Comparative analysis of epidemiology, clinical features and cytokine response of Respiratory Syncytial and Human Metapneumovirus infected children with acute lower respiratory infections

Prevalence of human metapneumovirus infection among children suffering from acute respiratory illness in India: a systematic review and meta-analysis

Acute respiratory infections (ARI) are a leading cause of pediatric morbidity and mortality worldwide, with India bearing a significant burden. Human metapneumovirus (HMPV), an under-recognized respiratory pathogen, has been implicated in ARI, yet its prevalence in India remains inadequately characterized. The objective of this study was to estimate the prevalence of HMPV among children with ARI in India and assess regional, temporal, and demographic trends to guide public health interventions. This systematic review and meta-analysis was conducted following PRISMA guidelines. Data were extracted from 30 studies encompassing 12,534 children with ARI across India from 2004 to 2024. A random-effects model was used to calculate pooled prevalence, with subgroup and sensitivity analyses to explore heterogeneity. Publication bias was assessed using Egger's test and funnel plots. The pooled prevalence of HMPV was 5% (95% confidence interval: 4-6%), with significant heterogeneity (I²=95%). Subgroup analyses revealed higher prevalence in the northeast region (7%) and among children under 5 years (6%), compared to older age groups (2%). No significant differences were observed in prevalence pre- and post-COVID-19. Sensitivity analyses confirmed the robustness of findings, with minimal impact of publication bias. HMPV is a significant contributor to pediatric ARI in India, particularly among children under 5 years, highlighting its public health importance. The lack of a post-COVID-19 surge in prevalence suggests sustained circulation and widespread immunity. These findings underscore the need for enhanced diagnostic capacities, routine surveillance, and targeted interventions to mitigate the burden of HMPV-related ARI in vulnerable populations.

Clinical Course and Molecular Characterization of Human Bocavirus Associated with Acute Lower Respiratory Tract Infections in a Tertiary Care Hospital in Northern India

Respiratory samples from 139 hospitalized children were screened for the human bocavirus (HBoV) genome. Positive samples were sequenced for the partial VP1/VP2 gene followed by molecular and phylogenetic analyses. HBoV positivity was noted in 7.2% (10/139) of patients. All HBoV-positive children presented with fever, cough, and respiratory distress (90%, 9/10). Three children developed multisystemic viral illness, with one fatality. Eight children required intensive care management and five required mechanical ventilation. The nucleotide percent identity of the partial VP1/VP2 gene in the HBoV study strains ranged from 97.52% to 99.67%. Non-synonymous mutations in the VP1 protein were T591S (n = 8) and Y517S (n = 1) in the HBoV St1 strain and N475S (n = 8) and S591T (n = 2) in the HBoV St2 strain. One strain showed A556P, H556P, I561S, and M562R non-synonymous mutations. All the study strains belonged to the HBoV1 type. Seven HBoV strains belonged to the same lineage, and three belonged to another lineage. For evolutionary dynamics, GTR+I substitution model with uncorrelated relaxed lognormal clock and Bayesian Skyline tree prior showed 9.0 × 10-4 (95% highest probability density interval: 3.1 × 10-6, 2.1 × 10-3) nucleotide substitutions per site per year. Clinical suspicion and virological screening are necessary to identify HBoV infections in children.

Molecular investigation of human metapneumovirus in children with acute respiratory infections in Chennai, South India, from 2016-2018

Human metapneumovirus (hMPV) has emerged as a frequent cause of acute respiratory infections (ARI) among young children. The prevalence and genetic diversity of hMPV circulating in Chennai, Southern India, has not been studied yet. Hence, this study was aimed to investigate the prevalence, co-infection with other respiratory viruses like HRSV A and B, influenza A and B, hRV and HPIV 1-4 viruses, socio-demographic associations, and genotypes of hMPV among children in Chennai. A total of 350 nasal swab specimens were collected from children with ARI during April 2016 to August 2018 and tested for hMPV by real time PCR method. In this study, hMPV was detected in 4% (14/350) of the samples. One hMPV positive sample was found to be co-infected with influenza B virus. The mean and median ages of the children with hMPV infection were 61.5 months (5.1 years) and 83 months (6.9 years), respectively. Phylogenetic analysis of the partial F gene revealed the presence of A2c subcluster among the study strains as well as with B1 and B2 lineages. The prevalence data obtained in this study is important in evaluating the role of hMPV in childhood ARI and emphasizes the importance of routine viral diagnosis in hospitals. To the best of our knowledge, this is the first study to report the prevalence, seasonality, and genetic diversity of hMPV in Chennai as well as the first study to report A2c subcluster of hMPV among children in India.