Before it claimed her mother's life last fall, Lornell Haggerty didn't pay much attention to the antibiotic-resistant bacteria commonly known as MRSA.

"But once Mom died of this, you just see it everywhere," said the daughter of the late Carole Hillard, speaking about the invasive infection to which Hillard succumbed Oct. 25.

The globe-trotting Hillard, a former South Dakota lieutenant governor, likely acquired her MRSA infection in a Croatian hospital. But her daughter's observation about MRSA in her personal sphere is also a pretty accurate description of the growing prevalence of the "superbug" in U.S. communities, according to Dr. James Keegan, infection specialist at Rapid City Regional Hospital.

According to the South Dakota Department of Health, the incidence of MRSA cases is increasingly common in South Dakota, too. Thirty-five cases of invasive MRSA were reported to the state health department in the first six months of 2008, an increase of 52 percent over the five-year average in the state.

Once thought to be a rare hospital-acquired infection, methicillin-resistant staphylococcus aureus is now known to be a problem that is found outside acute care facilities in a wide range of settings. Keegan said that as many as one in five people may carry the MRSA bacteria on their skin at any given time and not know it.

"In fact, one third of all people have staph A on their skin at any point. They're colonized and don't know it," Keegan said.

Not all staph A germs are resistant to antibiotics, but about 60 percent of staph cultures nationally prove to be resistant to antibiotics, giving them the MRSA designation. That translates to as much as 20 percent of the general population being colonized by MRSA, Keegan said.

To be colonized by a bacterium means that it lives on your skin or in your nose but does not make you ill. Staph bacteria, even MRSA, can be harmless, unless it enters the body through a cut or a wound. Even then, it often causes only minor skin infections - such as boils or abscesses - in otherwise healthy people.

Only invasive MRSA kills. That designation means the bacteria has entered the blood, brain, spinal fluid or other sterile place.

It killed Hillard Oct. 25 as she lay in a Swiss hospital, less than 10 days after leaving a Croatian hospital where she underwent emergency surgery to repair fractured vertebrae in her neck. She was injured in a fall on a sailing boat in the Adriatic Sea.

As a consultant for the U.S. State Department, Hillard hadn't suffered so much as a bad bout of food poisoning, despite all the health risks she encountered in the primitive locations she visited, Haggerty said.

"She drank the water and ate the nastiest foods and never got sick," Haggerty said.

Haggerty worried about the possibility of a bad surgical outcome in Croatia, but when her mother walked out of the Croatian hospital and took a commercial airplane flight to Switzerland to recuperate before returning to the United States, she never gave a thought to a hospital-acquired infection.

Just days later, Haggerty and other family members were keeping bedside vigil at University Hospital in Lausanne, Switzerland. "By the time they tried to treat it, it was just too late," Haggerty said. "They were just so frustrated. The doctor kept saying, 'If we'd just had more time.'"

Hillard had a lifelong penchant for adventure, and she always did what she could to minimize her risks, such as getting all immunizations and vaccinations required for

international travel to protect her from disease, Haggerty said. But she also accepted the medical risks that

came with her job.

"Mom knew the risk, and she chose to take it. She felt that the good that could be done in the world was worth it," Haggerty said.

And the risks of MRSA are everywhere.

Hospital-acquired infections, and exposure to community-associated MRSA, happen in the finest world-class hospitals and the smallest village clinics. Hillard might as easily have been exposed to any number of antibiotic-resistant bacteria in Rapid City or Croatia or any of the Third-World countries where she traveled often.

"The increasing MRSA cases here are part of a very concerning national trend," said Dr. Lon Kightlinger, state epidemiologist.

In 2005, the most recent data available, more than 94,000 Americans developed a serious MRSA infection. About 18,650 people died during a hospital stay of causes related to those infections. People 65 years old or older were most at risk.

MRSA is evenly distributed across South Dakota. Of the 35 cases reported through June, 20 were in the state's most populated county, Minnehaha, and four were from Pennington County. Eighteen other counties reported one, two or three cases each. The state health department does not specify reporting hospitals, and only invasive MRSA must be reported to the state within three days. MRSA cultures found in skin-only infections do not have to be reported. Keegan believes part of the explanation for the rising number of MRSA cases in South Dakota is that medical providers are reporting it more faithfully now.

According to data from the Centers for Disease Control and Prevention, in 1974, MRSA infections accounted for 2 percent of the total number of staph infections in the U.S.; in 1995, it was 22 percent; and by 2004, it was 63 percent.

Regional Health System laboratories confirm about 100 positive staph A cultures per month. But unlike national MRSA rates - which are about 60 percent - Regional has a positive MRSA rate of only about 30 percent.

Keegan credits a community-wide effort by Rapid City physicians to prescribe careful, conscientious and targeted antibiotic usage for the lower MRSA rates here.

About eight years ago in Rapid City, Regional's infection control specialists launched an aggressive educational campaign to convince medical providers here to curb the overuse of broad-spectrum antibiotics. Public health data showed an alarming association between the increasing use of new, broad-spectrum antibiotics by local doctors and rising MRSA rates in the area.

"With the newer antibiotics in use, we saw a dramatic change in MRSA rates going up in a relatively short period of time," Keegan said.

Suddenly, staph A cultures that proved resistant to antibiotics had risen to 40 and 50 percent of all cultures, up from local rates of just 20 percent six to 12 months earlier.

Rapid City's size and relative geographic isolation made it easier for specialists to spot that MRSA trend quickly. Those same factors also contributed to its successful reversal in a relatively short period of time, Keegan said.

"In many communities, there's not a lot of opportunity to locally recognize the consequences of overuse of antibiotics," he said.

Today, MRSA rates here are back down to 30 percent because local pediatricians, emergency physicians and nursing homes don't overtreat for viral infections, Keegan said.

"The more we can do to decrease the use of broad-spectrum antibiotics … the better for bringing those rates back down," he said.

Public health officials have learned that the historical approach of trying to create stronger and stronger antibiotics with which to treat the general public is flawed, Keegan said. Bacteria evolve and adapt more quickly than medical science can.

Instead, the use of narrow spectrum antibiotics targeted for specific bacteria is the best public health defense against antibiotic-resistant bacteria.

"Going back to the older, more narrowly focused antibiotics actually protects people better," he said. "We've shown that you can influence MRSA rates, favorably decreasing those rates, by avoiding overuse of broad-spectrum antibiotics," he said.