Food poisoning, also referred to as foodborne illness, results from consuming contaminated, spoiled, or toxic food. The food is often tainted by infectious organisms — usually bacteria, parasites, or viruses.
Food poisoning is quite common. Approximately 50 million people in the United States and millions more worldwide contract food poisoning every year. Most cases of food poisoning require little more than hydration and rest, although a small number of cases are severe and even life-threatening. The severity of symptoms primarily depends on the type of agent that contaminated the food and the health of the immune system of the person who contracted the illness.
Food can become contaminated at any point of the production process: growing, harvesting, storing, shipping, or preparing. The transfer of harmful organisms from one surface to another — also known as cross-contamination — is a frequent cause of foodborne illness. Since raw, ready-to eat foods are not heated or cooked, these items are particularly at risk.
The agents that cause food poisoning include bacteria, viruses, parasites, mold, toxins, contaminants, and allergens. Of these, most cases of food poisoning can be attributed to bacteria, parasites, or viruses. Bacteria and viruses are the most common, with symptoms varying in type and severity based on the agent that has contaminated the food.
Bacterial food poisoning
Bacteria are the most frequent cause of food poisoning by a slight margin. Salmonella, E.coli, and listeria are all variations of bacteria that comprise the most frequent strains of bacterial food poisoning. Salmonella infection (Salmonellosis), which is the most common cause of poisoning, is generally transmitted during the processing and handling phases of food preparation. The symptoms, which last between four and seven days, generally include diarrhea, fever, and abdominal cramps.
Clostridium Botulinum (Botulism) is a very serious, rare type of bacterial food poisoning. Generally attained through improperly canned or preserved food, botulism is life-threatening. Symptoms include abdominal cramps, breathing difficulties, difficulty swallowing and speaking, double vision, vomiting, and muscle weakness. The inherent danger of the illness is due to the potency of the botulism neurotoxin — one of the most potent and lethal substances in existence. Without prompt treatment, this neurotoxin can paralyze the muscles and cause respiratory failure, resulting in death.
Virus-based food poisoning
The second leading cause of foodborne illness is virus-based food poisoning. The Norovirus, also called the Norwalk virus, causes over 19 million cases of food poisoning annually. Viruses are categorized into three main groups: norovirus, rotavirus, and adenovirus. Symptoms of virus-based food poisoning include abdominal pain, vomiting, diarrhea, fever, headache, nausea, loss of appetite, and fatigue. Most people will recover from this type of food poisoning within a few days.
Of the three, parasites are the least common cause but they still pose a significant threat. Common foodborne parasites include protozoa, roundworms, and tapeworms. Toxoplasma gondii — the parasite that causes toxoplasmosis — contributes to the most food poisoning hospitalizations and deaths in the United States. Symptoms of this illness generally include body aches, swollen lymph nodes, headache, fever, and fatigue. Individuals with weakened immune systems and pregnant women are particularly prone to this type of food poisoning.
Pathogens — microorganisms including bacteria, viruses, and parasites — can be found in almost all of the food that people eat. The heat derived from cooking generally kills such pathogens, drastically reducing the odds of contracting food poisoning. Various types of food poisoning are caused by undercooked and raw food. Properly handling and preparing food is important to prevent food poisoning.
Certain sectors of the population are also more prone to foodborne illness. Young children, pregnant women, older adults, and individuals with weakened immune systems are especially at risk for food poisoning. Thus, food safety guidelines should be followed with particular care.
Most instances of foodborne illness are preventable. Among the 50 million Americans who become sick, 128,000 who are hospitalized, and 3,000 who die each year due to food poisoning, the vast majority of these cases could have been prevented. Certain risky behaviors, such as eating or drinking raw eggs or milk, increase the odds of contracting food poisoning.
Symptoms and preventive measures
As noted, most types of food poisoning have a common set of symptoms: diarrhea, vomiting, abdominal pain, fever, and nausea. Although most cases of food poisoning include symptoms that will generally subside within a few days, it is important to identify potentially dangerous symptoms. They include bloody stools, prolonged vomiting and diarrhea, signs of dehydration, a high fever of over 101.5 degrees Fahrenheit, muscle weakness, and difficulty breathing.
Of course, taking preventative measures when preparing food can help to minimize the risk of contracting a foodborne illness. Foodsafety.gov breaks down four memorably simple “steps” to help increase food safety: clean, separate, cook, and chill.
The “Clean” stage involves properly washing your hands, utensils, and surfaces. The “Separate” stage involves separating food types, cutting surfaces, and cooking areas — a measure that is particularly helpful in preventing cross-contamination. The “Cook” stage involves simply heating food at the appropriate temperature and microwaving it thoroughly. The final step is to “chill” food by refrigerating it promptly and properly after cooking.