Postal irradiation may have some effect, but CDC still considers ricin to be fully functional and just as dangerous even after irradiation. If ricin was released into the air, some ricin might have gotten onto the clothing of people who were present and might have then been transported on the clothing to their homes. The likelihood is very low in this instance that enough ricin would have gotten onto your clothing and would have been transported home with you for your health to be threatened.
Ricin poisoning is not contagious. People who were not present where the ricin was found are not likely to have been exposed at levels high enough to negatively affect their health. No long-term direct effects are known to exist from ricin exposure that did not result in symptoms. Following severe ricin poisoning, the damage done to vital organs may be permanent or have lasting effects.
Although it is unknown whether these populations are at higher risk, the possibility of higher risk does exist. People who have existing illnesses of the respiratory or GI tract may have pre-existing tissue irritation or damage as a result of their illness. If this damaged or irritated tissue is exposed to ricin, the result may be further injury and greater absorption of the ricin toxin. The information that exists on ricin poisoning in humans is extremely limited.
Much of what we know about ricin poisoning comes from animal studies and only a few human cases. Nevertheless, enough information exists on ricin poisoning by ingestion swallowing to say that it is extremely unlikely that the onset of signs and symptoms of ricin poisoning by ingestion would occur more than 10 hours after exposure. Much less information exists on ricin poisoning by inhalation breathing in ricin , but initial poisoning symptoms are very unlikely to begin more than 24 hours after exposure.
There are several tests used to detect ricin, including tests for environmental samples of suspicious materials, and for clinical specimens from human body fluids. Some LRN laboratories can test clinical urine samples for the presence of ricinine, an indicator of ricin exposure. The rapid tests indicate whether components of the castor bean are present in the environmental sample and whether ricin toxin is present.
Another assay for environmental samples measures the activity of the ricin toxin, since ricin toxicity can be affected by several factors including temperature.
The toxin activity test tells officials whether the toxin is still dangerous. The presence of ricinine in urine helps to establish whether ricin exposure has occurred, and may help estimate the degree of exposure if the time of exposure is known. The rapid detection tests used by the LRN can be completed within hours after receipt of samples. The toxin activity test takes about 48 hours to perform but the availability of cultured cells used in the test may delay testing.
For a clinical urine specimen, measurement of ricinine can be completed within several hours after the samples are received. A preliminary test result — such as a positive for ricin components — must be confirmed by a second LRN test, which detects ricin toxin. The ricin toxin test is considered the best test for determining the presence of ricin. A positive result for ricin components can be used in public health decision making while officials wait for confirmatory results from the ricin toxin test.
They may be updated as new information becomes available. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Emergency Preparedness and Response. Two poisoned-laced letters-one sent to President Barack Obama and one to Senator Roger Wicker of Mississippi-have put the toxin ricin in the headlines this week. It's not the first time the toxin has made headlines.
In , Georgi Markov , a Bulgarian dissident, was assassinated in London when a man approached and jabbed him with an umbrella modified to fire a ricin pellet. Ricin is a naturally occurring toxin that comes from the castor bean, Ricinus communis, an ornamental plant introduced from India. For an adult, it is 20, however because the toxin protein is largely destroyed by the intestine, the mortality rate from swallowing the beans is low—less than 10 per cent.
What about ricin that has been modified into a powder or other form as an agent of biological terrorism-as with the toxin-laced letters? This makes these letters quite different from the anthrax-laced letters sent through the U. Postal Service that killed five in Which suggests, he adds, that the ricin letters carry a low probability of risk for anyone in the mail-handling chain.
It's all developing news. Here is a primer on ricin, adapted from information on the CDC website. Ricin works by preventing cells from making the proteins they need. Without the proteins, cells die. Eventually this is harmful to the whole body and may cause death. As with most chemicals, whether or not a person becomes ill after exposure to ricin depends on how much ricin the person was exposed to, how long the exposure lasted, what the exposure method was inhalation, ingestion, or injection.
Exposure to ricin comes about by ingesting or inhaling material containing ricin. In a few rare cases, injections of ricin have led to poisoning. If ricin is ingested, initial symptoms typically occur in less than hours. These are most likely to affect the gastrointestinal system and include nausea, vomiting, and abdominal pain.
Figure 1. Castor bean plant Ricinus communis , b. CASE A year-old male Saudi patient presented to the emergency department with a hour history of epigastric pain, nausea, repeated attacks of vomiting, chest tightness, and mild nonproductive cough. Ricin poisoning. A comprehensive Review. J Agric Food Chem. Stillmark R. Ueber Ricen. Arbeiten des Pharmacologischen Institutes zu Dorpat, iii, Cited in: Flexner, J. The histological changes produced by ricin and abrinintoxications. J Exp Med.
Lectin-mediated drug targeting: history and applications. Adv Drug Deliv Rev. Interstitial chemotherapy with ricin-loaded thermosensitive hydrogel in pancreatic cancer xenograft. Hepatobiliary Pancreat Dis Int. Combination chemotherapy followed by an immunotoxin anti-B4-blocked ricin in patients with indolent lymphoma: Results of a phase II study.
Cancer J. Anti-B4 blocked ricin post chemotherapy in patients with chronic lymphocytic leukemia--long-term follow-up of a monoclonal antibody-based approach to residual disease. Leuk Lymphoma. Ricin: Structure, mode of action, and some current applications. Cure of multidrug-resistant human B-cell lymphoma xenografts by combinations of anti-B4-blocked ricin and chemotherapeutic drugs.
Centers for Disease Control and Prevention. Forensic determination of ricin and the alkaloid marker ricinine from castor bean extracts. J Forensic Sci. It can also be used to poison an individual person by injecting it. Symptoms depend on the amount of ricin, and how a person is exposed to it:. Right now, there is no antidote for ricin, but the symptoms of ricin poisoning can be treated. Treatment will depend on how the patient was exposed to the poison, but may include help in breathing, as well as fluids and medications given through a vein.
People who survive more than five days have a good chance of recovering. Right now there is no way to protect people, in advance, against the effects of ricin. The possibility of developing a vaccine is being studied. Ricin is a type of poison. Ricin has been studied as a possible weapon for almost a century. The U. A militia group in northwestern Minnesota plotted to use ricin against law enforcement personnel in the early nineties.
0コメント