The correct words to fill in the blanks are:
"Reportable diseases are conditions whose reporting is mandatory, whereas notifiable diseases are conditions that warrant monitoring."
Reportable diseases are those that require mandatory reporting to public health agencies or authorities to enable effective public health surveillance, monitoring, and control. In contrast, notifiable diseases are those that require monitoring and follow-up, but do not necessarily require reporting to public health agencies.
The terms may vary slightly depending on the context and country. However, in general, reportable and notifiable diseases are important concepts in public health that help to ensure effective monitoring and control of infectious diseases and other health conditions.