Harmful Fungi

Fungi cause about 100,000 diseases of plants, including about 70 percent of the major crop diseases, resulting in an economic loss of billions of dollars each year. These plant pathogens cause extensive disease to seeds, seedlings, mature plants, and aging plants, resulting in decreased growth and reproduction of crop plants. Fungi also attack forest trees and wooden structures.A number of fungi cause diseases in humans and other vertebrates. In general, these fungus infections, or mycoses, develop slowly, recur more frequently than bacterial infections, and do not produce a lasting immunity in the body. A mycosis is classified in one of two groups, depending on the part of the body that is infected.

A dermatomycosis is an infection of the skin, hair, or nails, such as ringworm or athlete’s foot. These infections rarely progress to the internal organs. Most respond well to medication, although treatment may take several weeks.A systemic mycosis, which is an infection of the entire body, is typically more serious and can be fatal for individuals whose immune system has been weakened by diseases such as acquired immunodeficiency syndrome (AIDS) or cancer. Fungal infections are typically spread by spores that enter the body through inhalation or through an opening in the skin. Some infections are passed from animals to humans or between humans. A few drugs are effective at treating systemic infections, but because treatment may last for several months to years to prevent relapse of the infection, these drugs often cause toxic side effects.