Rhinovirus Viremia in Patients Hospitalized With Community-Acquired Pneumonia

Abstract

Background: Rhinoviruses (RVs) are ubiquitous respiratory pathogens that often cause mild or subclinical infections. Molecular detection of RVs from the upper respiratory tract can be prolonged, complicating etiologic association in persons with severe lower respiratory tract infections. Little is known about RV viremia and its value as a diagnostic indicator in persons hospitalized with community-acquired pneumonia (CAP).

Methods: Sera from RV-positive children and adults hospitalized with CAP were tested for RV by real-time reverse-transcription polymerase chain reaction. Rhinovirus species and type were determined by partial genome sequencing.

Results: Overall, 57 of 570 (10%) RV-positive patients were viremic, and all were children aged <10 years (n = 57/375; 15.2%). Although RV-A was the most common RV species detected from respiratory specimens (48.8%), almost all viremias were RV-C (98.2%). Viremic patients had fewer codetected pathogens and were more likely to have chest retractions, wheezing, and a history of underlying asthma/reactive airway disease than patients without viremia.

Conclusions: More than 1 out of 7 RV-infected children aged <10 years hospitalized with CAP were viremic. In contrast with other RV species, RV-C infections were highly associated with viremia and were usually the only respiratory pathogen identified, suggesting that RV-C viremia may be an important diagnostic indicator in pediatric pneumonia.

Keywords: community-acquired pneumonia; rhinovirus; viremia.

Figure 1.

Neighbor-joining tree of rhinovirus (RV) VP4/VP2 nucleotide sequences from 57 viremic patients (open and solid circles); numbers are genotype designations of RV-A, -B, and -C reference strain sequences available from GenBank. Solid circle denotes patient with RV-C detected in the acute serum and RV-A detected in the respiratory specimen. Box highlights 4 similar sequences obtained from different patients that show >23% divergence from known RVs and may represent a new virus genotype. Scale bar shows genetic distance as nucleotide substitutions per site. Boostrap values (1000 replicates) are indicated at the RV species nodes.

Figure 2.

Box-and-whisker plots of rhinovirus (RV) real-time reverse-transcription polymerase chain reaction cycle threshold (Ct) values obtained from respiratory specimens from patients with RV-A, RV-B, and RV-C infections and comparing patients with RV-C with and without RV viremia. Note that of 56 patients with RV-C viremias, only 55 had corresponding RV-C detections from respiratory specimens (*). Whiskers mark the lowest and highest Ct values; boxes are bounded by the 25th and 75th percentiles; and box bisecting lines represent median Ct values. Sample size is indicated for each category. Differences (Δ) in median Ct values for each category are given as well as P values calculated by the Mann-Whitney U test. Abbreviations: Ct, cycle threshold; NP/OP, nasopharyngeal/oropharyngeal; NS, not significant, rRT-PCR, real-time reverse-transcription polymerase chain reaction; RV, rhinovirus.