Using remotely sensed data to identify areas at risk for hantavirus pulmonary syndrome

The 1993 U.S. hantavirus pulmonary syndrome (HPS) outbreak was attributed t o environmental conditions and increased rodent populations caused by unusu al weather in 1991-92. In a case-control study to test this hypothesis, we estimated precipitation at 28 HPS and 170 control sites during the springs of 1992 and 1993 and compared it with precipitation during the previous 6 y ears by using rainfall patterns at 196 weather stations. We also used eleva tion data and Landsat Thematic Mapper satellite imagery collected the year before the outbreak to estimate HPS risk by logistic regression analysis. R ainfall at case sites was not higher during 1992-93 than in previous years. However, elevation, as well as satellite data, showed association between environmental conditions and HPS risk the following year. Repeated analysis using satellite imagery from 1995 showed substantial decrease in medium- t o high-risk areas. Only one case of HPS was identified in 1996.