Enhancement of influenza surveillance with aggregate rapid influenza test results: New Mexico, 2003-2007.

Objectives: We sought to determine whether monitoring rapid influenza laboratory tests improved the influenza-like illness surveillance already in place in New Mexico.

Methods: For the past 3 influenza seasons, the New Mexico Department of Health examined influenza-like illness visits and positive rapid influenza test results.

Results: The proportion of positive rapid influenza test results started to rise earlier than did the percentage of clinical visits because of influenza-like illness in each of the past 3 influenza seasons: 5 weeks earlier during the 2004-2005 season; 3 weeks earlier in 2005-2006; and 2 weeks earlier in 2006-2007. In addition, rapid influenza tests showed a spike in influenza B activity late in the 2005-2006 season that influenza-like illness syndrome surveillance did not.

Conclusions: Laboratory-based rapid influenza test surveillance required relatively few resources to implement and offered a sensitive mechanism to detect the onset of influenza activity while allowing for the distinction of influenza types.