Contaminated food can make kids — and adults — very sick within hours. Here's what to do if someone in your family gets food poisoning, plus the most common culprits to avoid.

Sick Boy Laying With Dog Eating Popicle
Credit: Stephanie Rausser

Foodborne illness, which affects more than 75 million people a year, is caused by toxins, parasites, viruses, and especially bacteria — including salmonella, E. coli, and staphylococcus. Children, whose immune systems are not fully developed, are at high risk for serious complications, as are pregnant women and the elderly. But some simple precautions can help keep your family safe. Here's what to know:

The Food Poisoning Timeline

Food poisoning starts anywhere from an hour to three days after eating tainted or undercooked food. Symptoms include vomiting, diarrhea, cramps, and fever. Here are some red flags to watch for.

Top Food Poisoning Causes

Common food-poisoning culprits include the following:

  • Raw or undercooked eggs
  • Salads mixed with homemade mayonnaise
  • Raw fruits, vegetables, meat, or poultry
  • Shrimp, oysters, clams, mussels, and scallops
  • Fresh cider and other unpasteurized fruit juices
  • Alfalfa and other kinds of sprouts
  • Unpasteurized milk and cheeses
  • Home-canned foods
  • Deli meats and hot dogs

How to Treat Food Poisoning

The Situation: A few hours after a family picnic, your 9-year-old son starts vomiting.

What it could be: Staphylococcus aureus

What to do: Have your child rest and drink plenty of water. You can also give him a hydrating solution such as Pedialyte. But if he develops a fever above 101.5°F or has difficulty keeping water down, you should call the pediatrician.

The Situation: Your 6-month-old baby shows signs of abdominal pain or has diarrhea.

What it could be: Salmonella

What to do: Give your baby plenty of water, and call your pediatrician. Because food poisoning can be more dangerous in babies than in older children, take her to the doctor if she has more than two episodes of diarrhea or vomiting, especially if she shows signs of dehydration (dry mouth, rapid heartbeat, or reduced urination).

The Situation: The day after eating a fast-food hamburger, your 6-year-old daughter develops severe, bloody diarrhea.

What it could be: E. coli O157:H7, shigella, or salmonella

What to do: Take your child to the pediatrician as soon as possible; the doctor can take a stool sample to see what's making her sick. Bloody diarrhea is a sign of serious infection. Don't give your child an antidiarrheal medication, which can make her sicker.

The Situation: Your 11-month-old baby is listless and seems weak.

What it could be: Botulism

What to do: Botulism is rare, but it has a high fatality rate if not treated immediately and properly. Get your child medical attention right away, especially if he has eaten honey, which is often the culprit in babies. If left untreated, botulism can lead to paralysis or respiratory failure.

Food Poisoning and Pregnancy

Listeriosis, a type of food poisoning that's 20 times more likely to affect pregnant women than other adults, can result in premature delivery, miscarriage, or stillbirth if left untreated. If you have flulike symptoms such as fever, vomiting, diarrhea, or muscle aches for more than 12 hours after eating, call your gynecologist. The bacteria that causes listeriosis is found in soft cheeses such as feta, Brie, Camembert, blue cheese, and queso blanco; lunch meats; unpasteurized milk; and pates and other meat spreads. Avoid these foods if you're pregnant.

Some fish may contain high levels of mercury, which can damage an unborn baby's nervous system. Avoid eating shark, swordfish, tilefish, and king mackerel. Freshwater fish such as salmon, pike, and trout could also be tainted, so check with your state or local health department.

Parents Magazine