The causative role of respiratory viruses detected in upper airway secretions in childhood pneumonia needs further investigation.
To measure the association between infection with respiratory RNA viruses and pneumonia in children.
From March 2006 to July 2007, we conducted a case-control study of 680 pneumonia cases (WHO criteria) and 680 randomly selected, concurrently sampled age-matched controls among children aged 2–35 months in Bhaktapur, Nepal. A nasopharyngeal aspirate from each child was examined for 7 respiratory viruses using reverse transcription polymerase chain reaction. We calculated the matched odds ratios (MORs) for the detection of the individual viruses from a case compared with a control as measures of pathogenicity using conditional logistic regression.
At least 1 virus was recovered in 248 (36.5%) cases and 48 (7.1%) controls. The MOR varied from 2.0 to 13.0; the highest associations were observed for parainfluenza virus type 3 (MOR 13.0; 95% confidence interval [CI] 6.0–28.0), respiratory syncytial virus (MOR 10.7; CI 4.6–24.6), and influenza A (MOR 6.3; CI 1.9–21.4). We observed that the association was lower for children age 2–5 months compared with older children for parainfluenza virus type 3 (P value for interaction 0.002).
All of the 7 respiratory viruses were associated with pneumonia, but their pathogenicity varied. Parainfluenza type 3, RSV, and influenza A were most strongly associated with pneumonia.
From the *Centre for International Health, University of Bergen, Bergen, Norway; †Department of Laboratory Medicine, Medical Microbiology, Sykehuset Innlandet, Lillehammer, Norway; ‡Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway; §Statens Serum Institut, Department of Epidemiology, Division of Epidemiology, Copenhagen, Denmark; ¶Child Health Department, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal; ∥Department of Microbiology, Tribhuvan University Teaching Hospital, Kathmandu, Nepal; and **Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
Accepted for publication February 18, 2010.
Supported by the European Commission (EU-INCO-DC contract number INCO-FP6–003740), the Norwegian Council of Universities' Committee for Development Research and Education (NUFU project number 2007/10177), the Research Council of Norway (RCN project number 151054 and 172226), and the Danish Council of Developmental Research (91128).
Address for correspondence: Tor A. Strand, Centre for International Health, University of Bergen, P.O. Box 7804, N-5020 Bergen, Norway. E-mail: firstname.lastname@example.org.