When’s the last time you cleaned your spice jars? Many of us will automatically reach for the paprika or chilli powder when we’re cooking dinner, without considering the germs that may have accumulated on those little pots. A study in the Journal of Food Protection examined 371 adults making turkey burgers and found that spice containers had the highest degree of cross-contamination out of all of the kitchen surfaces. After cooking, the researchers discovered bacteria from the turkey present on 48% of the spice jars. To prevent cross-contamination, make sure you wash your hands before and after handling raw meat. It’s a good idea to regularly wipe down your spice containers with a disinfectant solution or hot soapy water.

While some germ hotspots are immediately obvious, other high-contact areas of the home are all too easy to overlook. A frequently used appliance, your microwave might not strike you as a particularly dirty space, especially if you frequently wipe out the interior. However, it’s the exterior that often gets neglected – in particular the handle where bacteria can build up, especially when you’re cooking. Independent public health and safety organisation NSF International found microwave handles to be especially dense with harmful microbes. To keep germs at bay, they recommend cleaning the handle once a week with a disinfectant product. 

Light switches are one of the most frequently touched surfaces in any home – and one many of us seldom think about when it comes to cleaning. Shockingly, NSF International found that bathroom light switches ranked higher for germs than bathroom door handles. To limit the spread of germs in your home, make a note to include light switches in your weekly cleaning routine. You can remove all that built-up bacteria by wiping down the whole panel thoroughly with an alcohol-based disinfectant. 

A startling finding by the United States Department of Agriculture might be enough to put you off your dinner. Their research revealed that there are more than 1.8 million units of bacteria lurking inside your fridge, undetectable to the eye. Worryingly, some of these microbes have been linked to everything from food poisoning to respiratory conditions, urinary tract infections and even miscarriages. Particular germ hotspots are the vegetable and meat drawers, as well as shelves where dairy products are stored. You should deep clean your fridge every three to six months. Remove shelves and drawers and wash with hot water and washing-up liquid, then wipe down the interior with a sterilising solution. Don't forget the exterior and handles of your fridge too. 

We all know public offices aren't the cleanest of places, but that stylish home office of yours can be just as bad. Areas on your desk where you rest your hands tend to accumulate the most germs, as well as equipment like keyboards. Try to disinfect the whole area with an antibacterial wipe once a day.

We put everything on our kitchen worktops, from raw meat and filthy sponges to shopping bags that have been on dirty floors, all of which carry an array of germs. In a study by NSF International, kitchen worktops had coliform bacteria present in 30% of the homes they tested. To keep bacteria at bay, it's best to clean natural solid surfaces like this with washing up liquid and hot water. 

As a rule, wherever water collects will be a breeding ground for bacteria and your refrigerator's water dispenser is a prime culprit – with the double threat of having many hands touching it repeatedly every day. Use an antibacterial spray on the push button and remove any exterior parts to wash in warm soapy water. To clean the inside, shut off the water connection and flush it with white vinegar. Make sure to rinse the line thoroughly before use and take an old toothbrush to any nozzles.

While there are many more obvious contenders for germ hotspots in your kitchen, believe it or not, the hob controls are one of the filthiest areas. Covered in food splatters and touched a number of times during food preparation, the best way to clean them is to remove the knobs and rinse them in hot soapy water. 

The kitchen sink is one of the most germ-laden places in the house and can often be worse than the toilet. Particles of food from plates left to soak can provide a breeding ground for bacteria, including salmonella and E. coli. To keep germs at bay in the pipes as well as the sink, pour one cup of hot water into the drain, followed by a cup of bleach and leave overnight, repeating every week or so.

Chopping boards are used every day for food prep and can be laden with germs from raw meat and fish, so it's easy for them to collect bacteria. If you only have one chopping board, ditch this bad home habit and invest in multiple, colour-coded boards to avoid cross-contamination. For a wooden board that's likely to harbour more germs, white vinegar is a great cleaning tool. Simply apply with a clean cloth to disinfect and eliminate any odours.

Spatulas, especially the rubber variety, are full of nooks and crannies that were found to hide  E. coli, yeast and mould by NSF International – not the ingredients you want to be adding to your cooking! If your spatula is made from two parts, make sure to separate them when washing. Generally, metal models are better as they aren't as vulnerable to collecting germs. 

Almost perpetually damp, shower curtains are the ideal breeding ground for mould, a serious hidden hazard in your home. A study conducted by SafeHome found that your shower curtain can hold up to 60 times more bacteria than your toilet seat. To keep it as clean as possible, you can spray your shower curtain with distilled white vinegar after showering to help kill any mould or mildew that has started to form. 

The grout between your bathroom tiles and the sealant around your bath both offer the perfect places for mould to lurk. And that's not all as the drain itself could contain 119,468 bacteria per square inch according to a study by Soakology. It's a good idea to disinfect your bath with a bathroom cleaner and then wipe it down with a clean, dry towel. 

According to NSF International, it’s not the toilet that’s the dirtiest place in your bathroom, it's the toothbrush holder. Often placed in proximity to the toilet, they collect nasty germs transferred from flushes, plus bacteria from the toothbrush itself. It’s a good idea to give your toothbrush holder a deep clean once a week by either putting it in the dishwasher or giving it a rinse with soapy water. 

You may think that your washing machine is safe from germs, but you couldn't be further from the truth. To save energy, many machines wash clothing at a lower temperature, however, this means more bacteria survive, according to research by the American Society for Microbiology. Be sure to remove washed laundry as soon as possible and at least once a month, run an empty hot cycle with bleach. After an illness in the house, wash any clothes, sheets and towels at a high temperature.

The growing, harvesting and transportation of fruit involves many hands, as well as mud, manure and chemicals. Just as you should not eat fruit without washing it, you also should keep your fruit bowl clean before you stock it up. If it's safe to put it through the dishwasher, the steam will kill most bacteria. If not, give it a good scrub with dish soap and hot water and allow it to air dry on a rack.

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