Summer is prime time for the spread of Campylobacter enteritis, a type of intestinal infection resulting in stomach cramping, watery or bloody diarrhea, nausea, vomiting, and fever. When food is left outside for picnics or cookouts, "bugs can proliferate in greater numbers," says Michael Gold, past chair of gastroenterology and senior gastroenterologist at the Washington Hospital Center in Washington. Symptoms of Campylobacter infection usually start two to four days after infection occurs and typically last about a week.
But unrefrigerated leftovers aren't the only things that can spread Campylobacter enteritis. A study to be published in Emerging Infectious Diseases in September points out several seemingly harmless activities that can put you at risk of infection by this nasty bug, which is estimated to infect more than 2.4 million people and cause about 124 deaths every year in the United States. The study, done in England, looked at 1,592 people who had confirmed cases of Campylobacter infection and 3,983 people who hadn't been sick. The participants completed questionnaires about their habits prior to getting sick, and researchers found that certain habits were associated with high rates of illness. Here are four activities linked to increased risk of infection in either the new study or prior research:
Eating chicken regularly—at least once a week—may increase the risk of getting sick, the study suggests. It's not the consumption of cooked chicken that's the issue, experts say. It's how the raw food is handled and prepared. "There are probably as many cases of Campylobacter through the mishandling of poultry [as] through the consumption of the meat products," says Brendan Wren, professor of microbial pathogenesis in the department of infectious and tropical diseases at the London School of Hygiene and Tropical Medicine, who wasn't involved in the new study but has been researching the bacteria for 20 years. "Most poultry have high numbers of Campylobacter, although the poultry don't exhibit signs of illness, so hands and surfaces have to be washed thoroughly after preparing meat dishes." Testing by the Food and Drug Administration in 2005 found Campylobacter in 47 percent of raw chicken breasts.
To ensure that you prepare chicken safely, wash the raw chicken thoroughly and make sure that any surfaces that touch the carcass are cleaned thoroughly before being used again. That includes cutting boards and your hands. "You've got to wash your hands well between handling the raw chicken and putting it in the boiling pan and then going to handle other things," Gold says.
While the new study primarily focused on transmission through consumption of chicken, it's also possible to get a Campylobacter infection from undercooked meats and meat products of other types, according to the World Health Organization. Campylobacter infection is prevalent among cattle, poultry, ostriches, pigs, sheep, and shellfish.
Getting a pet dog, even one that appears healthy, may put you at higher risk for Campylobacter illness. Feces from dogs, cats, and farm animals can carry Campylobacter, according to the Centers for Disease Control and Prevention. The new study found that people who had recently gotten a dog were at higher risk of infection. Long-term dog owners, on the other hand, seemed to have a lesser risk of infection, which may be because they build up partial immunity over time, the authors wrote. An animal that does not appear to be sick can still spread the illness to humans.
In order to avoid getting Campylobacter from a pet, wash your hands thoroughly after handling animals. If you have a compromised immune system, stay away from animals that have diarrhea, and if your pet develops diarrhea, call a veterinarian, advises the CDC. Anyone who develops symptoms of Campylobacter—which include diarrhea, nausea, vomiting, or stomach cramps—should call a doctor and tell him or her if there's a sick pet at home.
Traveling abroad can put you at risk for infection with Campylobacter or other types of bacteria. Drinking contaminated food or water while traveling can make you ill. The purity of the water supply where you're traveling is particularly important "because a lot of infections that enter through our gastrointestinal tract are water-borne," Gold says. "If water gets contaminated, you can get a whole host of things that way."