Molecular Diversity of Human Respiratory Syncytial Virus before and during the COVID-19 Pandemic in Two Neighboring Japanese Cities.

Human respiratory syncytial viruses (HRSVs) are divided into subgroups A and B, which are further divided based on the nucleotide sequence of the second hypervariable region (HVR) of the attachment glycoprotein (G) gene. Understanding the molecular diversity of HRSV before and during the coronavirus disease 2019 (COVID-19) pandemic can provide insights into the effects of the pandemic on HRSV dissemination and guide vaccine development. Here, we analyzed HRSVs isolated in Fukushima Prefecture from September 2017 to December 2021. Specimens from pediatric patients were collected at two medical institutions in neighboring cities. A phylogenetic tree based on the second HVR nucleotide sequences was constructed using the Bayesian Markov chain Monte Carlo method. HRSV-A (ON1 genotype) and HRSV-B (BA9 genotype) were detected in 183 and 108 specimens, respectively. There were differences in the number of HRSV strains within clusters prevalent at the same time between the two hospitals. The genetic characteristics of HRSVs in 2021 after the COVID-19 outbreak were similar to those in 2019. HRSVs within a cluster may circulate within a region for several years, causing an epidemic cycle. Our findings add to the existing knowledge of the molecular epidemiology of HRSV in Japan. IMPORTANCE Understanding the molecular diversity of human respiratory syncytial viruses during pandemics caused by different viruses can provide insights that can guide public health decisions and vaccine development.

Changes in virus detection in hospitalized children before and after the severe acute respiratory syndrome coronavirus 2 pandemic.

The impact of strengthening preventive measures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the prevalence of respiratory viruses in children was examined. After the SARS-CoV-2 pandemic, the rate of multiple virus detection among hospitalized children decreased. Immediately after the SARS-CoV-2 pandemic, respiratory syncytial and parainfluenza viruses were rarely detected and subsequently reemerged. Human metapneumovirus and influenza virus were not consistently detected. Non-enveloped viruses (bocavirus, rhinovirus, and adenovirus) were detected to some extent even after the pandemic. Epidemic-suppressed infectious diseases may reemerge as susceptibility accumulates in the population and should continue to be monitored.

Epidemiological and clinical characteristics of infections with seasonal human coronavirus and respiratory syncytial virus in hospitalized children immediately before the coronavirus disease 2019 pandemic.

INTRODUCTION: Seasonal human coronavirus (HCoV)-229E, -NL63, -OC43, and -HKU1 are seasonal coronaviruses that cause colds in humans. However, the clinical characteristics of pediatric inpatients infected with HCoVs are unclear. This study aimed to compare and clarify the epidemiological and clinical features of HCoVs and respiratory syncytial virus (RSV), which commonly causes severe respiratory infections in children. METHODS: Nasopharyngeal swabs were collected from all pediatric inpatients with respiratory symptoms at two secondary medical institutions in Fukushima, Japan. Eighteen respiratory viruses, including RSV and four HCoVs, were detected via reverse transcription-polymerase chain reaction. RESULTS: Of the 1757 specimens tested, viruses were detected in 1272 specimens (72.4%), with 789 single (44.9%) and 483 multiple virus detections (27.5%). RSV was detected in 639 patients (36.4%) with no difference in clinical characteristics between RSV-A and RSV-B. HCoV was detected in 84 patients (4.7%): OC43, NL63, HKU1, and 229E in 25 (1.4%), 26 (1.5%), 23 (1.3%), and 16 patients (0.9%), respectively. Patients with HCoV monoinfection (n = 35) had a significantly shorter period from onset to hospitalization (median [interquartile range] days, 2 [1-4.5] vs. 4 [2-5]), significantly shorter hospitalization stays (4 [3-5] vs. 5 [4-6]), and more cases of upper respiratory infections (37.1% vs. 3.9%) and croup (17.1% vs. 0.3%) but less cases of lower respiratory infection (54.3% vs. 94.8%) than patients with RSV monoinfection (n = 362). CONCLUSION: Seasonal HCoV-infected patients account for approximately 5% of children hospitalized for respiratory tract infections and have fewer lower respiratory infections and shorter hospital stays than RSV-infected patients.

Glucocorticoid receptor expression in whole blood with preterm infants.

BACKGROUND: Although glucocorticoid hormones play important roles in fetal development, the expression of their receptors in the whole blood of preterm infants remains unknown. OBJECTIVES: The aim of this study was to investigate the levels of glucocorticoid receptor (GR) α and ß in the whole blood of preterm and term infants. STUDY DESIGN: The study group consisted of 131 infants, of which 54 (41%) were preterm. Whole blood from preterm and term infants was analyzed by real-time PCR to monitor the levels of each receptor mRNA. RESULTS: GRß mRNA were detected in 96.6% and GRα mRNA in 100% of participants. The GRα and GRß isoforms were detected at a ratio of 1:0.0002. GRß mRNA/GAPDH expression in preterm infants was significantly higher than that in term infants (p=0.002). There was significant correlation between GRα/GRß ratio and birth weight in preterm infants (rs=0.317, p=0.019), as well as between GRß/GAPDH expression and birth weight (rs=-0.296, p=0.030). Furthermore, in preterm infants, GRß/GAPDH expression was higher in those with SGA than in those without SGA (p=0.022). CONCLUSION: Importantly, in preterm infants, both the expression of GRß and the GRα/GRß ratio were associated with birth weight. Further studies with larger populations are necessary to determine the relation between the expression of GR and the clinical relevance of preterm infants.

Low frequency of observed anti-HLA among transfused preterm infants.

BACKGROUND: Although low-birth-weight infants (LBWI) often receive multiple transfusions, there is controversial information on their development of antibodies against WBCs or platelets. STUDY DESIGN AND METHODS: A total of 52 LBWI with birth weights less than 1500 g were randomly assigned to receive either RBCs that had been WBC- reduced (n = 25) or nonfiltered blood (n = 27). Serum samples collected from 37 infants at 3 months of age and from 30 children when they were 5 to 11 years old were tested. Anti-HLA was assayed with an anti-human globulin-augmented lymphocytotoxicity test against a panel consisting of 13 lymphocytes and against parental cells. RESULTS: None of 52 transfused LBWI of either group developed anti-HLA (95% CI, 0%-6.8% for overall, 0%-13.7% for the WBC-reduced group, and 0%-12.7% for the nonfiltered group). CONCLUSION: Multiply transfused LBWI rarely produced antibodies to HLA of blood donors and to noninherited maternal antigens. The benefits of WBC reduction to prevent HLA alloimmunization during infancy were not supported by this study and need further investigation.