Awash in antimicrobial soaps and wipes, Americans these days seem to be fending off germs at every turn.
Rhode Island bought nearly 15,000 wall dispensers filled with alcohol-based hand sanitizers to combat an outbreak of meningitis and encephalitis in its schools this month. Many supermarkets now routinely offer wipes for sanitation-conscious customers.
At the entrance of the new Martin's Food Market in Eldersburg, shoppers can disinfect their grocery carts at the door. "I use them all the time. ... I'm a germ freak," said Cindy Tack, 40, of Glenelg as she wiped down the basket before sliding her son Ben, 3 1/2 , into the seat. "And when I walk in the door at home, I wash my hands."
"I think it's overkill," she confessed. "But having kids, and as I've gotten older, I've gotten more like that. They're touching everything."
Annually, this bacterial backlash is fueling the introduction of 200 to 300 new or redesigned antimicrobial products. Consumers spend more than $200 million a year on antimicrobial wipes alone, according to Mike Richardson, an industry analyst at the Freedonia Group in Cleveland. "We're expecting something close to double-digit annual growth for the next several years," he said.
On store shelves, alcohol-based cleaners join a proliferating variety of antibacterial soaps and similar products aimed at snuffing out microscopic life wherever people perceive a threat to health.
Yet Rolf Halden, an environmental scientist at the Johns Hopkins Bloomberg School of Public Health, contends that the introduction of the hundreds of antimicrobial products has had no discernible impact on the rates of infectious disease in the United States. "Not a blip on the radar screen," he said.
"The money's been spent, but the benefit is doubtful, or absent," said Halden, co-founder of the school's Center for Water and Health. "The flood of antimicrobial products is driven by monetary profits, and not by scientific evidence."
Germ-fighting hand cleaners are not all created equal.
In a scrub-off, several scientists said, plain soap and water - when used properly - are the preferred tools to rid germs from human hands.
Next are the alcohol-based gels and wipes, which they describe as adequate alternatives when vigorous hand-washing at a faucet isn't possible. Studies have found that most hand sanitizers can reduce gastrointestinal illnesses in households, classrooms and dormitories.
Last are antibacterial soaps and related applications, which, some research suggests, could generate problems for the environment and human health.
And they don't kill viruses that cause colds, flu and intestinal illnesses. These include noroviruses that have sickened cruise ship passengers and were found last week at a hotel near Washington Dulles International Airport in Virginia.
While there's debate about what people should use to clean their hands, there's no debate about the health benefits of doing it properly. The U.S. Centers for Disease Control calls hand-washing "one of the most critical control strategies" in managing a disease outbreak. Pathogenic viruses and bacteria pass among us by our hands and can infect us when we touch our mouth, nose and eyes.
The "gold standard" for hand cleaning, experts agree, is to wash them vigorously with plain old soap and warm water. Do it for 15 to 20 seconds - two verses of "Mary Had a Little Lamb."
The mechanics of rubbing all surfaces of the hands together loosens bacteria and viruses from the oils of the skin, suspends them in the soapy solution and rinses them away. Thorough drying with a single-use towel curbs transfer of any remaining germs. Use the towel to turn off the water and open the door.
"Plain soap is an antimicrobial," Halden said. It kills bacteria by causing cell membranes to leak.
"The biggest problem with hand hygiene is ... people don't do it," said Dr. L. Clifford McDonald, a medical epidemiologist at the Centers for Disease Control and Prevention.
Timing matters. Wash before eating. Wash after using the bathroom, sneezing or coughing into your hands, handling raw meats or caring for someone who has an infection.
Two years ago, an observational study of 6,000 people by the industry's Soap and Detergent Association found that 10 percent of women and 25 percent of men didn't wash their hands after using the bathroom. Even fewer washed after sneezing or coughing into their hands.
If people don't or can't wash at the sink, experts say it's safe to use alcohol-based gels and wipes, which kill most viruses and bacteria. They degrade rapidly in the environment and have "a pretty good safety profile," Halden said.
But they have their shortcomings. McDonald said the alcohol products don't work well when the hands are visibly dirty. They also won't kill some bacteria that form protective spores, such as Clostridium difficile, which can cause a life-threatening form of diarrhea and colitis.
Using them to clean your hands after handling drippy packages in the meat department makes sense, McDonald said. But "alcohol is not generally a good surface disinfectant." Shoppers would be better off using hand wipes to clean their hands after working with the cart than attempting to disinfect it first.
For some, such as Terry Powell, 60, of Eldersburg, the reason for using the wipes on the handle as he rolled his cart into Martin's was unscientific. "My wife uses them," he said, "and she tells me to use them."
Giant Food Stores of Carlisle, Pa., a chain that includes 143 Giant and Martin's supermarkets in four states, began providing wipes in 2004. "Customers are increasingly interested in staying healthy," said company spokeswoman Tracy Pawelski. "The popularity of these products is booming. ... We're always looking for ways to differentiate ourselves from other operators."
Alcohol-based hand gels are catching on with the public in part because they have become so ubiquitous in medical settings, said the CDC's McDonald.
Use by health care workers grows out of the push to combat hospital-based infections. But the broader demand for sanitizers might be motivated by several factors, including marketing and a growing germophobia.
The news media contribute to that perception, said McDonald, with coverage of outbreaks such as sudden acute respiratory syndrome (SARS), anthrax and "now these very prominent food-borne outbreaks," he said. He referred to people who were sickened or killed by produce contaminated by E. coli bacteria.
Kimberly Thompson, author of Overkill: Repairing the Damage from our Unhealthy Obsession with Germs, Antibiotics and Antibacterials, said of the public demand, "The goal is to annihilate all germs." But that isn't possible, "and it's not necessary or desirable," she said.
"We rely on bacteria and viruses as part of our environment," said Thompson, a professor of risk analysis and decision science at Harvard University.
A panel of experts and industry representatives convened in 2005 by the U.S. Food and Drug Administration found "no firm scientific evidence that the flood of antimicrobial products we observe has any discernible benefit over the use of regular soap and water," said Hopkins' Halden, who served on the review panel.
Part of the problem, he said, is that the household antibacterial products are weak versions of those used in health care. "We're using a diluted product and giving it to everybody for every purpose, and the outcome is no measurable benefit."
There's also concern that overuse of antibacterial soaps might encourage the evolution of bacteria that could resist clinically important antibiotics. While laboratory evidence suggests that it could happen, there's been no proof yet that it has, Halden said.
What is clear is that two of their ingredients - triclosan and triclocarban - have been found in fish, breast milk and wastewater. Halden said the chemicals might kill beneficial organisms in the soil and waterways.
While there's no scientific evidence that they're harming humans, he added, "nobody has looked."
Brian Sansoni, spokesman for the Soap and Detergent Association, said the chemicals are detectable in the environment because the detection technology is so "spectacular ... you can find anything just about anywhere if you look closely for it."
"From everything we have seen, we feel it does biodegrade safely in the environment," Sansoni said.
And the products do their job, he said. "We believe that antibacterial soaps are effective at eliminating or reducing germs on the skin that make us sick."
While soap and water remain the "gold standard," Sansoni said, "in those cases where people aren't washing their hands enough, at least there's that extra ingredient that we think can make a difference."
The CDC's McDonald agrees, to a point. Antibacterial soaps "do seem to kill more quickly, and seem to have more postcleaning effect than soap and water," he said. "Does that translate into a lower infection rate? We've never been able to show that."
At the gym, workers have long seen the need to vanquish germs after shaking members' sweaty hands or collecting their stray towels. Employees of the LifeBridge Health & Fitness Center in Pikesville kept sanitizing hand gels in their offices.
Last month, in response to members' requests, six motion-activated dispensers were installed across the exercise floor. Given the repeated refilling, said club director Joel Schlossberg, "we know they're getting used."