Which of the following definitions most accurately distinguishes an emerging infectious disease from a reemerging infectious disease?

• A. An emerging disease refers to any infectious disease present in remote regions only while a reemerging disease is strictly limited to urban populations that had past exposure; both are distinguished primarily by the socioeconomic status of affected communities rather than by novelty or prior control.
• B. An emerging disease is defined solely by the severity of symptoms it causes at first presentation, while reemerging diseases are defined exclusively by the mode of transmission (for example, airborne versus vector-borne), independent of incidence trends or historical control measures.
• C. An emerging disease is novel or newly spreading; a reemerging disease was previously controlled then resurged.
• D. An emerging disease is always caused by viruses that jump species barriers and therefore always requires development of vaccines from scratch, whereas a reemerging disease is bacterial and always responds to the same antibiotics used historically, so it rarely requires public health intervention beyond diagnostic confirmation and routine treatment.

Answer: (C)