infectious diseases

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Opting-Out Of Vaccines; Dipping Below Herd Immunity

Graphic Credit: Jan Willem Tulp http://tulpinteractive.com

Graphic Credit: Jan Willem Tulp http://tulpinteractive.com

With more and more families opting out of vaccinating their kids, one of the most sacred of public health goals, the concept of herd immunity, is being threatened.

A recent piece in Scientific American featured tantalizing graphics — on view above — illustrating this scary trend.  According to this analysis, the vaccination rates in some states — Oregon, West Virginia and Colorado, for instance, are shockingly low. So low, in fact, that they’ve dropped below the “herd immunity” levels (or what is thought to be the safe threshold) for MMR (measles, mumps and rubella) and DTP (diphtheria, tetanus and pertussis).

So what’s the deal with herd immunity?  According to the CDC, a population has reached herd immunity when a sufficient proportion is immune to a particular infectious disease.  Immune population members get that protection either by being vaccinated or by having a prior infection.

The epidemiological concept is based on this logic: Continue reading

As Of Today In Mass., You Can Just Say Yes To The HIV Test

Dr. Paul Sax (Courtesy of BWH)

As of today in Massachusetts, you can get an HIV test without having to sign a written consent form. That means you can also skip that potentially embarrassing walk down to the lab to hand over your consent paperwork. You can just say yes.

Massachusetts is a leader in HIV care and research, but it is the last — yes, the very last — state to switch from written to verbal consent for HIV tests, said Dr. Paul Sax, clinical director of the Infectious Disease Department at Brigham and Women’s Hospital.

In other states that switched to verbal consent, experience has borne out the rationale for making HIV testing easier, he said: More people get tested, so more people know their HIV status, and those who find out they’re positive can get treatment and avoid spreading the virus to others.

How will the new Massachusetts law play out in the clinic? Dr. Sax says that typically, a medical staffer recommends an HIV test to a patient — “For example, you could say, ‘The CDC recommends everyone in the US get at least one HIV test, so I recommend you get one.’” Then the clinician should ask if the patient has any questions about accuracy or other implications of the test. If the patient says yes to the test, that should be noted in the medical record.

(Speaking of the CDC, how cool is this little tool? They have the public-health equivalent of a storefinder: You type in your zipcode and it gives you the addresses of clinics where you can get tested for HIV and other sexually transmitted diseases in your area. It’s here.)

Why is Massachusetts so late on this when we’re normally out front on public health? Dr. Sax theorizes that the existing law also included privacy protections that no one wanted to lose. Testing and privacy were “very entangled, and it was very hard to change one without changing the other.” All previous privacy protections have in fact been preserved.

Why Not To Demand Antibiotics For Your Post-Christmas Crud


You drag into your doctor’s office for help after a week of a ruthless, chest-ripping cough. “Doc, I think it’s lung cancer,” you say.

“Okay,” your doctor says. “I’ll write you out a prescription for the chemo drug methotrexate.”

Not exactly a realistic scenario, is it? So then why, when you’ve got garden-variety winter phlegm, might you push your doctor to do your bidding and write you an order for antibiotics?

That’s a point paraphrased from a recent talk by Dr. John Powers, a physician and researcher at the George Washington University School of Medicine, and formerly the lead medical officer for antimicrobial drug development and resistance initiatives at the FDA.

I share it now because it’s the season of bugs and crud, and chances are you’ve been kissing and hugging a lot of people who were sharing their germs along with their cheer. That means you may soon be tempted to demand a nice little course of a “-cillin” or a “-mycin” from your doctor — but hold on a minute:

Antibiotics remain tremendously valuable treatments when prescribed appropriately for bacterial infections, but the reasons to avoid using them unnecessarily have been multiplying of late, and the information below might tip you a bit toward restraint.

‘Up to about 10% of antibiotic prescriptions can cause some adverse effects.’

Personally, I just got over a cough so violent that each spasm threw me backward like the recoil of a rifle. Friends told me to get a lung X-ray and to ask for antibiotics, but under the influence of Dr. Powers and others like him, I decided to just wait and see. The message had finally started to penetrate that if an upper respiratory infection is likely to be a virus — and yes, my children had just been through one — time might be the best cure. (It was.)

No question, antibiotics can work wonders. But they’re also hugely over-used, particularly for coughs. A study last month in the journal “Pediatrics” found that American pediatricians order unnecessary antibiotics at least 10 million times a year, for conditions the drugs do not affect such as asthma and flu.

Health authorities say that what doctors and patients alike need to aim for is the sweet spot known as “judicious use” of antibiotics. But where is it? And how do we get there when we tend to focus on the wonder-drug aspects of antibiotics rather than the downsides?

I asked Dr. Ben Kruskal, director of infection control at Harvard Vanguard Medical Associates and director of infectious disease at Atrius Health, who has worked on “judicious use” campaigns both within Harvard Vanguard and as part of a statewide project. (The CDC works on the issue at the federal level; its”Get Smart” materials are here.) Continue reading

Radio Boston Today: Equalizing Hospital Rates, And ‘Pox’ History


Tune in to Radio Boston at 3 today for a health coverage bonanza:

Meeting in the middle:
Doctors and hospitals in Massachusetts charge vastly different rates for the same services—that’s the big finding of a recent Patrick administration report. But buried within that report was another finding: the state could save hundreds of millions of dollars a year if all health care providers met in the middle and charged the median rate for procedures. Blue Cross Blue Shield Foundation president Sarah Iselin says that would be a hard sell, as it would require the government setting the prices for providers.

Fascinating vaccine history:
An interview with Brandeis professor Michael Willrich, author of “Pox: An American History.” He tells riveting tales of the Draconian vaccine policies during the smallpox epidemic at the turn of the 20th century. From WHYY’s Fresh Air: “There were scenes of policemen holding down men in their night robes while vaccinators began their work on their arms. Inspectors were going room to room looking for children with smallpox. And when they found them, they were literally tearing babes from their mothers’ arms to take them to the city pesthouse [which housed smallpox victims.]”