<prompt> Occurence of disease in excess of expected frequency is known asEndemic diseaseEpidemic diseaseEcdemic diseaseSporadic  <response>: Endemic: refers to the constant presence of a disease or infectious agent within a given geographic area or population group without impoation from outside. Exotic: diseases which are impoed into a country in which they do not otherwise occur as for example rabies in the UK . Epizootic: an outbreak of the disease in an animal population. Ref: 25th edition, Parks Textbook of Preventive and Social Medicine, Page no. 101 