Seasonality of respiratory syncytial virus infection in children hospitalized with acute lower respiratory tract infections in Hunan, China, 2013-2022.

BACKGROUND: In China, respiratory syncytial virus (RSV) infections traditionally occur during the spring and winter seasons. However, a shift in the seasonal trend was noted in 2020-2022, during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This study investigated the seasonal characteristics of RSV infection in children hospitalized with acute lower respiratory tract infections (ALRTIs). The RSV epidemic season was defined as RSV positivity in > 10% of the hospitalized ALRTI cases each week. Nine RSV seasons were identified between 2013 and 2022, and nonlinear ordinary least squares regression models were used to assess the differences in year-to-year epidemic seasonality trends. RESULTS: We enrolled 49,658 hospitalized children diagnosed with ALRTIs over a 9-year period, and the RSV antigen-positive rate was 15.2% (n = 7,566/49,658). Between 2013 and 2022, the average onset and end of the RSV season occurred in week 44 (late October) and week 17 of the following year, respectively, with a typical duration of 27 weeks. However, at the onset of the COVID-19 pandemic, the usual spring RSV peak did not occur. Instead, the 2020 epidemic started in week 32, and RSV seasonality persisted into 2021, lasting for an unprecedented 87 weeks before concluding in March 2022. CONCLUSIONS: RSV seasonality was disrupted during the COVID-19 pandemic, and the season exhibited an unusually prolonged duration. These findings may provide valuable insights for clinical practice and public health considerations.

Persistent viral shedding of human adenovirus type 7 in children with severe pneumonia.

To understand host-pathogen interactions and develop effective prevention and control strategies for human adenovirus (HAdV), it is essential to explore the characteristics of HAdV shedding. Hospitalized children <14 years who had severe HAdV pneumonia were tested for HAdV DNA by quantitative real-time PCR in nasopharyngeal aspirate (NPA). A total of 132 children were enrolled, including 102 patients with HAdV type 7 (HAdV-7) infection and 12 patients with HAdV type 3 (HAdV-3) infection. A total of 1372 qualified NPA samples were collected. There was a significant negative correlation between the viral load of HAdV and the course of the disease (Spearman r = -0.547, p = .000). HAdV-7 load decreased at a rate of 0.089 log10 copies/mL per day (95% CI: -0.096 to -0.081; R 2 = 0.332), and the duration of viral shedding was predicted to be 96.9 days (y = 8.624-0.089x). However, HAdV-3 load decreased more quickly (95% CI: - 0.229 to - 0.143; R 2 = 0.403), and the duration of viral shedding was 51.4 days (y = 9.558-0.186x). The median viral load of the HAdV-7 group at weeks 2 and 3, and more than 3 weeks postinfection was higher than that of the HAdV-3 group. No significant differences in the duration of viral shedding were found in different gender, age (>2 vs. ≤2 years), and with or without underlying diseases groups. Viral shedding in children with severe HAdV pneumonia persisted, among which HAdV-7 lasted longer than 3 months and the viral load decreased slowly than HAdV-3.

Viral loads in nasopharyngeal aspirates and tracheal aspirates among children hospitalized with invasive ventilation for human adenovirus pneumonia.

PURPOSE: To evaluate viral loads in children with human adenovirus (HAdV) pneumonia at different stages of disease and compare the viral load between upper and lower respiratory tract samples. METHODS: We prospectively enrolled children who required invasive ventilation for HAdV pneumonia. Nasopharyngeal aspirate (NPA) and tracheal aspirate (TA) samples were collected throughout the entire period of invasive ventilation. Viral detection and quantification were performed using quantitative real-time polymerase chain reaction. RESULTS: Ninety-four children were enrolled. The median age of the children was 12.0 months (IQR: 11.0-24.0), and > ninety percent of patients were aged between 6 and 59 months. Seven hundred and nine paired NPA-TA samples were collected. The median viral loads of the NPA and TA samples were 7.31 log10 and 7.50 log10 copies/mL, respectively. Viral loads generally decreased steadily over time. The median viral load after 1, 2, 3, and > 3 weeks of the disease course was 8.65, 7.70, 6.69, and 5.09 log10 copies/mL, respectively, in NPA samples and 8.67, 7.79, 7.08, and 5.53 log10 copies/mL, respectively, in TA samples. Viral load showed a significant negative correlation with time since symptom onset in both NPA samples (Spearman r = - 0.607, P = 0.000) and TA samples (Spearman r = - 0.544, P = 0.000). The predicted duration of HAdV shedding was 60.17 days in the NPA group and 65.81 days in the TA group. Viral loads in NPA and TA from the same subjects correlated well with each other (R2 = 0.694). HAdV loads in NPA and TA were most comparable during the early phase of infection (95% limits of agreement, - 1.36 to 1.30 log10 copies/mL, R2 = 0.746). Variation increased during the late phase of infection (i.e., in follow-up samples), with viral loads remaining significantly higher in TA than NPA. CONCLUSIONS: In children with HAdV pneumonia, viral loads in both NPA and TA steadily decreased during the course of the disease, and the predicted duration of viral shedding was more than 2 months. The HAdV DNA load of NPA is highly correlated with that of TA, especially in the initial phase of infection.

Identification of 12 Cases of Acute Measles Encephalitis Without Rash.

Twelve cases of acute measles encephalitis without rash were identified from October 2011 to July 2013 in Changsha city, China; 5 were found to be genotype H1 and 2 were B3. Our data suggest that screening for measles virus is necessary in children with viral encephalitis, to eliminate the disease.

Human parainfluenza virus types 1-4 in hospitalized children with acute lower respiratory infections in China.

Human parainfluenza viruses (HPIVs) are an important cause of acute lower respiratory tract infections (ALRTIs). HPIV-4, a newly identified virus, has been associated with severe ALRTIs recently. A total of 771 nasopharyngeal aspirate samples were collected from hospitalized children between March 2010 and February 2011. HPIVs were detected by Nest-PCR, and other known respiratory viruses were detected by RT-PCR and PCR. All amplification products were sequenced. HPIVs were detected in 151 (19.58%) patients, of whom 28 (3.63%) were positive for HPIV-4, 12(1.55%) for HPIV-1, 4 (0.51%) for HPIV-2, and 107 (13.87%) for HPIV-3. Only three were found to be co-infected with different types of HPIVs. All HPIV-positive children were under 5 years of age, with the majority being less than 1 year. Only the detection rate of HPIV-3 had a significant statistical difference (χ2 = 29.648, P = 0.000) between ages. HPIV-3 and HPIV-4 were detected during the summer. Sixty (39.74%) were co-infected with other respiratory viruses, and human rhinovirus (HRV) was the most common co-infecting virus. The most frequent clinical diagnosis was bronchopneumonia, and all patients had cough; some patients who were infected with HPIV-3 and HPIV-4 had polypnea and cyanosis. No significant difference was found in clinical manifestations between those who were infected with HPIV-4 and HPIV-3. Two genotypes for HPIV-4 were prevalent, although HPIV-4a dominated. HPIV-4 is an important virus for children hospitalized with ALRTIs in China. HRV was the most common co-infecting virus. Two genotypes for HPIV-4 are prevalent, HPIV-4a dominated. J. Med. Virol. 88:2085-2091, 2016. © 2016 Wiley Periodicals, Inc.

Clinical features of human metapneumovirus genotypes in children with acute lower respiratory tract infection in Changsha, China.

To explore the epidemiological and clinical features of different human metapneumovirus (hMPV) genotypes in hospitalized children. Reverse transcription polymerase chain reaction (RT-PCR) or PCR was employed to screen for both hMPV and other common respiratory viruses in 2613 nasopharyngeal aspirate specimens collected from children with lower respiratory tract infections from September 2007 to February 2011 (a period of 3.5 years). The demographics and clinical presentations of patients infected with different genotypes of hMPV were compared. A total of 135 samples were positive for hMPV (positive detection rate: 5.2%). Co-infection with other viruses was observed in 45.9% (62/135) of cases, and human bocavirus was the most common additional respiratory virus. The most common symptoms included cough, fever, and wheezing. The M gene was sequenced for 135 isolates; of these, genotype A was identified in 72.6% (98/135) of patients, and genotype B was identified in 27.4% (37/135) of patients. The predominant genotype of hMPV changed over the 3.5-year study period from genotype A2b to A2b or B1 and then to predominantly B1. Most of clinical features were similar between patients infected with different hMPV genotypes. These results suggested that hMPV is an important viral pathogen in pediatric patients with acute lower respiratory tract infection in Changsha. The hMPV subtypes A2b and B1 were found to co-circulate. The different hMPV genotypes exhibit similar clinical characteristics.

Prevalence of human rhinovirus in children admitted to hospital with acute lower respiratory tract infections in Changsha, China.

Human rhinovirus (HRV) is a causative agent of acute respiratory tract infections. This study analyzed the prevalence and clinical characteristics of three HRV groups (HRV-A, -B, and -C) among 1,165 children aged 14 years or younger who were hospitalized with acute lower respiratory tract infection in China. PCR or reverse transcription-PCR was performed to detect 14 respiratory viruses in nasopharyngeal aspirates collected from September 2007 to August 2008 in Changsha, China. HRV was detected in 202 (17.3%) of the 1,165 children; 25.3% of the HRV-positive children were 13-36 months of age (χ(2) = 22.803, P = 0.000). HRV was detected year round and peaked between September and December. Fifty-three percent of the HRV-positive samples were also positive for other respiratory viruses; respiratory syncytial virus (RSV) was the most common secondary virus. Phylogenetic analysis using the VP4/VP2 region grouped the HRV-positive strains as follows: 101 HRV-A (50.0%), 21 HRV-B (10.4%), and 80 HRV-C (39.6%). HRV-A infections occurred predominantly in spring and autumn, and the peak prevalence of HRV-C was in early winter and late autumn. HRV-B infections were less common in spring (χ(2) = 31.914, P = 0.000). No significant difference in clinical severity or presentation was found between patients with HRV single infection and HRV co-detections. Furthermore, the clinical characterizations did not differ among the three HRV species. These results suggest that HRV-C is an important viral agent along with HRV-A and HRV-B and that among hospitalized children with acute lower respiratory tract infection in China, the three HRV genotypes have similar clinical characteristics.

Metformin Mitigates Sepsis-Induced Acute Lung Injury and Inflammation in Young Mice by Suppressing the S100A8/A9-NLRP3-IL-1ß Signaling Pathway.

Background: Globally, the subsequent complications that accompany sepsis result in remarkable morbidity and mortality rates. The lung is among the vulnerable organs that incur the sepsis-linked inflammatory storm and frequently culminates into ARDS/ALI. The metformin-prescribed anti-diabetic drug has been revealed with anti-inflammatory effects in sepsis, but the underlying mechanisms remain unclear. This study aimed to ascertain metformin's effects and functions in a young mouse model of sepsis-induced ALI. Methods: Mice were randomly divided into 4 groups: sham, sham+ Met, CLP, and CLP+ Met. CLP was established as the sepsis-induced ALI model accompanied by intraperitoneal metformin treatment. At day 7, the survival state of mice was noted, including survival rate, weight, and M-CASS. Lung histological pathology and injury scores were determined by hematoxylin-eosin staining. The pulmonary coefficient was used to evaluate pulmonary edema. Furthermore, IL-1ß, CCL3, CXCL11, S100A8, S100A9 and NLRP3 expression in tissues collected from lungs were determined by qPCR, IL-1ß, IL-18, TNF-α by ELISA, caspase-1, ASC, NLRP3, P65, p-P65, GSDMD-F, GSDMD-N, IL-1ß and S100A8/A9 by Western blot. Results: The data affirmed that metformin enhanced the survival rate, lessened lung tissue injury, and diminished the expression of inflammatory factors in young mice with sepsis induced by CLP. In contrast to sham mice, the CLP mice were affirmed to manifest ALI-linked pathologies following CLP-induced sepsis. The expressions of pro-inflammatory factors, for instance, IL-1ß, IL-18, TNF-α, CXCL11, S100A8, and S100A9 are markedly enhanced by CLP, while metformin abolished this adverse effect. Western blot analyses indicated that metformin inhibited the sepsis-induced activation of GSDMD and the upregulation of S100A8/A9, NLRP3, and ASC. Conclusion: Metformin could improve the survival rate, lessen lung tissue injury, and minimize the expression of inflammatory factors in young mice with sepsis induced by CLP. Metformin reduced sepsis-induced ALI via inhibiting the NF-κB signaling pathway and inhibiting pyroptosis by the S100A8/A9-NLRP3-IL-1ß pathway.

[Viral etiology of 1165 hospitalized children with acute lower respiratory tract infection].

OBJECTIVE: To explore the viral etiology of acute low respiratory tract infection (ALRTI) among hospitalized children in Changsha of Hunan Province of China. METHODS: Nasopharyngeal aspirates were collected from 1165 hospitalized children with ALRTI in Changsha from September 2007 to August 2008. Respiratory syncytin virus (RSV), human rhinovirus (HRV), influenza virus A (IFVA), influenza virus B (IFVB), parainfluenza 1-3 (PIV 1-3), human metapneumovirus (hMPV), human coronaviruses NL63 (HCoV-NL63), and human coronaviruses HKU1 (HCoV-HKU1) were detected by reverse transcription polymerase chain reaction (RT-PCR). Adenovirus (ADV) and human bocavirus (HBoV) were detected by standard polymerase chain reaction (PCR). WU polyomaviruses (WUPyV) and KI polyomaviruses(KIPyV) were detected by nested PCR. The positive samples further underwent genetic sequencing. RESULTS: Among the 1165 nasopharyngeal aspirates, viruses were detected in 871 samples (74.76%), among which RSV (27.03%) was the most common virus, followed by HRV (17.33%), PIV3 (13.73%), HBoV (8.67%) and hMPV (6.52%). The overall positive rate of viral detection showed no significant differences between males and females (X2=2.241, P=0.134), whereas the positive rates of PIV3, hMPV, and HBoV in males were higher than in females. The positive rate of viral detection showed significant differences among different age groups (X2=10.934, P=0.027), and the highest positive rate was noted in the age group of 6 months to 1 year. Furthermore, the overall positive rate of viral detection showed a significant difference in term of seasonal distribution, with a peak prevalence in winter. CONCLUSIONS: Virues predominate in the etiology of pediatric ALRTI in Changsha, and RSV, HRV and PIV3 are the main viruses for ALRTI. HBoV and hMPV have become increasingly important. Viral infection-associated ALRTI shows a prevail in the age group of 6 months to 1 year as well as in winter.

Epidemiologic and clinical characteristics of 10 children with coronavirus disease 2019 in Changsha, China.

BACKGROUND: The outbreak of a new coronavirus, first reported in Wuhan, China, is spreading around the world. Information on the characteristics of children with Coronavirus Disease 2019 (COVID-19) is limited. METHODS: In this retrospective study, we recruited 10 children infected with SARS-COV-2 from January 27 to March 10, 2020, in Changsha, China. We report the epidemiological, clinical, laboratory, and high-resolution CT findings for these children. Qualitative descriptive analysis was used to describe the key results. RESULTS: Ten children were included. Three were male and seven were female. Three were from Wuhan, Hubei Province, and seven were from Changsha. All had a history of close contact with adults with COVID-19 before the onset of disease. Clinical manifestations included fever in four cases, respiratory symptoms in three cases, febrile convulsions in one case, vomiting in one case, abdominal pain in one case, and asymptomatic infection in two cases. All the children tested positive for nucleic acid in throat swabs at admission. Stool swabs of three cases were positive for nucleic acid after several days of fever. In nine children, blood routine results were normal, whereas in one case the white blood cell count was elevated. In four cases, CT findings of the lungs showed light ground-glass opacities, one case showed changes similar to bronchopneumonia, and the remaining cases were normal. All were treated with symptomatic support without complications. CONCLUSION: Our findings indicate that intrafamily transmission may be the main form of transmission of COVID-19 in children, and persistent intestinal excretion of virus is another characteristic among children. The results of stool swab tests should be considered for discharge and release from isolation.

Identification of human bocaviruses in the cerebrospinal fluid of children hospitalized with encephalitis in China.

BACKGROUND: Encephalitis is a major cause of death and disability in adults and children; different members in the family Parvoviridae are known to be associated with encephalitis to some extent. OBJECTIVES: To determine the presence of human bocaviruses (HBoVs) and corresponding HBoV-specific immunoglobulins (Igs) in cerebrospinal fluid from children with suspected viral encephalitis. STUDY DESIGN: Employing real-time PCR and nested touchdown PCR, 67 cerebrospinal fluid (CSF) samples from children with suspected viral encephalitis were screened for HBoV and routine encephalitis-causing viruses. Using ELISA, Western blot and IFA, HBoV-specific Ig were determined in the samples. RESULTS: Nine samples (134%) were HBoV1 DNA-positive, while one sample (15%) was HBoV2 DNA-positive. HBoV-specific IgM and IgG antibodies were detected in the CSF samples from three children; two samples were HBoV1 DNA-positive and one sample was negative. One death was recorded; CSF from this child was the only HBoV-IgM-positive CSF samples among the 67 CSF tested. CONCLUSION: We screened CSF samples obtained from children with encephalitis for the presence of HBoV1 and HBoV2 and specific IgM- or IgG-responses. Detection of viral DNA and/or immunological response to HBoV1/HBoV2 highlights the significance of these viruses as causes of encephalitis in children. Further studies are needed to examine the role of HBoV infection in children encephalitis.

[Establishment and clinical application of TapMan real-time RT-PCR method for detection of HHV-6].

OBJECTIVE: To establish a rapid, sensitive and specific real-time PCR method for detection of Human Herpesvirus-6 (HHV-6). METHODS: According to the reference, a pair of primers and a probe were designed located in U65-66 gene and to set up the standards. We established a real-time RT-PCR method for detection of HHV-6, and to verify the specificity, sensitivity, reproducibility. RESULTS: The correlation coefficient was 0.999, E = 97.9%, the coefficient of variation values of Ct were 0.61% and 3.13% in real-time PCR assay for inter and intra assay, respectively. The results of all viruses were negative except of HHV-6 for the assay. The quantitative detection limit of the assay was 3 x 10(0) copies/microl. CONCLUSION: The real-time PCR assay is highly specific, sensitive and reproducible, which can be used to quatitative detecting clinical samples.