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 45 of 2021, rhinovirus remained the predominant circulating non-influenza respiratory virus, with approximately 34% of tested specimens positive for rhinovirus. Over the past weeks, rhinovirus activity has increased, and is currently circulating at higher levels than previous seasons. Parainfluenza 2 and parainfluenza 3 virus activity has also continued to circulate at higher levels than previously seen. Recently, human metapneumovirus and adenovirus activity has begun to increase to higher levels of circulation than previous seasons. RSV, which had an unusually significant peak in September, had decreasing activity until the end of October, when activity began to increase again, though this recent increase is consistent with past seasons. Parainfluenza virus 1 activity remains lower than previous seasons.

Laboratory-Based Surveillance for RSV

Laboratory-Based Surveillance for Rhinovirus

Laboratory-Based Surveillance for Respiratory Adenovirus

Laboratory-Based Surveillance for Human Metapneumovirus

Laboratory-Based Surveillance for Parainfluenza