The following graphs depict the aggregate results of PDPH's respiratory virus surveillance. Care should be taken with the interpretation of these results.

These summaries display the provisional, year-to-date counts (or, in some cases, percentage positivity) of respiratory viruses by week of report. Comparable data for preceding years are shown as well.

All surveillance data are preliminary and are not intended for further distribution.

Activity Summary

For week 35 of 2021, RSV was the predominant circulating non-influenza respiratory virus, with approximately 19% of tested specimens positive for RSV. Over the past weeks, RSV activity has continued to increase to abnormally high levels compared to recent seasons for this time of year. Additionally, parainfluenza virus 2 activity has increased recently compared to previous years. In contrast, rhinovirus activity has decreased to levels consistent with previous seasons while parainfluenza virus 3 activity has also continued to decrease since its summer peak. Parainfluenza virus 1, human metapneumovirus, and adenovirus are currently circulating at levels consistent with previous seasons.

Laboratory-Based Surveillance Rhinovirus

Laboratory-Based Surveillance Respiratory Adenovirus

Laboratory-Based Surveillance Human Metapneumovirus

Laboratory-Based Surveillance Parainfluenza




Updated: 10/05/2021