Thursday, January 10, 2013

Unnecessary Antibiotic Use & C. Difficile Infections

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C. difficile – Credit CDC PHIL 


# 6842

 


We’ve more evidence today on the perils of unnecessary antibiotic usage from a study that appears in the February 2013 edition of Infection Control and Hospital Epidemiology.

While the most publicized concern over the overuse of antibiotics is the creation of resistant bacteria, it is far from being the only danger.  

 

Two years ago in The Other Reason Not To Abuse Antibiotics, we looked at the what happens to our beneficial intestinal bacteria (gut flora or microbiota) after we take a course of antibiotics, and how that might affect our health.

 

In recent years the the NIH sponsored Human Microbiome Project has spurred new research into these ubiquitous micro-organisms that reside not only in our intestines, but on our skin, in our nasal passages, oral cavities, gastrointestinal tract, and urogenital tract.

 

For all the good they do, antibiotics can indiscriminately kill off good bacteria along with the bad, and that can upset the bacterial balance in our gut.

 

When this happens, we often see the blooming of a nasty Gram-Positive bacteria called Clostridium Difficile – or C. diff – an infection which claims tens of thousands of lives each year.

 

And as the name implies, C. diff is most difficult to treat (see Referral: Maryn McKenna On Regulatory Obstacles To Fecal Transplants).

 

Today’s study, looks at the antibiotic history of patients at the Minneapolis Veterans Affairs Medical Center and found that not only are antibiotics often prescribed unnecessarily, their use substantially increased the patient’s chances of developing a C. diff infection.

 

First a link to the study, then some excerpts from the Press Release.

 

Unnecessary Antimicrobial Use in Patients with Current or Recent Clostridium difficile Infection (pp. 109-116) 

Megan K. Shaughnessy, MD; William H. Amundson, MD; Michael A. Kuskowski, PhD; Douglas D. DeCarolis, PharmD; James R. Johnson, MD; Dimitri M. Drekonja, MD, MS

DOI: 10.1086/669089

 

While the bulk of this article is behind a pay-wall, we get more details from the SHEA press release.

 

Society for Healthcare Epidemiology of America

Unnecessary antimicrobial use increases risk of recurrent infectious diarrhea

The impact of antibiotic misuse has far-reaching consequences in healthcare, including reduced efficacy of the drugs, increased prevalence of drug-resistant organisms, and increased risk of deadly infections. A new study featured in the February issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America, found that many patients with Clostridium difficile infection (C. difficile) are prescribed unnecessary antibiotics, increasing their risk of recurrence of the deadly infection. The retrospective report shows that unnecessary antibiotics use is alarmingly common in this vulnerable patient population.

 

C. difficile is a bacteria that usually affects people with recent antibiotic use or hospitalization. The symptoms of C. difficile range from mild diarrhea to severe illness and death, and it is now one of the most common healthcare-associated infections. Patients with C. difficile often experience recurrent episodes of the infection, especially if they receive antibiotics again in the future.

 

Researchers at the Minneapolis Veterans Affairs Medical Center reviewed patient cases with new-onset C. difficile infection. In total, 57 percent (141) of patients with new-onset C. difficile infection received additional antimicrobials during or within 30 days after their initial C. difficile treatment, raising their risk of recurrence substantially. From this group, 77 percent received at least one dose of unnecessary antibiotic, and 26 percent of patients received unnecessary antibiotics exclusively. Common reasons noted for unnecessary antibiotic use included urinary tract infections and pneumonia (despite little-to-no evidence of either being present), inappropriate surgical prophylaxis, and asymptomatic bacteriuria.

 

"Our findings serve as a reminder to both doctors and patients to use antibiotics only when absolutely necessary, particularly in patients with a history of C. difficile," said lead researcher Megan K. Shaughnessy, MD. "Patients with C. difficile are at high-risk for recurrence, especially with additional antibiotic use. Because of this heightened risk, clinicians should be exercising increased caution with antimicrobial therapy."

 

The researchers advise that providers contemplating antimicrobial therapy should be more aware of the risk of recurrent C. difficile with antimicrobial use, patients' previous C. difficile history, and which clinical conditions require antimicrobial therapy.

 

Obviously, when you are faced with a serious bacterial infection, antibiotics are a prudent, even lifesaving form of treatment.

 

But we should not fool ourselves into believing that antibiotics are always benign, or that there are not potential consequences from taking them.

 

There is a risk-reward ratio for every drug we take.

 

For more on the importance of proper antibiotic stewardship, you may wish to revisit these earlier blogs.

 

Chan: World Faces A `Post-Antibiotic Era’

Get Smart About Antibiotics Week

IDSA: Educational Guidelines Lower Antibiotic Use

 

And for a far more complete (and eye-opening) discussion of antimicrobial resistance issues, I can think of no better primer than Maryn McKenna’s book SUPERBUG: The Fatal Menace of MRSA.

 

And Maryn’s SUPERBUG Blog, part of Wired Science Blogs, continues to provide the best day-to-day coverage of these issues.