CDC warns of potential for ricin poisoning

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Nov 20, 2003 (CIDRAP News) – Because someone who recently mailed a container of ricin remains at large, the Centers for Disease Control and Prevention (CDC) is urging health workers to be alert for possible cases of ricin poisoning.

An envelope containing a threatening note and a sealed container of ricin turned up at an airport mail-processing facility in Greenville, S.C., Oct 15. Until the perpetrator is found, "healthcare providers and public health officials must consider ricin to be a potential public health threat and be vigilant about recognizing illness consistent with ricin exposure," the CDC says in the Nov 21 issue of Morbidity and Mortality Weekly Report.

The investigation in the South Carolina case found no environmental contamination at the postal facility and no ricin-related illnesses, according to the CDC. The report provides general information on ricin and discusses the clinical signs of illness, laboratory testing, and treatment.

Ricin is a toxin derived from castor beans. The report says processed and purified ricin can be spread by aerosol, contaminated food or water, or injection. (The perpetrator in the South Carolina case threatened to put ricin in water supplies, according to news reports at the time.) Ricin particles less than 5 microns in size can stay suspended in calm air for several hours, the article says.

Ricin poisoning can cause mild, severe, or fatal illness, the CDC notes. In moderate to severe illness due to ricin ingestion, vomiting and diarrhea typically lead to dehydration and possibly to hypovolemic shock.

There is no specific antidote for ricin, and it cannot be removed by dialysis, according to the article. The CDC recommends supportive treatment, including intravenous fluids and vasopressors for hypotension. If a patient may have ingested ricin and is not vomiting, a single dose of activated charcoal should be given as soon as possible. Gastric lavage is an option if it can be done within 1 hour after ingestion of the ricin.

No existing tests can identify ricin in biological fluids, but a fluorescence immunoassay, available from the CDC and Laboratory Response Network labs, can detect it in environmental samples. All known or suspected cases of ricin exposure should be reported to the regional poison control center (1-800-222-1222) and local and state health departments, the CDC says.

CDC. Investigation of a ricin-containing envelope at a postal facility—South Carolina, 2003. MMWR 2003 Nov 21;52(46):1129-31 [Full text]

See also:

Oct 24 CIDRAP News story on South Carolina ricin episode

CDC fact sheet on ricin

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