[Current status of surveillance systems for human respiratory syncytial virus].

To conduct timely surveillance of the seasonal characteristics and disease burden of Human Respiratory Syncytial Virus (HRSV) in various geographical regions of China, and further develop more precise and effective prevention and intervention strategies, there is an urgent need for China to establish a nationwide, effective, and stable HRSV surveillance system. Through combining the current status of domestic and international HRSV surveillance systems and the existing surveillance framework in China, this study proposed an HRSV surveillance type applicable to China based on different surveillance purposes, and considering the feasibility of implementation. This article aimed to provide solid scientific and technical support to monitor the dynamic changes of HRSV epidemic timely, carry out a risk assessment and early warning, and further understand the disease burden of HRSV in China. It also helps to improve the diagnosis, prevention, and control of the HRSV diseases research and development, use, and evaluation of HRSV vaccines and drugs in China.

[Genotype and epidemiological characteristics of human metapneumovirus among hospitalized cases of acute respiratory infection in children in Changchun City, Jilin Province from 2019 to 2023].

Objective: To investigate the genotype and epidemiological characteristics of human metapneumovirus (HMPV) among hospitalized cases with acute respiratory infections (ARI) in children in Changchun City, Jilin Province, China. Methods: From June 2019 to June 2023, throat swabs of ARI inpatients in Changchun Children's Hospital were collected, and their epidemiological and clinical information were also collected. Quantitative reverse transcription-PCR was used to identify HMPV-positive cases, followed by the amplification of the G gene and genetic analysis in the HMPV-positive cases. Results: A total of 3 311 children hospitalized with ARI were included in this study. Their age ranged from 0 to 17 years old, and the M (Q1, Q3) of age was 2 (1, 3) years. About 1 811 (54.70%) cases were males. A total of 167 HMPV-positive cases were detected with a positive rate of 5.04%, of which 92.81% (155/167) were children under 5 years old. The positive rate of HMPV in 2019 was 6.37% (30/471), which dropped to the lowest in 2020 (2.31%, 10/432). The HMPV-positive rate was then rebounded in 2021 (4.70%, 60/1 277) and 2022 (4.56%, 21/461), which increased to 6.87% (46/670) in 2023. The difference in HMPV-positive rate among each year was statistically significant (P<0.05). The prevalence peak of HMPV varied in different years, showing either a unimodal or bimodal distribution in one year. A total of 79 HMPV G gene sequences were obtained, of which subtype A and subtype B accounted for 48.10% and 51.90%, respectively. All of the subtype A sequences were clarified as A2c duplicated variants, and subtype B was mainly B2 genotype. Besides, subtypes A and B were prevalent alone or co-circulated in different years, and there was a subtype replacement pattern in HMPV. Conclusion: The positive rate of HMPV in hospitalized ARI cases in children is significantly different from 2019 to 2023 in Changchun City. Notably, there are certain switch patterns of HMPV subtypes A and B in different years.

[Infection status and Molecular types of Rhinovirus among Cases of Acute Respiratory Tract Infections in Luohe City, Henan Province, from 2017 to 2022].

Objective: To understand the infection status and molecular types of rhinovirus (RV) among cases of Acute Respiratory Infections (ARIs) in Luohe City, Henan Province, from 2017 to 2022. Methods: From October 2017 to June 2022, clinical and epidemiological data were collected from 2 270 cases of ARIs at Luohe Central Hospital in Henan Province. Throat swab specimens were obtained from these cases. Real-time quantitative polymerase chain reaction (qPCR) was used to screen for RV-positive specimens. Subsequently, the positive samples were subjected to nested reverse transcription polymerase chain reaction (nested RT-PCR) to amplify the full-length VP1 region. Using the MEGA software, along with 169 RV reference strains recommended by the International Committee on Taxonomy of Viruses, a phylogenetic tree was constructed to determine RV types. Results: Among the 2 270 cases of ARIs, there were 1 283 male cases (56.52%). The median age (Q1, Q3) was 3 (1, 6) years, with the population under 5 years old accounting for 68.59% (1 557/2 270). RV was detected in 137 cases (6.04%), of which 68 cases (49.64%) showed co-detection with other viruses, with the most common being co-detection with enterovirus, accounting for 14.60% (20/137). The RV detection rates in the age groups of 0~4 years, 5~14 years, 15~59 years, and≥60 years were 6.42% (100/1 557), 4.69% (21/448), 3.80% (6/158), and 9.35% (10/107), respectively, with no statistically significant differences (χ2=5.310, P=0.150). The overall detection rates of RV before (2017-2019) and during (2020-2022) the COVID-19 pandemic showed no statistically significant difference (χ2=1.823, P=0.177). A total of 109 VP1 sequences were obtained, including 62 types. Among them, RV-A, RV-B, and RV-C had 42, 3, and 17 types respectively. Conclusion: RV is one of the predominant pathogens in ARIs cases in Luohe City, Henan Province, from 2017 to 2022. Multiple types of RV co-circulate without any apparent dominant type.

[Epidemiological characteristics of human respiratory syncytial virus among acute respiratory infection cases in 16 provinces of China from 2009 to 2023].

Objective: To understand the epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023. Methods: The data of this study were collected from the ARI surveillance data from 16 provinces in China from 2009 to 2023, with a total of 28 278 ARI cases included in the study. The clinical specimens from ARI cases were screened for HRSV nucleic acid from 2009 to 2023, and differences in virus detection rates among cases of different age groups, regions, and months were analyzed. Results: A total of 28 278 ARI cases were enrolled from January 2009 to September 2023. The age of the cases ranged from<1 month to 112 years, and the age M (Q1, Q3) was 3 years (1 year, 9 years). Among them, 3 062 cases were positive for HRSV nucleic acid, with a total detection rate of 10.83%. From 2009 to 2019, the detection rate of HRSV was 9.33%, and the virus was mainly prevalent in winter and spring. During the Corona Virus Disease 2019 (COVID-19) pandemic, the detection rate of HRSV fluctuated between 6.32% and 18.67%. There was no traditional winter epidemic peak of HRSV from the end of 2022 to the beginning of 2023, and an anti-seasonal epidemic of HRSV occurred from April to May 2023. About 87.95% (2 693/3 062) of positive cases were children under 5 years old, and the difference in the detection rate of HRSV among different age groups was statistically significant (P<0.001), showing a decreasing trend of HRSV detection rate with the increase of age (P<0.001). Among them, the HRSV detection rate (25.69%) was highest in children under 6 months. Compared with 2009-2019, the ranking of HRSV detection rates in different age groups changed from high to low between 2020 and 2023, with the age M (Q1, Q3) of HRSV positive cases increasing from 1 year (6 months, 3 years) to 2 years (11 months, 3 years). Conclusion: Through 15 years of continuous HRSV surveillance analysis, children under 5 years old, especially infants under 6 months old, are the main high-risk population for HRSV infection. During the COVID-19 pandemic, the prevalence and patterns of HRSV in China have changed.

[Analysis of enterovirus infection type among acute respiratory tract infection cases in Luohe City, Henan Province from 2017 to 2021].

Objective: To understand the infection status of Enterovirus (EV) in cases of acute respiratory infections (ARIs) in Luohe City, Henan Province from 2017 to 2021, and analyze the prevalence and type composition of EV in ARIs. Methods: From October 2017 to May 2021, pharyngeal swab samples were collected from 1 828 patients with ARIs in Luohe Central Hospital and the clinical epidemiological data of these cases were also collected. EV-positive samples were identified by Quantitative Real-time Polymerase Chain Reaction (qPCR). The 5'-untranslated region (5'UTR) was amplified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). The results of 5'UTR region were initially typed by Enterovirus Genotyping Tool Version 1.0. Based on the typing results, the full-length of VP1 region was amplified by RT-PCR. The EV typing was identified again by VP1 region. Results: Among 1 828 cases of ARIs, 56.7% (1 036) were males. The median (Q1, Q3) age was about 3 (1, 5) years. Patients under 5 years old accounted for 71.6% (1 309 cases). Among all cases, a total of 71 EV-positive samples were identified by qPCR, with a detection rate of 3.88% (71/1 828). The EV detection rates for men and women were 3.28% (34/1 036) and 4.67% (37/792), without statistically significant differences (χ2=2.32, P=0.14). The EV detection rates for 2 to <6 years, 6 months to <2 years, 6 to <10 years, and <6 months were 6.29% (48/763), 3.00% (18/600), 2.52% (4/159), and 1.67% (1/60) (χ2=27.91, P<0.001). The EV detection rate was 0.92% (3/326) in autumn and winter of 2017. The EV detection rates were 1.18% (6/508), 2.47% (12/485) and 8.31% (34/409) in each year from 2018 to 2020, with an increasing trend year by year(χ2trend=29.76, P<0.001). The main prevalent seasons were summer and autumn. The detection rate in spring of 2021 was 4.00% (4/100). A total of 12 types were identified and classified as CVA2, CVA4, CVA5, CVA6, CVA10, CVB3, CVB5, E5, E11, E30, PV-1, and EV-D68. The types of CVA2, CVA10, CVA6, and CVB3 were the dominant phenotypes. In 59 sample of EV typing, the main clinical manifestation was upper respiratory tract infection (36/59, 61.01%). The dominant types detected in upper respiratory tract infections were CVA10 (10/36, 27.78%), CVA6 (9/36, 25.00%) and CVB3 (8/36, 22.22%). The dominant type detected in lower respiratory tract infections was CVA2 (7/19, 36.84%). Conclusion: In Luohe City, Henan Province from 2017 to 2021, EV infection in ARIs cases has clear seasonal and age-specific patterns, and the dominant types of upper and lower respiratory tract infections are different.

[Efficacy comparison of zero-profile intervertebral fusion and stand-alone interbody cage combined with cage-titanium plate construct in treatment of two-segment skip cervical spondylosis].

Objective: To investigate the difference in clinical efficacy between zero-profile interbody fusion (ROI-C) and stand-alone interbody cage combined with cage-titanium plate construct for patient with two-segment skipped cervical spondylosis who received the anterior cervical discectomy and fusion (ACDF) surgical strategies. Methods: The clinical data of 62 patients with two-segment skipped cervical spondylosis who underwent surgical treatment in the First Affiliated Hospital of Zhengzhou University from June 2017 to June 2020 were retrospectively analyzed, included 38 males and 24 females, aged (53.3±8.5) years. Thirty-three cases were treated with ROI-C (ROI-C group), and 29 cases with stand-alone interbody cage combined with cage-titanium plate construct (cage+titanium plate group). The following parameters, including operation time, intraoperative blood loss, dysphagia Bazaz grade, Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) of pain, neck disability index (NDI), average intervertebral height of operated segments, C2-7 Cobb angle, and related complications, were compared between the two groups. Results: The patients were followed up for (28±5) months (16-34 months). The operation time of ROI-C group was (127.6±34.2) min, which was shorter than that in cage+titanium plate group [(157.1±43.9) min, P=0.004]. The scores of JOA and VAS in both ROI-C group and cage+titanium plate group were significantly improved 3 months after operation when compared with those before operation, and there was no significant difference between the two groups (all P>0.05). The average intervertebral space height of fusion segment in ROI-C group was (6.02±1.03) mm before operation, it was improved to (8.38±1.47) mm at 3 months after operation, (8.16±1.40) mm at 12 months after operation, and it was (6.24±1.05) mm, (8.58±1.18) mm and (7.87±0.73) mm in cage+titanium plate group, respectively, and there was no significant difference between the two groups at each time point (all P>0.05). The Cobb angle of cervical vertebrae in ROI-C group was 10.5°±6.8° before operation, improved to 19.2°±9.0° at 3 months after operation, 18.2°±5.8° at 12 months after operation, and it was 10.9°±4.6°, 18.5°±7.8°, 17.1°±5.2° in cage+titanium plate group, respectively, and there was no significant difference between the two groups at each time point (all P>0.05). The incidence of postoperative dysphagia was 9.1%(3/33) in the ROI-C group and 37.9%(11/29) in the cage+titanium plate group, and the difference was statistically significant (P=0.007). Conclusions: Both ROI-C and stand-alone interbody cage combined with cage-titanium plate construct can achieve good results for two-segment skipped cervical spondylosis. However, ROI-C is more advantageous in shortening the operation time and reducing early postoperative dysphagia.

[Viral pathogenic spectrum analysis of severe acute respiratory infection cases in Luohe City, Henan province from 2017 to 2019].

Objective: The purpose of this study was to investigate the characteristics of viral pathogen spectrum and the epidemiological characteristics of each viral pathogen in hospitalized cases associated with severe acute respiratory infection (SARI) in Luohe City, Henan Province from 2017 to 2019. Methods: Based the SARI Case Surveillance Platform, SARI cases were collected in Central Hospital of Luohe City, Henan Province from November 2017 to February 2019. In the end, 783 SARI cases were included, whose throat swabs were taken within 24 h of admission, as well as their demographic characteristics, onset time, clinical characteristics and other information recorded. At the same time, viral identification was performed, and the age and time distribution of each virus were analyzed. Results: The age of 783 SARI cases shown as M (P25, P75) was 3 (1, 5) years old, ranging from 1 month to 95 years old. Children under 5 years old were the majority (71.01%). The males (61.81%) were more than females (38.18%). Among the 783 SARI cases, a total of 9 kind of viruses were identified with 64.88% (508/783) of the throat swabs tested positive for at least one virus. The positive rate of influenza virus and human respiratory syncytial virus were both 20.18% (158 cases), which was the highest among all the detected respiratory virus. The co-infection rate was 15.84% (124/783), among which double infection was the most common, accounting for 85.48% (106/124) of the co-infected cases. And human respiratory syncytial virus, human rhinovirus and influenza virus were the most common pathogen in co-infection cases. Moreover, the viral positive rate was 68.71% in children aged 5 years and 63.27% in people aged 60-95 years. Influenza and human respiratory syncytial virus dominated in winter and spring, while human parainfluenza virus was the main infection in summer. Conclusion: Influenza virus and human respiratory syncytial virus were the main viruses in throat swabs of SARI cases from 2017 to 2019 in Luohe City, Henan Province. There were differences in the age and seasonal epidemiological characteristics of each virus.

Analyzing urban ecosystem variation in the City of Dongguan: A stepwise cluster modeling approach.

In this study, a stepwise cluster modeling approach (SCMA) is developed for analyzing urban ecosystem variation via Normalized Difference Vegetation Index (NDVI). NDVI is an indicator of vegetation growth and coverage and useful in reflecting urban ecosystem. SCMA is established on a cluster tree that can characterize the complex relationship between independent and dependent variables. SCMA is applied to the City of Dongguan for simulating the urban NDVI and identifying associated drivers of human activity, topography and meteorology without specific functions. Results show that SCMA performances better than conventional statistical methods, illustrating the ability of SCMA in capturing the complex and nonlinear features of urban ecosystem. Results disclose that human activities play negative effects on NDVI due to the destruction of green space for pursuing more space for buildings. NDVI reduces gradually from the south part to the north part of Dongguan due to increased gross domestic product and population density, indicating that the ecosystem in Dongguan is better in the south part. NDVI in the northeast part (dominated by agriculture) is sensitive to the growth of economy and population. More attention should be paid to this part for sustainable development, such as increasing afforestation, planting grass and constructing parks. Precipitation has a positive effect on NDVI due to the promotion of soil moisture that is beneficial to plants' growth. Awareness of these complexities is helpful for sustainable development of urban ecosystem.