1129. Detection of Influenza and Other Respiratory Viruses from Outpatients Presenting with Influenza-like Illness through the Influenza Incidence Surveillance Project
Session: Poster Abstract Session: Influenza and H1N1 Diagnosis, Epidemiology, and Viral Outcome
Saturday, October 22, 2011
Room: Poster Hall B1

The incidence of acute respiratory infection (ARI) and influenza like illness (ILI), and the relative contributions of different pathogens are not well defined and depend on factors, such as season and age. The Influenza Incidence Surveillance Project (IISP) monitored medically-attended ARI and ILI to determine the associated etiologies and estimate incidence.


From August 2010 through April 2011, 55 health care providers in 12 states and jurisdictions conducted surveillance of patients with ARI (> 2 respiratory symptoms) and ILI (fever with cough and/or sore throat).  Respiratory specimens were collected for influenza and other respiratory virus testing by real-time reverse transcriptase polymerase chain reaction (RT-PCR) or multiplex RT-PCR from the first 10 ILI patients each week; demographic and clinical data were collected. 


During the surveillance period, 364,817 outpatient visits occurred among participating providers, of which 2.1% and 3.7% were for ILI and ARI, respectively. During peak weeks of ILI activity, 23 January to 19 February 2011, the median incidence of ILI and ARI, was 105 and 116/100,000 patient population, respectively. Pediatric ILI visits occurred 4.5 (95% CI 3.8-5.4) times more frequently than adult visits, ARI visits differed less by age (RR=1.7, 95% CI 1.5-2.0). An etiology was identified in 60% of ILI patient-specimens; influenza was detected in 27% overall and, during peak weeks of ILI activity, 48% were influenza positive giving an extrapolated influenza incidence of 46/100,000. Subtyping results showed that 29% of influenza-positive specimens were subtype A/2009 H1N1, 38% were A/H3N2 and 33% were B. Also detected among ILI patients were rhinovirus (15%), respiratory syncytial virus (8.1%), adenovirus (5.1%), coronavirus (4.6%), parainfluenza viruses and human metapneumovirus (<4% each). 


The IISP is the first surveillance program using modern molecular virologic techniques in all age groups, and of long enough duration to evaluate annual respiratory infection etiology and incidence. Influenza infections represent a substantial burden in the outpatient setting especially during weeks of peak ILI activity. 

Subject Category: V. Virology including clinical and basic studies of viral infections, including hepatitis

Ashley Fowlkes, MPH1, Heidi Davidson, MPH1, Lisa Ferland, MPH2, Kate Goodin, MPH3, Yumei Sun, PhD4, Sovirny Norng, MPH5, Karen Martin, MPH6, Michelle Feist7, Steve Di Lonardo, MS8, Lisa McHugh, MPH9, Jose Lojo, MPH10, Rachel Linz, MPH11, Rachelle Boulton, MSPH12, Katie Kurkjian, DVM, MPH1,13, Jonathan Temte, MD, PhD14 and Lyn Finelli, DrPH, MS1, (1)Centers for Disease Control and Prevention, Atlanta, GA, (2)Council of State and Territorial Epidemiologists, Atlanta, GA, (3)Florida Department of Health, Tallahassee,, FL, (4)Iowa Department of Public Health, Des Moines, ID, (5)Los Angeles County Department of Public Health, Los Angeles, CA, (6)Minnesota Department of Health, St. Paul, MN, (7)North Dakota Department of Health, Bismarck,, ND, (8)New York City Department of Health and Mental Hygiene, Long Island City , NY, (9)New Jersey Department of Health and Senior Services, Trenton, NJ, (10)Philadelphia Department of Public Health, Philadelphia , PA, (11)Oregon Public Health Division, Portland, OR, (12)Utah Department of Health, Salt Lake City, UT, (13)Virginia Department of Health, Richmond, VA, (14)University of Wisconsin School of Medicine and Public Health, Madison, WI


A. Fowlkes, None

H. Davidson, None

L. Ferland, None

K. Goodin, None

Y. Sun, None

S. Norng, None

K. Martin, None

M. Feist, None

S. Di Lonardo, None

L. McHugh, None

J. Lojo, None

R. Linz, None

R. Boulton, None

K. Kurkjian, None

J. Temte, None

L. Finelli, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.