464. Burden of Outpatient Illness due to Respiratory Viruses in US Preterm Infants: Findings from a Two-Year Prospective Cohort Study
Session: Poster Abstract Session: Prevention and Treatment of Viral Infections
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C

Background: Preterm infants are at high risk for severe RSV disease. The relative burden of other respiratory viruses in preterm infants is not well established.

Methods: In the RSV Respiratory Events Among Preterm Infants Outcomes and Risk Tracking (REPORT) study, preterm infants <6 months of age born between 32–35 weeks GA not receiving RSV prophylaxis were prospectively enrolled from 188 US clinics and followed from September–May of 2009–2010 or 2010–2011. Nasal and throat swabs were collected during outpatient medically-attended acute respiratory illnesses (MAARI). Samples were tested for RSV, adenovirus, parainfluenza virus types (PIV) 1-3, human metapneumovirus (hMPV), and influenza A and B using quantitative reverse transcriptase PCR (qRT-PCR). Lower respiratory tract illness (LRI) was defined as pneumonia, bronchiolitis, or wheezing. Incidence per 1000 infant-months was calculated.

Results: 1646 subjects were enrolled. At least one virus was detected in 745 (34.4%) of 2163 MAARI samples, including RSV in 300, adenovirus in 220, PIV3 in 144, and hMPV in 81. Co-infections were detected in 72 of these 745 samples; there were 62 co-infections involving adenovirus, 39 with RSV, 26 with PIV3, and 13 with hMPV. Viruses were more commonly identified in outpatient MA-LRI samples (58.9%) than in outpatient non-LRI MAARI samples (28.3%; P<0.0001). LRI was more common among subjects with MAARI due to RSV compared to other viruses (61% of subjects for RSV vs. 31% for non-RSV [range: 23%-47% for other viruses], P<0.001).

Conclusion:   Among preterm infants 32-35 weeks GA not receiving RSV prophylaxis, RSV was the principal cause of MAARI and MA-LRI between September and May. Infants with RSV were more likely to have LRI relative to those with other viruses. MA-LRI rates due to adenovirus, PIV3, and hMPV were 14%-29% of the RSV MA-LRI rate.

Evan J. Anderson, MD1, Eric A. F. Simoes, MB BS, DCH, MD2, Christopher S. Ambrose, MD3, Xionghua Wu, PhD3 and Jessie R. Groothuis, MD4, (1)Pediatrics and Medicine, Emory University School of Medicine, Atlanta, GA, (2)Pediatric Infectious Disease, University of Colorado School of Medicine, Aurora, CO, (3)MedImmune, LLC, Gaithersburg, MD, (4)Former Employee of MedImmune, LLC, Santa Fe, NM


E. J. Anderson, None

E. A. F. Simoes, MedImmune, LLC: Grant Investigator, Research grant

C. S. Ambrose, MedImmune, LLC: Employee, Salary

X. Wu, MedImmune, LLC: Employee, Salary

J. R. Groothuis, MedImmune, LLC: Consultant and Employee, Consulting fee and Salary

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