Molecular Epidemiology of Rhinovirus Detections in Children in the Peruvian Andes

Background:

Human rhinoviruses (HRVs) are frequently detected in children with acute respiratory illnesses (ARI), but also in asymptomatic children, confounding clinical interpretation of these detections. We compared clinical features of ARI by HRV group (A, B, and C) and the genotypes associated with repeated symptomatic and asymptomatic detections within individuals.

Methods:

We used clinical data and archived respiratory samples obtained from children aged <3 years through active household-based surveillance from the prospective study of Respiratory Infections in Andean Peruvian children (RESPIRA-Peru). Respiratory samples were collected monthly and during each episode of ARI. We identified a random subset of samples in which HRV was detected by RT-PCR from individual children during both an ARI and an asymptomatic period within 120 days of the ARI. A subset of these isolates was sequenced using primers targeting the VP4/VP2 region and the hypervariable region in the 5'-non-coding region. Alignment was performed using published HRV sequences (Genbank). Features of ARI were compared by HRV group using Chi-square or ANOVA. Concordance of HRV genotype among repeated HRV detections in individuals was assessed.

Results:

To date, 48 HRV isolates obtained during ARI have been sequenced. HRV-A, HRV-B, and HRV-C were detected in 19 (40%), 6 (13%), and 23 (48%), respectively. There were no significant differences in duration of fever, cough, or the presence of severe ARI among HRV groups. Genotypes associated with sequential HRV detections during ARI and asymptomatic period were available for 11 children, with 13 paired detections. Of these 13 paired HRV detections, 2 (15%) of repeated detections within individuals were caused by identical genotypes of HRV, while 11 (85%) represented infections with new genotypes (Figure).

Conclusion:

In this subset, repeated detections of HRV in young children frequently represented acquisition of new HRV strains. Small sample size may have limited our ability to detect differences in the clinical features of HRV infection between groups. Analysis of >200 additional samples is ongoing. Further longitudinal studies with genotypic HRV characterization will enable improved understanding of the pathogenicity of HRV.