986. Evaluation of Moderate-to-Severe Influenza Disease in Children 6 months to 8 years of age in Colorado
Session: Poster Abstract Session: Adult and Pediatric Influenza Vaccine
Friday, October 5, 2018
Room: S Poster Hall
Background:

A clinical endpoint of moderate-to-severe (M/S) influenza has been proposed in children, defined as fever >39 ⁰C, otitis media, lower respiratory tract infection, or serious extrapulmonary manifestations. This definition has not been evaluated against clinically-relevant outcomes like hospitalization, emergency room care, antimicrobial use and child/parental absenteeism.

Methods: We conducted a prospective observational study of children aged 6 months-8 years with influenza at the Children’s Hospital Colorado Emergency Department (ED) and its affiliates during two influenza seasons (2016-17 & 2017-18). Children with influenza-like-illness (ILI) were enrolled and tested for influenza by polymerase chain reaction (PCR). Parents of influenza cases and matched influenza-negative controls were contacted two weeks later for follow up. The primary outcome was hospitalization for M/S influenza versus mild influenza. Secondary outcomes included recurrent ED visits, antimicrobial use, child/parental absenteeism. Interim analyses were conducted using SAS v9.4.

Results: Among the 1480 enrolled children with ILI, 410(28%) tested positive for influenza by PCR. The median age of influenza cases was 4.0 years (IQR 2.2-6.1), and 20% were considered high-risk for influenza complications. Of influenza cases, 284 (69%) met the definition for M/S influenza. Among M/S influenza subjects, 8.4% were hospitalized, compared with 1.6% with mild influenza (Risk difference (RD) 6.9%; 95% CI: 3.0-10.8, p <0.01). Subjects with M/S influenza were more likely to receive antibiotics (RD 12.0%, 95% CI: 3.4-20.6, p <0.01) with a trend to higher antiviral use (RD 6.9%, 95% CI: -0.7-14.5, p = 0.09). There was no significant difference for recurrent ED visits nor child/parental absenteeism. After adjusting for comorbidities, age, and influenza strain, the relative risk (RR) of hospitalization or recurrent ED visits was higher among those with M/S influenza versus mild influenza (RR 2.18, 95% CI: 1.02-4.64, p = 0.04).

Conclusion: Children with M/S influenza have a higher risk of hospitalization compared with mild disease. This proposed definition is a useful clinical endpoint to study the public health and clinical impact of influenza interventions in children.

Suchitra Rao, MBBS1, Molly Lamb, PhD2, Angela Moss, MS3, Emad Yanni, MD, MSC4, Rafik Bekkat-Berkani, MD5, Anne Schuind, MD4, Bruce Innis, FIDSA6, Jillian Cotter, MD3, Rakesh Mistry, MD7 and Edwin J. Asturias, MD8, (1)Pediatric Infectious Diseases, Hospital Medicine and Epidemiology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, (2)Department of Epidemiology, Colorado School of Public Health, Aurora, CO, (3)University of Colorado School of Medicine, Aurora, CO, (4)GSK, Rockville, MD, (5)GSK, Philadelphia, PA, (6)GlaxoSmithKline Biologicals, King of Prussia, PA, (7)Univ. of Colorado Denver, Denver, CO, (8)Department of Infectious Disease, Children's Hospital Colorado/University of Colorado School of Medicine, Aurora, CO

Disclosures:

S. Rao, GSK: Investigator , Research grant .

M. Lamb, None

A. Moss, None

E. Yanni, GSK: Employee , Salary .

R. Bekkat-Berkani, GSK: Employee , Salary .

A. Schuind, GSK: Employee , Salary .

B. Innis, GSK: Employee , Salary .

J. Cotter, None

R. Mistry, GSK: Investigator , Research support .

E. J. Asturias, GSK: Investigator , Research grant and Research support .

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