Human Rhinovirus C Infection in Thai Children with Acute Respiratory Tract Diseases
Session I – Piyada Linsuwanon – Young Investigator Applicant
Title of Contribution:
Human Rhinovirus C Infection in Thai Children with Acute Respiratory Tract Diseases.
Author(s): Piyada Linsuwanon, Sunchai Payungporn, Apiradee Theanboonlers, Rujipat Samransamruajkit, Yong Poovorawan
Affiliation(s): Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University
Abstract:
Human rhinoviruses (HRVs) are one of the most common agents causing acute respiratory tract infections (ARTIs). HRVs are divided by molecular analysis into 3 genetic subgroups (A, B and recently C). Several studies showed the association between HRVs and wheezing and asthma exacerbation. However, the epidemiology of the new isolated genotype C and its ability to trigger human ARTIs was limited. We analyzed 289 nasopharyngeal aspirates (NPAs) from 286 hospitalized pediatric patients with ARTIs from February 2006 to February 2007. Each specimen was tested for common viruses causing ARTIs including Respiratory syncytial virus (RSV), Parainfluenza type 1-3, Influenza A and B viruses, Adenovirus, Human metapneumovirus (hMPV) and Human bocavirus (HBoV). Based on amplification of VP4/2 by semi-nested RT-PCR, 87 NPAs were positive for HRVs (age 11 days to 10 years 5 months, median 1 year 3 months) indicating an annual prevalence of 30.1%. Wheezing or asthma exacerbation was the most common clinical presentation. From phylogenetic analysis of VP4 regions showed that 29 (33.3%) and 8 (9.2%) NPAs belonged to HRV-A and HRV-B respectively. Most of all HRV positive NPAs were belonged to HRV-C (57.5%). Moreover, genotype C was found to predominate in pediatric population in fall and winter in Thailand. The sequence homology among HRV-C ranged from 67.6-99.5% (mean 75%). It is also closely related to previously HRV-C isolated in other countries. The frequently of co-infection of HRV-C with other respiratory viral pathogens was 40%. Co-infection between HRV and RSV had higher risk of wheezing and asthma than single infection. We concluded that HRV-C circulated worldwide and was an important cause of recurrent or asthma exacerbation in infant and young children.
