Food poisoning is an illness caused by eating contaminated food. It’s not usually serious and most people get better within a few days without treatment.
In most cases of food poisoning, the food is contaminated by bacteria, such as salmonella or Escherichia coli (E. coli), or a virus, such as the norovirus.
Common Food Poisoning Germs
A number of microorganisms can cause food poisoning. Common culprits include:
Salmonella. Salmonella bacteria are the leading cause of food poisoning in the United States. These bacteria usually get into foods when they come into contact with animal feces. The main causes of salmonella poisoning are eating dairy products, undercooked meat, and fresh produce that hasn’t been washed well.
E.coli (Escherichia coli). E. coli bacteria, too, usually get into food or water when they come into contact with animal feces. Eating undercooked ground beef is the most common cause of E. coli poisoning in the United States.
Listeria. These bacteria are mostly found in unpasteurized dairy products, smoked seafood, and processed meats like hot dogs and luncheon meats. Listeria bacteria also can contaminate fruits and vegetables, although that’s less common.
Campylobacter. These bacteria most commonly infect meat, poultry, and unpasteurized milk. Campylobacter also can contaminate water. As with other kinds of bacteria, these usually get into foods through contact with infected animal feces.
Staphylococcus aureus. These bacteria (which can be found in meats, prepared salads, and foods made with contaminated dairy products) spread through hand contact, sneezing, or coughing. That means the infection can be transmitted by people who prepare or handle food.
Shigella. Shigella bacteria can infect seafood or raw fruits and vegetables. Most of the time, these bacteria spreads when people prepare or handle food don’t wash their hands properly after using the bathroom.
Hepatitis A. People mostly get this virus from eating raw shellfish or foods that have been handled by someone who is infected. It can be hard to pinpoint the source of an infection because people may not get sick for 15 to 50 days afterward.
Noroviruses. These viruses usually contaminate food that’s been prepared by an infected handler.
Signs and symptoms
The symptoms of food poisoning usually begin within one to two days of eating contaminated food, although they may start at any point between a few hours and several weeks later.
The main symptoms include:
- feeling sick (nausea)
- diarrhea, which may contain blood or mucus
- stomach cramps and abdominal (tummy) pain
- a lack of energy and weakness
- loss of appetite
- a high temperature (fever)
- aching muscles
In most cases, these symptoms will pass in a few days and you will make a full recovery.
What to do?
Most people with food poisoning recover at home and don’t need any specific treatment, although there are some situations where you should see your GP for advice (see below).
Until you feel better, you should rest and drink fluids to prevent dehydration. Try to drink plenty of water, even if you can only sip it.
Eat when you feel up to it, but try small, light meals at first and stick to bland foods – such as toast, crackers, bananas and rice – until you begin to feel better.
Oral rehydration solutions (ORS), which are available from pharmacies, are recommended for more vulnerable people, such as the elderly and those with another health condition.
When to see your GP
You should contact your GP if:
- your symptoms are severe – for example, if you’re unable to keep down any fluids because you are vomiting repeatedly
- your symptoms don’t start to improve after a few days
- you have symptoms of severe dehydration, such as confusion, a rapid heartbeat, sunken eyes and passing little or no urine
- you’re pregnant
- you’re over 60
- your baby or young child has suspected food poisoning
- you have a long-term underlying condition, such as inflammatory bowel disease (IBD), heart valve disease, diabetes or kidney disease
- you have a weak immune system – for example, because of medication, cancer treatment or HIV
In these situations, your GP may send off a stool sample for analysis and prescribe antibiotics, or they may refer you to hospital so you can be looked after more closely.
How is food contaminated?
Food can become contaminated at any stage during production, processing or cooking. For example, it can be contaminated by:
- not cooking food thoroughly (particularly meat)
- not correctly storing food that needs to be chilled at below 5C
- leaving cooked food for too long at warm temperatures
- not sufficiently reheating previously cooked food
- someone who is ill or who has dirty hands touching the food
- eating food that has passed its “use by” date
- the spread of bacteria between contaminated foods (cross-contamination)
Foods particularly susceptible to contamination if not handled, stored or cooked properly include:
- raw meat and poultry
- raw eggs
- raw shellfish
- unpasteurized milk
- “ready-to-eat” foods, such as cooked sliced meats, pâté, soft cheeses and pre-packed sandwiches
Bacteria grow and multiply on some types of food more easily than on others. The types of foods which bacteria prefer include:
- dairy products
- small goods
- cooked rice
- cooked pasta
- prepared salads, fruit salads, coleslaws, and pasta salads
Don’t let your food turn nasty!
- Food poisoning is a serious health problem. It can cause severe illness and even death.
- Food poisoning is frequently caused by bacteria from food that has been poorly handled, stored or cooked.
- Symptoms of food poisoning can include nausea, stomach cramps, diarrhea, fever, and headaches.
- Symptoms can occur within 30 minutes of eating, or a number of hours or days later. They can be mild or severe. Some bacteria can also cause other symptoms.
- Listeria bacteria may cause miscarriage or other serious illness in susceptible people. Certain people are more at risk from food poisoning.
- This includes young children, pregnant women, the elderly, and people with other illnesses.
Some ways of preventing food poisoning
- Good personal hygiene, such as thoroughly washing and drying hands when handling food.
- Avoid cross-contamination, such as keeping raw foods and ready-to-eat foods separate, and using separate, clean utensils, containers and equipment.
- Cook foods thoroughly; make sure foods such as meats and poultry are cooked until their core temperature reaches 75°C.
- Avoid the Temperature Danger Zone; keep chilled foods cold at 5°C or colder, and hot food hot at 60°C or hotter.
- Avoid spoiled foods, foods past their use-by dates, or food in damaged containers or packaging.
- When in doubt, throw it out.
10 Acts on food safety
· More than 200 diseases are spread through food.
Millions of people fall ill every year and many die as a result of eating unsafe food. Diarrheal diseases alone kill an estimated 1.5 million children annually, and most of these illnesses are attributed to contaminated food or drinking water. Proper food preparation can prevent most food borne diseases.
· Contaminated food can cause long-term health problems.
The most common symptoms of food borne disease are stomach pains, vomiting and diarrhea. Food contaminated with heavy metals or with naturally occurring toxins can also cause long-term health problems including cancer and neurological disorders.
· Food borne diseases affect vulnerable people harder than other groups.
Infections caused by contaminated food have a much higher impact on populations with poor or fragile health status and can easily lead to serious illness and death. For infants, pregnant women, the sick and the elderly, the consequences of food borne disease are usually more severe and may be fatal.
· There are many opportunities for food contamination to take place
Today’s food supply is complex and involves a range of different stages including on-farm production, slaughtering or harvesting, processing, storage, transport and distribution before the food reaches the consumers.
· Globalization makes food safety more complex and essential.
Globalization of food production and trade is making the food chain longer and complicates food borne disease outbreak investigation and product recall in case of emergency.
· Food safety is multi-sectoral and multidisciplinary
To improve food safety, a multitude of different professionals are working together, making use of the best available science and technologies. Different governmental departments and agencies, encompassing public health, agriculture, education and trade, need to collaborate and communicate with each other and engage with the civil society including consumer groups.
· Food contamination also affects the economy and society as a whole.
Food contamination has far reaching effects beyond direct public health consequences – it undermines food exports, tourism, livelihoods of food handlers and economic development, both in developed and developing countries.
· Some harmful bacteria are becoming resistant to drug treatments.
Antimicrobial resistance is a growing global health concern. Overuse and misuse of antimicrobials in agriculture and animal husbandry, in addition to human clinical uses, is one of the factors leading to the emergence and spread of antimicrobial resistance. Antimicrobial-resistant bacteria in animals may be transmitted to humans via food.
· Everybody has a role to play in keeping food safe.
Food safety is a shared responsibility between governments, industry, producers, academia, and consumers. Everyone has a role to play. Achieving food safety is a multi-sectoral effort requiring expertise from a range of different disciplines – toxicology, microbiology, parasitology, nutrition, health economics, and human and veterinary medicine. Local communities, women’s groups and school education also play an important role.
· Consumers must be well informed on food safety practices.
People should make informed and wise food choices and adopt adequate behaviors. They should know common food hazards and how to handle food safely, using the information provided in food labeling.
Street foods are defined as foods and beverages prepared and sold by vendors in streets and other public places for immediate consumption without further processing or preparation.
Today, local authorities, international organizations and consumer associations are increasingly aware of the socioeconomic importance of street foods but also of their associated risks.
The major concern is related to food safety, but other concerns are also reported, such as sanitation problems (waste accumulation in the streets and the congestion of waste water drains), traffic congestion in the city also for pedestrians (occupation of sidewalks by street vendors and traffic accidents), illegal occupation of public or private space, and social problems (child labor, unfair competition to formal trade, etc.).
The risk of serious food poisoning outbreaks linked to street foods remains a threat in many parts of the world, with microbiological contamination being one of the most significant problems.
Food-borne pathogens are recognized as a major health hazard associated with street foods, the risk being dependent primarily on the type of food, and the method of preparation and conservation.
A lack of knowledge among street food vendors about the causes of food-borne disease is a major risk factor.
Poor hygiene, inadequate access to potable water supply and garbage disposal, and unsanitary environmental conditions (such as proximity to sewers and garbage dumps) further exacerbate the public health risks associated with street foods.
Improper use of additives (often unauthorized coloring agents), mycotoxins, heavy metals and other contaminants (such as pesticide residues) are additional hazards in street foods.
Although many consumers attach importance to hygiene in selecting a street food vendor, consumers are often unaware of the health hazards associated with street vended foods.
Benefits of Street Foods
Street foods provide:
- A source of cheap, convenient and often nutritious food for urban and rural poor
- A major source of income
- A chance for self employment and the opportunity to develop business skills with low capital investments.
- In contrast to the potential benefits, it is also recognized that street food vendors are often poor and uneducated and lack appreciation for safe food handling.
- Street foods are perceived to be a major public health risk.
Treating Food Poisoning
A doctor will ask about what your child ate most recently and when symptoms began. The doctor will do an exam, and might take a sample of blood, stool, or urine and send it to a lab for analysis. This will help the doctor find out which microorganism is causing the illness.
Usually, food poisoning runs its course and kids get better. Occasionally, though, doctors prescribe antibiotics to treat more severe types of bacterial food poisoning. If dehydration is severe, a child may need to be treated in a hospital with intravenous (IV) fluids.
Food poisoning usually goes away on its own in a few days. To help your child feel better in the meantime, make sure that he or she:
- Gets plenty of rest.
- Drinks fluids to protect against dehydration. Electrolyte solutions work, but anything except milk or caffeinated beverages will do.
- Takes small, frequent sips to make it easier to keep the fluids down.
- Avoids solid foods and dairy products until any diarrhea has stopped.
Do not give over-the-counter anti-diarrhea medications. These can make the symptoms of food poisoning last longer. When diarrhea and vomiting have stopped, offer your child small, bland, low-fat meals for a few days to prevent further stomach upset.
If symptoms become serious or you see signs of dehydration, call your doctor.