Exploring the inverse relationship between serum total bilirubin and systemic immune-inflammation index: insights from NHANES data (2009-2018).

BACKGROUND: Bilirubin is known for its multifaceted attributes, including antioxidant, anti-inflammatory, immunomodulatory, and antiapoptotic properties. The systemic immune-inflammation index (SII) is a recent marker that reflects the balance between inflammation and immune response. Despite the wealth of information available on bilirubin's diverse functionalities, the potential correlation between the total bilirubin (TB) levels and SII has not been investigated so far. METHODS: Leveraging data from the National Health and Nutrition Examination Survey spanning 2009-2018, the TB levels were categorized using tertiles. Employing the chi-squared test with Rao and Scott's second-order correction and Spearman's rank correlation analysis, the association between TB and SII was examined. The potential nonlinearities between TB and SII were evaluated using restricted cubic spline (RCS) analysis. Weighted linear regression, adjusted for covariates, was used to explore the correlation between TB and SII, with further subgroup analyses. RESULTS: A total of 16,858 participants were included, and the findings revealed significant SII variations across TB tertiles (p < 0.001). The third tertile (Q3) exhibited the lowest SII level at 495.73 (295.00) 1000 cells/µL. Spearman rank correlation disclosed the negative association between TB and SII. RCS analysis exposed the lack of statistically significant variations in the nonlinear relationship (p > 0.05), thereby providing support for a linear relationship. Weighted linear regression analysis underscored the negative correlation between TB and SII (ß 95% CI - 3.9 [- 5.0 to - 2.9], p < 0.001). The increase in the TB levels is associated with a significant linear trend toward decreasing SII. After controlling for relative covariates, this negative correlation increased (p < 0.001). Subgroup analysis confirmed the significant negative TB-SII association. CONCLUSION: A notable negative correlation between TB and SII implies the potential protective effects of bilirubin in inflammation-related diseases.

Molecular Epidemiology of Human Norovirus Variants from Outbreaks in Zhejiang Province, China, during 2021.

Background: Noroviruses are the most frequent cause of epidemic acute viral gastroenteritis in China. Objectives: The aim of this study was to determine the molecular epidemiological characteristics of norovirus outbreaks and the molecular genetic features of norovirus in Zhejiang Province during 2021. Methods: First, the local Centers for Disease Control and Prevention in the outbreak area conducted on-site epidemiologic investigations and collected samples from ill patients for initial testing. The general epidemiologic characteristics of the demographic information are presented through descriptive analysis. Positive samples were sent to the Microbiology Laboratory of Zhejiang Provincial Center for Disease Control and Prevention for further verification. The presence of norovirus genogroups I (GI) and II (GII), along with sapovirus, was detected. Subsequently, the specimens positive for norovirus were sequenced for genotyping purposes. Furthermore, the whole genomes of positive samples were sequenced, enabling the characterization of both nucleotide and amino acid differences within the virus. Finally, phylogenetic trees were constructed to further analyze and understand the genetic relationships among the detected viruses. Result: 227 norovirus outbreaks were reported in Zhejiang Province, China, during 2021. Schools were the main setting while January was the peak month for outbreaks. A total of 17 diverse genotypes of norovirus were identified in 2021, and GII.P16-GII.2 was the most frequent genotype (30.19%). Seven genomes (five GI.P4-GI.5 and two GII.P16-GII.2) were obtained. Although GI.P4-GI.5 is considered to be a rare genotype of norovirus, the prevalence might have been underestimated. Capsid microvariation of GII.2 displayed histo-blood group antigen binding patterns compared to the GII.2 prototype, although VP1 sequences were considered to have a minimal impact on antigenicity. Conclusion: This study revealed the diversity of norovirus strains' genotypes circulating in Zhejiang Province in 2021. Continued molecular surveillance of noroviruses should be strengthened in our further efforts to the development of vaccines.

Low neutralization of SARS-CoV-2 Omicron BA.5.2.48 and XBB.1 sub-variants in response to breakthrough infection by booster.

To assess the levels of and neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its mutants in serum samples from patients with breakthrough infection. Sixty-four patients with breakthrough infections were recruited for this cross-sectional study. All samples were used to neutralizing antibodies (nAbs) against SARS-CoV-2 and its mutants using a focused reduction neutralization assay. A total of 512 serum samples were obtained from unvaccinated patients who received one dose of vaccine (n = 12), received two doses of vaccine (n = 15), and received three doses of vaccine (n = 37). The geometric mean titer (GMT) of neutralizing antibodies against the Omicron subvariant was significantly lower (GMT 66.8 and 56.1) compared to the original strain, regardless of whether two or three doses of vaccine were administered. This result highlights that sera from breakthrough infections induce broad neutralization, but Omicron XBB.1.16 exhibits high immune evasion potential.

Epidemiological and etiological investigations of hand, foot, and mouth disease in Jiashan, northeastern Zhejiang Province, China, during 2016 to 2022.

Background: Hand, foot, and mouth disease (HFMD) is a common infectious disease in children. Enterovirus A71 (EV71) and coxsackievirus A16 (CA16) have been identified as the predominant pathogens for several decades. In recent years, coxsackievirus A6 (CA6) and coxsackievirus A10 (CA10) have played increasingly important roles in a series of HFMD outbreaks. We performed a retrospective analysis of the epidemiology of HFMD and the spectrum of different viral serotypes, to elucidate the genetic and phylogenetic characteristics of the main serotypes in the Jiashan area during 2016 to 2022. Methods: Descriptive epidemiological methods were used to analyze the time and population distribution of HFMD in Jiashan during 2016 to 2022 based on surveillance data. Molecular diagnostic methods were performed to identify the viral serotypes and etiological characteristics of HFMD. Phylogenetic analyses was based on VP1 region of CA16 and CA6. Results: The average annual incidence rate of HFMD fluctuated from 2016 to 2022. Children aged 1-5 years accounted for 81.65% of cases and boys were more frequently affected than girls. Except when HFMD was affected by the COVID-19 epidemic in 2020 and 2022, epidemics usually peak in June to July, followed by a small secondary peak from October to December and a decline in February. Urban areas had a high average incidence and rural areas had the lowest. Among 560 sample collected in Jiashan, 472 (84.29%) were positive for enterovirus. The most frequently identified serotypes were CA6 (296, 52.86%), CA16 (102, 18.21%), EV71 (16, 2.86%), CA10 (14, 2.50%) and other enteroviruses (44, 7.86%). There were 71 and 142 VP1 sequences from CA16 and CA6, respectively. Substitution of N218D, A220L and V251I was detected in CA16 and may have been related to viral infectivity. Phylogenetic analysis showed that CA16 could be assigned to two genogroups, B1a and B1b, while all the CA6 sequences belonged to the D3a genogroup. Conclusion: CA6 and CA16 were the two major serotypes of enteroviruses circulating in the Jiashan area during 2016 to 2022. Continuous and comprehensive surveillance for HFMD is needed to better understand and evaluate the prevalence and evolution of the associated pathogens.

The impact of brominated flame retardants (BFRs) on pulmonary function in US adults: a cross-sectional study based on NHANES (2007-2012).

Brominated flame retardants (BFRs) are a group of chemicals widely used in various applications to prevent or slow down the spread of fire. However, they have adverse effects on human health. There is a relative scarcity of population-based studies regarding BFRs, particularly their impact on the respiratory system. This study aimed to investigate the influence of BFRs on pulmonary function using data from the National Health and Nutrition Examination Survey. The study found that elevated serum concentrations of certain BFRs were associated with pulmonary ventilatory dysfunction. Adjusted analyses revealed positive correlations between PBDE47, PBDE183, and PBDE209 concentrations and ventilatory dysfunction. The analysis of mixed BFRs showed a positive relationship with pulmonary ventilation dysfunction, with PBDE47 making the most significant contribution. Our study demonstrates that both individual and combined BFRs exposure can lead to impaired pulmonary ventilation function. These findings provide evidence of the adverse effects of BFRs on lung function, emphasizing the importance of further investigating the potential health consequences of these compounds. Further large-scale longitudinal studies are needed to investigate this relationship in the future.

Influence of storage solution, temperature, assay time and concentration on RT-qPCR nucleic acid detection for SARS-CoV-2 detection of SARS-CoV-2 by the RT-qPCR.

Real-time reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is an important method for the early diagnosis of coronavirus disease 2019 (COVID-19). This study investigated the effects of storage solution, temperature and detection time on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection by RT-qPCR. Various concentrations of SARS-CoV-2 were added to inactive and non-inactive storage solution and the viral suspensions were stored at various temperatures (room temperature, 4, -20 and -80 °C). Then, at five different detection time points, the Ct values were determined by RT-qPCR. Active and inactive storage solutions and storage temperature have a great impact on the detection of N gene of SARS-CoV-2 at different concentration corridors but have little impact on the ORF gene. The storage time has a greater impact on the N gene and ORF gene at high concentrations but has no effect on the two genes at low concentrations. In conclusion, storage temperature, storage time and storage status (inactivated, non-inactivated) have no effect on the nucleic acid detection of SARS-CoV-2 at the same concentration. For different concentrations of SARS-CoV-2, the detection of N gene is mainly affected.

Caffeinated beverages intake and risk of deep vein thrombosis: A Mendelian randomization study.

This study aimed to explore the potential link between coffee and tea consumption and the risk of deep vein thrombosis (DVT) through Mendelian randomization (MR) analysis. Employing the MR, we identified 33 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for coffee intake and 38 SNPs for tea intake. The investigation employed the inverse-variance weighted (IVW) method to evaluate the causal impact of beverage consumption on DVT risk. Additionally, MR-Egger and MR-PRESSO tests were conducted to assess pleiotropy, while Cochran's Q test gauged heterogeneity. Robustness analysis was performed through a leave-one-out approach. The MR analysis uncovered a significant association between coffee intake and an increased risk of DVT (odds ratio [OR] 1.008, 95% confidence interval [CI] = 1.001-1.015, P = 0.025). Conversely, no substantial causal effect of tea consumption on DVT was observed (OR 1.001, 95% CI = 0.995-1.007, P = 0.735). Importantly, no significant levels of heterogeneity, pleiotropy, or bias were detected in the instrumental variables used. In summary, our findings suggest a modestly heightened risk of DVT associated with coffee intake, while tea consumption did not exhibit a significant impact on DVT risk.

Adenosine Triphosphate/Chitin Whisker/Phenylboronic Acid-Modified Wool Fabrics with Enhanced Dyeability.

Promoting the uptake of dyes is an important part of the sustainable processing of wool products. This study presents an effective modification approach to enhance the dyeability of wool fabric with adenosine triphosphate as an activator, 3-carboxyphenyl boronic acid as a ligand-binding agent, and chitin whisker as a couple agent. The structure and surface morphology of the as-prepared wool fabric was characterized in detail. Natural luteolin and acid red 1 were used to dye the modified wool fabric, and the effect of different dyeing parameters on dyeing properties was discussed. The results indicated that the modified wool gained better surface color depth (K/S) and uptake without additional agents than the untreated wool fabric. When the modified wool fabric was dyed at 45 °C with luteolin and at 60 °C with acid red 1, the dyeing processes of the two dyes on the modified wool fabrics followed the Langmuir isotherm and the pseudo-second-order kinetic model. Furthermore, the dyed modified wool fabrics possessed improved color fastness. Overall, this work offers a facile, effective, and sustainable way to improve the low-temperature dyeability of wool products.

Synthesis and application of multifunctional lignin-modified cationic waterborne polyurethane in textiles.

Waterborne polyurethanes (WPUs) often have limitations like inadequate weathering resistance and thermal stability. To overcome these shortcomings, lignin has been selected as a modifier for its abundant availability, renewability, and biocompatibility. This study synthesized a cationic WPU using isophorone diisocyanate and polyethylene glycol as raw materials. Hydrophilicity was attained through the inclusion of dihydroxyethyl dodecylamine as a chain extender, while the introduction of epoxy monomers and lignin served to modify the polyurethane. Furthermore, a dye dispersion for cotton fabric dyeing was prepared by combining the synthesized polyurethane, chitosan, and dyes. The cationic nature of the polyurethane played a crucial role in facilitating dye adhesion and uptake on the fabric surface, resulting in improved dyeing performance. The incorporation of epoxy side chains and chitosan cross-linking contributed to the excellent color fastness of the dyed fabrics. Moreover, the incorporation of lignin and chitosan endowed the fabric with antibacterial properties. Simultaneously, it provided effective UV protection, characterized by a high UV protection factor value for the fabrics. This lignin-modified WPU exhibits tremendous potential in applications such as textile coatings, adhesives, and color fixation agents. It effectively addresses the limitations of traditional WPUs and offers notable advantages, including a renewable source, cost-effectiveness, and biocompatibility.

Analysis of the correlation between serum Klotho and FeNO: a cross-sectional study from NHANES (2007-2012).

BACKGROUND: Klotho is an anti-aging protein that has multiple functions and may play a key role in the pathogenesis and progression of chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD). Fractional Exhaled Nitric Oxide (FeNO) is a non-invasive and novel biomarker that has the advantages of being simple, fast and reproducible. It can effectively assess the degree of airway inflammation in diseases such as asthma and COPD. Despite these insights, the relationship between serum Klotho levels and FeNO has not been explored yet. METHODS: Leveraging data from the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2012, we investigated the correlation between FeNO and serum Klotho levels. This association was scrutinized both as continuous variables and within quartile distributions, utilizing the Kruskal-Wallis H test. The correlation between the two variables was assessed through Spearman rank analysis. Employing survey weight-adjusted linear regression models, we gauged the strength of these associations. RESULTS: This study included 6,527 participants with a median FeNO level of 14.5 parts per billion (ppb). We found that FeNO levels varied significantly across different quartiles of Klotho protein (H = 7.985, P = 0.046). We also found a significant positive correlation between serum Klotho levels and FeNO levels in the whole population (Spearman's rho = 0.029, P = 0.019). This correlation remained significant after adjusting for covariates such as age, gender, lung function, smoking status, alcohol use, BMI, cardiovascular disease (including hypertension, heart failure, coronary heart disease, and myocardial infarction), diabetes, inflammatory markers, serum vitamin D level and BUN (P < 0.05 for all). Furthermore, this correlation was stronger at the high (K3) and super high (K4) levels of Klotho than at the low (K1) and medium (K2) levels (ß = 1.979 ppb and ß = 1.993 ppb for K3 and K4 vs. K1, respectively; 95% CI: 0.497 ~ 2.953 and 95% CI: 0.129 ~ 2.827, respectively; P = 0.007 and P = 0.032, respectively). The ß coefficient for serum Klotho was 0.002 ppb/pg/ml. CONCLUSIONS: Our study illuminates a positive correlation between serum Klotho levels and FeNO. Further study is needed to verify the causality of this association and elucidate the underlying mechanisms.

Multivariate Machine Learning Models of Nanoscale Porosity from Ultrafast NMR Relaxometry.

Nanoporous materials are of great interest in many applications, such as catalysis, separation, and energy storage. The performance of these materials is closely related to their pore sizes, which are inefficient to determine through the conventional measurement of gas adsorption isotherms. Nuclear magnetic resonance (NMR) relaxometry has emerged as a technique highly sensitive to porosity in such materials. Nonetheless, streamlined methods to estimate pore size from NMR relaxometry remain elusive. Previous attempts have been hindered by inverting a time domain signal to relaxation rate distribution, and dealing with resulting parameters that vary in number, location, and magnitude. Here we invoke well-established machine learning techniques to directly correlate time domain signals to BET surface areas for a set of metal-organic frameworks (MOFs) imbibed with solvent at varied concentrations. We employ this series of MOFs to establish a correlation between NMR signal and surface area via partial least squares (PLS), following screening with principal component analysis, and apply the PLS model to predict surface area of various nanoporous materials. This approach offers a high-throughput, non-destructive way to assess porosity in c.a. one minute. We anticipate this work will contribute to the development of new materials with optimized pore sizes for various applications.

A systematic review and meta-analysis of prognostic indicators in patients with head and neck malignancy treated with immune checkpoint inhibitors.

INTRODUCTION: Tumor immunotherapy has recently emerged as a crucial focal point in oncology treatment research. Among tumor immunotherapy approaches, tumor immune checkpoint inhibitors (ICIs) have attracted substantial attention in clinical research. However, this treatment modality has benefitted only a limited number of patients. We conducted a meta-analysis of various biomarkers to decipher their prognostic implications in patients with head and neck squamous cell carcinoma (HNSCC) who are treated with ICIs, and thus identify predictive markers with practical clinical relevance. METHODS: A systematic search of electronic databases was conducted to identify clinical studies that examined the correlation between biomarkers and treatment outcomes in the HNSCC patients. The included articles were screened and analyzed to extract data regarding overall survival (OS) and progression-free survival (PFS). RESULTS: The relationship between the biomarkers included in the summary and prognosis was as follows: HPV positivity was associated with improved OS (HR = 0.76, 95% CI = 0.58-1.99), PFS (HR = 1.16, 95% CI = 0.81-1.67), and response (OR = 1.67, 95% CI = 1.37-2.99). PD-L1 positivity was associated with OS (HR = 0.71, 95% CI = 0.59-0.85), PFS (HR = 0.56 95% CI = 0.43-0.73), and response (OR = 2.16, 95% CI = 1.51-3.10). Neither HPV positivity nor PD-L1 positivity was associated with DCR. The following markers were collected for OS and PFS data and were associated with longer OS: lower Glasgow prognostic score (GPS/mGPS) grading, lower PS grading, high body mass index (BMI), low neutrophil-to-lymphocyte ratio (NLR), low platelet-to-lymphocyte ratio (PLR), high albumin (Alb), low lactate dehydrogenase (LDH). Factors associated with better PFS were lower GPS/mGPS grading, lower PS grading, high BMI, low NLR, high absolute lymphocyte count, and low LDH. Hyperprogressive disease was associated with worse OS and PFS. Fewer clinical studies have been completed on the tumor microenvironment and hypoxia, microsatellite instability/DNA mismatch repair, and microbiome and systematic analysis is difficult. CONCLUSION: In our meta-analysis, different immune checkpoint factors were associated with different prognoses in HNSCC patients receiving immunotherapy. HPV, PD-L1, BMI, Alb, HPD, PS, GPS/mGPS, LDH, NLR, and PLR predicted the ICI outcome in HNSCC patients.

Low neutralization of SARS-CoV-2 Omicron BA.5.2.48, BF.7.14, XBB.1 subvariants by homologous or heterologous booster.

The recently mutated severe acute respiratory syndrome coronavirus 2 variant Omicron has very high infectivity and a strong ability to evolve and evade immunity. We collected six sets of sera from uninfected individuals and individuals recovering from breakthrough infections who completed homologous or heterologous booster immunization and assessed their susceptibility against the BA.5.2.48, BF.7.14, XBB.1.5, XBB.1.5.4, and XBB.1.16 subvariants. The results demonstrated that the Omicron variants possess an exceptional potential to evade the immune barriers strengthened by vaccine administration and natural infections in the population, particularly XBB.1.16, and showed that heterologous boosters exhibit higher vaccine efficacy compared with homologous boosters.

The analysis of the genotype of Sapovirus outbreaks in Zhejiang Province.

BACKGROUND: Sapovirus (SaV) infection is increasing globally. Concurrently, several SaV-outbreaks were observed in children of Zhejiang province, China, in recent years, In this study, the genotypes of Sapovirus from seven outbreaks in the Zhejiang province were analysed. METHODS: A total of 105 faecal samples were collected from children aged between 4 and 17 years from the Zhejiang Provincial Center for Disease Control and Prevention between October 2021 and February 2023. Genotypes were processed using reverse transcription polymerase chain reaction and Sanger sequencing, while next-generation sequencing was used to generate a complete viral genome. Deduced amino acid sequences were analysed to detect VP1 gene mutations. RESULTS: In total, 60 SaV-positive patients were detected at a 57.14% (60/105) positivity rate. Positive rates in the seven outbreaks were: 22.22% (2/9), 15.00% (3/20), 93.10% (27/29), 84.21% (16/19), 28.57% (2/7), 53.33% (8/15) and 33.33% (2/6), respectively. Four genotypes were identified in the seven outbreaks, of which, GI.1 accounted for 14.29% (1/7), GI.2 accounted for 14.29% (1/7), GI.6 and GII.5 accounted for 14.29% (1/7), and GI.6 accounted for 57.14% (4/7). All patients were children and outbreaks predominantly occurred in primary schools and during cold seasons. Additionally, the complete sequence from the GI.6 outbreak strain showed high homology (identity: 99.99%) with few common substitutions (Y300S, N302S and L8M) in VP1 protein. CONCLUSIONS: SaV genotype diversity was observed in the seven outbreaks, with GI.6 being the main SaV genotype in Zhejiang province. It demonstrated high homology and may provide a platform for SaV prevention and control measures.

Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal-organic framework.

In nature, nonheme iron enzymes use dioxygen to generate high-spin iron(IV)=O species for a variety of oxygenation reactions. Although synthetic chemists have long sought to mimic this reactivity, the enzyme-like activation of O2 to form high-spin iron(IV) = O species remains an unrealized goal. Here, we report a metal-organic framework featuring iron(II) sites with a local structure similar to that in α-ketoglutarate-dependent dioxygenases. The framework reacts with O2 at low temperatures to form high-spin iron(IV) = O species that are characterized using in situ diffuse reflectance infrared Fourier transform, in situ and variable-field Mössbauer, Fe Kß x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O2, the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.

Vitamin D and idiopathic pulmonary fibrosis: a two-sample mendelian randomization study.

BACKGROUND: A prospective study of multiple small samples found that idiopathic pulmonary fibrosis (IPF) is often accompanied by a deficiency in Vitamin D levels. However, the causal relationship between the two remains to be determined. Therefore, our study aims to investigate the causal effect of serum 1,25-hydroxyvitamin D (25(OH)D) on the risk of IPF through a two-sample Mendelian randomization (MR) analysis. METHODS: Through data analysis from two European ancestry-based genome-wide association studies (GWAS), including 401,460 individuals for 25(OH)D levels and 1028 individuals for IPF, we primarily employed inverse-variance weighted (IVW) to assess the causal effect of 25(OH)D levels on IPF risk. MR-Egger regression test was used to determine pleiotropy, and Cochran's Q test was conducted for heterogeneity testing. Leave-one-out analysis was conducted to examine the robustness of the results. RESULTS: 158 SNPs related to serum 25(OH)D were used as instrumental variables (IVs). The MR analyses revealed no evidence supporting a causal association between the level of circulating 25(OH)D and the risk of IPF. The IVW method [OR 0.891, 95%CI (0.523-1.518), P = 0.670]; There was no significant level of heterogeneity, pleiotropy and bias in IVs. Cochran's Q test for heterogeneity (MR Egger P = 0.081; IVW P = 0.089); MR-Egger regression for pleiotropy (P = 0.774). CONCLUSIONS: This MR Study suggests that genetically predicted circulating vitamin D concentrations in the general population are not causally related to IPF.

Molecular epidemiological characteristics of SARS-CoV-2 in imported cases from 2021 to 2022 in Zhejiang Province, China.

Backgrounds: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a global threat since 2020. The emergence of the Omicron variant in 2021, which replaced Delta as the dominant variant of concern, has had a significant adverse impact on the global economy and public health. During this period, Zhejiang Province implemented dynamic zeroing and focused on preventing imported cases. This study aimed to gain clear insight into the characteristics of imported COVID-19 cases in Zhejiang Province. Methods: We conducted a systematic molecular epidemiological analysis of 146 imported cases between July 2021 and November 2022 in Zhejiang Province. Virus samples with cycle threshold (Ct) value less than 32 were performed next generation sequencing. Basing the whole genome sequence obtained after quality control and assembly of reads, the whole genome variation map and phylogenetic tree were constructed and further analyzed. Results: Our study identified critical months and populations for surveillance, profiled the variation of various lineages, determined the evolutionary relationships among various lineages of SARS-CoV-2, and compared the results in Zhejiang with those obtained worldwide during this period. Conclusion: The continuous molecular epidemiological surveillance of imported cases of COVID-19 in Zhejiang Province during 2021 to 2022 is consistent with the global epidemic trend.

Importation of a novel Indian Ocean lineage carrying E1-K211E and E2-V264A of Chikungunya Virus in Zhejiang Province, China, in 2019.

The chikungunya virus (CHIKV) is widespread. In Zhejiang province, China, CHIKV infection is often associated with travelers from tropical and subtropical countries. In the present study, three CHIKV isolates from serum samples of travelers in Zhejiang province in 2019 were sequenced, and phylogenetically analyzed to study their molecular characteristics. Sequence analysis showed that the non-structural protein and the structural protein had 37 and 28 amino acid mutations, respectively; no mutation site was found at the E1-A226 residue, which could increase the adaptability of CHIKV to Aedes albopictus. All three samples carried two mutations, namely, E1-K211E and E2-V264A, which were introduced to Bangladesh around late 2015 and Thailand in early 2017. Phylogenetic analysis revealed that these three CHIKVs were Indian Ocean lineage of the East Africa/Central/South Africa genotype (ECSA) and that the MF773566 strain from Bangladesh (Australia/Bangladesh 2017) had the closest evolutionary relationship. The three CHICKs imported into Zhejiang province in 2019 belonged to the ECSA genotype and had multiple amino acid variation sites. The variation in the three samples provides a certain reference for the subsequent research on CHIKV evolution.