The Translational Potential of Next-Generation Sequencing and Biological Mass Spectrometry in Patients with Central Nervous System Infections in Vietnam.

Central nervous system (CNS) infections cause significant mortality and morbidity worldwide. Novel diagnostic approaches are therefore urgently needed to improve patient outcomes. My study was conducted at a tertiary referral hospital for Southern Vietnam between September 2017 and September 2020, aiming at improving the diagnosis in adult patients with CNS infection syndromes using a combination of metagenomics- and proteomics-based approaches. I set out to study significant insights into the epidemiology, causes, clinical features, and outcomes of 581 patients. Despite extensive laboratory investigations, the causes were established in 58.7% of the study patients. Diverse infectious agents encompassing bacteria, viruses, fungi, and parasites were detected with Mycobacterium tuberculosis, Streptococcus suis, HSV and VZV as the major causes. My research also revealed for the first-time that anti-NMDAR encephalitis is a common cause of CNS infection syndromes, accounting for 21.3% of 221 patients with suspected encephalitis, and disability documented up to 12 months post-discharge. CNS infection syndromes in our setting are associated with high morbidity and mortality (2397/581, 68.3% and 29/581, 5.0%, respectively) and with overlapped clinical and laboratory findings. To address diagnostic challenges of CNS infection syndromes, I developed and prospectively evaluated a metagenomic pipeline for simultaneous detection of both bacterial and viral causes. The results emphasised that metagenomics could provide a complementary approach to improve pathogen identification alongside conventional diagnostic assays. Additionally, I evaluated the diagnostic performance of two novel CSF biomarkers, Lipocalin 2 (LCN2) and a disintegrin and metalloprotease like decysin (ADAMDEC1). The results showed that LCN2 outperformed existing CSF parameters (leukocytes, protein, lactate, and glucose) in discriminating bacterial meningitis from other causes. In contrast, ADAMDEC1 did not offer any extra diagnostic values as compared to current CSF biomarkers. Collectively, my findings open new research opportunities to improve the diagnosis of patients with CNS infections in Vietnam and other regions where pathogen exposure is prevalent

Board Independence and Financial Performance: Empirical Evidence on Mediating Role of Market Competition From the Vietnamese Market

Purpose: The aim of this study is to examine the effect of board independence on the financial performance of companies listed on the Vietnamese stock exchanges with the mediating role of market competition.   Theoretical framework: The topic is based on agency theory, resource dependency theory and stewardship theory. The independence of the board of directors (BOD) is measured in two aspects: the duality and the non-executive members of BOD. This study approaches the measurement of market competition according to the Herfindahl-Hirschman index (HHI). After calculating the HHI, the study will classify companies in a highly competitive market or a low competitive market.   Design/methodology/approach: The study uses secondary data from the financial statements of companies listed on the Vietnamese stock market with the collection period from 2016 to 2020. The data analysis methods comprise of Pooled ordinary least squares (OLS), Fixed effects model (FEM), Random effects model (REM) and Generalized method of moments estimation (GMM).   Findings: The results of GMM showed that CEO duality is found to have a negative effect on the financial performance of listed firms. Meanwhile, the statistical evidence shows that the percentage of non-executive board members and market competition positively affect the financial performance. In addition, the evidence showed that market competition could reduce the positive influence of the percentage of non-executive board members on financial performance of listed companies.   Research, Practical & Social implications: The study has proposed some governance implications to improve the financial performance of listed firms such as limiting CEO duality, increasing the percentage of non-executive board members and empower the management board in a highly competitive market and choosing the appropriate size of the board.   Originality/value: The value of the study is to provide more scientific basis for policy makers in Vietnam and help listed companies choose and make decisions related to BOD to improve financial efficiency

Public healthcare system utilization for chronic hepatitis C infection in Vietnam

Background Healthcare utilization is typically adversely affected when the treatment is expensive and requires multiple visits. We examined the determinants of healthcare-seeking for Hepatitis C virus (HCV) infection which is asymptomatic, chronic, and requires costly treatment in an urban tertiary care referral hospital in Vietnam. Methods We conducted a secondary analysis of hospital data for patients attending the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam between 2017 and 2020 specifically for HCV infection treatment. Poisson regression was used to determine the effect of personal factors (age, sex, comorbidities) and structural factors (health insurance, proximity to the facility, seasonality, year of visit) on the number of hospital visits. Results From 2017 to 2020 a total of 22,052 eligible patients sought treatment in the hospital. Among the patients, 50.4% were males and 58.7% were > 50 years of age. The mean number of visits per person was 2.17. In the multivariate analysis compared to 2017, the number of hospital visits increased by 4% in 2018 and then significantly decreased in 2019 and 2020. Visit numbers were significantly lower (6%) among South East region residents compared to those from Central Highlands and for those who lived further away from the hospital. The visit numbers were significantly higher among older age groups (5–11%), those with health insurance (6%), and those with comorbidities (5%) compared to others. Although the number of hospital visits by females was higher (7%) than males in 2017, it significantly decreased in subsequent years. Conclusions Our study indicated that there are both structural and individual factors affecting the number of visits for HCV treatment. To meet the global strategy for elimination of HCV, Vietnam Government needs to address the structural and personal barriers to healthcare seeking, with a special focus on women

Current challenges and possible solutions to improve access to care and treatment for hepatitis C infection in Vietnam: a systematic review.

BACKGROUND: Hepatitis C infection is a major public health concern in low- and middle-income countries where an estimated 71.1 million individuals are living with chronic infection. The World Health Organization (WHO) has recently released new guidance for hepatitis C virus (HCV) treatment programs, which include improving the access to new direct-acting antiviral agents. In Vietnam, a highly populated middle-income country, the seroprevalence of HCV infection is approximately 4% and multiple genotypes co-circulate in the general population. Here we review what is currently known regarding the epidemiology of HCV in Vietnam and outline options for reducing the significant burden of morbidity and mortality in our setting. METHODS: We performed a systematic review of the currently available literature to evaluate what has been achieved to date with efforts to control HCV infection in Vietnam. RESULTS: This search retrieved few publications specific to Vietnam indicating a significant gap in baseline epidemiological and public health data. Key knowledge gaps identified included an understanding of the prevalence in specific high-risk groups, characterization of circulating HCV genotypes in the population and likely response to treatment, and the extent to which HCV treatment is available, accessed and utilized. CONCLUSIONS: We conclude that there is an urgent need to perform up to date assessments of HCV disease burden in Vietnam, especially in high-risk groups, in whom incidence is high and cross infection with multiple genotypes is likely to be frequent. Coordinating renewed surveillance measures with forthcoming HCV treatment studies should initiate the traction required to achieve the WHO goal of eliminating HCV as a public health threat by 2030, at least in this region

ẢNH HƯỞNG CỦA CÔNG NGHỆ THỰC TẾ ẢO TĂNG CƯỜNG ĐẾN Ý ĐỊNH MUA HÀNG TRỰC TUYẾN CỦA NGƯỜI TIÊU DÙNG

The study shows the effects of factors affecting consumers' purchase intention after experiencing Virtual Try-on (VTO) in Vietnam. The study is carried out by quantitative method through data from 408 subjects of different ages in Hanoi and Northern provinces. The findings of the study demonstrate that perceived usefulness, perceived ease of use, perceived enjoyment, and perceived privacy risk, have a significant impact on users' attitudes toward Virtual Try-On (VTO). Consequently, these factors increase their influence on customers' purchase intentions. Based on these results, the research group recommends that, in practical settings, enterprises concentrate on providing high-quality services, promoting their products to augment the aforementioned factors, and simultaneously addressing users' attitudes to enhance the overall customer experience. Therefore, this study provides valuable insights into the factors that influence customers' attitudes toward VTO technology, thereby contributing to the existing literature on the topic.Nghiên cứu chỉ ra những tác động của các nhân tố ảnh hưởng tới ý định mua hàng của người tiêu dùng qua hành vi sử dụng công nghệ trải nghiệm sản phẩm trực tuyến (Virtual Try-on - VTO) tại Việt Nam. Phương pháp định lượng được sử dụng để phân tích dữ liệu từ 408 đối tượng trong nhiều độ tuổi khác nhau trên địa bàn thành phố Hà Nội và các tỉnh thành phố miền Bắc. Kết quả cho thấy rằng các nhân tố như cảm nhận tính hữu ích, cảm nhận tính dễ sử dụng, cảm nhận tính thích thú, và cảm nhận rủi ro về quyền riêng tư có tác động đến thái độ của người dùng với công nghệ VTO từ đó gia tăng ảnh hưởng tới ý định mua sắm của khách hàng. Nhóm nghiên cứu đề xuất rằng, trong bối cảnh thực tiễn, doanh nghiệp cần tập trung vào cung cấp dịch vụ chất lượng, quảng bá sản phẩm để nâng cao các yếu tố đã được đề cập, đồng thời quan tâm đến thái độ của người dùng để cải thiện trải nghiệm tích cực cho khách hàng

A novel diagnostic model for tuberculous meningitis using Bayesian latent class analysis

Background Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of a gold standard. Current microbiological tests lack sensitivity and clinical diagnostic approaches are subjective. We therefore built a diagnostic model that can be used before microbiological test results are known. Methods We included 659 individuals aged ≥ 16 years with suspected brain infections from a prospective observational study conducted in Vietnam. We fitted a logistic regression diagnostic model for TBM status, with unknown values estimated via a latent class model on three mycobacterial tests: Ziehl–Neelsen smear, Mycobacterial culture, and GeneXpert. We additionally re-evaluated mycobacterial test performance, estimated individual mycobacillary burden, and quantified the reduction in TBM risk after confirmatory tests were negative. We also fitted a simplified model and developed a scoring table for early screening. All models were compared and validated internally. Results Participants with HIV, miliary TB, long symptom duration, and high cerebrospinal fluid (CSF) lymphocyte count were more likely to have TBM. HIV and higher CSF protein were associated with higher mycobacillary burden. In the simplified model, HIV infection, clinical symptoms with long duration, and clinical or radiological evidence of extra-neural TB were associated with TBM At the cutpoints based on Youden’s Index, the sensitivity and specificity in diagnosing TBM for our full and simplified models were 86.0% and 79.0%, and 88.0% and 75.0% respectively. Conclusion Our diagnostic model shows reliable performance and can be developed as a decision assistant for clinicians to detect patients at high risk of TBM. Summary Diagnosis of tuberculous meningitis is hampered by the lack of gold standard. We developed a diagnostic model using latent class analysis, combining confirmatory test results and risk factors. Models were accurate, well-calibrated, and can support both clinical practice and research

A real-time RT-PCR for detection of clade 1 and 2 H5N1 Influenza A virus using Locked Nucleic Acid (LNA) TaqMan probes

<p>Abstract</p> <p>Background</p> <p>The emergence and co-circulation of two different clades (clade 1 and 2) of H5N1 influenza viruses in Vietnam necessitates the availability of a diagnostic assay that can detect both variants.</p> <p>Results</p> <p>We developed a single real-time RT-PCR assay for detection of both clades of H5N1 viruses, directly from clinical specimens, using locked nucleic acid TaqMan probes. Primers and probe used in this assay were designed based on a highly conserved region in the <it>HA </it>gene of H5N1 viruses. The analytical sensitivity of the assay was < 0.5 PFU and 10 - 100 ssDNA plasmid copies. A total of 106 clinical samples (58 from patients infected with clade 1, 2.1 or 2.3 H5N1 viruses and 48 from uninfected or seasonal influenza A virus-infected individuals) were tested by the assay. The assay showed 97% concordance with initial diagnostics for H5 influenza virus infection with a specificity of 100%.</p> <p>Conclusions</p> <p>This assay is a useful tool for diagnosis of H5N1 virus infections in regions where different genetic clades are co-circulating.</p

Differential prevalence and geographic distribution of hepatitis C virus genotypes in acute and chronic hepatitis C patients in Vietnam.

BACKGROUND: The highest burden of disease from hepatitis C virus (HCV) is found in Southeast Asia, but our understanding of the epidemiology of infection in many heavily burdened countries is still limited. In particular, there is relatively little data on acute HCV infection, the outcome of which can be influenced by both viral and host genetics which differ within the region. We studied HCV genotype and IL28B gene polymorphism in a cohort of acute HCV-infected patients in Southern Vietnam alongside two other cohorts of chronic HCV-infected patients to better understand the epidemiology of HCV infection locally and inform the development of programs for therapy with the increasing availability of directly acting antiviral therapy (DAAs). METHODS: We analysed plasma samples from patients with acute and chronic HCV infection, including chronic HCV mono-infection and chronic Human Immunodeficiency Virus (HIV)-HCV coinfection, who enrolled in four epidemiological or clinical research studies. HCV infection was confirmed with RNA testing. The 5' UTR, core and NSB5 regions of HCV RNA positive samples were sequenced, and the genotype and subtype of the viral strains were determined. Host DNA from all HCV positive patients and age- and sex-matched non-HCV-infected control individuals were analysed for IL28B single nucleotide polymorphism (SNP) (rs12979860 and rs8099917). Geolocation of the patients were mapped using QGIS. RESULTS: 355 HCV antibody positive patients were analysed; 54.6% (194/355) and 46.4% (161/355) were acute and chronic infections, respectively. 50.4% (81/161) and 49.6.4% (80/161) of chronic infections had HCV mono-infection and HIV-HCV coinfection, respectively. 88.7% (315/355) and 10.1% (36/355) of the patients were from southern and central regions of Vietnam, respectively. 92.4% (328/355) of patients were HCV RNA positive, including 86.1% (167/194) acute and 100% (161/161) chronic infections. Genotype could be determined in 98.4% (322/328) patients. Genotypes 1 (56.5%; 182/322) and 6 (33.9%; 109/322) predominated. Genotype 1 including genotype 1a was significantly higher in HIV-HCV coinfected patients compared to acute HCV patients [43.8% (35/80) versus 20.5% (33/167)], (p = <0.001), while genotype 6 was significantly higher in chronic HCV mono-infected patients [(44.4% (36/81) versus 20.0% (16/80)] (p = < 0.004) compared to HIV-HCV coinfected patients. The prevalence of IL28B SNP (rs12979860) homozygous CC was 86.46% (83/96) in control individuals and was significantly higher in acutely-infected compared to chronically-infected patients [93.2 (82/88) versus 76.1% (35/46)] (p = < 0.005). CONCLUSION: HCV genotype 6 is highly prevalent in Vietnam and the high prevalence in treatment naïve chronic HCV patients may results from poor spontaneous clearance of acute HCV infection with genotype 6

Laboratory Capacity Building in Asia for Infectious Disease Research: Experiences from the South East Asia Infectious Disease Clinical Research Network (SEAICRN)

Heiman Wertheim and colleagues discuss a network that aims to improve infectious disease management through integrated, collaborative clinical research in South East Asia