By Cheryl Platzman Weinstock
Roughly one in six Americans contracts food poisoning every year. Here's how to protect yourself.
When Claudine Rad fell ill in June, she thought she'd come down with a severe case of the flu. Her doctor prescribed some medicine and told her to rest for a few days until she felt better. But when she returned to her new job, her symptoms worsened -- to the point at which she was forced to drop out of her company's three-day training course. "My whole body ached, I had zero energy, and I was constantly in the bathroom," says Rad, 36. She had no idea what had hit her -- until, while recuperating at home, she heard about an outbreak of hepatitis A linked to a particular frozen berry and pomegranate blend used to make smoothies.
"I had been on a health kick, drinking the smoothies a few times a week in the month before I got sick," says Rad, who lives in Mesa, Ariz. Turns out, she was one of at least 161 people across the country who had been sickened by the same blend and developed hep A, an acute infectious disease that can spread through contaminated food and impair liver function.
Food poisoning is nothing new. One undercooked chicken wing or bad piece of Brie could sideline anyone for a few days of intense nausea and stomach cramps. But there's been a rise in foodborne illnesses linked to imported food in the last several years, according to the Centers for Disease Control and Prevention (CDC). This year alone there's been the hep A outbreak that made Rad ill; the incident with Salmonella-infected cucumbers that sent 17 people to the hospital from January through April; and a recent parasitic infection (known as cyclosporiasis), linked to a bagged salad mix in many cases, that had sickened more than 645 people as of mid-September.
The CDC estimates there are about 48 million cases of foodborne illness every year, leading to roughly 128,000 hospitalizations and 3,000 deaths. Experts say one reason behind the outbreaks is the globalization of products and the vast quantities of food coming to our shores. From 1998 to 2007, food imports grew by $37 billion; today, roughly 15 percent of all food eaten in the U.S., including up to 90 percent of seafood and 60 percent of fresh produce, is shipped here. "Many of our most vulnerable commodities, including fruits and vegetables, come from countries with less vigorous inspection and food safety practices," says Food and Drug Administration (FDA) commissioner Margaret Hamburg, MD. But according to a recent FDA budget report, barely two percent of imports are inspected once they reach the U.S.
As we bring in more food from all over the world, we also increase the risk of introducing less common infectious agents. Take, for example, the parasite Cyclospora, which is responsible for the recent contaminated salad mix. "Cyclospora is predominantly found in tropical and subtropical areas of the world," says Barbara Herwaldt, MD, a medical epidemiologist at the CDC. The organism first made a big splash in the U.S. 17 years ago, when it was linked to imported Guatemalan raspberries. Herwaldt says, "We still have a lot to learn about what causes it and how it spreads." This helps explain why the CDC and FDA have had difficulty stemming the outbreak that's now infected people in 24 states.
From Herwaldt's perspective, it's critical for people to see a doctor if their food poisoning symptoms last three days or longer. The more closely scientists can track potential pathogens, the better they can study them and prevent future outbreaks. As it is, researchers estimate that scientists have been able to identify the pathogens responsible for only a fifth of foodborne illnesses in the U.S.
Ironically, the biggest driver of improved food safety tends to be a food crisis. In 2006, for instance, when a strain of E. coli sickened more than 200 people and killed three after they consumed bagged baby spinach, food safety measures were overhauled. "Knowing we'd been operating at the best standard of quality before the outbreak, I realized we needed to rethink what we were considering the 'best'?" says Will Daniels, head of the quality, food safety, and organic integrity program at Earthbound Farm, a facility associated with the outbreak. In response, the company created an extensive safety program that focuses on eradicating pathogens during every step of production. Other companies cleaned up their act too, and the rate of E. coli infections in the U.S. is now 10 percent lower than it was in 2006.
There's hope that we may be able to prevent outbreaks from other infectious pathogens: In July, the FDA proposed new rules in conjunction with the Food Safety Modernization Act (a landmark law passed in 2011 -- the first major update to food safety regulations in more than 70 years) to help stop unsafe food from making its way into the U.S. The FDA is now putting the onus on importers, requiring them to verify that their suppliers meet the same standards as domestic food manufacturers. "Most people consume produce and other foods every day and don't get sick," says Michael Taylor, the FDA's deputy commissioner for foods and veterinary medicine. "There's always going to be some risk of illness -- it's impossible to have a pristine food supply -- but we continue to make it safer all the time."
Tracking an Outbreak
Here's how CDC officials, along with the FDA and other public health agencies and experts, found the culprit in the recent hepatitis A outbreak and helped stop the contamination from spreading.
In May, state health departments in Colorado and New Mexico received reports of cases of hepatitis A. By analyzing blood samples from infected patients, the CDC determined that the patients had a strain of hep A common in North Africa and the Middle East. Interviews revealed that all the patients had eaten a frozen berry blend, containing pomegranate seeds, that was purchased at the same food chain.
In Oregon, FDA officials did a thorough sweep of the plant that produces the blend. "In any outbreak investigation, we review records, collect samples, and look for potential sources of contamination at the processor," says FDA official Theresa Eisenman. "Multiple factors led us to believe the source of the outbreak was from an ingredient of the frozen berry blend, rather than contamination at the facility."
CDC officials determined the sources of all ingredients. As it happened, the pomegranate seeds were the only ones imported from the Middle East—the company was located in Turkey. Future shipments were swiftly detained.
Cheryl Platzman Weinstock is a science writer based in Connecticut.