OPHEPR; Tricothecene Mycotoxins - Profile for Healthcare Workers

Causative Agent: Tricothecene mycotoxins (T-2 mycotoxins) are nonvolatile compounds produced by filamentous fungi primarily of the genera Fusarium, Myrotecium, Trichoderma, and Stachybotrys.

Routes of Exposure: Inhalation, Dermal, and Oral.

Toxic Dose:

Inhalation – Unknown.

Dermal – Unknown.

Oral – Leukopenia seen with as little as 0.1mg/kg/day for several weeks.

Incubation Period:

Inhalation – Minutes

Dermal – Minutes to hours

Oral – Minutes to days

Clinical Effects: Mycotoxins act by inhibition of protein synthesis. Symptoms start within minutes to hours after exposure, and involve eyes, skin, respiratory and gastrointestinal tracts.

Eyes – Eye pain, excessive lacrimation, visual blurring and scleral injection.
Inhalation – Nasal itching and pain, epistaxis, rhinorrhea, cough, dyspnea, wheezing.
Dermal – Burning skin, redness, blistering progressing to necrosis, skin sloughing.
Oral – Anorexia, mouth pain, nausea, vomiting, hematemesis, abdominal pain, watery or bloody diarrhea, abdominal cramps.
Early systemic effects – Weakness, loss of coordination, dizziness, ataxia, tachycardia, hypothermia, hypotension or death.
Late systemic effects – Two to eight weeks after ingestion on contaminated food, bone marrow suppression occurs with with severe neutropenia and hemorrhagic syndromes such as diffuse bleeding into skin with petechiae, melena, hematuria, hematemesis, epistaxis, and vaginal bleeding. Other common problems include fever, oral and GI ulceration, and secondary sepsis. These effects are similar to the effects seen with exposure to radiation.

Lethality: There is a death rate of 10-20% with ingestion of contaminated food.

Transmissibility: Person-to-person transmission of intoxication does not occur, although exposure could occur by contact with contaminated objects and surfaces that had not bee appropriately decontaminated.

Primary dissemination: There were reports that mycotoxins may have been used in the past as bioterrorism weapons in Iran and Southeast Asia. These were described as aerosol attacks in the form of “yellow rain” with droplets of yellow fluid contaminating clothes and the environment.

Secondary Contamination: There is no person-to-person transmission but contaminated fomites, such as clothing, could be a source of exposure.

Decontamination & Isolation:

Patients – Outer clothing should be removed and exposed skin decontaminated by washing thoroughly with soap and water. Eye exposure should be treated with copious saline or water irrigation. Once decontamination is complete, isolation is not required.
Equipment, clothing & other objects – T-2 mycotoxins are stable in the environment, resistant to heat and ultraviolet light. Environmental decontamination requires the use of a chlorine bleach solution under alkaline conditions such as a 1% sodium hypochlorite (1 part bleach + 4 parts water) and 0.1M sodium hydroxide solution with one hour contact time.

Personal Protective Equipment: Respiratory, skin and eye protection are required since toxin can be absorbed by the respiratory, gastrointestinal, dermal and ocular routes.

Health Care Facility: There is no person-to-person transmission. However, avoid contact with contaminated clothing. If a contaminated person arrives fully clothed, protective clothing should be worn until decontamination of the patient is completed and contaminated clothing discarded.

Identification of Exposure: Exposure to T-2 mycotoxins should be suspected if an aerosol attack occurs in the form of “yellow rain”. Currently, there are no commercially available rapid field diagnostic tests available. Confirmation requires testing of blood, tissue, and environmental samples using gas liquid chromatography-mass spectrometry techniques.

Laboratory testing: Serum, nasopharyngeal swab, and urine can be sent for toxin.

Therapeutic Treatment: Superactivated charcoal should be administered to persons who may have ingested T-2 mycotoxins in order to adsorb the toxin. There is no vaccine and no specific antidote or therapeutic regimen. Treatment is symptomatic and supportive.

Prophylactic Treatment: None

Differential Diagnosis: Mustard gas has a delay of several hours before symptoms start. Staphylococcus enterotoxin B can cause fever, cough, dyspnea and wheezing but does not involve the skin. Ricin can cause severe respiratory distress, and gastrointestinal symptoms, but does not involve the skin.

References:

Chin J. Control of Communicable Diseases Manual, Seventeenth Edition, American Public Health Association; 2000.
Kortepeter M, Christopher G, Cieslak T, et al. Medical Management of Biological Casualties Handbook, U.S. Army Medical Research Institute of Infectious Diseases, U.S. Department of Defense; 2001: 78-85
Wannemacher RW, Wiener SL. Trichothecene Mycotoxins. In: Zajtchuk R, Bellamy RF, eds. Medical Aspects of Chemical and Biological Warfare. Washington, DC: Office of the Surgeon General, U.S. Department of the Army; 1997: 655-676.
Wortmann G. Ricin Toxin. In: Physician’s Guide to Terrorist Attack. Roy MJ, ed. Physician’s Guide to Terrorist Attack. Totowa, NJ: Humana Press, Inc.; 2004:175-179

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