Final answer:
Epidemiologists primarily gather surveillance data through the analysis of clinical records and by conducting patient interviews. Large-scale surveys such as the BRFSS are also instrumental in providing data for public health decisions.
Step-by-step explanation:
The two main ways that epidemiologists and public health officials collect surveillance data are through the analysis of clinical records and conducting patient interviews. Clinical records provide historical data on disease incidence, treatments, and outcomes, and are essential for tracking long-term trends and changes in disease patterns. Patient interviews can give immediate insight on the potential modes of transmission, risk factors, and personal experiences related to a disease, which are crucial for rapid response during an outbreak.
Moreover, large-scale surveys like the Behavioral Risk Factor Surveillance System (BRFSS) conducted by the Centers for Disease Control and Prevention (CDC) also serve as a significant source of health data. This data assists epidemiologists in understanding the distribution of health-related events and conditions both geographically and temporally, influencing the public health strategies and policies.