CDC Studies Assess Effects of Antibiotic-Resistant Infections, MRSA

More than two million U.S. residents develop antibiotic-resistant infections in hospitals annually, and at least 23,000 die as a result, according to a CDC study published Monday in JAMA Internal Medicine, the New York Times reports.

The report studied 18 drug-resistant bacteria and fungi and ranked them according to how lethal they could be if humans were to develop an infection from them. It used data from five disease-tracking systems nationwide (Tavernise, New York Times, 9/16).

According to the report, three of the drug-resistant bacteria and fungi were ranked "urgent" and had few treatment options, 12 were "serious" and three were "concerning."

Those bacteria ranked urgent were:

• CRE;
• Clostridium difficile; and
• Gonorrhea.

The report found that CRE -- also called "nightmare bacteria" -- causes about 9,000 health care-associated infections annually in 44 states.  The report also found that deaths related to c. difficile have risen more than five times between 2000 and 2007.

Researchers cited several reasons for the increase in antibiotic-resistant bacteria, including excessive use of antibiotics and frequent use of antibiotics in food-producing animals. Humans can be infected with drug-resistant germs through food consumed from these animals, the report noted.

The report stated, "Up to half of antibiotic use in humans and much of antibiotic use in animals is unnecessary and inappropriate and makes everyone less safe."

Recommendations

The report recommended:

• A more prudent use of antibiotics;
• Better inspection of drug-resistant bacteria;
• Development of new drugs; and
• New tests that quickly can identify antibiotic-resistant bacteria.

Using these recommendations, hospitals could save about $20 billion annually in medical costs, according to the report (McKay, Wall Street Journal, 9/16).

Reaction

The study's researchers noted that the number of U.S. residents who die annually from such infections is lower than previous estimates. However, Steven Solomon -- director of CDC's office of antimicrobial resistance -- called the report's number a "floor" and said researches were encouraged to be cautious and only include deaths definitively considered to be caused by drug-resistant bacterial infections (New York Times, 9/16).  

While many hospitals have implemented "antibiotic stewardship" programs, more needs to be done to ensure patient safety, some health experts said. Edward Septimus, a professor of internal medicine at the Texas A&M University Health Science Center, said, "These things we're talking about have to be done across a continuum of care" in health systems and in the community (Wall Street Journal, 9/16).

Hospital-Acquired MRSA Infections Decline Steeply

Meanwhile, a separate CDC study also published Monday in JAMA Internal Medicine found that the number of all hospital-acquired infections declined by nearly 30% over the past 10 years (Seaman, Reuters, 9/16).

The number of Methicillin-resistant Staphylococcus aureus cases saw the largest decline, at about 54%, with the number of serious cases down from 111,261 in 2005 to 80,461 in 2011 (Walsh, MedPage Today, 9/16).

Researches cite the dramatic increase in MRSA infections from 1995 to 2005 and the development of stricter hygiene protocols in response as the reason for the steep decline. Raymund Dantes -- the study's lead author, former CDC epidemiologist and current associate professor of hospital medicine at Emory University -- said, "Certainly there has been a big focus on trying to reduce health care-associated infections like MRSA in many hospitals and health care settings." He added, "We certainly hope that this dramatic decrease in MRSA infections ... suggests that these efforts are paying off" (Ross Johnson, Modern Healthcare, 9/16).

However, community-acquired MRSA infections declined by only 5% over the same time period, according to the report. Researchers attributed the small decline in part to the use of antibiotics in animals, as resistant strains can end up in manure used as fertilizer (MedPage Today, 9/16). In communities where this type of manure was present, the report found that residents were 38% more likely to develop a MRSA infection (New York Times, 9/16).

Frank Lowy of Columbia University said, "[T]his investigation provides yet another reason to be concerned regarding the use of antibiotics as growth enhancers in animal feed and argues for legislation that restricts the use of antibiotics in this setting" (MedPage Today, 9/16).

Researchers also said that among those who experience community-based infections, "[t]here are higher rates of diabetes, there is a higher rate of HIV and there is a higher rate of intravenous drug use." Dantes said that while "some of them can be explained by these risk factors, ... more research needs to be done to determine the best recommendation for preventing these types of infections" (Modern Healthcare, 9/16).