Trichothecene mycotoxins lethality

Yellow Rain A lethal yellow substance thought to have been dispersed aerially as a warfare agent in Southeast Asia and Afghanistan the lethal component is though to have been a trichothecene mycotoxin that was reported to produce severe nausea and vomiting, disturbances in the central nervous system. Fever, chills, and abnormally low blood pressure with a case mortality of approximately 50 percent. 

When delivered at low doses, trichothecene mycotoxins cause skin, eye, and gastrointestinal problems. In nanogram amounts,4,25 they (T-2 toxin, in particular) cause severe skin irritation (erythema, edema, and necrosis).4,6 Skin vesication has been observed in a number of humans exposed to yellow rain attacks.4,14,15 T-2 toxin is about 400-fold more potent (50 ng vs 20 pg) than mustard in producing skin injury.26 Lower-microgram quantities of trichothecene mycotoxins cause severe eye irritation, corneal damage, and impaired vision.4 16 26 27 Emesis and diarrhea have been observed at amounts that are one fifth to one tenth the lethal doses of trichothecene mycotoxins.26... 

From these data, we can conclude that the trichothecene mycotoxins very rapidly cross the pulmonary and intestinal mucosa and enter the systemic circulation to induce the toxin-related toxicoses. In contrast, trichothecene mycotoxins are only slowly absorbed through skin, especially when applied as a dust or powder.56 Systemic toxicity and lethality can be produced by dermal exposure to higher concentrations of T-2 toxin, however, especially if the mycotoxin is dissolved in a penetrant such as DMSO.6... 

Limited data are available on the respiratory effects of inhaled trichothecene mycotoxins, although acute pulmonary edema is one of the serious, often lethal consequences of a yellow rain attack.16,27 One of the major symptoms following the yellow rain attacks was an upper respiratory irritation (sore throat, hoarseness, nonproductive cough),716,27 which can be relieved by steam inhalation, codeine, or another substance to suppress the cough, and other simple measures.85 A casualty who develops severe respiratory symptoms should be under the care of a physician skilled in respiratory care. 

Trichothecene mycotoxins are noted for their marked stability under different environmental conditions. On a weight-for-weight basis, they are less toxic than other toxins such as ricin, botulinum, and staphylococcal enterotoxin B, but trichothecene mycotoxins are proven lethal agents in warfare. Symptoms include vomiting, pain, weakness, dizziness, ataxia, anorexia, diarrhea, bleeding, skin redness, blistering, and gangrene, as well as shock and rapid death. Sensitive immunoassays and chemical procedures are available for the identifi-... 

Lethality due to ingestion of food contaminated by trichothecenes has been reported in horses (Rodricks and Eppley, 1974), cattle (Hsu et al, 1972), and humans (Joffe, 1974). General clinical signs include emesis, food refusal and weight loss, dermal effects, and immune suppression with secondary infection. Clinical signs are dependent on the specific trichothecene involved, the dose, species, route of exposure, as well as the nature of the exposure. Spontaneous and experimental exposures may give somewhat different results, as can exposure to field contaminated materials, when compared to purified toxin. In the case of field contamination or experimental use of crude extracts, multiple mycotoxins, both known and unknown, may be present at the same time. 

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