Methods: We conducted an observational, longitudinal study of ILI among otherwise healthy children and adults from 2009-2015. Information on demographics, potential risk factors and symptom severity were collected at baseline. Participants reported symptom severity for an additional 7 days via diary. Nasopharyngeal swabs were collected at baseline and tested on a multiplex viral respiratory panel (Diatherix Laboratories, Inc.; Huntsville, AL).
Results: Of 898 patients with ILI, 58 (7%) were positive for hMPV. hMPV was detected between December and May, and peaked in February. Twenty-eight (48.2%) cases were ≥18y; these accounted for 4.4% of adults. Of the 28 adult cases, 7 (25%) had co-detected viral pathogens, 1 (3.5%) had pneumococcus co-detection. Adults with hMPV were white (68%), male (68%), and non-smokers (50%), with a median (range) age of 33 (21-58)y. We did not identify significant risk factors for detection of hMPV in adults including exposure to young children. Over 75% reported classic flu symptoms (e.g., sore throat, cough, muscle aches). hMPV symptom severity did not differ between men and women, nor between adults and children. When compared to those with influenza, adults with hMPV reported less severe systemic and gastrointestinal symptoms (p=0.03 and p<0.01, respectively) in the first 3 days of illness. By contrast, upper respiratory symptoms were more severe for hMPV than influenza, particularly at days 5 and 6 of illness.
Conclusion: Although hMPV appears to be a relatively minor contributor to the burden of ILI among otherwise healthy adults, its spectrum of symptom severity and clinical presentation is comparable to that of influenza. Infected adults did not have increased exposure to young children who are at risk for hMPV. hMPV was a less common cause of ILI in adults, but the severity of illness and co-detection of other pathogens was similar to that seen in children.
M. Fairchok, None
C. Schofield, None
T. Lalani, None
P. Danaher, None
M. Rajnik, None
E. Mcdonough, None
L. Malone, Diatherix Lab: Investigator , Salary
E. Grigorenko, Diatherix lab: Investigator , Salary
D. Stalons, Diatherix Lab: Investigator , Salary
D. Mor, None
T. Burgess, None
J. Arnold, None
E. Millar, None