Endemic in disease frequency means what?

• A. Random, unpredictable outbreaks
• B. Occurrence with predictable regularity with minor fluctuations over time
• C. No disease in population
• D. High mortality rate

Answer: (B)

Endemic means a disease is constantly present in a population at a baseline level that is relatively stable over time, with predictable frequency and only minor fluctuations from year to year. This reflects steady transmission where the number of new cases stays within a usual range, influenced by regular factors like seasonality, population immunity, and contact patterns. It does not imply completely random, unpredictable outbreaks or the absence of disease, and it doesn't inherently imply a high mortality rate—the defining idea is the steady, expected presence and small variation around that baseline. For example, malaria in a seasonally suitable region often remains at a predictable level year to year, with some seasonal peaks but no large, unexplained surges.