Figure. . . . Areas of New Mexico, USA, considered in the current analysis on the basis of those defined as high risk for human plague by Eisen et al. (6) for each time frame examined. A) 1976–1985, B) 1986–1995, C) 1996–2007. Distributions of human cases are displayed and census block groups are color coded as negative or positive for plague cases. Census block group boundaries are indicated in light gray, and counties are outlined in dark gray. Ovals or circle indicate census block groups with significantly (p<0.05) high human plague incidence rates per 1,000 persons, identified by using the Kulldorff space scan statistic (9). Analyses were conducted by using the Poisson probability model and 999 Monte Carlo replications to test for significance.