Single Versus Dual Respiratory Virus Infections in... : The Pediatric Infectious Disease Journal (original) (raw)

Original Studies

Single Versus Dual Respiratory Virus Infections in Hospitalized Infants

Impact on Clinical Course of Disease and Interferon-γ Response

Aberle, Judith H. MD*; Aberle, Stephan W. MD*; Pracher, Elisabeth MD‡; Hutter, Hans-Peter MD†; Kundi, Michael MD†; Popow-Kraupp, Therese MD*

From the Institute of *Virology and †Environmental Hygiene, Medical University of Vienna, and the ‡Department of Pediatrics, St. Anna Kinderspital, Vienna, Austria

Accepted for publication January 27, 2005.

Address for reprints: Dr. Judith Aberle, Institute of Virology, Kinderspitalgasse 15, 1095 Vienna, Austria. Fax 43-1-40490 ext. 9795; E-mail [email protected].

The Pediatric Infectious Disease Journal 24(7):p 605-610, July 2005. | DOI: 10.1097/01.inf.0000168741.59747.2d

Abstract

Background:

Dual respiratory viral infections are frequently associated with lower respiratory tract illness in infants. This study aimed to determine the impact of a dual respiratory viral infection on specific aspects of the infant's immune response and the clinical course of illness.

Methods:

A prospective study was performed with 772 infants hospitalized from October 2000 through July 2004. Sensitive polymerase chain reaction methodology revealed the presence of a single respiratory virus in 443 (57%) of 772 cases, whereas dual infections were identified in 153 (20%) of cases. From 250 infants with confirmed respiratory viral infection, fresh heparinized blood was analyzed for interferon-γ (IFN-γ) responses by flow cytometry. Of these, 191 patients had a single infection with respiratory syncytial virus (RSV), rhinoviruses, adenoviruses or influenza viruses; and 59 patients had a dual infection with RSV and rhinoviruses, RSV and adenoviruses, influenza viruses and rhinoviruses or adenoviruses and rhinoviruses. The clinical features and peripheral lymphocyte IFN-γ responses were compared among infants with single or dual infections.

Results:

It was found that dual infections with non-RSV respiratory viruses induced peripheral blood mononuclear cell IFN-γ responses that mimic those of single infections, whereas coinfection with RSV was associated with reduced IFN-γ responses and a more severe clinical course of lower respiratory tract disease.

Conclusions:

The results indicate that the clinical characteristics and the IFN-γ response differ significantly in single and dual respiratory viral infection, depending on the nature of the simultaneously detected viruses. In dual infections, RSV involvement was associated with a decreased IFN-γ response in peripheral blood mononuclear cell and an increase in severity of illness.