What It Measures

This CDC dataset labels each state’s overall acute respiratory illness (ARI) activity as very low, low, moderate, high, or very high.

ARI is broader than flu-like illness alone. It reflects emergency department visits related to respiratory symptoms, which can include influenza, RSV, COVID-19, common colds, and other respiratory infections.

How Local Health Signal Uses It

Local Health Signal uses this feed as a first-answer statewide signal on selected state overview pages.

It is useful when someone wants the fastest possible answer to:

“Is respiratory illness generally up right now in this state?”
“Does this state feel quiet or active before I drill into flu, RSV, or COVID?”

What It Tells You

ARI is good for a quick statewide read because it compresses multiple respiratory patterns into one broad activity label.

That makes it easier to orient quickly before moving into the disease-specific pages for flu, RSV, COVID-19, measles, or vaccination context.

Limitations

ARI is a broad syndrome signal, not a diagnosis-specific case count.
It reflects emergency department visits, so it is biased toward people who seek acute care.
It can tell you that respiratory illness activity is elevated, but not exactly which virus is driving the change.
It is statewide, not neighborhood-level.

Why We Like It

For Local Health Signal, this feed is valuable because it can make the main statewide answer simpler:

“Overall respiratory activity is low” is easier for many people to understand than asking them to synthesize multiple surveillance charts before they know where to click.