BackgroundThe 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).MethodsWe 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.Results355 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).ConclusionHCV 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.
Background Hepatitis E virus (HEV) infection is endemic in Bangladesh and there are occasional outbreaks. The molecular characteristics and pathogenesis of endemic and outbreak HEV strains are poorly understood. We compared the genetic relatedness and virulence associated mutations of endemic HEV strains with outbreak strains. Methods We analyzed systematically collected serum samples from HEV immunoglobulin M (IgM) positive patients attended at Bangabandhu Sheikh Mujib Medical University, Dhaka from August 2013 to June 2015. HEV RNA positive samples were subjected to whole genome sequencing. Genotype and subtype of the strains were determined by phylogenetic analysis. Virulence associated mutations e.g. acute viral hepatitis (AVH), fulminant hepatic failure (FHF), chronic hepatitis, ribavirin treatment failure (RTF), B and T cell neutralization epitopes were determined. Results 92 HEV immunoglobulin M (IgM) antibody positive plasma samples (43 in 2013–2014 and 49 in 2014–2015) were studied. 77.1% (70/92) of the samples were HEV RNA positive. A 279 bp open reading frame (ORF) 2 and ORF 3 sequence was obtained from 54.2% (38/70) of the strains. Of these 38 strains, whole genome sequence (WGS) was obtained from 21 strains. In phylogenetic analysis of 38 (279 bp) sequence all HEV sequences belonged to genotype 1 and subtype 1a. Further phylogenetic analysis of 21 HEV WGS, Bangladeshi HEV sequences clustered with genotype 1a sequences from neighboring countries. Within genotype 1a cluster, Bangladesh HEV strains formed a separate cluster with the 2010 HEV outbreak strains from northern Bangladesh. 80.9 to 100% of the strains had A317T, T735I, L1120I, L1110F, P259S, V1479I, G1634K mutations associates AVH, FHF and RTF. Mutations in T cell recognition epitope T3, T5, T7 was observed in 76.1%, 100% and 100% of the strains respectively. Conclusion Strains of HEV genotype 1a are dominant in Bangladesh and are associated with endemic and outbreak of HEV infection. HEV isolates in Bangladesh have high prevalence of virulence associated mutations and mutation which alters antigenicity to B and T cell epitopes.
We present here the first complete genome sequence of Helicobacter pylori strain GD63, isolated from a 72-year-old male Vietnamese patient with a chronic gastric ulcer. The genome consists of a 1.6-Mbp chromosome and an 8.9-kbp plasmid.
Background: Laboratory staff is at higher risk of infection owing to the handling and testing of coronavirus disease 2019 (COVID-19) patient samples. Reviewing the existing risk assessment and improving risk management are essential for preventing laboratory acquired infections (LAIs) related to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) testing during the COVID-19 epidemic. We present herein the steps taken to prevent LAIs related to SARS-CoV-2 testing in a tertiary care hospital in Vietnam. Methods: A SARS-CoV-2-focused risk assessment exercise was conducted for laboratory processes and workflow. Risk management strategies, including engineering, administrative and operations control procedures, were established. Standard operating procedure (SOP), staff training, COVID-19 symptom reporting, enhanced cleaning and decontamination, and inventory monitoring protocols were implemented. Sample reception and results reported from February 1, 2020 to September 17, 2020 were documented. Results: Based on risk assessment, a risk management strategy for SARS-CoV-2 testing was developed. This strategy includes the use of dedicated facility, instrument, and cold chain units for testing; SOPs; training (testing, decontamination and cleaning staff); the introduction of biosafety level (BSL)2+ laboratory practices; enhanced cleaning protocols for testing; and the assigning of additional staff for testing and safety system implementation. In total, 38,377 (daily mean and range: 166; 3 – 2,377) samples were received, including 301 (0.8%) samples that were rejected. The turnaround time (median ± standard deviation (SD)) was 3.54 ± 2.97 days. Altogether, 32 staff members were involved with SARS-CoV-2 testing and biosafety management, and there were no reports of COVID-19 symptoms among them. Conclusion: For epidemics and outbreak diagnostics, risk assessment and risk management strategies are important for the prevention of LAIs. Clear instruction on revised risk management protocols, necessary training, and leadership in risk management strategy implementation are essential.
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