Rapidly evolving adult respiratory distress syndrome with eosinophilia of unknown cause in previously healthy active duty soldiers at an army training center: Report of two cases

Background: Two previously healthy soldiers presented with rapidly evolving adult respiratory distress syndrome (ARDS) within days of their return fro m the National Training Center at Fort Irwin, California. There have been s ix similar cases reported in the National Training Center area, five with f atal outcomes. Methods: Both patients were treated in an intensive care uni t setting. Extensive diagnostic testing was performed, and patients were tr eated empirically with doxycycline, ceftriaxone, and ribavirin. Results: Bo th patients had complete recovery. Intensive care unit course was notable f or circulatory collapse, respiratory distress requiring ventilatory support , similar to 10% eosinophils on bronchoalveolar lavage, and dramatic periph eral eosinophilia. All cultures, including serology cultures for hantavirus , were negative. Conclusion: There have been no previously described syndro mes comprising "viral" prodrome, rapid progression to ARDS, and eosinophili a. Based on the geographic, temporal, and clinical similarity of these two cases, we believe that they share a common, yet undetermined, cause. Both e nvironmental exposures and any undescribed pathogens warrant further invest igation.