Incidental infections from accidental exposures are simply infections from exposures caused by chance and are often not statistically significant. The CDC or some infectious disease centers study the infection trajectory of an infectious agent by compiling a complete chain of transmission. An “incidental infection due to accidental exposure” is one in which an individual is infected by the pathogen but does not appear in any of the currently known chains of infection or is not infected by conventional means. The probability of this type of event is very small, and therefore it is often not given statistical significance or similar reference power. In summary, as a chance event, incidental infections from accidental exposures are rare in infectious disease survey statistics.