Christmas food poisoning and how to avoid it – by a microbiologist

Food poisoning affects millions of people in the UK every year, and the risk rises during the Christmas period. Large family meals, raw poultry, packed fridges and buffet food all increase the chances of contamination.

In the UK, the most common bacterial causes of food poisoning are campylobacter and salmonella, both of which are frequently found on raw poultry.

While most cases of food poisoning are mild and clear up on their own, they can be serious for vulnerable groups. These include very young children, older adults, pregnant people and those with weakened immune systems.

Symptoms can include nausea, vomiting, fever, diarrhoea and a general feeling of being unwell.

Although there are no UK statistics published specifically for food poisoning at Christmas, the UK experiences more than 2.4 million cases of food poisoning every year. Public health agencies consistently see a seasonal rise in cases over the festive period, thought to be linked to the widespread preparation of poultry such as turkey.

So what is it about Christmas that makes it such a risky time of year? Here’s a closer look at the festive food habits that raise the risk of food poisoning, and how to avoid them.

Not checking use-by dates

Checking use-by dates is especially important at Christmas, when fridges are often full and food has been bought well in advance. Foods labelled “use by” are highly perishable and must be stored correctly in the fridge and eaten within the stated time to prevent bacterial growth.

Even if food is still within date, it should not be eaten if the packaging looks swollen or if the food smells or looks unusual when opened. These are signs of possible bacterial or fungal contamination, and it is safer to throw the food away.

Under-thawing frozen poultry or washing it

Large frozen birds such as turkeys can take several days to thaw fully in the fridge. Cooking poultry that is not completely defrosted can result in uneven cooking, allowing bacteria to survive in the centre of the meat.

Washing raw poultry before cooking is unnecessary and increases the risk of food poisoning. Poultry sold by supermarkets and butchers is already cleaned. Washing it can splash bacteria such as campylobacter and salmonella onto sinks, work surfaces, hands, clothes and nearby foods, leading to cross-contamination.

Undercooking your Christmas dinner

Poultry can contain bacteria throughout the meat, not just on the surface, so the entire bird must be thoroughly cooked to make it safe to eat.

Always follow the cooking instructions on the packaging. These timings are usually based on an unstuffed bird. Poultry cooked with stuffing inside the cavity often takes longer, and heat may not reach the centre properly, allowing bacteria to survive.

The only way to make poultry safe is by cooking it thoroughly. Using a food thermometer can help. Poultry is safe to eat when the thickest part reaches at least 75°C, a temperature that effectively kills food poisoning bacteria.

For this reason, it is much safer to cook stuffing in a separate dish rather than inside the bird.

Hand washing and kitchen hygiene

Good hygiene is essential when preparing raw meat, poultry, fish or vegetables.

After handling raw foods, wash your hands thoroughly with soap and water. Clean and disinfect chopping boards, knives, and work surfaces to prevent cross-contamination.

Do not prepare food for others if you have vomiting or diarrhoea, particularly if caused by highly contagious viruses such as norovirus or rotavirus.

Incorrect storage of Christmas leftovers

Food poisoning bacteria are present everywhere, including kitchens and fresh foods. Refrigeration slows their growth, but only if the fridge temperature stays between 0 and 5°C.

At Christmas, fridges are often overloaded, which can raise internal temperatures and allow bacteria to multiply. Avoid storing items that do not need refrigeration in the fridge.

Leftovers should be cooled, covered, and refrigerated within two hours. At room temperature, some bacteria can double in number every 20 minutes. Leftovers should be eaten within two days.

If you cannot eat leftovers within this time, freeze them. When stored at -18°C, they can be kept safely for up to three months.

Christmas dining out and party buffets

Around 60% of food poisoning cases in the UK are linked to food eaten outside the home.

Even in restaurants with high hygiene ratings, food can still be exposed to contamination from people, insects or the environment.

Buffets carry particular risks because perishable foods may be left out too long.

Food should not be left out for more than two hours unless refrigerated or, in the case of hot food, kept above 60°C. If you take buffet leftovers home, refrigerate them promptly and reheat until piping hot before eating.

Following these food safety tips can help reduce your risk of food poisoning this Christmas. In addition to food-related hazards, St John Ambulance has highlighted a range of other festive accidents to watch out for.

I hope your holiday is happy, healthy, and safe.

Merry Christmas.

Primrose Freestone does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.