Expected prevalence of a disease is:.
a) the expected occurrence of a disease based on past observations
b) the total number of cases of a disease over a period of time
c) the anticipated geographical spread of a disease based on past observances
d) the number of new cases of a disease over a period of time

Answer is option "a"

Explanation:

The occurrence of new instances of ailment or injury in a populace over a predefined timeframe. Albeit a few disease transmission specialists use occurrence to mean the number of new cases in a network, others use frequency to mean the number of new cases per unit of population.  The measure of a specific disease that is typically present in a network is alluded to as the pattern or endemic degree of the sickness. This level isn't really the ideal level, which may in truth be zero, but instead is the watched level. Without intercession and accepting that the level isn't sufficiently high to drain the pool of powerless people, the sickness may keep on happening at this level inconclusively. Along these lines, the gauge level is regularly viewed as the normal degree of the disease.  While a few infections are so uncommon in a given populace that a solitary case warrants an epidemiologic examination (e.g., rabies, plague, polio), different sicknesses happen all the more usually with the goal that lone deviations from the standard warrant examination. Sporadic alludes to a sickness that happens rarely and irregularlyHence, the right answer is option a "the expected occurance of a disease based on past observations"