RSV Activity

Respiratory Viral Activity

Respiratory Viral Activity Slowing Down

There has been a considerable decline in the number of positive specimens for RSV and both Influenza A and B. We are now at below endemic levels of RSV (9.4%) and seeing virtually no influenza. Reports from the CDC show that this was a particularly brisk year for Influenza (both A and B) probably due in part to the poor match of vaccine virus(es) to circulating isolates. The CDC reports that there was approximately a 44% match (much less than previous years). We will continue to report out viral isolates in to May and hopefully will continue to see the predictable decline.

RSV Activity

Respiratory Viral Activity

RSV Activity

Influenza and RSV Activity

Respiratory Viral Activity

Respiratory viruses still active in Southern California

Our local data looks very similar to the nation wide data collected by the CDC (see graph)

Although we are certainly seeing a downward trend in the number and percent positives for both RSV and Influenza, we are still seeing endemic levels of RSV (defined as >10% of samples tested). Past history shows that once there are signs of drop off (as we have seen over the past 2-3 weeks) the trend accelerates and we will most likely be out of RSV season in the next 4 weeks. As for influenza A and B, we are continuing to see both still circulating in the community, although at much lower levels than 1 month ago. Interestingly, this year proved to be a big "B" year, much in part due the mismatch of not only A virus but of B as well. In light of these new strains, all three virus strain s in the influenza vaccine for the next year (2008-9 season) will differ from this year's vaccine. The choices for NEXT year's vaccine will be A/Brisbane/59/2007-like H1N1; A/Brisbane/10/2007-like H3N2and a B/Florida/4/20006-like virus.

RSV Activity Graph

Respiratory Viral Activity