We've all been there: you wake up feeling a little green around the gills, and before you know it, you're holed up in the bathroom for days. As you sip Gatorade and munch on saltine crackers in the brief respites from your body's need to evacuate its contents, you wonder, "What the heck did I eat?" While it's natural to assume that last night's fancy dinner is to blame (why did I have to order the mussels?!), chances are, you have to look back further than that. Food poisoning takes time, and it rarely sets in fast enough to come from the last thing you ate.
The U.S. Centers for Disease Control and Prevention (CDC) estimates that every year, 1 in 6 Americans gets sick from something they ate. That's usually because a pathogen found its way into the food, whether during production, preparation, or from your own unwashed hands. But here's the thing: Just like you don't get sick the same day you encounter someone with the flu, you don't start heaving as soon as you're done eating a tainted burger. Pathogens bide their time.
According to the CDC., the top four pathogens that cause the most foodborne illnesses each year are norovirus, Salmonella enterica, Clostridium perfringens, and Campylobacter jejuni. Among those, the microbe with the shortest time it needs to cause illness is Salmonella, and even that's six hours at the minimum; it can take up to two days. C. perfringens, meanwhile, takes at least eight hours, norovirus requires at least 12 hours, and Campylobacter takes two days at the very least.
That means that if you come down with diarrhea and vomiting, chances are that it's because of a meal you had before your last one - maybe even several days before. The good news is that most people don't require a doctor's visit when they get food poisoning, although the CDC recommends calling the clinic if you have a temperature above 101.5 degrees Fahrenheit (38.6 degrees Celsius), you can't keep liquids down, or if your diarrhea lasts more than three days.
To avoid a weekend praying to the porcelain god, the first step is to play it safe at your own table and kitchen. That means washing your hands and preparation surfaces regularly, avoiding cross-contamination between raw and ready-to-eat food, and cooking everything to a safe internal temperature (145 degrees Fahrenheit/63 degrees Celsius for whole red meat, pork, and fin fish; 160 degrees Fahrenheit/71 degrees Celsius for eggs and ground meat; 165 degrees Fahrenheit/74 degrees Celsius for poultry and everything else). And obviously, keep food cold until it's ready to cook. Outside of your kitchen, though, you may not have much control; because bulk ingredients come from many different sources, restaurant food is a bit riskier. Diner beware!
It's also good to be extra careful with the types of food that are most commonly contaminated. That includes the obvious suspects like raw shellfish, red meat, poultry, and eggs, but also something not everyone thinks about: fruit and vegetables. In fact, a CDC study found that produce is responsible for nearly half of foodborne illnesses in the U.S., and causes nearly as many deaths as contaminated meat and poultry.