When Mr. Wilson (name changed to protect confidentiality) arrived at the emergency department at the James A. Haley Veterans Hospital in Tampa, Fla., one night in October, he had a common complaint.
"I think I've gotten bitten by a spider," he said. On his thigh, several large raised skin lesions were visible.
"These aren't spider bites," his physician, Dr. Yvonne Dunn, remarked. "You have a skin infection called community-acquired MRSA. Your boils will need to be opened and drained, but with proper care, you should be OK."
The patient listened intently. "Just my luck," he said.
Staphylococcus aureus is one of the most common germs we encounter each day. It is a normal (and usually harmless) germ on our skin and in our nose.
Infections may occur when the organisms get into the body through breaks in the skin (such as cuts, scrapes, open wounds, surgical incisions or catheters in a person's vein) and multiply rapidly. MRSA stands for methicillin-resistant Staphylococcus aureus. MRSA is a more resistant form of the germ that has become a serious cause of human infections in the hospital, and recently, in the community.
MRSA has been a serious problem in hospitals since the early 1960s, when increasing use of powerful antibiotics led to germ resistance.
In health care settings, MRSA causes tens of thousands of surgical infections, bloodstream infections, pneumonias and infections of medical devices each year. Concern over the spread of MRSA between patients in the hospital is so great, that many hospitals isolate patients who have MRSA so that other patients are not exposed.
Over the past decade, there has been a substantial increase in the number of MRSA infections in people who have never been hospitalized. Experts believe these are due to a new strain of MRSA that originated outside of the hospital. This germ, called "USA 300," is spreading across the country and producing hundreds of thousands of new infections each year. These infections can range from simple skin boils or abscesses to pneumonia and even to life-threatening infections.
Because USA 300 has become so widespread, the strain is now commonly found in hospitals, where MRSA made its first appearance decades ago.
"We've really come full circle with MRSA," Dunn said. "Now the community strain of staph is the predominant strain in the hospital, and it's far more aggressive in many ways."
Outside the hospital, most MRSA infections cause simple skin infections.
"If it is on your skin and has lumps, bumps or pus, then there's a good chance it's due to Staphylococcus aureus," said Dr. John Toney, an infectious diseases specialist at the Tampa VA Hospital.
In many cases, these lesions are initially misdiagnosed as brown recluse spider bites or other insect bites.
"Brown recluse spiders tend to be indigenous to the central and Southwestern U.S.," Toney said. "They are much rarer in places such as Florida and the Atlantic and Pacific coastal states. In fact, many of these 'spider bites' are being misdiagnosed and are really MRSA skin infections."
Though there is a tendency for physicians to prescribe antibiotics for infections, an antibiotic pill may not be the answer for MRSA.
"With the community strains," Toney asserted, "the most common class of antibiotics, which include penicillin, are usually not effective. Although we have other antibiotics we can prescribe, the best therapy is to drain the pus."
For patients in a medical facility, hospital-acquired infections can lead to serious complications. MRSA is the leading cause of these hospital-acquired infections. Hospital-acquired MRSA infections may result from germs on medical devices such as IVs, urinary catheters, pacemakers and artificial joints.
A hospital-acquired staph infection may only have subtle signs at first, such as a change in alertness or a low fever. An infectious disease specialist's role "is to assist other health care providers in identifying patients with early hospital infections. If discovered early, serious infections should be treated quickly and aggressively to prevent severe complications or death," Toney noted.
Outside of the hospital, Staphylococcus aureus infections are easily spread by close personal contact. This may include shaking hands, sharing exercise equipment or participating in close contact sports.
Recent studies have demonstrated sexual transmission of MRSA -- a testament to the germ's versatility. Some people, including those who have recently taken antibiotics, those who have had MRSA in the past and those in close contact with an infected person, are more likely to get the infection.
The simplest way to prevent MRSA is through regular hand washing and use of antiseptic hand gels. Other approaches, such as not sharing personal grooming items and towels, can also decrease the risk to you and your family.
For people admitted to a hospital or health care facility, some of the same precautions apply, but a patient needs to be proactive in other ways to keep safe.
"Ask questions," Dunn said. "Find out what your hospital does to control MRSA infections. Do they have an effective infection control program? Do their surgical site infection rates differ from other similar hospitals in your community? And lastly, if a hospital staff person or physician walks in or out of your room and does not wash his or her hands, don't be afraid to remind them to do so."
After a three-day hospital stay, Mr. Wilson returned home to continue his recovery from his brush with "the superbug." He was much more informed about protecting himself from MRSA -- and perhaps, a little less wary of spiders.
Dr. Richard Oehler is assistant professor of medicine in the division of infectious disease and international medicine at the University of South Florida College of Medicine.