Pet chicks and ducklings seem unlikely culprits in a serious public health problem. But they’re responsible for infecting more than 900 people with salmonella this year — the highest number to date, according to the Centers for Disease Control and Prevention.
The agency is investigating multistate outbreaks of salmonella infections linked to people who keep poultry in their backyards. As the local-food movement grows across the nation, more people are raising chickens, ducks and other birds. But along with the benefits of connecting with nature and easy access to fresh eggs comes the risk of disease.
So far this year, 961 people in 48 states have contracted the disease from backyard birds. More than 200 people have been hospitalized, and one person in North Carolina has died. Outbreaks have been reported for several years now, but case numbers shot up sharply last year and are expected to continue to rise.
“Over the years, we’ve accumulated a pretty serious health issue,” said Dr. Megin Nichols, a veterinarian at the C.D.C. who tracks outbreaks. “Ownership of live poultry and the interest in raising backyard chickens and ducks is really growing.”
Salmonella is a bacterial disease people often associate with eating raw cookie dough and other products with undercooked eggs or meat. But it can also be contracted when people put their hands, or equipment, that has been in contact with live poultry, in or around their mouth.
Risk of that type of contact increases as backyard birds become more popular.
That doesn’t mean people shouldn’t get backyard birds, Dr. Nichols said. But it is important to take appropriate precautions to avoid the spread of salmonella.
Always wash your hands after handling poultry, she advised. Keep a separate pair of boots and clothes to use in the coop, so you don’t carry germs back into the home. Don’t let poultry live inside the house, never eat or drink in the area they live and avoid kissing or snuggling them.
While there isn’t comprehensive national data yet, a 2010 U.S. Department of Agriculture study of four major metro areas found that 0.8 percent of households owned chickens, and another 4 percent were planning to get them in the next five years. Experts say that the predicted increase appears to have come true.
“Instead of just selling baby poultry in the spring, they’re being sold year-round now,” Dr. Nichols said.
Traci Torres, a founder of My Pet Chicken, a Connecticut-based backyard chicken vendor, said the birds were becoming so popular that the company often sells out months in advance. Ten years ago, the company sold about 5,000 chicks in a year, Ms. Torres said, and now it sells hundreds of thousands a year. “We don’t see any signs of it slowing down,” she said.
Andy Schneider, a backyard poultry expert known as the Chicken Whisperer, said people join the backyard bird movement for many reasons. Chickens are great composters, their feces make excellent fertilizer and they eat bugs and pests that you may not want in your backyard. But the largest motivator is a supply of fresh eggs, he said.
“The No. 1 issue of why it’s growing, without a doubt, is the local-food movement,” Mr. Schneider said. “People want to know where their food comes from.” In a 2014 survey, 95 percent of respondents said the main reasons they kept chickens were for eggs, meat or both.
There’s a common belief that those eggs will be safer than commercial eggs, Mr. Schneider said. But that’s not the case. A recent study found that eggs from small flocks are more likely to be contaminated with salmonella than eggs sold in grocery stores because those typically come from larger flocks that are regulated by the Food and Drug Administration.
For many people, there’s another reason to keep chickens, and it has nothing to do with food production. It can be seen in the growth of websites selling chicken clothes and toys, Mr. Schneider said. People want poultry pets.
They give the birds clever names, like Oprah Henfrey and Sir Lays-a-lot, Mr. Schneider said. “They hug them, kiss them, put clothes on them, bring them inside the house,” he added — all behaviors that increase the risk of infection.
“Many people who bring poultry into their home as pets don’t necessarily know they can carry germs that make people sick,” Dr. Nichols said, “so they may not take the appropriate precautions.”
And it’s not just chickens. A small but growing number of people are acquiring ducks, too. “It’s a trend that’s increased gradually in the last five years,” Dr. Nichols said. “Some outbreaks have been linked to ducklings.”
Not to mention pet amphibians and reptiles. The C.D.C. has reported a salmonella outbreak linked to pet turtles this year. Thirty-seven people have been infected and 16 were hospitalized. In previous years, a few hundred people have contracted the illness from turtles, typically through contact with dirty water in the pet’s habitat.
In 1975, the Food and Drug Administration banned the sale of turtles with shells less than 4 inches long as pets because they are often linked to salmonella infections. Even larger turtles pose a risk, though, and pet owners need to take proper precautions just as they would with poultry, the agency advises.
Bob Smith and his wife, who live in Hershey, Pa., have owned chickens for four years and never had an issue. The couple got Daisy, Patsy and Lily primarily as pets, teaching them tricks like jumping into the air and flying to a designated spot on command. “They’re amazing pets,” Mr. Smith said. “They’re probably more responsive to me than my cats are.”
But having worked as a microbiologist in a hospital for many years, Mr. Smith knew the risks they carried, too. He was quick to enforce hand-washing practices among anyone who visited the chicks and regularly cleans the coop to reduce the risk of spreading feces.
“I know what salmonella is,” he said. “I’ve seen it. And if washing my hands keeps me from having that, then I’m definitely going to wash my hands.”