Key takeaways
Food poisoning happens when you consume food or drinks contaminated with bacteria, viruses, and other pathogens.
The most common signs of food poisoning are nausea, vomiting, stomach cramps, and diarrhea. However, fever, weakness, and fatigue can occur, too.
How long a fever from food poisoning lasts depends on the contaminant, your overall health, and how sick you get.
Fever from food poisoning can be treated with OTC pain relievers, rest, and extra hydration.
Every year, 1 in 6 Americans gets a foodborne illness from eating contaminated food or drinks. One kind of foodborne illness is food poisoning, caused by pathogens like bacteria, viruses, and other microbes. Food poisoning occurs when food is not properly stored, handled, or cooked, causing symptoms like stomach cramps, diarrhea, nausea, and vomiting. It can also make you feel weak and tired.
While it’s probably not the first symptom that comes to mind when you think about food poisoning, fever is common, too. However, not all cases of food poisoning will cause a fever. Here’s what to know about fever from food poisoning, including how long it lasts, treatment options, and when to see a healthcare professional for medical advice.
Can food poisoning cause a fever?
Yes, food poisoning can cause a fever. Common symptoms of food poisoning can last from hours to days (and, less frequently, weeks) and can be mild to severe. They include:
- Abdominal pain
- Diarrhea
- Nausea
- Vomiting
- Headache
- Fever
- Chills
- Muscle and joint aches
- Fatigue
Infectious bacteria, viruses, and parasites in food and drinks can cause food poisoning. Foods can be exposed to these microbes when grown, harvested, processed, shipped, packaged, and prepared.
According to the Centers for Disease Control and Prevention (CDC), raw meat, poultry, seafood, eggs, produce, grains (like raw flour), and sprouts are the most likely causes of food poisoning. You can develop food poisoning when food is not cooked or stored correctly, left out too long, expired, or handled by someone who is ill or hasn’t washed their hands.
“The onset of symptoms, including a fever, can vary depending on the type of contaminant,” says Raj Dasgupta, MD, internist and associate professor of clinical medicine at the Keck School of Medicine at the University of Southern California. Fever can occur within a few hours to several days after consuming contaminated food.
Here’s how long it takes symptoms to start for the most common types of food poisoning:
- Staphylococcus aureus: A classic food-poisoning scenario caused by staph aureus is the summer picnic, says David Cutler, MD, a board-certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, California. Say a mayonnaise-containing potato salad is left outside in the sun for too long. Staph aureus may grow and cause food poisoning, he says. Symptoms can occur rapidly—30 minutes to eight hours after consumption.
- Salmonella: This bacteria is found in many foods, including chicken, eggs, meat, sprouts, nut butter, and fresh produce. Salmonella poisoning can also occur from exposure to pets at farms or petting zoos. Symptoms appear six hours to six days after exposure.
- Vibrio: Found in raw or undercooked shellfish like oysters, symptoms begin within 24 hours of exposure to this bacteria.
- Clostridium perfringens: The bacteria C. perfringens is one of the most common causes of food poisoning. It typically occurs when large batches of food containing poultry or meat are cooked and stored at improper temperatures. Symptoms appear within six to 24 hours.
- Campylobacter: Caused by consuming raw or undercooked poultry, this bacteria is another common cause of food poisoning. Symptoms occur two to five days after ingestion.
- Norovirus: A highly contagious virus, norovirus often causes gastroenteritis, or the stomach bug common in daycares, nursing homes, and cruise ships. Though it’s not technically food poisoning, it is usually categorized as such because it can spread through contaminated foods or liquids. Symptoms begin 24 to 48 hours after exposure.
- E. coli: This bacteria resides in the intestines, but sometimes, certain strains (like E. coli O157:H7) can contaminate water and food, resulting in food poisoning. The onset of symptoms is typically within three to four days of exposure but can occur anywhere between one to seven days of ingestion.
- Toxoplasma gondii: This parasite often causes food poisoning from undercooked meat (such as pork, venison, and lamb) and shellfish (like clams, mussels, and oysters). It can also be caused by exposure to cat feces when cleaning the litter box. Symptoms start about one to three weeks after exposure.
- Listeria monocytogenes: Listeria is a bacteria that can inhabit raw, unpasteurized milk and dairy products like soft cheeses, raw fruits and vegetables, and raw or unprocessed sausages, deli meats, fish, and hot dogs. Symptoms usually occur within 24 hours.
Is it normal to have a fever with food poisoning?
“Fever is pretty common if you have food poisoning, especially in response to bacterial and viral infections,” says Dr. Dasgupta. However, not everyone will develop a fever from food poisoning, and individuals with mild symptoms usually get better without treatment, he says.
Research is lacking on the frequency of fever with food poisoning. Dr. Cutler says that most cases of food poisoning are mild and, as a result, unreported. He says that when a fever does occur with food poisoning, it’s typically low-grade (no higher than 100 to 101 degrees). A high fever from food poisoning is anything over 102 degrees.
How long does a fever last with food poisoning?
“How long a fever from food poisoning lasts can be different for everyone,” says Dr. Dasgupta. Usually, it’s a day or two, but it depends on how sick you are, your overall health, and whether you seek medical help when needed.
Here’s how long symptoms, including fever, typically take to go away by organism:
- Staphylococcus aureus: 24 hours or less
- Salmonella: Four to seven days
- Vibrio bacteria: Up to three days
- Clostridium perfringens: 24 hours or less
- Campylobacter: Up to one week
- Norovirus: One to three days
- E. coli: Up to one week
- Toxoplasma gondii: Two to four weeks
- Listeria: One to three days
How to treat a fever from food poisoning
“For a fever from food poisoning, focus on staying hydrated with water, getting rest, and eating simple, easy-to-digest foods (like crackers and bananas),” says Dr. Dasgupta. Over-the-counter (OTC) fever reducers like Tylenol (acetaminophen), Advil (ibuprofen), or Aleve (naproxen sodium) can help. However, you should avoid using antidiarrheal medicine like Imodium A-D (loperamide) or Pepto Bismol (bismuth subsalicylate) with a fever or bloody diarrhea unless advised to do so by a healthcare provider, says Dr. Dasgupta.
When to see your healthcare provider
Severe dehydration is a serious risk when you have food poisoning, says Dr. Cutler. Rehydration with water, broths, and electrolyte-containing fluids is essential.
“It’s time to see your doctor for food poisoning with a fever if you experience severe symptoms,” advises Dr. Dasgupta such as:
- Constant vomiting
- Bloody diarrhea
- Diarrhea lasting longer than three days
- High fever (greater than 102 degrees)
- Severe stomach pain
- Signs of dehydration (extreme thirst, dry mouth, dark urine, dizziness, and lightheadedness)
Dr. Dasgupta says high-risk patients, including those with kidney disease or weakened immune systems, young children, pregnant women, older adults, or those who have recently traveled to areas prone to foodborne illnesses should also seek prompt medical attention.
Sources
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- Are you sure it wasn’t food poisoning?, U.S. Department of Agriculture (2017)
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- Vibrio and food, Centers for Disease Control and Prevention (2019)
- Prevent illness from C. perfringens, Centers for Disease Control and Prevention (2023)
- Campylobacter questions and answers, Centers for Disease Control and Prevention (2023)
- Campylobacter symptoms, Centers for Disease Control and Prevention (2019)
- Norovirus illness: Key facts, Centers for Disease Control and Prevention (2015)
- Norovirus infection – symptoms and causes, The Mayo Clinic (2022)
- E. coli, The Mayo Clinic (2022)
- Toxoplasmosis: General FAQs, Centers for Disease Control and Prevention (2022)
- Toxoplasmosis fact sheet, Minnesota Department of Health (2022)
- Listeria (Listeriosis), U.S. Food & Drug Administration
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- Fast facts about food poisoning, Centers for Disease Control and Prevention (2023)