When three members of the McClow family got a bad cold, 16-month-old Evan didn't get better when his twin sister, Alison, and their father, Keith, did.
Teresa McClow, Evan's mother, said she remembers coming home from church one night and Keith telling her that Evan was experiencing rapid breathing and a fever.
"I could feel his heart pounding," Keith said. "We decided to call the pediatrician. ... She was very concerned and asked us to go to the ER."
"We were given Tylenol or Motrin to treat the fever," Teresa said.
The couple brought Evan home, but that night his temperature rose to 103 degrees.
"The pediatrician wanted to admit us to the hospital because the chest X-ray looked serious," Theresa said. Their pediatrician began to worry that Evan might have tuberculosis.
Evan was taken to Advocate Hope Children's Hospital, in Oak Lawn, Ill., where doctors suspected he might have an infection. Lung specialist Dr. Javeed Akhter began asking about the McClows' family history.
"Evan was doing much worse than either Alison or Keith. ... It was indeed a little bit worrisome," Akhter said.
If it was a genetic problem, surely the twins would both be showing it, doctors thought. Then they asked whether the family had pet birds, or lived near a farm, because there's a serious allergy some people develop called Farmer's Lung.
"This was interesting to me because I work on a farm," said Keith, who works on a "living history" farm that's based on how people lived in the late 19th century and is also a tourist attraction where visitors can work on the farm with the "family" that runs it.
Because of Keith's job, doctors began to do blood work on Evan, and Theresa recalls that "Dr. Akhter wanted to perform a lung wash." A bronchoscopy was ordered to take samples from Evan's lungs.
"We actually tested for everything that could possibly cause pneumonia in this child," Akhter said. "After we did the extensive testing, we found only one slightly abnormal result. We said, 'We're not certain what Evan may have, but it's possible that he may have some histoplasmosis.'"
Histoplasmosis comes from a fungus, and the McClows had a big pile of mulch -- brimming with fungi -- that the kids had played in.
"We had requested that two tons be delivered so that we could distribute this mulch around plants and trees," Teresa said.
"Mulch exposure can be problematic because it has lots of fungi in it," Akhter said.
"Dr. Akhter never said to me that he was sure it was the mulch pile, the wood chips," Keith said. "But he said it was a good idea to get rid of it."
After being treated with anti-fungals, Evan was sent home after a few days. Keith said his son "looked good" and "was playful," but suddenly his fever returned, and Evan was coughing and couldn't keep food down.
"Of course we immediately hospitalized him," Akhter said.
"I just remember thinking to myself, 'What's the next step? What do we do now?'" Teresa said.