Estell is small but hard-working, on the job night and day at Essentia Health-St. Mary's Medical Center, asking nothing for herself.
And she's a killer.
Estell -- her formal name is AA0258 Estell -- is a robot with the brand name Xenex. Developed by two Houston epidemiologists in 2008, Xenex robots use xenon ultraviolet-C light pulses that are 25,000 times brighter than sunlight to eliminate viruses, bacteria and bacterial spores, said Melinda Hart, spokeswoman for the San Antonio-based Xenex Healthcare Services.
Used in addition to normal cleaning, the little robot with the big punch kills spores that most methods don't touch, Essentia Health environmental specialists say.
"It kills spores from Clostridium difficile, which causes colon infections," said Dr. Jeff Lyon, Essentia Health patient quality officer. "The CDC is really concerned about its impact on health care."
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Indeed, the Centers for Disease Control and Prevention reports that C. diff -- the shortened form used in health circles -- is at historically high levels in hospitals and other health-care facilities. It causes diarrhea linked to 14,000 American deaths each year, the agency's health care-associated infections Web page said on March 1.
What makes C. diff difficult is that it can live in a hospital room for as long as six months, Hart said. And it's notoriously difficult to kill.
"It forms a hard shell," she said. "So unlike the flu virus or norovirus, which are easy to eliminate ... the only way to destroy C. diff until now has been to soak it with bleach, and the bleach has to remain wet for about 10 minutes.
Bleach has other disadvantages, said Cindi Welch, St. Mary's infection prevention manager.
"Bleach is not a real user-friendly product," Welch said. "It leaves an odor. It stains clothes and leaves a hole in clothing."
Moreover, some C. diff escapes even the most thorough human cleansings, Hart said.
"Studies show that only about 50 percent of the surfaces in the room are touched when the housekeeping team comes in," she said. "And that's when they're doing an awesome job."
Xenex first was introduced commercially in 2010, Hart said, and it's now in about 200 hospitals nationwide. Enough data are in to give the company some numbers about which to boast. Cooley Dickinson Hospital in Northampton, Mass., reported its C. diff rates down by 67 percent after introducing a Xenex robot. Cone Health System in Greensboro, N.C., had a 58 percent overall reduction in infections.
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Essentia Health personnel demonstrated Estell, which arrived on Sept. 9, in a vacant room of the St. Mary's Newborn Intensive Care Unit on Thursday.
Estell, which is the only Xenex robot with that name, didn't appear all that deadly at first glance. Andrea Williams, an environmental services supervisor who is 5 feet tall, towered over Estell as she punched a few buttons on its console. A bland off-white with gray trim, it looked like an extremely clean trash bin.
Williams placed another unit -- shaped like a small, portable room heater -- next to it. This, she explained, was a motion detector. The robot has to work alone, so the motion detector automatically shuts it off if anyone opens a door to the room. There's also a manual shutoff switch attached to a small barricade placed outside the door.
The robot isn't nearly as hard on people as it is on bacteria, Hart explained later, but its ultraviolet pulses could harm human eyes over time. Outside of the room, even watching through a window, there's no danger at all.
Ultraviolet-C light, which does not occur naturally on earth, cannot penetrate anything thicker than Saran wrap, Hart said.
Williams punched the start button and walked out of the room, closing the door behind her. After 30 seconds, a circle-shaped extension popped up above the rest of the robot. At a rate of more than one per second, it emitted bright, purple pulses as it rotated "like the restaurant on top of the Radisson," Lyon said.
After five minutes, it was done.
The robot's use has been prioritized, Welch said. The first priority is isolation units after they are vacated. That's followed by operating rooms, then by rooms where other procedures take place.
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"We want to keep it in use 24-7," she said.
It cost $80,000, but preventing even one hospital-acquired infection would make that expense worthwhile, Welch said.
But no matter how impressive the technology, Lyon said Essentia Health is only interested in seeing infection rates reduced. "That's the ultimate goal," he said.
Yet for all the technological gains, the first line in reducing infections remains the simplest:
"If you had to pick one thing to stop hospital infections, it would be washing your hands," Lyon said.
Even Xenex's Hart agreed with that.
"It's number one," she said. "Wash your hands."
