Final answer:
A surveillance system requiring local clinicians to report overdose deaths for tracking opioids is considered passive surveillance. This relies on routine reports from healthcare providers as opposed to actively seeking out cases or monitoring through selected networks.
Step-by-step explanation:
The surveillance system you described, which requires local clinicians to report deaths due to drug overdose for the purpose of tracking the opioid epidemic, is an example of passive surveillance.
In passive surveillance, data collection relies on the willingness of healthcare providers to submit reports as a part of their routine practice, which often happens with notifiable diseases that providers are legally required to report, as discussed in the Morbidity and Mortality Weekly Report (MMWR).
Unlike active surveillance, there is typically no proactive seeking out of cases beyond the regular reporting mechanisms. Active surveillance would involve public health personnel actively contacting healthcare providers to solicit case reports. Sentinel surveillance, on the other hand, involves careful monitoring of selected network sites or groups to signal trends and identify outbreaks.