Gotcha: bacteria found on stuff

BART is not an overly enthusiastic Simpson’s fan; it stands for Bay Area Rapid Transit, rode it a couple of years ago, didn’t notice any bugs up, or out, my butt.

The New York Times reports that riders on the BART system (that’s in and around San Francisco) have long complained about germs in the hard-to-clean cloth seats. As Bob Franklin, the BART board president, acknowledged, “People don’t know what’s in there.”

The Bay Citizen commissioned Darleen Franklin, a supervisor at San Francisco State University’s biology lab, to analyze the bacterial content of a random BART seat.

Fecal and skin-borne bacteria resistant to antibiotics were found in a seat on a train headed from Daly City to Dublin/Pleasanton. Further testing on the skin-borne bacteria showed characteristics of methicillin-resistant staphylococcus aureus, or MRSA, the drug-resistant bacterium that causes potentially lethal infections, although Ms. Franklin cautioned that the MRSA findings were preliminary.

High concentrations of at least nine bacteria strains and several types of mold were found on the seat. Even after Ms. Franklin cleaned the cushion with an alcohol wipe, potentially harmful bacteria were found growing in the fabric.

Dr. John Swartzberg, a clinical professor at the School of Public Health at the University of California, Berkeley, played down the threat of infection from harmful bacteria on a BART seat. “I suspect it’s not a very big problem. That said, if there’s another way to do it, where you can clean it better, then you should do it.”

The rest of the story is about hygiene concerns as BART officials determine what kind of seats to install for a new fleet of cars in 2017.

It’s another in a long line of Gotcha-type stories that find bacteria on things – doorknobs, money, keyboards, sex toys.

Does it mean anything? And where are the sick people?

These kinds of Gotcha stories have been going on a long time.

In 1995, the front page of Toronto’s Globe and Mail proclaimed, "you probably handle an unimaginably dangerous collection of harmful bacteria" while going about your kitchenly chores, and that "90 per cent of food-related illness in the home could be prevented by using paper towels when preparing foods, especially meats."

The killer-dishrag story did meet the primary goal of its creators: to sell more sponges. Specifically, anti-bacterial sponges manufactured by 3M Co. of Minneapolis, Minn.

Dr. Charles P. Gerba, an environmental microbiologist at the University of Arizona in Tucson, was contracted by 3M to perform tests of household dishrags and sponges in five U.S. cities and compare the results to the 3M sponge. Not surprisingly, Dr. Gerba found about 100 times more bacteria in dishrags retrieved from households.

Then the public relations firm hired by 3M peddled the results, taking Dr. Gerba on a five-city tour to release the results. That was in Aug. 1995. Several stories appeared on the U.S. wire services. Why the Globe decided to run the story at the end of Dec. 1995 remains a mystery.

Gerba showed up again with a bugs-in-reusable grocery bags report last year, that has not been published in a peer-reviewed journal. And last week, Gerba was in the news again, saying his group had swabbed the handles of 85 grocery carts in four states for bacterial contamination and that 72 per cent of the carts had a positive marker for fecal bacteria.

Scientists say this study helps explain why earlier investigations found kids who touch the handles, are more likely than others, to get infected with bacteria like salmonella. Researchers reported in the Journal of Food Protection in June 2010 that kids can be exposed to raw meat and poultry products while riding in shopping carts.

But that was a study published in a peer-reviewed journal. The bugs-on-shopping-cart handles is a news story with legs – it keeps showing up – but the experimental design and conclusions have not been subject to peer-review, and the conclusions may be erroneous. Who knows?

On the shopping cart results, Dr. Neil Fishman, an infectious disease expert and director of health care epidemiology and infection prevention at the University of Pennsylvania Health System, is concerned that risk isn’t very big.

“I’d be worried if there was any evidence of any disease outbreaks related to shopping cart use. There isn’t — and we’ve been using them for a long time.”

While there may, indeed, be bacteria on shopping cart handles, they can also be found on doorknobs, countertops and a host of other items we touch every day, Fishman said. “My guess is that there are more bacteria on a car seat than on a shopping cart,” he added.

Josh Rosenau , writing for Science Blogs last night, picked up on the same theme, citing microbiologist Pat Fidopiastis as saying “none of this means much unless you can show me a significant risk involved with coming in contact with a shopping cart. You might be able to say that "X percent" more kids get sick if they touch a shopping cart handle versus a bathroom door knob, for example. But what are the actual numbers? Is this like saying, "More people get struck by lightning if they walk around outside in a storm than those who stay in their homes?”