With the spread of swine flu and mounting concern over drug-resistant superbugs like MRSA, it’s no wonder we are a nation of germophobes, as I write in my latest WSJ Informed Patient column. The CDC warns that in addition to spreading from person to person by coughing and sneezing, the flu virus can be transmitted by touching a surface or object that has flu virus on it and then touching their mouth or nose.
Reliable data on the direct link between contact with germy surfaces and the development of disease are scant — in other words, we don’t know if touching that airplane bathroom handle was the reason we got sick a few days later. But if we want to know where the microbes are most likely to be lurking -– and which occupations are more likely to be exposed — researchers at the University of Arizona’s Department of Soil, Water and Environmental Sciences have been diligently swabbing offices, homes and public spaces over the last few years to find out.
Studies conducted in 2006 and 2009 showed that women’s offices are dirtier than men’s (see here and here) but that MRSA was isolated twice as often in men’s than women’s offices. The germiest jobs? Not surprisingly, school teachers, from close contact with children who each year pass around billions of germs that cause colds, flu and digestive problems, head the list. Surfaces regularly used by teachers had 10 times more bacteria per square inch when compared with other professions.
Accountants and bankers were high on the germy scale, while lawyers were found to have the least amount of bacteria per square inch. Accountants had the germiest doorknobs and pens, while teachers had the germiest computer keyboards.
The University of Arizona studies have earned microbiologist Charles Gerba, who heads the research, the nickname “Dr. Germ.” Much of his funding comes from consumer-products companies such as Clorox and Procter & Gamble, which market cleaners and disinfectants, but he says he also has grants from the federal government.
Dr. Gerba tells the Health Blog that the amount of bacteria or germs found on each surface is thought to be directly related to cleaning practices, and corporate sponsors hope to use the studies to identify the benefits of disinfection and develop more targeted cleaning products. In one of his studies on germs in the office, people who said they use disinfectants have less than a quarter of the bacteria than those that said they don’t.
A co-worker infected with salmonella, which causes fever, abdominal cramps and diarrhea, can leave traces of stool on his or her hands after using the bathroom, then transmit them to communal surfaces like microwave oven keypads, telephone receivers and pens. Bacteria can last on surfaces for several hours, so the next person to touch the same surface is at risk of picking up the germs and ingesting them with an errant finger in the mouth. While our immune systems protect us from most germs we might encounter in the office, it’s better to be safe than sorry.
Like most hygiene experts, Dr. Gerba recommends regular hand washing with soap or an alcohol-based hand sanitizer after shaking hands, and after contact with surfaces routinely touched by others. In fact, it’s generally a good idea to wash up after coming inside from any public place.
If you are especially paranoid, avoid certain places where germs are likely to be in high concentrations. “I stay out of day-care centers,” says Dr. Gerba.
