Health officials say soil-transmitted fungal pneumonia may be the cause of a flu-like illness that struck a group of trail volunteers at Dinosaur National Monument Sunday.
Sixteen people were doing volunteer work at the monument, half of them digging in an Indian sweat cave off the monument's main road and the other half working on the quarter-mile trail leading to the cave, called the "Swelter Shelter."
Eight of the volunteers, including one from inside the cave and seven from the trail, were taken to Ashley Valley Medical Center in Vernal. All but two were released Tuesday, according to Joseph B. Shaffer, director of the Tri-County Health Department, which is investigating the mysterious illness. The two still in the hospital are being held for observation at least through Wednesday.
Health officials ruled out bubonic plague, hantavirus and deer-fly bites as possible causes.
The volunteers have been treated for fungal and bacterial infection, Shaffer said. The fungal infection comes from the soil, with no possible person-to-person transmission.
All 16 of the volunteers who became ill — high school graduates and college students — were from outside the area. They came from Alaska, Florida, Kansas, Vermont, Virginia and one from Poland. Volunteers from Utah and Colorado were not affected. "My suspicion is we develop a lot of immunities to things that knock people out who are not living here," Shaffer said.
The investigation team includes representatives from the Centers for Disease Control and Prevention and local and state health officials.
None of the young adults is in danger, said Shaffer, who praised the "great cooperation" between the hospital and public health officials in launching an immediate investigation.
Contributing: Diane Urbani