Saturday, January 31, 2015

Measles Continues to Make a Comeback

Childhood diseases that were virtually eliminated by childhood vaccination programs over the past 50 years are beginning to show up again. For example, on average there were fewer than 100 cases of measles per year between 2001 and 2013. Last year alone there were 644 cases - more than a 5-fold increase in a single year! The majority of the persons who contracted measles in 2014 were unvaccinated. The latest outbreak apparently began at Disneyland in December with a family of four who had not been vaccinated. By the end of January there were 54 more cases, 40 of them Disneyland park employees or visitors.

Measles is one of the most contagious viral infections known. On average, a person with measles will infect 12-18 people who are unvaccinated. In contrast, a person with the flu only infects 1-4 other people. Fortunately, there's been vaccine against measles for the past 50 years. The vaccine is 97% effective if the person has received the two prescribed doses, according to the Centers for Disease Control and Prevention (CDC). But with more and more parents choosing not to have their children vaccinated there's always the potential for an outbreak such as the one we're having now. This outbreak is simply not a surprise. I first discussed the resurgence of measles more than six years ago (see this blog Aug. 25, 2008), when the number of measles cases spiked up briefly.

I won't beat around the bush here; I hold the anti-vaccine movement responsible for the recent resurgence of preventable infectious diseases.  I'm disappointed when people deliberately choose to remain uninformed.

Monday, January 26, 2015

Preventing the Spread of Bioengineered Bacteria

Bacteria have been bioengineered (genetically modified) for all sorts of reasons. Some are used to make pharmaceuticals or chemicals; others can degrade specific toxic substances. And although it hasn't happened yet, scientists are concerned that sooner or later, one of these bacteria will get out of the laboratory or industrial plant and cause disease or damage the environment. Could such an accident be prevented?

Scientists at Yale University think they have found a way. They insert a genetic code into bacteria that encodes for a synthetic amino acid that is not present in the environment naturally. That way, the bacteria are totally dependent on that particular amino acid for growth and reproduction. Any bacteria that escape into the environment simply wouldn't survive or reproduce.

Most bioengineered bacteria are used within enclosed environments, such as a research laboratory or an industrial production facility. But one could envision how making a bioengineered bacteria totally dependent on a synthetic amino acid might allow the bacteria to be used effective outside the laboratory as well, without fear of the bacteria getting out of control. For example, bacteria that had been modified to degrade oil at an oil spill site could be restricted to that site by spraying the synthetic amino acid only on the location of the spill.

It's an interesting idea.

Wednesday, January 21, 2015

A Wearable Patch for Allergy Desensitization

Food allergies can sometimes be so severe that they can lead to anaphylaxis, an allergic reaction in which a person's airway swells, blocking normal breathing. Some food allergies are so severe that exposure to even the tiniest amount can be life-threatening. Peanuts, eggs, milk, fish, shellfish, and wheat are among the most common food allergens.

One way to treat a person with a food allergy is to inject the allergen - at truly miniscule doses at first, and then when the patient's immune system begins to tolerate the allergen, slowly raising the dose. Another is to have the patient eat (ingest) miniscule amounts of the allergen. Both methods must be done under close supervision. If done properly, the patient gradually becomes "desensitized" to the allergen, that is, he/she becomes able to tolerate higher doses of the allergen. Although there is no guarantee that a person's food allergy will go completely away, desensitization can potentially reduce an allergic reaction enough that an allergic reaction is no longer life-threatening. The problem is that these desensitization methods (injection or ingestion) are somewhat risky - there's always the possibility that too big of an immune reaction (anaphylaxis) will be triggered by one of the treatment doses.

But now a French firm may have a better way. DBV Technologies has developed a plastic patch called Viaskin designed to deliver small doses of allergen slowly and directly into the skin. In the skin the allergen is taken up by cells of the lymphatic system and delivered directly to immune cells in lymph nodes, where the immune response takes place. Because the allergen never enters the bloodstream, the risk of anaphylaxis is reduced.

Initial clinical trials to test the safety and effectiveness of Viaskin using peanut allergen are encouraging. It is likely to be several years before Viaskin is available (more clinical trials are planned), but the company is so confident that it is already working on Viaskin products for milk allergies and for allergies to house dust and mites.

For more on this subject, go to a previous blog post titled "New Uses for Wearable Skin Patches."

Tuesday, January 13, 2015

Screening for Lung Cancer

Testing individuals who appear to be healthy for signs of a particular disease is called screening. The hope is to find the disease before it has caused undue harm and while it can still be treated. But when the disease is not common or the screening test is expensive, it's simply not cost effective to screen everyone. That's why epidemiologists and health professionals try to develop screening guidelines that focus sub-populations of the population that are at the highest risk. By screening only those most likely to have or get the disease or condition, expensive screening tests DO become cost-effective, at least for that specific group.

So, how about screening for lung cancer? The best test for detecting lung tumors while they are still small enough to be treated is low-dose computed tomography (LDCT). The test is expensive, so screening everyone just isn't practical. That's where the U.S. Preventive Services Task Force USPSTF comes in. The task force is charged with determining which screening tests should be made available to whom, based on a risk/benefit analysis. In 2014 the USPSTF revised their screening recommendations for lung cancer. Under the new guidelines, annual LDCT screening for lung cancer is now recommended for all persons aged 55-80 who have a 30 pack-year history and who are still smoking or have quit within the past 15 years. In 2008, over 7 million U.S. adults were 30- pack-year smokers! Screening all smokers in this high-risk group every year could save more than 20,000 lives per year.

For your information, "pack-years" is the product of packs smoked per day times years smoked. A thirty pack-year smoker has smoked at least a pack a day for 30 years, or two packs a day for 15 years, or three packs a day for 10 get the idea. If you're not a 30 pack-year smoker you aren't eligible for this screening, meaning that your medical insurance probably won't pay for it.

Monday, January 12, 2015

Bone Broth: The Latest Trendy Drink

Are you a believer in the health benefits of bone broth? Do you make it from scratch in your own home, or sip it in a trendy boutique? Seriously? You need to read two articles: A feature article in the New York Times, and a rebuttal article in the Huffington Post. Together, they'll give you a pretty good sense of the breadth of opinions about bone broth.

Who is right, do you think?

Sunday, January 4, 2015

Current Guidelines for HIV Screening

The USPSTF currently recommends routine screening for HIV infection for all adults between the ages of 15 and 64, all pregnant women, and persons of any age who are "at risk". The current recommendations were last updated in 2013; before that, the USPSTF did not recommend routine screening for HIV.

The Centers for Disease Prevention and Control (CDC) has been recommending routine screening for HIV since 2006, so the fact that the USPSTF ultimately came to the same conclusion (albeit seven years later) shouldn't have been a big surprise. However, the USPSTF's recommendations carry more weight than the CDC's, because under the Affordable Care Act private insurance companies are required to pay for preventive services that the USPSTF recommends with grades of "A" or "B". These recommendations were given a grade "A" level of approval.

For more on this subject, see a previous blog post titled "A Home Test for HIV". 

Friday, January 2, 2015

Compounding Pharmacy Executives Face Murder Charges

Back in 2012 a compounding pharmacy in New England made some injectable steroid compounds that caused an outbreak of fungal meningitis, ultimately killing 64 people in nine states. At the time, (see "Drug Compounding Pharmacies") I pointed out that compounding pharmacies are regulated by state boards of pharmacy, not by the federal government, making it difficult to oversee facilities pharmacies that sell their products across state lines. It wasn't even clear when (or if) anyone would be held accountable.

Well, finally: the United States attorney's office in Massachusetts has just charged 14 people with crimes associated with the event. An owner of the company and the company's head pharmacist were each charged with 25 counts of second-degree murder in seven states; both could receive maximum sentences of life in prison if convicted. According to the indictment, the two knew that the drugs they were producing were not being tested properly for sterility, but they permitted the company to continue producing and shipping the drugs anyway. (Oops!) Twelve other people were charged with various related crimes including mail fraud, conspiracy, and violation of the Food, Drug and Cosmetic act. Some of those charged were pharmacists working at the company.

The company ceased operation and declared bankruptcy after the 64 deaths. But that probably wasn't enough for relatives of the deceased, especially when (according to an FBI press release), several of the owners tried to transfer 33 million in assets to various banks after a court had ordered the company's assets frozen. We'll be watching to see who (if anyone) actually goes to jail.