Luke Gabriele was a healthy 14-year-old football player in Pennsylvania when he began to feel soreness in his chest that grew increasingly painful. After his breathing became difficult, doctors detected a mass that appeared to be a tumor.
For a week, Dan and DeAnna Gabriele thought their son was dying until tests identified the cause: not cancer, but chickens - the ones he cared for at home. They had apparently infected him with salmonella that produced a severe abscess.
The popular trend of raising backyard chickens in U.S. cities and suburbs is bringing with it a soaring number of illnesses from poultry-related diseases, at least one of them fatal.
Since January, nearly 1,000 people have contracted salmonella poisoning from chickens and ducks in 48 states, according to the Centers for Disease Control. More than 200 were hospitalized and one person died. The toll was four times higher than in 2015.
The CDC estimates that the actual number of cases from contact with chickens and ducks is likely much higher.
"For one salmonella case we know of in an outbreak, there are up to 30 others that we don't know about," CDC veterinarian Megin Nichols said.
A "large contributing factor" to the surge, Nichols said, comes from natural food fanciers who have taken up the backyard chicken hobby but don't understand the potential dangers. Some treat their birds like pets, kissing or snuggling them and letting them walk around the house.
Poultry can carry salmonella bacteria in their intestines that can be shed in their feces. The bacteria can attach to feathers and dust and brush off on shoes or clothing.
But illnesses can be prevented with proper handling. The CDC recommends that people raising chickens wash their hands thoroughly after handling the birds, eggs or nesting materials, and leave any shoes worn in a chicken coop outside.
Salmonella is much more common as a food-borne illness. More than 1 million people fall ill each year from salmonella contamination in food, resulting in more than 300 deaths, according to the CDC.
There are no firm figures on how many households in the U.S. have backyard chickens, but a Department of Agriculture report in 2013 found a growing number of residents in Denver, Los Angeles, Miami and New York City expressed interest in getting them. Coops are now seen in even the smallest yards and densest urban neighborhoods.
For Tanya Keith, the nine hens and a rooster that she keeps behind her home in Des Moines provide fresh eggs and lessons for her three children about where food comes from.
But even as her kids collect eggs and help keep the six nesting boxes tidy, she warns them not get too affectionate.
"We don't transfer chicken germs to our face," Keith tells them.
Stopping the germs at home is important because safeguards against salmonella are limited at the commercial sources that sell most of the birds.
A large share of baby chicks and ducks sold to consumers come from about 20 feed and farm supply retailers across the U.S. They get their chicks from a half dozen large hatcheries that supply tens of millions of baby chicks and ducklings each year.
While the Agriculture Department encourages hatcheries to be tested regularly for salmonella contamination, the program is voluntary. Unsanitary conditions or rodent infestations can help salmonella spread in hatcheries.
Dr. Stacene Maroushek, a pediatric infectious disease physician in Minneapolis, sees both sides of the popular trend. She manages her own flock of about 50 birds.
"I think it's really important to know where your food comes from, but I do think they need to be educated on how to do it safely," Maroushek said. "There are things growing up as a farm kid you know instinctively but city people don't know."
In her clinic, she's seen young children suffering from salmonella poisoning. The bacteria often cause flu-like symptoms, including diarrhea, and can produce more serious infections in children, the elderly and people with weak immune systems.
"It gets into their blood and it can get into organs," she said. "It can be much more significant in people with underlying health problems."
Even those who have had chickens for years can fall victim, as Luke Gabriele did in 2013 in his hometown of Felton in southeast Pennsylvania.
DeAnna Gabriele said her son was responsible for feeding and watering the chickens, but he didn't really like the birds and certainly didn't treat them as pets.
"They really never figured out specifically how Luke got the salmonella," she said. "They theorized that maybe he inhaled something because it can live in the environment and you can breathe it in in the dust."
He recovered after nine days in the hospital with the help of antibiotics.
She and her husband said that anyone buying chickens for the first time should try to find out whether the hatchery they came from tests for salmonella.
Nichols said the best way chicken raisers can protect themselves is to assume all birds carry salmonella and treat them carefully.
"We view this as a preventable public health problem and are really hoping we start to see some change," she said.