NPS hantavirus response followed policy

May 21, 2013, 12:07 PM EDT

YOSEMITE NATIONAL PARK, Calif. (AP) — Federal investigators probing the hantavirus outbreak blamed for three deaths at Yosemite National Park recommended on Monday that design changes to tent cabins and other privately run lodging first be reviewed by National Park Service officials.

The report released by the Interior Department's Office of Inspector General found that park officials responded to last summer's outbreak appropriately and within department policy.

"When the outbreak was identified, NPS mobilized to contain and remediate the outbreak and to prevent further outbreaks," Mary Kendall, a deputy inspector general, wrote in a letter attached to the report.

Still, the report found that current policy didn't require park officials to approve design changes made to the "Signature tent cabins" by concessionaire Delaware North Companies Parks and Resorts, which added rafters and wall studs to the structures.

Investigators determined that deer mice, which can carry the illness, nested inside the double walls of the new tents in Yosemite's family friendly Curry Village.

At least eight of the nine tourists who fell ill stayed in the tent cabins.

Because the changes to the cabins were considered routine maintenance, current park service policy did not require prior approval, the report found.

The report also recommended that the park service begin cyclical pest monitoring and inspections of all public accommodations.

While there is a current pest monitoring program at Yosemite, Delaware North was responsible for Curry Village, which was not considered at high risk for hantavirus.

The company issued a statement late Monday saying it would follow the recommendations in the report.

"DNC Parks & Resorts at Yosemite has consistently worked hand-in-hand with the National Park Service and public health officials on this issue," spokeswoman Lisa Cesaro said in the statement. "The Signature Tent Cabins have been removed from Curry Village. We are following the recommendations by the National Park Service, which were developed in consultation with the California Department of Public Health and the Centers for Disease Control and Prevention."

Prior to the outbreak, Delaware only responded to pests in the cabins when visitors or housekeeping staff complained, the report said.