Background: Several gay bars in the Capitol Hill area of Seattle received letters today from a person threatening to "target clients" with the toxin ricin. The incident is under investigation by law enforcement; there is no information at this time suggesting that anyone has been exposed to ricin. The following information is provided as a precaution to help health care providers recognize ricin poisoning in the event of a ricin exposure.

Incubation period: Approximately 4-12 hours following inhalation or ingestion of ricin. Symptom onset is unlikely more than 10 hours after ricin ingestion and more than 24 hours after inhalation exposure.

Symptoms: Systemic effects depend upon route of exposure and exposure dosage. Dermal and ocular exposure by ricin in powder or mist form can cause erythema and pain of the skin and eyes.

Ingestion exposure may result in some or all of the following symptoms: Profuse vomiting, profuse diarrhea (bloody or nonbloody); severe dehydration; weakness; influenza-like symptoms (fever, myalgia, arthralgia); hallucinations; seizures; hematuria; hypotension; hypovolemic shock; multiple system organ failure.

Inhalational exposure may include some or all of the following symptoms: Cough, respiratory distress, bronchoconstriction; pulmonary edema, cyanosis, nausea, excessive diaphoresis, weakness, influenza-like symptoms (fever, myalgia, arthralgia) hypotension, respiratory failure; multisystem organ failure.

Laboratory findings are nonspecific and include: metabolic acidosis, increased liver function tests; increased renal function tests; hematuria; leukocytosis. Public Health can facilitate testing at CDC for urinary ricinine, an alkaloid in the castor bean plant in selected cases.

Treatment: Largely supportive, contact WA Poison Center at 1-800-222-1222.

Please review additional clinical information about ricin from the Centers for Disease Control and Prevention, available at: www.bt.cdc.gov/agent/ricin/clinicians/index.asp

To subscribe to receive e-mail and/or fax health alerts from Public Health, contact Maybelle Tamura at 206-296-4774 or Maybelle.Tamura@kingcounty.gov