Farmer’s fever, also called organic dust toxic syndrome (ODTS), is caused by breathing in dust which contains moulds from spoiled plant materials such as baled hat, stored grain or silage. It is a common respiratory illness in farmers, particularly those working with grain, hay, silage and confined animals. The symptoms are a fever and flu-like symptoms which occur four to 12 hours after exposure to contaminated dust.
The symptoms of farmer’s fever will usually disappear within one to three days after you are no longer exposed to the dust. ODTS is often misdiagnosed, so it is important to tell your doctor about any recent dust exposures you may have had.
You can reduce your risk of developing ODTS by wearing a mask or respirator to reduce your exposure to organic dust.
References used for this topic page
Centers for Disease Control (US)
Preventing organic dust toxic syndrome [PDF 33kb]
Farm Respiratory Hazards (2014)
University of Missouri
Organic dust toxicity syndrome (ODTS or grain fever)
Australian Centre for Agricultural Health and Safety
Organic Farm Dusts
Research & reviews:
Occupational and Environmental Medicine
Determinants for asthma in farmers with special reference to odts (organic dust toxic syndrome)
American Association of Swine Veterinarians
Organic dust toxic syndrome: a non-infectious febrile disease after exposure to the hog barn [PDF 453kb]
Respiratory illness in farmers (free PDF download)
Journal of Clinical Toxicology
Organic Toxic Dust Syndrome: A review 2003
Last updated: 27th April, 2020