About This Year's Flu

What Public Health Tracks

Public Health tracks cases of influenza (flu) and respiratory syncytial virus (RSV). The team that tracks these cases creates weekly reports during the influenza/RSV season. At the end of the year, a yearly report summarizes the data. 

The first day of the 2018-2019 season was September 30, 2018. Flu/RSV season will continue through September 28, 2019.

Public Health tracks flu and RSV cases by MMWR weeks, which is a standard way across the United States of numbering weeks in a year to track disease. (Learn more about MMWR weeks.) Weekly reports start on Sunday and end the following Saturday.

This Week's Flu Report

All data are preliminary as of September 4, 2019, and may change as more reports are received.

How widespread is the flu in Arizona right now?

flu activity level at sporadic

See definitions >

How do this season's current numbers compare to previous years' data?

Flu Case Counts Table as of August 31, 2019

How does flu in Maricopa County this year compare to flu in previous years?

Flu Frequency Chart as of August 31, 2019

Learn More

Help Track Flu

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More Info: 
Flu Near You on Science Friday