inside the shell.

The risk of getting sick is decreased substantially by safe food procedures that kill Salmonella or inhibit its growth.  Eggs should be kept refrigerated at all times.  Eggs should be cooked thoroughly so that the whites and yolk are solid.  And eggs should be eaten promptly after they are cooked.

Check out the tips from the Centers of Disease Control (link below) for more simple suggestions to avoid a Salmonella side dish.

Learn more:

The Centers for Disease Control and Prevention:  Tips to Reduce your Risk of Salmonella from Eggs

Wall Street Journal article:  Eggs’ ‘Grade A’ Stamp Isn’t What It Seems

Tangential miscellany:

I wish everyone a happy and safe Labor Day, and I wish my Jewish readers a healthy, sweet and prosperous year.  There won’t be a post next week, but your appetite for health-related news will again be sated the week after that.

Summertime, and the livin’ is uneasy
Stocks are slumpin’
Unemployment is high

(with apologies to George Gershwin)

Reminders of the end of summer are upon us.  Kids are returning to school.  Rain covers are thrown over backyard grills.  Flu vaccines are arriving in doctor offices.

This season’s influenza vaccine is here.  It contains the flu strains most likely to reach North America this fall including H1N1, the flu strain formerly known as swine flu which caused so much hoopla last year.

The Centers of Disease Control this year decided that that the flu shot should be recommended for everyone over 6 months of age so as to limit the spread of flu and protect more people.  The vaccine is particularly important for the following groups:

• Pregnant women
• Children younger than 5, but especially children younger than 2 years old
• People 50 years of age and older
• People of any age with certain chronic medical conditions
• People who live in nursing homes and other long-term care facilities
• People who live with or care for those at high risk for complications from flu, including:
  • Health care workers
  • Household contacts of persons at high risk for complications from the flu
  • Household contacts and out of home caregivers of children less than 6 months of age (these children are too young to be vaccinated)

The following people should not be vaccinated:

• People who have a severe allergy to chicken eggs.
• People who have had a severe reaction to an influenza vaccination.
• People who developed Guillain-Barré syndrome (GBS) within 6 weeks of getting an influenza vaccine.
• Children less than 6 months of age (influenza vaccine is not approved for this age group), and
• People who have a moderate-to-severe illness with a fever (they should wait until they recover to get vaccinated.)

So get your flu shot now, and start dreaming of an influenza-free winter.

Learn more:

The Centers for Disease Control and Prevention:  Key Facts About Seasonal Flu Vaccine

Varicella zoster virus (VZV) is the virus that causes chicken pox, usually a relatively minor childhood illness.  Unlike other viruses that are cleared from our bodies after infection, VZV stays in our sensory nerve cells forever.  Over the subsequent decades our immunity to VZV wanes.  When our immunity falls too low, VZV can reactivate and cause shingles.  Shingles is a painful blistering rash along the distribution of one sensory nerve.  The rash resolves in a few weeks, but in some older patients the effected patch of skin can remain painful for months or even permanently.  This painful condition after shingles is called postherpetic neuralgia and it can be quite debilitating.

In 2006 a vaccine to prevent shingles, Zostavax, became available.  It is recommended for everyone over 60 who has had chicken pox.  It has been proven effective in preventing shingles, and therefore in preventing postherpetic neuralgia.

But is Zostavax safe?  A large study in the current issue of Annals of Internal Medicine answered that question.  The study randomized over 38,000 patients to receive Zostavax or a placebo injection.  The side effects from Zostavax were not worse than from placebo.  Most of the side effects (like most vaccines) involved inflammation at the site of injection.

So to summarize, Zostavax is safe, and it effectively prevents a very painful potentially disabling condition. Recall also that all children are now being vaccinated against chicken pox, so that in 60 years Zostavax will not even be necessary since a generation will have grown up uninfected with VZV.

In anything resembling a rational healthcare delivery system champagne corks would fly, the makers of Zostavax would get a pat on the back (and well-deserved profits) and we would all shift our attention to more pressing matters.  Some patients would decide to buy Zostavax; some would not.  Private or government charity programs would pay for the vaccine for indigent patients.  Joy and health would reign.

But instead, there is gnashing of teeth and wringing of hands.  Why?  Because only about 7% of eligible patients have received the vaccine.  It turns out Zostavax is the most expensive vaccine recommended for adults (about $200) and the first to be covered by Medicare part D, the Medicare drug “benefit”.  That means pharmacists are paid to dispense it to patients, not doctors.

To sort out why more patients aren’t receiving Zostavax, another study in the same issue of Annals of Internal Medicine surveyed hundreds of primary care doctors about the barriers that might be preventing them from recommending and administering Zostavax to their patients.  The results: the biggest barrier was financial.  Many patients without coverage don’t want to pay for it, and doctors aren’t being paid by insurance companies to administer it.

This was such a staggeringly shocking finding, that it merited an editorial in the very same issue of Annals.  That’s three articles about a vaccine that works as intended and is safe.  The editorial opines that reimbursement should be revised to promote increased utilization of the vaccine.  In other words, we should take more money from other people to assure that patients who don’t want to pay for their own Zostavax can get it for free.

Now don’t get me wrong, I’m all for charity care for indigent patients.  (I volunteer at a clinic that serves indigent patients two afternoons a month.)  But the vast majority of patients who aren’t getting Zostavax aren’t poor; they just have better things to do with $200.

What the editorial didn’t say is that you can’t do much better than a product or service in which the main barrier to obtaining more is the price.  After all, that’s the only reason we don’t get twice as many clothes or cars or homes.  If the price was lower, we would.  If Zostavax was free, some other barrier to its use would necessarily arise, perhaps a lengthy wait, or a difficult to navigate bureaucracy, or rationing by some other means.

So perhaps each patient should shoulder the cost of his or her own Zostavax.  We should also all donate a little time or money for those who truly can’t afford it.  And some of us may rationally choose to accept the risk of shingles.  Alternatively, we could riot in Athens until the EU pays to keep us all shingles-free.

Learn more:

Annals of Internal Medicine Summary for Patients:  Safety of the Vaccine to Prevent Shingles

Annals of Internal Medicine article:  Safety of Herpes Zoster Vaccine in the Shingles Prevention Study

Annals of Internal Medicine article:  Barriers to the Use of Herpes Zoster Vaccine

Annals of Internal Medicine editorial:  The Looming Rash of Herpes Zoster and the Challenge of Adult Immunization

In a world where journalism was free of hype the above headline would have been atop the many stories this week relating to a press release by the CDC about food-borne illness.  The numbers are far less sensational than the headlines.

The CDC report reviewed statistics about food-borne illnesses in 2009.  Overall there were 17,468 laboratory-confirmed food-borne infections in 2009.  What the CDC press release doesn’t mention is that this number has stayed about the same for several years.  (It was 17,883 in 2007.)  But rather than putting out a press release that declares “We’re Doing About the Same!” they focused on the bacteria that seem to have caused fewer infections this year, like a toxic strain of E. coli.  (See the link below.)

The bottom line is that you’re about twice as likely to die in a car accident in the US than to get sick from contaminated food.  (There were 39,800 fatalities related to motor vehicles in 2008.)  The CDC may in fact deserve some credit for that.

But the last several years suggest that the easy improvements have already been made and that further progress will be more difficult and incremental.  The bacteria, after all, will continue doing their best to contaminate our food.

Learn more:

CDC Press Release:  CDC Report Shows Success in Fighting E. coli O157:H7

Wall Street Journal article:  E. Coli Infections Dropped Last Year

Reuters article:  U.S. sees big drop in 6 food poisoning bugs: CDC

LA Times Booster Shots:  Early signs of progress against E. coli and shigella, but listeria, salmonella …?

Ideas have consequences.  False ideas, especially popular false ideas, can cause harm.  For example, the very popular false idea “corduroy pants and wide lapels are far out, man” made an entire nation ugly for about a decade.  And some false ideas do even more harm than that.

In 1998 the British medical journal The Lancet published a paper authored by Dr. Andrew Wakefield that claimed to link autism to the vaccine against measles, mumps and rubella (MMR).  The study looked at 12 children (that’s right, twelve, not twelve thousand) with developmental abnormalities and intestinal conditions that may have presented after the administration of MMR.

This supposed association spawned a large popular movement that urged suspicion of vaccines and recommended that parents refuse vaccines or delay their children’s immunizations.  Multiple subsequent larger studies have refuted the conclusions of the 1998 article, repeatedly finding no link between vaccinations and autism.  But undeterred by the actual evidence, the anti-vaccine movement continued to spread unfounded allegations, frightening parents about vaccines.

The consequences of this false idea were predictable, and devastating.  In the UK and US, vaccination rates dropped and in the last few years epidemics of measles have occurred.  Despite the decreased vaccination rate, the incidence of autism has not decreased, and the true cause of autism remains elusive.  Meanwhile Dr. Wakefield, the author of the 1998 study, has become a celebrity in the anti-vaccine movement, as its disciples have only his small study to lean on.

Recently, The Lancet learned that the study itself was deeply flawed.  First, the 12 patients were chosen in a way that could have introduced a great element of bias.  Second, many invasive and medically unnecessary procedures were done on the children without oversight of a research ethics board and without parental consent (an important protection that is mandatory in all research on human subjects).  Finally, Dr. Wakefield did not disclose that he received funding from attorneys with litigation against vaccine manufacturers.

So this week the editors of The Lancet publicly retracted the 1998 study.  Dr. Wakefield has been discredited and the anti-vaccination movement lost their last thread of scientific credibility.

I hope that public figures like Jenny McCarthy and Robert F. Kennedy Jr. who have promoted the false and lethal idea that vaccines cause autism will take this opportunity to publically recant and find less pernicious crusades to pursue.  I’m waiting for their announcement, but I may be waiting until corduroy pants make a comeback.

Tangential miscellany:

My post last week about normal weight obesity generated many interesting comments.  One attentive reader corrected me that fat is never converted to muscle.  That’s true.  I should not have used that phrase.  Fat cells remain fat cells forever, and muscle cells remain muscle cells.  Exercise burns fat, shrinking fat cells and enlarging muscle cells.  I appreciate the correction and changed the wording of the original post.

Learn more:

NY Times article:  Journal Retracts 1998 Paper Linking Autism to Vaccines

Retraction in The Lancet:  Retraction—Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children

BBC News article from a year ago:  Rise in measles ‘very worrying’

You may not yet have heard of the bacterium Clostridium difficile (C. dif.), but in the next few years it will likely become a household name, as well known as Staph and Strep.  C. dif. causes a severe infection of the colon leading to severe diarrhea.  It frequently results as a consequence of antibiotic use.  Antibiotics can kill the normal intestinal bacteria and allow harmful bacteria like C. dif. to proliferate.

Decades ago, C. dif. infection was a minor nuisance, but in the last decade, due perhaps to increasing use of broad-spectrum antibiotics, C. dif. has become more common and more severe.  Many patients, especially older patients, require hospitalization for C. dif. diarrhea.  Besides causing severe dehydration, C. dif. can cause systemic infection and sometimes death.

Ironically, the typical treatment for C. dif. colitis is antibiotics.  But since antibiotics don’t allow the normal gut bacteria to return, recurrence of C. dif. diarrhea after treatment is completed is a frequent problem.  In hospitals and nursing homes spread of C. dif. has become a menace.

A study published in this issue of the New England Journal of Medicine offers hope against this worsening problem.  The study randomized 200 patients with C. dif. diarrhea.  All patients received conventional antibiotic treatment.  Half the patients also received a new intravenous antibody directed at C. dif. toxin; the other half received intravenous placebo.  The results were encouraging.  Only 7% of the patients that received the intravenous antibody developed another episode of C. dif. infection, compared to 25% receiving placebo.  That means that for every about six patients that receive the antibody, one recurrent infection is prevented.

This new treatment will have to undergo larger trials before it is approved.  In the meantime the cornerstones of C. dif. prevention remain judicious antibiotic use and preventing spread between patients in hospitals and nursing homes.

Learn more:

New England Journal of Medicine article:  Treatment with Monoclonal Antibodies against Clostridium difficile Toxins

New England Journal of Medicine editorial:  Clostridium difficile — Beyond Antibiotics

Forbes post on The Science Business:  Why You Should Care About Treatment with Monoclonal Antibodies against Clostridium difficile Toxins

Short work weeks make for short posts, doubly so when virtually all the health-related news is about the healthcare bill in Congress. So I’ll end the year with two unrelated bits of good news.

The first is that the H1N1 flu pandemic is mostly behind us. The peak numbers of people getting sick both nationally and in California was about two months ago, with decreasing numbers ever since. As predicted by yours truly in April, the world did not end (though a bunch of my patients were plenty miserable).

The second bit of good news is that Americans are living longer then ever. In 2007, the most recent year for which statistics are available, average life expectancy at birth crept up to a record high of 77.9 years. That’s an average, so many of us will live longer. So for everyone who had a mediocre 2009, here’s hoping you have many better years ahead.

Tangential miscellany:

Posting will be suspended next week and will resume in the New Year. Merry Christmas to all who are celebrating, and to all of us a prosperous, healthy and happy 2010!

Learn more:

Follow the H1N1 flu trends at the Centers for Disease Control FluView Weekly Report or at Google Flu Trends

The statistic about your increasing life expectancy is from the LA Times Booster Shots post: U.S. birth rates back on the rise

One of the first outpatient problems a primary care trainee learns to manage is sore throat.  The current algorithm is fairly simple.  Most sore throats are caused by viruses and will not improve with antibiotics.  Symptomatic medication for pain and fever is the best we can offer.  But a significant minority of sore throats is caused by a bacterium called group A β-hemolytic streptococcus.  These cases are more commonly known as “strep throat”.  In strep throat antibiotics shorten the duration of symptoms by a day or two, but more importantly antibiotics prevent acute rheumatic fever, a potentially dangerous complication of untreated strep throat.

So the algorithm for evaluating sore throats is: decide if it’s strep.  If it is (or has a reasonable likelihood of being) strep then treat with antibiotics; otherwise don’t.

An article in this issue of Annals of Internal Medicine suggests that this algorithm is inadequate in adolescents and young adults.  The reason is that about 10% of sore throats in patients between 15 and 24 years old is caused by a bacterium called Fusobacterium necrophorum.  (Please memorize that name and mention it at your next holiday party.)  F. necrophorum also causes Lemierre Syndrome, a bacterial infection of the internal jugular vein that results in the bacteria spreading elsewhere in the body.  Lemierre Syndrome frequently results in permanent harm and is sometimes fatal.  Though much remains unknown about F. necrophorum, it appears to cause sore throats as commonly as strep in adolescents and young adults, and Lemierre Syndrome in this age group appears to be more common than acute rheumatic fever.

Diagnosing F. necrophorum pharyngitis is problematic.  F. necrophorum doesn’t grow on a standard throat culture.  (It’s anaerobic, meaning it only grows in the absence of oxygen.)  And specific molecular tests for it are not commercially available.

So the author recommends that antibiotics be prescribed for 15 to 24 year olds with sore throats and at least 3 of the following 4 findings.

• history of fever
• pus on the tonsils
• swollen tender lymph nodes in the neck
• absence of cough

(Note for doctors: use penicillins or cephalosporins.  Macrolides are ineffective against F. necrophorum.)

In that age group worsening symptoms or neck swelling should be alarm signs that F. necrophorum is present.

Our simplest clinical problem just got more complicated.  That’s a good sign that we’re learning something.

Learn more:

Annals of Internal Medicine article:  Expand the Pharyngitis Paradigm for Adolescents and Young Adults

My last post, “Should You Have a Pap Smear?”, generated an avalanche of wisecracks from my male readers, mostly declining.  Thanks for that!

I want to write another post about H1N1 flu about as much as I’d like to pour lemon juice on my paper cuts.  But there’s absolutely no other medical news to report and many of you are still much attuned to this developing story.

Today’s Wall Street Journal summarized the most recent data well (link below).  Since the virus first spread to humans in April, swine flu has sickened 22 million Americans.  That’s about 7% of us.  The vast majority of illnesses have been mild.  Still, 98,000 people have been hospitalized.  That sounds like a lot, but it’s fewer than 1 in 200 people who have contracted swine flu.  3,900 have died so far, a terrifying number until we compare it to the approximately 36,000 who die annually of garden-variety seasonal flu.  That means that, on average, fewer than one in 75,000 swine flu patients die.

Having said that, flu activity both nationally and in California are very high, not just high for this time of year, but higher than some previous flu seasons at their December-January peaks.  That means a lot of people are getting sick.  (Among them are several of my patients and my wife and my son.)  The best advice to minimize transmission is still to stay home if you’re sick, wash your hands frequently and cover your cough.

So the most important bit of good news to keep in mind is that for most people, swine flu is a mild illness.  The second bit of good news is that both Google Flu Trends and the CDC (links below) suggest that the peak of new cases may have happened two weeks ago.  If that’s the case, then the rate of new infections is on the decline and the worst may be behind us.  Only time will tell.

Take a big breath.  We’ll get through this.

Learn more:

Wall Street Journal article:  Swine Flu Sickens 22 Million

Google Flu Trends

If you really want to dive into the latest data, there’s no better place than the Centers for Disease Control H1N1 Flu Situation Update page

Last week I lamented that we can prevent so few cancers.  Cervical cancer screening is one of the success stories of prevention.  Regular pap smears can drastically decrease the risk of cervical cancer and makes death from cervical cancer virtually unheard of.

Cervical cancer is a sexually transmitted disease, caused by human pappilomavirus (HPV).  Pap smears check for telltale changes in the cervix that happen after HPV infection.   Over many years these changes lead to cervical cancer.

But while potentially life-saving for some women, other women can not benefit from pap smears and should not have them.  A study in this issue of the Annals of Internal Medicine interviewed physicians about the kinds of patients to whom they would recommend pap smears and found that many doctors perform pap smears on women for whom it is not helpful.

Below is a summary of the U.S. Preventive Services Task Force recommendations for pap smears.  More details are available by following the links below.

• Women who have been sexually active and have a cervix should have pap tests. Pap tests should begin within 3 years of onset of sexual activity or age 21, which ever comes first, and should be repeated at least every 3 years.
• Women older than 65 who have had recent normal pap smears should not have further pap tests. This is because cervical cancer this late in life is very rare and would have already caused abnormal pap smears.
• Women who no longer have a cervix because of a hysterectomy for a benign disease (that is, not for cancer) should not have further pap tests. That’s because it’s impossible to get cervical cancer without a cervix.

Like all good things, the benefit is derived from judicious use.  Even though in other women the test is crucial, performing pap tests on women who can not benefit from it is just bad medicine.  It falsely reassures women that they are taking care of themselves.  It wastes patients’ time and scarce resources.  And it ultimately decreases physician credibility.

Learn more:

U.S. Preventive Services Task Force recommendations for cervical cancer screening

Wall Street Journal Health Blog:  Who Should Get a Pap Smear?

Annals of Internal Medicine article:  Specialty Differences in Primary Care Physician Reports of Papanicolaou Test Screening Practices: A National Survey, 2006 to 2007