The trichothecene mycotoxins are highly toxic compounds produced by certain species of fungi. Because these mycotoxins can cause massive organ damage, and because they are fairly easy to produce and can be dispersed by various methods (dusts, droplets, aerosols, smoke, rockets, artillery mines, portable sprays), mycotoxins have an excellent potential for weaponization.
Strong evidence suggests that trichothecenes (“yellow rain” have been used as a biological warfare agent in Southwest Asia and Afghanistan. From 1974-1981, numerous attacks resulted in a minimum of 6310 deaths in Laos, 981 deaths in Cambodia, and 3042 deaths in Afghanistan. When taken from fungal cultures, the mycotoxins yield a yellow-brown liquid that evaporates into a yellow crystalline product (thus, the “yellow rain” appearance). These toxins require certain solutions and high heat to be completely inactivated.
Signs and symptoms
After exposure to the mycotoxins, early symptoms begin within 5 minutes. Full effects take 60 minutes.
- If skin exposure occurs, the skin burns, becomes tender, swollen, and blisters. In lethal cases, large areas of skin die and slough (fall off).
- Respiratory exposure results in nasal itching, pain, sneezing, a bloody nose, shortness of breath, wheezing, cough, and blood-tinged saliva and sputum.
- If ingested, the person feels nausea and vomits, loses appetite, feels abdominal cramping, and has watery and/or bloody diarrhea.
- Following entry into the eyes, pain, tearing, redness, and blurred vision occur.
- Systemic toxicity may occur and includes weakness, exhaustion, dizziness, inability to coordinate muscles, heart problems, low or high temperature, diffuse bleeding, and low blood pressure. Death may occur within minutes to days depending on the dose and route of exposure.
Diagnosis of an attack of trichothecene mycotoxin depends on the symptoms and identifying the toxin from biological and environmental samples. Many people with these symptoms may report being in a yellow rain or smoke attack.
Initial laboratory tests are not always helpful. Currently, a rapid identification kit for any of the trichothecene mycotoxins does not exist. Gas-liquid chromatography has been used in the past with great success. However, chromatographic methods lack great sensitivity, and presently alternative methods of detection are under investigation.
Treatment is mainly to help with symptoms. The immediate use of protective clothing and mask during a mycotoxin aerosol attack should prevent illness. If a soldier is unprotected during an attack, the outer clothing should be removed within 4-6 hours and decontaminated with 5% sodium hydroxide for 6-10 hours. The skin should be washed with copious amounts of soap and uncontaminated water. The eyes, if exposed, should be washed out with large amounts of normal saline or sterile water. US military personnel can use a skin decontamination kit effectively against most chemical warfare agents, including the mycotoxins.
No specific therapy exists for a trichothecene exposure. After appropriate skin decontamination, victims of inhalation and oral exposures may be given superactivated charcoal orally. Activated charcoal removes mycotoxins from the GI tract. Some victims may need help breathing with a ventilator. Early use of steroids increases survival time by decreasing the primary injury and shock-like state that follows significant poisoning.
No vaccine exists for trichothecene mycotoxin exposure. Currently, 2 topical skin protectants as well as vaccines are in advanced development but have not been approved yet for use in humans.