December 18, 2007

UNIT 4: EvolutionRise of the Superbug

On October 15, 2007, a 17-year-old senior at Staunton River High School in Virginia lost his brief battle with the “superbug” bacterium known as methicillin-resistant Staphylococcus aureus (MRSA). Ashton Bonds was admitted to the hospital a week earlier after first being sent home when doctors could not determine what was causing pain in his side. By the time doctors had diagnosed his MRSA infection, it had spread to several vital organs. Just before he was to undergo surgery to drain the infection from his lungs, a blood clot was detected near his heart. The clot proved fatal.

At around the same time as Ashton’s death, the U.S. Centers for Disease Control and Prevention (CDC) released a report highlighting how dangerous and widespread MRSA had become.

• In 2005, 94,360 Americans suffered invasive MRSA infections.
• MRSA caused or contributed to the deaths of 18,650 Americans, making MRSA more deadly than AIDS in the U.S.
• The incidence of MRSA in Americans is about twice as high as it was believed to be prior to the study.
• About 2 percent of the U.S. population carries MRSA on the skin or in the nostrils, where it has little effect on health. Once MRSA gets into the body via a scrape or other wound, invasive infection can occur and prove fatal.
• 85 percent of invasive MRSA cases occur in hospitals and nursing homes, where people are more likely to have open wounds through which the bacterium can invade the body.

A separate study conducted by the University of Florida found that hospitalizations due to MRSA had doubled over six-year period from 1999 to 2005.

While MRSA deaths, along with the release of the CDC’s report, have generated great public and media interest in MRSA, some scientists and doctors warn that an overreaction to the problem could only help make MRSA more resistant to antibiotics. CDC experts Dr. John Jernigan and Dr. Rachel Gorwitz reminded the public that some Staphylococcus bacteria became resistant to antibiotics shortly after antibiotics were introduced to medicine more than 50 years ago. “We know that antimicrobial resistance will follow antimicrobial use as sure as night follows day. It’s just a biological phenomenon,” they said. In fact, MRSA itself evolved just a few months after methicillin was first produced in 1960. The more that antibiotics are prescribed for and used by humans or other animals, the more likely it is that “superbugs” like MRSA will continue to evolve and become public health problems.

Nonetheless, the CDC takes MRSA seriously, and recommends that all people wash their hands and shower frequently to reduce the presence of staph bacteria on their bodies, and to clean and bandage all wounds until fully healed. People should not share personal items so that bacteria will not be transmitted from one person’s skin to another’s. Athletes who play sports such as football and soccer, in which scrapes or “turf burn” are common, should be especially careful to treat their wounds and not let others come in contact with them.

Hospitals are also doing their part to reduce the presence and transmission of MRSA among staff and patients. Some facilities are screening every new patient for the bacterium so that further precautions can be taken. Others are monitoring doctors and nurses to ensure that they are washing their hands and changing gloves frequently.

More to Explore

• New York Times: A (Sometimes) Deadly Scourge
• New York Times: Another Very Scary Germ (Editorial)
• Med Headlines: Superbugs Reaching Epidemic Stage
• USA Today: Hospitals Marshal Resources to Wipe Out MRSA
• CNN: MRSA Infection
• Scientists Shed Light on How Superbugs Spread

Last updated December 18, 2007 | Comments (15) | Permalink | UNIT 4: Evolution