Genotypic and Clinical Features of Human Metapneumovirus Infections in Hospitalized Children With Acute Respiratory Infections

Abstract

Background: Human metapneumovirus (hMPV) is a newly discovered emerging virus known to cause acute respiratory tract infections (ARTIs) in children and adults. In particular, hMPV is one of the main viral etiological agents that significantly contribute to development of severe respiratory diseases and pneumonia in children. Objective: To illuminate the virological and clinical features in children with respiratory infections caused by hMPV. Methods: A total of 156 nasopharyngeal aspirate (NPA) samples collected from hospitalized children with acute respiratory tract infections were tested for hMPV by RT-PCR with specific primers to hMPV. In addition to, DNA sequence analysis and Phylogenetic analysis of the specific hMPV amplicons were performed. Results: In RT-PCR with primers targeting the hMPV fusion glycoprotein (F), nucleoprotein (N), and polymerase (L) genes, single and very sharp amplication bands of the expected length of 0.45Kb, 0.16Kb, and 0.17Kb revealized NPA samples. Overall, hMPV was detected in 8 (5.12%) of analized samples. DNA sequence analysis and Phylogenetic analysis of the specific amplicons of hMPV F, N,  and L genes revealed that the virus detected by RT-PCR was hMPV A2 genotype with 83.5~100%, 85.7~100%, and 95.7~97.8% sequence similarity, respectively. The mean ages and mean treatment and hospitalization duration of hMPV positive children was 16.1 months and 6.5 days, respectively. The main symptoms of hMPV positive children were fever (100%), cough (87.5%), rhinorrhea (87.5%), sputum (62.5%), sore throat (62.5%), and dyspnea (37.5%), etc. Also, clinical diagnosis of hMPV positive children were pneumonia (50%), acute bronchiolitis (37.5%), and acute wheezing bronchitis (12.5%). Conclusions: The obtained result revealed that our study provides strong support that hMPV infection is an important cause of severe respiratory disease in children, including pneumonia, bronchiolitis, and acute wheezing attacks, strongly suggesting that hMPV A2 genotype is the major genotype to cause acute and severe respiratory disease associated with hMPV infection.