Question

Define incidence and prevalence of disease. Name a microbial disease for which the numerical values of annual incidence and annual prevalence are likely similar and name another microbial disease for which the numerical values of annual incidence and annual prevalence are likely quite different; explain why this is the case for both diseases.

Answer 1

The incidence of a disease is basically the rate of newly diagnosed diseases and majorly talks about number of new cases that appears within a stipulated amount of time. The best way to calculate the same is by considering a fraction of population and finding out the number of individuals who are at risk of the disease. The accuracy of the incidence of disease purely depends on how accurately things have been diagnosed and reported. In this the whole population is at risk and it majorly is involved in onset or reporting of new disease.

The prevalence is basically the actual number of existing cases with a disease during the spread of the infection or within a stipulated time frame. The measure for both of this is done by including the number of new cases that are reported and the number of deaths within that time. In this case, it is basically focused on presence or absence of disease and majorly helps in studying chronic disease.

An disease where the numerical value for both incidence and prevalence is same is AIDS as it is the fundamental frequency for measuring the disease. When it comes to the difference, the incidence and prevalence where numerical value is different can be considered as Ebola virus infection where the incidents reported to survival of existing cases is very different.