Understanding Contagious Diseases
Contagious diseases typically occur in well-defined clusters, otherwise known as outbreaks or epidemics. While early studies of fatiguing illness have been cited as evidence that chronic fatigue syndrome is contagious, these studies were not rigorously documented and patients were not defined as CFS patients. Therefore, these studies cannot be considered as proof that chronic fatigue syndrome is contagious.
Contagious diseases are typically associated with intravenous drug use, exposure to animals, occupational or travel history, or sexual behavior. However, none of these behaviors have been associated with chronic fatigue syndrome.