To date, the most severe Ebola outbreak in history began in Guinea in 2013 and spread to West African neighbors Liberia and Sierra Leone Before being declared extinguished in 2016, over 28,000 cases and 11,000 deaths occurred A few cases were imported to the United States, revealing issues with medical readiness for imported viral hemorrhagic fevers Ebola, depending on the strain, typically has a case fatality rate of 50% to 80% in African nations, raising concerns regarding its intentional release by terrorists A recombinant Ebola vaccine tested in Guinea during the outbreak has shown great promise in preventing spread of disease to close contacts Ricin The distinction between biologic agents, which are living organisms capable of causing infections, and chemical agents, which are nonliving poisons, is obvious Toxins such as ricin, however, are chemical poisons produced by biologic organisms and occupy a somewhat nebulous niche between chemical and biologic (infectious) agents Although discussed with biologic agents, it should be kept in mind that they cause intoxication (poisoning) rather than infection, not replicate in hosts, and not produce communicable, or contagious, conditions Ricin is a toxin derived from the castor bean, and its production is not technologically challenging It is quite toxic if ingested, and far more so if injected or inhaled It is infamous as a homicidal weapon of espionage used by the Bulgarian secret service in London during the Cold War against defector Georgi Markov More recently, in February 2004, it was discovered in a U.S Senate office building, apparently having been delivered through the mail At least 16 persons required decontamination, although no one became ill Ricin is an inhibitor of cellular protein synthesis via enzymatic attack on the 28S ribosomal subunit The clinical presentation of ricin intoxication depends on the route of exposure Exposures due to aerosols produce dose-dependent symptoms Four to hours after inhalation, fever, chest tightness, cough, dyspnea, nausea, and arthralgias can occur, followed within 36 hours by progressive cough, dyspnea, cyanosis, and pulmonary edema resulting in respiratory failure If ingested, necrosis of the GI epithelium, local hemorrhage, and hepatic, splenic, and renal necrosis can be expected followed by vascular collapse and death If injected, severe local necrosis of muscle and regional lymph nodes with moderate visceral organ involvement are seen Patients with ricin poisoning are not contagious Establishing a diagnosis of ricin intoxication may be challenging: Early postexposure (0 to 24 hours) nasal or throat swabs and respiratory secretions may be submitted for toxin assay for