Molecular epidemiology and phylogenetic analyses of human adenovirus in pediatric patients with acute respiratory infections from Hangzhou during COVID-19 pandemic

Systematic Review and Meta-Analysis of the Association Between Clinical Severity and Co-Infection of Human Adenovirus With Other Respiratory Pathogens in Children

The correlation between the co-infection of human respiratory adenovirus (HAdV) and clinical severity has not been firmly established yet. We carried out a systematic review and meta-analysis. We scoured six databases for studies published up to 16 May 2024. A total of 66 cohort studies, which involved 16 251 participants, were incorporated. When compared with patients suffering from HAdV single infection, those with co-infection of viruses (risk ratios [RRs] = 1.40, 95% confidence interval [CI]: 1.05-1.86), bacteria (RR = 1.50, 95% CI: 1.05-2.16), or fungi (RR = 2.86, 95% CI: 2.17-3.76) were more prone to experience severe clinical outcomes. Co-infection with Mycoplasma pneumoniae had a tendency to elevate the risk of common pneumonia (RR = 1.81, 95% CI: 1.66-1.97), and bacterial co-infection was likely to extend the hospital stay (mean differences = 2.23 days, 95% CI: 0.44-4.03). In summary, the co-infection of HAdV with other viral, bacterial, fungal respiratory pathogens or Mycoplasma pneumoniae heightened the risk of severe clinical outcomes in pediatric patients, leading to an increased utilization of medical resources. This implied that the ecological and biological mechanisms underlying the potential interactions between HAdV and other microorganisms merited further investigation.

Molecular characterization and evolutionary analysis of human adenovirus type 55, related to febrile respiratory illness in the South Korean military

Adenoviruses are non-enveloped, double-stranded deoxyribonucleic acid (DNA) viruses that belong to the family Adenoviridae. Human adenovirus (HAdV)-55 is associated with severe respiratory illnesses that often lead to respiratory failure and death. HAdV-55 caused a febrile respiratory illness (FRI) outbreak at a military base in the Republic of Korea. The Army Forces Capital Hospital provided DNA samples from 79 patients with FRI; among them, we obtained seven whole-genome sequences of HAdV-55 using next-generation sequencing. Phylogenetic analysis of the complete genome and penton base, hexon, and fiber gene sequences demonstrated type-specific genetic clustering among the seven HAdV-55 strains. We also demonstrated protein modeling, molecular phylogeny, and evolution based on whole-genome sequences of seven HAdV-55 isolates characterized using next-generation sequencing and bioinformatics. Additionally, HAdV-55 strains from different countries have contributed to multiple lineages and genetic evolution. Our findings provide important insights into the evolution, molecular phylogeny, protein modeling, and genome sequencing of HAdV-55 isolates. Further studies are needed to better understand the genetic variants of emerging or re-emerging HAdVs.

Prevalence of respiratory viruses in children with respiratory tract infections during the COVID-19 pandemic era: a systematic review and meta-analysis

BACKGROUND AND AIMS

The evaluation of the spread of respiratory viruses in the context of the COVID-19 pandemic is required to understand how SARS-CoV-2 may have impacted the spectrum of respiratory viruses among children. Our study aimed to examine the viral etiology of respiratory infections other than SARS-CoV-2 in children during the COVID-19 pandemic.

METHODS

Three databases including PubMed, Scopus, and Web of Science were systematically searched from 2020 to 2023 to assess the pooled prevalence of respiratory viruses in different regions, types of patient care, and types of respiratory disease.

RESULTS

A total of 68 studies were included in this systematic review and meta-analysis. Rhinovirus/Enterovirus (29.1%) and Respiratory syncytial virus (11.3%) were among the most common viruses among children with respiratory infections during the COVID-19 pandemic. In the case of patients younger than 5 years old, Rhinovirus/Enterovirus (36.2%) were the most prevalent viruses among all types of respiratory diseases. Also, Rhinovirus/Enterovirus were the most common viruses in the case of acute respiratory infection (26.1%), upper respiratory tract infection (21.0%), pneumonia (97.3%), and severe acute respiratory infection (54.7%). The most common viruses detected among inpatient cases were Rhinovirus/Enterovirus (47.4%) and Respiratory syncytial virus (14.9%). The prevalence of Influenza A + B viruses and Metapneumovirus among inpatients was also significantly higher than among outpatients.

CONCLUSION

The high prevalence of viruses such as Rhinovirus/Enterovirus and Respiratory syncytial virus in various respiratory conditions, shows the requirement for enhanced surveillance, vaccination, and treatment strategies. The significance of Influenza viruses and metapneumovirus in inpatient settings delineates the importance of prioritizing them in future preventive measures such as vaccine development to minimize respiratory infection-associated hospitalization.

Nonbacterial Respiratory Pathogens Following the Easing of COVID-19 Restrictive Measures

Nonbacterial respiratory pathogens are major acute respiratory infection (ARI) agents in children. We aimed to characterize the epidemiological changes in 11 common nonbacterial pathogens after easing COVID-19 restrictions in Zhejiang, China, to guide prevention and treatment. A retrospective study was conducted on children with ARIs at Children's Hospital, Zhejiang University School of Medicine in 2023, and epidemiological characteristics were analyzed for gender, age, month, sampling method, and immune status. In total, 59.48% of the children identified pathogens, and Mycoplasma pneumoniae ranked first. Various pathogens showed new features regarding detection rates, seasonal patterns, and susceptible populations. The host age, onset time, sampling method, and immunity status affected the mixed infection rate and unusual coinfection pairs emerged. The epidemiology of respiratory pathogens among children in Zhejiang has changed with local characteristics, and possible preventive actions are needed.

Prevalence of Human Adenovirus Type 3 Associated with Pharyngoconjunctival Fever in Children in Osaka, Japan during and after the COVID-19 Pandemic

The incidence and type distribution of human adenovirus (HAdV) infections among children with pharyngoconjunctival fever (PCF) in Osaka, Japan between 2019 and 2023 were analyzed to assess the effect of the coronavirus disease 2019 (COVID-19) pandemic. The number of reported PCF cases in Osaka decreased from 2020 to 2022, followed by an unprecedented increase in 2023. HAdV-C strains, including types C1, C2, and C5, were detected in throughout the study period. Conversely, HAdV-B3 was not detected for 2 years and 9 months from March 2020 to December 2022, but the number of detections increased from July 2023. Overall, HAdV-B3 was the most frequently detected type (27 of 52 strains), and genetic analysis of its hexon hypervariable regions showed that, except for one strain, the HAdV-B3 strains identified after 2022 had different amino acid substitutions to those identified in 2019 and 2020. These results suggest that the PCF epidemic in 2023 was predominantly caused by variant strains of HAdV-B3, and that children were susceptible owing to a lack of exposure to HAdV-B3 between 2020 and 2022. Ongoing surveillance is needed to evaluate the impact of COVID-19 on the prevalence of HAdV infection.

Epidemiological characteristics of respiratory viruses in children during the COVID-19 epidemic in Chengdu, China

IMPORTANCE

During the coronavirus disease 2019 epidemic, the Chinese government launched and used a series of nonpharmaceutical interventions (NPIs), including banning social gatherings, wearing face masks, home isolation, and maintaining hand hygiene, to control the disease spread. Whether and how NPIs influence other respiratory viruses in children remain unclear. In this article, we analyzed relative data and found that the number of samples and positive proportion of respiratory viruses decreased significantly compared with that before the epidemic. Clinicians and public health policymakers should pay attention to changes in the epidemic trends and types of respiratory viruses and maintain monitoring of respiratory-related viruses to avoid possible abnormal rebounds and epidemic outbreaks of these viruses.