525. Patterns of Viral and Bacterial Co-detection among Otherwise Healthy Adults with Influenza-like Illness: Utilization of a Multiplex Respiratory Pathogen Panel
Session: Poster Abstract Session: Respiratory Infections: Viral (non Influenza)
Thursday, October 8, 2015
Room: Poster Hall
Background: Bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus frequently colonize the nasopharynx of healthy individuals. During acute respiratory infection (ARI), the majority of which are viral in origin, these and other bacteria may worsen the severity of disease. To examine these associations, we used a multiplex assay to evaluate patterns of viral/bacterial co-detection among otherwise healthy individuals with influenza-like illness (ILI).

Methods:  From 2009-2014, we conducted an observational study of ILI at five US military treatment facilities, enrolling participants 0-65y with no co-morbidities. Nasopharyngeal specimens were obtained at study entry and were tested by target-enriched multiplex PCR (TEM-PCR) for the detection of 11 bacterial and 10 viral respiratory pathogens (Diatherix Laboratories, Inc.; Huntsville, AL). Odds ratios (OR) and 95% confidence intervals (CI) for associations between viral and bacterial pathogens were calculated.

Results: 895 specimens were evaluated by TEM-PCR with 583 (65%) positive for at least one virus, 643 (72%) positive for at least one bacterium, and 399 (44%) positive for both. The most common viruses were: rhinovirus, n=140 (16%); Influenza A, n=119 (13%); Coxsackie/Echovirus, n=89 (10%); Coronavirus, n=111 (12%); and RSV, n=89 (10%). The most common bacteria were: Streptococcus pneumoniae, n=330 (36.1%); Haemophilus influenzae, n=224 (24.5%); Moraxella catarrhalis, n=209 (22.9%); and Staphylococcus aureus, n=184 (20.1%). Detection of S. aureus was more common among those with influenza (OR: 1.68; 95% CI:1.12, 2.5) and coxsackie virus (OR:1.66; 95% CI:1.01, 2.72). These associations were significantly higher among children (OR: 2.33, and OR: 2.48, respectively). Increased detection of S. pneumoniae was observed only for children with RSV (OR: 2.06; 95% CI:1.13, 3.73). Increased detection of H. influenzae was not observed for any viral pathogen nor either age group.

Conclusion: Increased detection of S. aureus was found for several viral pathogens, whereas increases in S. pneumoniae were only observed in pediatric RSV.  Further evaluations of viral/bacterial co-detections are warranted, particularly as related to symptom severity.

Michelande Ridore, MS1, John Arnold, MD2, Wei-Ju Chen, PhD3, Mary Fairchok, MD4, Christina Schofield, MD FACP, FIDSA5, Kristina J. St. Clair, DO, MTM&H6, Leslie Malone, MS, MB(ASCP)CM7, Elena Grigorenko, PhD8, Donald Stalons, PhD, D(ABMM), MPH7, Deepika Mor, MS3, Timothy Burgess, MD, MPH9, Eugene Millar, PhD10 and Henry M. Jackson Foundation for the Advancement of Military Medicine, (1)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Rockville, MD, (2)Naval Medical Center San Diego, San Diego, CA, (3)Infectious Disease Clinical Research Program, Uniformed Services University, Bethesda, MD, (4)Infectious Disease Clinical Research Program, Tacoma, WA, (5)Madigan Army Medical Center, Tacoma, WA, (6)Naval Medical Center Portsmouth, Portsmouth, VA, (7)Diatherix Laboratories, Inc., Huntsville, AL, (8)Diatherix Laboratories, Inc, Huntsville, AL, (9)Walter Reed National Military Medical Center, Bethesda, MD, (10)Infectious Disease Clinical Research Program, Rockville, MD


M. Ridore, None

J. Arnold, None

W. J. Chen, None

M. Fairchok, None

C. Schofield, None

K. J. St. Clair, 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

E. Millar, None

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