Is there a more potent symbol of purity than the fluffy white snowflake, wafting from heaven and landing - ping! - on the tip of your tongue? Well, along comes the journal Science to spoil the fun, noting that bacteria called Pseudomonas syringae are lurking at the dark heart of many an earthbound crystal of frozen water. And if Frosty the Snowman is a target, what chance do the rest of us have?

A pretty good one, actually - if you make note of the places where the bugs lie and swat them before they can do harm. Here's an updated to-disinfect list for all the surprising places (and people) contagion clings to.

Your vacuum cleaner

The threat: researchers at the University of Arizona recently found that 50 per cent of the vacuum brushes they tested contained fecal bacteria, including 13 per cent with E. coli, and all were packing mould. Vacuuming can transfer the germs from contaminated surfaces to uncontaminated ones (think kitchen to living room).

The solution: spray the brush with a disinfectant after every use - traces of bacteria can survive as long as five days inside the vacuum after you empty the dirt. And disposable-bag vacuums promote more bacterial growth, according to the study, so buy the bagless variety.

Your weight-lifting gloves

The threat: a 2004 study at Japan's Osaka University found that staph bacteria bind strongly to polyester, which is used in many gloves. And yes, that includes MRSA bacteria, which lurk wherever jocks gather. You grab the bar, grunt a weight, wipe your eyes, nose, or mouth, and the bacteria are in.

The solution: ditch the gloves and not just to ditch the germs; hitting the weights with bare hands will strengthen your grip and forearms, says certified strength-and-conditioning specialist Mike Mejia. If your gym doesn't keep disinfectant wipes and alcohol-based hand sanitizer handy, insist that it start doing so.

The shopping trolley

The threat: the handles of almost two-thirds of shopping carts tested in a 2007 University of Arizona study were contaminated with fecal bacteria. The trollies had even more of these bacteria than the average public bathroom.

The solution: swab the handle with a disinfectant wipe before grabbing hold. And skip the free food samples, which are nothing but communal hand-to-germ-to-mouth zones. Finally, bag unpackaged items, like fruits and vegetables, before placing them in your fecal-matter carrier. Your trolley, that is.

Gym equipment

The threat: a 2006 study in the Clinical Journal of Sports Medicine found rhinoviruses (instigators of the common cold) on 63 per cent of the gym equipment at the fitness centres they tested. Researchers also discovered that weight equipment was contaminated significantly more often than aerobic equipment (73 per cent versus 51 per cent). Even worse, the study found that disinfecting the equipment twice a day didn't do anything to lower the virus count.

The solution: avoid touching your face between sets, since most colds are transmitted through hand-to-nose contact. Pack an alcohol-based hand sanitiser in your gym bag.

The restaurant menu

The threat: ever see anybody wash a menu? We didn't think so. A recent study in the Journal of Medical Virology reports that cold and flu viruses can survive for 18 hours on hard surfaces. If it's a popular joint, hundreds of people could be passing their germs on to you.

The solution: never let the menu touch your plate or silverware as you ponder the wine list, and wash your hands after you order. But how do you escape the bathroom without touching the door handle? Palm a spare paper towel after you wash up, and then use it to grab the handle. Execute this trick properly and nobody needs to know how much you fear germs.

The flight attendant

The threat: flight attendants are exposed to dozens of sniffling and coughing passengers. When attendants need a pee break, they head into the same latrine you use. Now consider that when Dr Charles Gerba, co-author of The Germ Freak's Guide to Outwitting Colds and Flu, tested commercial-plane bathrooms, he found that surfaces from faucets to doorknobs were contaminated with E. coli. Given all that germ exposure, it's no surprise that the Journal of Environmental Health Research recently revealed that you're 100 times as likely to catch a cold while flying than on the ground.

The solution: pack a green-tea pill. In a 2007 University of Florida study, people who took a 450-milligram green-tea supplement twice a day for three months had a third fewer days of cold symptoms. Try Microgenics Green Tea 10,000mg ($19.95 for 50 tablets, available at mrvitamins.com.au).

Your bed

The threat: more than 80 per cent of homes in coastal areas of Australia host dust mites and research from Sydney's Woolcock Institute of Medical Research shows that dust mite levels can increase 2-3 fold during late autumn, compared with summer levels. These microscopic critters live in your sheets and feed on your dead skin, and their fecal matter and corpses contribute to asthma and allergies.

The solution: don't make your bed. A study from London's Kingston University found that dust mites need humidity levels above 50 per cent to survive. And while they can't live in the arid conditions of an unmade bed, a made bed traps the moisture they need to thrive. Mount an air attack, too. Try bundling a dehumidifier with an oscillating fan for a two-pronged moisture eliminator.

The lemon wedge in your drink

The threat: in a 2007 study from the Journal of Environmental Health, nearly 70 per cent of the lemon wedges smashed onto restaurant glasses contained disease-causing microbes. Researchers ordered drinks at 21 different restaurants, securing 76 lemons. Testing revealed 25 different micro-organisms lingering on the lemons, including E. coli and other fecal bacteria.

The solution: tell the waiter you prefer your drink sans fruit. Why risk it?

Your contact lens case

The threat: a 2007 study by Hong Kong Polytechnic University's School of Optometry found 34 per cent of contact lens cases tested were found to be crawling with germs like Serratia and Staphylococcus aureus. These micro-organisms can cause keratitis, an inflammatory eye disease that can damage the cornea and lead to blindness.

The solution: dump the used solution and thoroughly rinse your case in hot water every day, and replace your lens case at least every three months. And buy a new bottle of solution every other month, even if you haven't used it all: a separate Chinese study discovered that multi-purpose solutions lose most of their germ-fighting power after two months.

Your shower curtain

The threat: the soap scum hanging out on your curtain is more than just unsightly. A study in Applied and Environmental Microbiology found that vinyl shower curtains are microbe meccas, breeding potential pathogens, such as infection-causing Sphingomonas and Methylobacterium. Plus, the force of the shower spray will make germs take flight, says the study author, Dr Norman Pace, a professor of molecular biology at the University of Colorado in the US.

The solution: hang a fabric shower curtain from the rod. It will still harbour bacteria, but it's much easier to clean than scrubbing down a vinyl curtain. Just toss it in the washer, and use the hottest water the fabric can handle. Pace washes his shower curtain once a month but advises anyone with a weakened immune system (that's you if you're highly stressed or battling a disease) to do so more frequently.