Viral Infections In Outpatients With Medically Attended Acute Respiratory Illness During the 2012-13 Influenza Season
Methods: Individuals presenting for outpatient visits with acute (<7 days) respiratory illness were swabbed and assayed for presence 18 viruses using a multiplex reverse transcriptase polymerase chain reaction method. Surveys provided clinical and demographic characteristics.
Results: Among 935 patients, 563 (60.2%) tested positive for single virus infections, 85 (9.1%) tested positive for ≥1 virus and 287 (30.7%) were negative for all tested viruses. Fever and fatigue were significantly more frequently associated with solo influenza detection while wheezing was significantly less frequently reported among those with only CoV (P=0.01). Most frequently co-detected viruses were influenza A (38 times), respiratory syncytial virus (25 times), influenza B (9 times); corona virus, human rhinovirus, adenovirus, human metapneumovirus, and parainfluenza virus also co-occurred. The percentages of single, multiple and no viruses detected varied by age. For children <18 years, the percentages of single virus, multiple viruses, and no virus detected were 63%, 14%, and 23%, respectively; whereas for younger adults 18-49 years, the percentages were 58%, 8%, and 34% and for older adults the percentages were 61%, 5%, and 32%, respectively (P <0.001). Co-detections were more common than single infections in children than older adults ( ≥65 years; P=0.01) and less frequent in households without children than in households with children (P = 0.003). Co-detections were less common if sore throat was present (P=0.01) but did not vary by other symptoms. Compared with individuals with single viral infections, those with co-detections missed fewer days of school (1.1 vs. 2 days; P=0.04) or work (2 vs. 3 days; P=0.03). These groups did not vary on other measures of illness severity.
Conclusion: In this study of outpatient medically attended acute respiratory illnesses, co-infections were infrequent but varied by demographic and household characteristics.
R. K. Zimmerman,
Sanofi: Grant Investigator, Research grant
Pfizer: Grant Investigator, Research grant
M. P. Nowalk, Sanofi: Grant Investigator, Research support
Pfizer: Grant Investigator, Research support
Merck: Grant Investigator, Research support
MedImmune: Consultant, Consulting fee
B. Goundappa K, None
K. Moehling, None
A. Bullotta, None
S. Wisniewski, None