Which type of surveillance is most commonly used by local and state health departments?

Passive surveillance is the most commonly used method by local and state health departments because it relies on healthcare providers and laboratories to report cases of disease. This approach is less resource-intensive than active surveillance, as it does not require health department personnel to proactively seek out information. Instead, they collect data from existing reports that are submitted voluntarily by those in the healthcare system. This system is cost-effective and allows for the continuous monitoring of disease trends while ensuring that the health department can gather vast amounts of data from various sources without overwhelming its resources.

Furthermore, passive surveillance is particularly effective for tracking common diseases and monitoring the overall health status of populations, making it an essential tool in public health. It enables health officials to detect outbreaks, monitor trends over time, and assess the effectiveness of health interventions. While other methods, such as active surveillance, can yield more precise data and are important in particular situations, passive surveillance remains the backbone of routine epidemiological data collection in many health departments.