The early stages of ricin intoxication are difficult to distinguish from those of some infections, and may mimic septicaemia, and so it was particularly important that healthcare workers in the UK be alerted of the possibility of ricin poisoning. A letter was cascaded via fax and email for immediate distribution from the Deputy CMO to all members of the National Health Service on 7 January. This included the text of the joint statement, and contact details for the National Poisons Information Service and the Public Health Laboratory Service (PHLS).

The PHLS made the joint statement available on its website, with links to interim guidance for the investigation and management of outbreaks and incidents of unusual illness, ricin guidelines (2), and information on other chemicals which could be used for deliberate release. On 9 January, interim guidelines for health professionals dealing with suspect packages and materials were posted on the website (3).

A toxalbumin extracted from the beans of the castor oil plant, ricin inhibits protein synthesis, which causes cell death. Death may be due to multi-organ failure. The onset of symptoms may be delayed for several hours after exposure (which may be via ingestion, inhalation or injection), and can include irritation, gastroenteritis, conjunctivitis, respiratory symptoms, seizures and CNS depression, fluid loss leading to tachycardia, allergic reactions, abnormal liver functions, and haematuria, proteinuria and elevated creatinine.

There is no known antidote for ricin, and treatment is symptomatic and supportive only. In the event of mass exposure to ricin, careful decontamination of patients is recommended. More detailed information is available in reference 2.

Ricin is considered to be one of the chemical warfare options available to bioterrorists if used in aerosols or injected. In 1977 a Bulgarian political dissident living in London died after being fired at or injected with a ricin filled bullet (http://news.bbc.co.uk/1/hi/uk/2636459.stm).