Hedgehog owners should refrain from kissing their small, spiky friends, health officials said on Friday.
Since October, 11 people across eight states have been infected with a particular strain of salmonella, the Centers for Disease Control and Prevention reported, and all but one of those infected said they had contact with a hedgehog.
“Don’t kiss or snuggle hedgehogs because this can spread salmonella germs to your face and mouth and make you sick,” the agency warned.
No deaths have been reported and one person has been hospitalized, the C.D.C. said. Three cases have been reported in Missouri and two in Minnesota. Infections have also been reported in Colorado, Maine, Mississippi, Nebraska, Texas and Wyoming.
Animals can pick up salmonella from contaminated food, or the bacteria can live naturally in their intestines. Some can even pick up the bacteria from their mothers before they are born, according to the C.D.C.’s website.
Although pet hedgehogs may not show signs of sickness, they can carry the bacteria and spread it through their droppings. Once the hedgehog passes the germs to their surroundings — like their toys and beddings — humans are vulnerable to infection when they handle those objects.
This is not the first time pet hedgehogs have been linked to a salmonella outbreak. From December 2011 to April 2013, 26 people were infected with the same bacterial strain, Salmonella typhimurium; a majority of them reported contact with hedgehogs. One person died and eight people were hospitalized in that outbreak, the C.D.C. reported.
“The fact that hedgehogs are a risk is not new,” said Jane Sykes, a professor of small animal internal medicine at the University of California, Davis. “But we don’t know how common the shedding of salmonella is among hedgehogs specifically.”
Scientists also are not sure exactly why hedgehogs seem to be more prone to transmitting salmonella than other animals are, Dr. Sykes said. For people with compromised immune systems, she recommends choosing a pet that poses a lower risk, like a dog.
Salmonella infections can lead to diarrhea, fever and stomach cramps. The illness typically resolves itself in four to seven days, although some patients may require hospitalization.
The C.D.C. recommended that owners take precautions, such as washing their hands after touching a hedgehog and not letting their pets loose around the kitchen. Owners should also practice good cage hygiene and avoid bathing a hedgehog in the kitchen sink or allowing it into bed, Dr. Sykes said.
Kim Tipton, a hedgehog breeder in Niagara Falls, N.Y., said a common mistake among owners is leaving leftover food like fruits, vegetables and meat in the hedgehog’s cage for too long. Any foods left uneaten after a couple hours could spoil and should be taken away, Mr. Tipton said. Leaving food out can cause bacteria like salmonella to multiply.
Regardless of the risk of salmonella, Mr. Tipton recommends that owners never cuddle or kiss their hedgehogs. They tend to be solitary animals and their quills can be sharp.
“It’s not a puppy. It’s not a kitten. It’s not a hamster,” he said on Saturday. “It’s not something you’re going to pet or cuddle.”
Mr. Tipton, who has been breeding hedgehogs for about 10 years and has about 100 of them at his business, Hog Heaven Hedgehogs, said he had not heard reports of symptoms of salmonella infection from any of his customers.
Hedgehogs are hardly the only pet known to spread disease. Pet reptiles are most commonly associated with passing salmonella to their owners, Dr. Sykes said.