Investigation of a ricin-containing envelope at a postal facility--South Carolina, 2003.

On October 15, 2003, an envelope with a threatening note and a sealed container was processed at a mail processing and distribution facility in Greenville, South Carolina. The note threatened to poison water supplies if demands were not met. The envelope was isolated from workers and other mail and removed from the facility, and an investigation was begun. On October 21, laboratory testing at CDC confirmed that ricin was present in the container. To assess the human health effects related to possible ricin exposure, the South Carolina Department of Health and Environmental Control (SCDHEC) and CDC interviewed all workers at the postal facility and initiated statewide surveillance for illness consistent with ricin exposure during October 15-29. On October 22, the facility was closed for a detailed epidemiologic and environmental investigation. This report summarizes the results of the investigation, which found no evidence of environmental contamination and no cases of ricin-associated illness. Clinicians and public health officials should be vigilant for illnesses suggestive of ricin exposure.