Eleven cases of human plague were reported in 6 states from April through August—a substantial increase compared with the annual number of US cases reported in recent years.
Public health experts who investigated the cases in Arizona, California, Colorado, Georgia, New Mexico, and Oregon said reasons for this year’s increase aren’t clear. From 2002 to 2012, the annual number of plague cases ranged from 1 to 17, with a median of 3 cases per year. In the current outbreak, 9 of the 11 patients are male with a median age of 52 years. Three patients aged 16, 52, and 79 years have died (Kwit N et al. MMMR Morb Mortal Wkly Rep. 2015;64:918-919).
Plague Increase in Western US. JAMA. 2015;314(14):1440. doi:10.1001/jama.2015.12513