What type of diseases does the CDC track through the National Notifiable Diseases Surveillance System (NNDSS)?

The National Notifiable Diseases Surveillance System (NNDSS) is designed specifically to monitor significant infectious diseases that exhibit public health implications. This system collects and analyzes data on diseases that have the potential to cause outbreaks, represent a significant threat to the community's health, or require public health interventions. The focus on important infectious diseases allows health authorities to respond swiftly to threats, implement preventative measures, and allocate resources effectively to manage these diseases' impact on public health.

In addition to infectious diseases, the NNDSS significantly aids in understanding trends, patterns, and outbreaks within populations, helping to refine and improve public health strategies. The diseases tracked through this system play a critical role in understanding epidemiological trends and guiding public health responses across various regions.

The other types of diseases mentioned in the choices, such as environmental diseases, chronic diseases, and psychiatric disorders, are not the primary focus of the NNDSS. While these areas are important in public health, NNDSS specifically targets infectious diseases with the potential to impact the population swiftly and significantly.