Accidental injury means an injury that results accidentally or from any external, violent and anticipated causes. For instance, an unintentional bodily injury resulting from any external force and against the normal course of events can be categorized as an accidental injury. Generally, the word "accident" and the word "injury" are not synonymous. Accidents occur without injury, and injuries occur without accident. The critical question in this examination is whether or not a disease is ever an injury, not whether a disease is ever an accident, or accidentally caused. If it can ever be said that there is involved an accident or an occurrence in the sudden invasion of the human body by bacteria, then in substantially all infectious diseases there is a precedent accident, and therefore an accidental injury. The accident must be something which is capable of being assigned to a particular date, and which is in the popular and ordinary sense an accident.
In Richardson v. Greenburg, 176 N.Y.S. 651 (N.Y. App. Div. 1919), the court observed that “ In disease the cause is neither external, violent, nor accidental. It can therefore never be an accidental injury, except where a statute expressly includes it therein by particular definition.”