It's enough to make you feel queasy: Every time you watch or read the news, there's one more story about people falling ill after eating or taking a cruise.
Stories about E. coli outbreaks, norovirus outbreaks or good ol' garden variety food poisoning -- large-scale cases of food-borne illnesses -- seem to appear every day. But while it may seem that there are more incidents of these illnesses than there used to be, most researchers disagree.
They say that surveillance techniques have increased and more afflicted people know what's happening to them and report their illnesses.
The Centers for Disease Control and Prevention said there are 73 million reports of food-borne illnesses each year -- a number it says falls far short of reality. To make a report, a doctor must give a sample to a state lab, and most cases don't make it that far.
According to the CDC, incidents of E. coli, listeria and campylobacteria have actually decreased by roughly 30 percent over the past decade.
However, certain organisms are now more infectious than they have been in the past, such as E. coli 0157H, the most common form of E. coli and the culprit believed to have contaminated food in this week's Taco Bell incident.
Health investigators Monday said an E. coli outbreak at three Taco Bell restaurants in New Jersey and on Long Island sickened at least 22 people, two of them seriously.
A Growing Threat
"This type of E. coli has been around for about two decades, but it is much stronger than it used to be," explains Dr. Pascal James Imperato, chairman of the department of preventive medicine at SUNY Downstate Medical Center. "We're not certain why it acquired its virulence, but it causes a more severe form of gastroenteritis in which a number of people can get very ill or even go into kidney failure."
E. coli, short for Escherichia coli, is a common bacteria that lives in human and animal intestines. Some strains produce toxins that can cause a wide range of symptoms, including mild and severe diarrhea, abdominal cramps and blood in the stool.
It is most usually contracted through undercooked beef or unpasteurized milk but can also be transmitted by vegetables or from food handlers who fail to wash their hands after going to the bathroom.
E. coli is normally found in the gastrointestinal tracts of a number of animals, like cows and sheep. Many of the outbreaks have been traced to contamination by animal feces in water supplies used to irrigate crops.
And as the human population grows, along with its proximity to animals, some researchers say E. coli infections are inevitable.
"As the number and size of cattle ranches grow, cows have become more confined and the presence of bacteria increases in the herd and that increases our contact with bacteria, " says Dr. Vanessa Sperandio, a microbiologist at Utah Southwestern Medical Center.
As was learned from the E. coli outbreak earlier this year that was caused by contaminated spinach -- which the CDC says was its largest outbreak on record -- washing with water doesn't always get rid of the bacteria.
According to Dr. Evgeni V. Sokurenko, associate professor of microbiology at the University of Washington, E. coli grabs on even harder during washing, though using hot water can help. Sokurenko says that the humid environment created by plastic bags makes it easy for the organism to multiply, "and if it's not properly refrigerated, then the organism can really multiply."
According to the Partnership for Food Safety, consumers have the power to keep food safe from harmful bacteria by following these four simple steps:
-- Keep It Clean: Wash hands and surfaces often.
-- Keep Items Separate: Don't cross-contaminate.
-- Cook Your Food: Cook to proper temperature.
-- Chill Your Food: Refrigerate promptly.
How to Stay Shipshape
Imagine coming down with the worst stomach virus you've ever had. Then imagine that you're hundreds of miles from home and confined to a small room with an even smaller bathroom. Oh, and your roommate is sick, too.
That's what happened to more than 380 passengers and crew members who were stricken with the stomach flu on the world's largest cruise ship, the Freedom of the Seas, which returned to port in Miami Sunday. Royal Caribbean says a sick passenger likely brought the norovirus onboard the ship last month.
The same type of virus struck about 700 people last month on Carnival Cruise Line's Liberty.
The virus can cause symptoms such as stomach pain, diarrhea and vomiting, as well as general lethargy and weakness.
Outbreak investigations by the CDC have shown that transmission among cruise ship passengers is almost always person to person. Cruise ship water supplies have never been implicated.
"Since 2002, we've seen a huge increase in this virus, but we're not sure why," says Dave Forney chief of the CDC's vessel sanitation program. "It is increasing in the general population. It's basically the most common cause of the 24-hour stomach bug. But the reason we're hearing more reports is partly because on cruise ships they are required to do surveillance and report every case."
The CDC says other reasons why noroviruses are associated with cruise ships include the fact that close living quarters may increase the amount of group contact, and new passenger arrivals may spread the virus to other passengers and crew.
"We now have huge cruise ships that carry thousands of people and certain pathogenic organisms such as the Norwalk virus. If it gets introduced to one of the cruise ships it can spread easily onto doorknobs and countertops and survive there," explains Imperato.
"If people don't have good personal hygiene and [don't] wash their hands they can spread it as they move around the ship."
The CDC recommends you do the following to protect yourself before embarking on a cruise ship:
-- Wash your hands. Before and after eating, smoking, touching your face or using the bathroom.
-- Leave the area if you see someone getting sick (vomiting or experiencing diarrhea). Notify the cruise staff. You could become sick if you ingest contaminated particles that travel through the air.
-- Take care of yourself. Get plenty of rest and drink lots of water. Resting helps rebuild your immune system. Drinking water helps to prevent dehydration.
-- Be considerate of other people's health. If you're ill before taking a cruise, call the cruise line to find out if there's an alternative cruise you could take.