Outbreak of pruritic rashes associated with mites--Kansas, 2004.

In late August 2004, the Kansas Department of Health and Environment (KDHE) received reports from the Crawford County Health Department (CCHD) of approximately 300 residents of Pittsburg, Kansas (2000 population: 19,243), seeking care for a pruritic rash of unknown etiology. In early September, three neighboring counties in Kansas and two neighboring states (Missouri and Nebraska) also reported such cases. These events prompted KDHE to request assistance from CDC. Additional cases subsequently were reported in Oklahoma and Texas. This report describes the investigation in Crawford County, Kansas, by public health agencies and entomologists to identify the etiology of the pruritic rash and to assess the extent of the outbreak. A microscopic itch mite (Pyemotes herfsi) was identified as the likely cause of the outbreak, which affected an estimated 54% of the Crawford County population (2000 population: 38,242). Entomologists confirmed the return of P. herfsi in Kansas in August 2005 and have recommended prevention measures, such as use of DEET-containing products, to help minimize exposure for persons outdoors.