Sept. 6, 2012  -- A pediatric critical care doctor's quick, outside-the-box thinking saved the life of a 7-year-old girl who'd contracted a rare case of bubonic plague while camping in southwest Colorado.

Sierra Jane Downing had come upon a half-eaten squirrel while on a picnic with her family on Aug.19 in Pagosa Springs. A passionate animal lover, the young girl asked her parents if she could bury the animal. Her mother said no.

"We told her to stay away from it, but when she went down to the creek to play with her 13-year-old sister, Sierra Jane went back to the squirrel, put her sweatshirt down next to it, and then picked up the sweatshirt and put it around her waist," her mother, Darcy Downing, told ABC News.

Five days later, Sierra Jane woke up with a fever and was vomiting, and by 9 p.m. her father found her lying on the bathroom floor. When he picked her up to bring her back to bed, the girl threw up again and then had a seizure.

At that point the girl's dad knew something was very wrong, and he rushed her to the local hospital near their Pagosa Springs home.

Sierra Jane's clear chest X-ray and only slightly elevated white blood cell count offered local doctors no clue that Sierra Jane had contracted the disease that wiped out one-third of Europe's population in the 14th century.

While the doctors called around to other Colorado hospitals, they managed to bring Sierra Jane's temperature down from 107 to 103 degrees. After speaking with doctors at the Rocky Mountain Hospital for Children in Denver, they had Sierra Jane flown there. When she arrived at 5 a.m. the next day she still very sick but stable, so doctors placed her in the hospital's intermediate care unit under continuous monitoring.

By 6:30 p.m. Saturday, Sierra Jane's condition had worsened and she was transferred to pediatric ICU for septic shock.

"It was touch-and-go for a while, and all we could do is pray," her father, Sean Downing said. Read: Plague, Hantavirus, West Nile: How to Avoid Them Doctors initially thought that Sierra Jane's altered mental state -- which included delirium and hallucinations -- was a result of a dose of the antibiotic ceftriaxone.

Dr. Jennifer Snow, the pediatric critical care specialist whose quick thinking proved so important, ran some blood tests on Sierra Jane, as the girl was in disseminated intravascular coagulopathy, meaning her blood would not clot. Snow then reinterviewed the family about where Sierra Jane had been and what she might have been exposed to.

"Mom told us the story of the exposure to the dead squirrel, and exposure to mouse droppings in chicken coops, and exposure to a dead skunk," Snow told ABC News.

By then Snow was getting an inkling of what Sierra Jane might have contracted. Snow did an immediate literature search, and found a report of a 16-year-old with fulminant septic shock in the chest whose cause of death was listed as bubonic plague.

Snow promptly contacted Dr. Wendi Drummond, a pediatric infectious disease specialist, who recommended starting the girl on gentamicin, an antibiotic used to treat many types of bacterial infections.

Sierra Jane completed her course of antibiotics on Wednesday and could be going home by the end of the week, according to Drummond.

This is the first case of bubonic plague that either Snow or Drummond had seen in their careers. In Colorado, the disease, that had killed an estimated 25 million Europeans more than 500 years ago and was once called the Black Death, had not been seen since 2006.

Bubonic plague is generally transmitted to people through the bites of infected fleas but can also be transmitted by direct contact with infected animals. Doctors at Rocky Mountain Hospital found tiny bites around Sierra Jane's torso, where she had tied that sweatshirt after it had been placed next to the dead squirrel.

While Sean Downing said that his daughter is "doing fantastic and now waiting for her lipase levels to go down," he said that he is amazed at how the community he lives in came together to support his family, who was combatting this rare disease just after their home had been foreclosed upon.

"I feel there's so much [danger] about bubonic plague and the Black Death, but it has been a catalyst for amazing things in our community. A whole town came together," he said.

"We would just sit and weep after hearing these things, and people would bring food and gifts for us and Sierra Jane. I hope that the infection of love never dies."