Tracking food poisoning outbreaks in NYC restaurants—what makes us sick and why

Each year, the NYC Health Department receives thousands of complaints of foodborne illness, commonly called “food poisoning.” When two or more people get sick after consuming a common food or drink, we investigate a potential foodborne illness outbreak.

We start by reviewing 311 complaints about food poisoning from eating and drinking establishments. These include restaurants, food carts and trucks, bakeries, bars, cafeterias, catering services, correctional facilities, hospitals, delis, soup kitchens, and summer camps.

There are around 40,000 eating and drinking establishments in NYC. From 2012 to 2022, there were 268 confirmed foodborne illness outbreaks in these establishments. However, many foodborne illnesses are not reported, so the true number of outbreaks was likely higher.

Over half of reported foodborne illness outbreaks nationwide came from restaurant meals.

There are three main ways food can become unsafe to eat:

• Contamination: pathogens, like bacteria, or other hazards get into food. Contact with sick workers or contaminants (such as chemicals, or raw meat) can introduce harmful substances or bacteria into food. Poisonous substances or toxins can naturally occur in plants or animals. For example, some fish can contain illness-causing toxins above safe limits.
  
  

• Proliferation: pathogens or toxins already in food proliferate (grow) to dangerous levels. When food is stored at incorrect temperatures for several hours, bacteria, toxins, and fungi can multiply to unsafe levels. Even cooking will not make the food safe. This “danger zone” temperature is between 41 and 140 degrees F. Cold food should be properly refrigerated, and hot food should be kept hot enough.
  
  

• Survival: pathogens survive a process meant to kill them. Pathogens can survive when cooking, freezing, pasteurization, or acidification processes are incomplete.
  
  

What is foodborne illness—and what causes it?

You or someone you know may have had “food poisoning.” But did you know that “food poisoning” could actually be one of more than 200 illnesses caused by bacteria, viruses, parasites, toxins, and chemical substances in food, each with their own symptoms?

There are many types of food-related illnesses. Symptoms can range from a mild stomachache to high fevers, vomiting, diarrhea, and dehydration. Certain groups, like older adults or those with compromised immune systems, are more likely to get serious illness.

Sometimes we can tell if food is rotten or spoiled, but most of the time, food that makes us sick smells and tastes normal. Symptoms can appear hours, days, or even weeks after eating contaminated food, so the cause of illness might not be your most recent meal. It all depends on the type of foodborne illness. For example, Scombroid toxin can cause illness within an hour, while Campylobacter infection symptoms typically appear 2 to 5 days after eating contaminated food. The time between eating contaminated food and the onset of symptoms is called the incubation period.

Unsafe on-site food preparation practices cause three of the top five contributing factors to foodborne illness at NYC eating and drinking establishments. Note that multiple contributing factors can happen at the same time leading to a single outbreak. Contributing factors associated with unsafe food preparation practices are:

• Contamination: Sick workers made contact with food.

• Proliferation: Food was held at dangerous temperatures, allowing pathogens to multiply.

• Survival: Food was undercooked, allowing pathogens to survive cooking.

Sick workers are the most common factor causing foodborne illness outbreaks with a confirmed cause. The Health Department requires that workers in eating establishments do not work when sick. We also promote NYC’s law entitling all employees to sick leave. To further promote safe on-site food preparation practices, we conduct routine inspections. You can find inspection results on ABC Eats.

While establishments that get “A” grades have demonstrated better food safety practices than those with Bs or Cs, this doesn’t guarantee that people can’t get sick eating there. A restaurant may have excellent food safety practices, but contamination and improper food handling can also occur in a food’s natural environment, or during harvesting, processing, or shipping. In NYC, 11% of foodborne illness outbreaks were caused by contamination before the food reached the establishment. If you get sick after eating at an establishment, it’s still important to report suspected foodborne illness to 311. The Health Department will investigate and work to prevent more illnesses.

Case studies of real foodborne illness outbreaks occurring in NYC

By looking at these real examples of foodborne illness outbreaks below, we can see how different outbreaks progress based on different contributing factors, types of dishes served, and when patrons developed symptoms.

Studying these cases helps public health officials understand how outbreaks happen and guides actions to prevent future illnesses, protect the public, and improve food safety practices.

What to do if you think you may have a foodborne illness

If you suspect you got sick from food or drink from a NYC restaurant, food cart, or truck:

• See a health care provider: Tell them about your symptoms and what you’ve had to eat and drink recently. They can run additional tests such as a stool test to find out what is causing your illness.

• Submit a 311 food poisoning complaint, so that the Health Department can investigate and help prevent further illness.