TỔNG HỢP DANH SÁCH CÁC BÀI BÁO ĐĂNG TRÊN MỘT SỐ TẠP CHÍ QUỐC TẾ
VIỆN VỆ SINH DỊCH TỄ TRUNG ƯƠNG NĂM 2012
Animal livestock and the risk of hospitalized diarrhoea in children under 5 years in Vietnam
To investigate the association between environmental exposure to Objective A livestock and incidence of diarrhoea among Vietnamese children. Methods 828 households in 525 individuals, living in 75 population-based cohort of 353 Khanh Hoa Province, Vietnam, with baseline data covering geo-referenced information on demography, socio-economic status and household animals was investigated. Geographic information system was applied to calculate the density of livestock. The data were linked to hospitalized diarrhoea cases of children years recorded at two hospitals treating patients from the area as under 5 Overall, 3116 children with diarrhoea inpatients in the study area. Results were hospitalized during the study period. The incidence of diarrhoea hospitalization was 60.8/1000 child-years. Male gender, age <years, higher 2 number of household members and lack of tap water were significantly associated with an increased risk of diarrhoea. There was no evidence that ownership of livestock increased the risk of diarrhoea. In spatial analysis, we found no evidence that a high density of any animals was associated with an increased risk of diarrhoea. Conclusions Exposure to animals near or in households does not seem to constitute a major risk for diarrhoea in children under the age of 5 in Vietnam. Public health interventions to reduce childhood diarrhoea burden should focus on well-recognized causes such as sanitation, personal hygiene, access to adequate clean water supply and vaccination.
2. Nguyễn Đồng Tú, Ngô Tuấn Cường, Trần Huy Hoàng, Lê Thanh Hương, Nguyễn Hoài Thu, Nguyễn Bình Minh, Trần Như Dương, Tetsu Yamashiroand Masahiko Ehara. Characterization of Vibrio cholerae O139 of an Aquatic Isolate in Northern Vietnam. The Open Microbiology Journal. 2012, Vol 6,p.14-21. 1874-2858/12 2012 Bentham Open.
Characterization of Vibrio cholerae O139 of an Aquatic Isolate in Northern Vietnam
Dong Tu Nguyen, Tuan Cuong Ngo, Huy Hoang Tran, Thanh Huong Le, Hoai Thu Nguyen, Binh Minh Nguyen, Nhu Duong Tran, Tetsu Yamashiro and Masahiko Ehara
During the cholera survey in Namdinh province (northern Vietnam) in July, 2010, one strain of Vibrio cholerae O139 was isolated from 7 environmental water samples positive for ctxA, toxR, VCO139 genes and named as V. cholerae O139, ND1 strain. This strain was lysogenic harbouring a genome similar to the filamentous phage fs1. The replicativeform DNA of this phage (named as ND1-fs1, 6856 bp) was sequenced and compared with the other filamentous phages.The filamentous phage ND1-fs1 integrates into the region between ctxB and rtxA genes. The genetic organization of theCTX of V. cholerae O139, strain ND1 was determined and the schematic representation of the genetic organization wasshown together with the ND1-fs1 prophage.
3. Duc NB, Hien BT, Wagar N, Trần Hồng Trâm, Giang le T, Yang C, Wolfe MI, Nguyễn Trần Hiển, Nguyễn Anh Tuấn. Surveillance of Transmitted HIV Drug Resistance Using Matched Plasma and Dried Blood Spot Specimens From Voluntary Counseling and Testing Sites in Ho Chi Minh City, Vietnam, 2007-2008. Clin Infect Dis. 2012 May;54 Suppl4:S343-7.
Surveillance of Transmitted HIV Drug Resistance Using Matched Plasma and Dried Blood Spot Specimens From Voluntary Counseling and Testing Sites in Ho Chi Minh City, Vietnam, 2007-2008
During 2007-2008, surveillance of transmitted human immunodeficiency virus (HIV) drug resistance (TDR) was performed following World Health Organization guidance among clients with newly diagnosed HIV infection attending voluntary counseling and testing (VCT) sites in Ho Chi Minh City (HCMC), Vietnam. Moderate (5%-15%) TDR to nonnucleoside reverse-transcriptase inhibitors (NNRTIs) was observed among VCT clients aged 18-21 years. Follow-up surveillance of TDR in HCMC and other geographic regions of Vietnam is warranted. Data generated will guide the national HIV drug resistance surveillance strategy and support selection of current and future first-line antiretroviral therapy and HIV prevention programs.
4. Horby P, Lê Quỳnh Mai, Fox A, Phạm Quang Thái, Nguyễn Thị Thu Yến, Lê Thị Thanh, Nguyễn Lê Khánh Hằng, Trần Như Dương, Thoang DD, Farrar J, Wolbers M, Nguyễn Trần Hiển.The epidemiology of interpandemic and pandemic influenza in Vietnam, 2007-2010: the ha nam household cohort study I. Am J Epidemiol. 2012 May 15;175(10):1062-74.Epub 2012 Mar 12.
The epidemiology of interpandemic and pandemic influenza in Vietnam, 2007-2010: the ha nam household cohort study I
Horby P, Mai le Q, Fox A, Thai PQ, Thi Thu Yen N, Thanh le T, Le Khanh Hang N, Duong TN, Thoang DD, Farrar J, Wolbers M, Hien NT
Prospective community-based studies have provided fundamental insights into the epidemiology of influenza in temperate regions, but few comparable studies have been undertaken in the tropics. The authors conducted prospective influenza surveillance and intermittent seroprevalence surveys in a household-based cohort in Vietnam between December 2007 and April 2010, resulting in 1,793 person-seasons of influenza surveillance. Age- and sex-standardized estimates of the risk of acquiring any influenza infection per season in persons 5 years of age or older were 21.1% (95% confidence interval: 17.4, 24.7) in season 1, 26.4% (95% confidence interval: 22.6, 30.2) in season 2, and 17.0% (95% confidence interval: 13.6, 20.4) in season 3. Some individuals experienced multiple episodes of infection with different influenza types/subtypes in the same season (n = 27) or reinfection with the same subtype in different seasons (n = 22). The highest risk of influenza infection was in persons 5-9 years old, in whom the risk of influenza infection per season was 41.8%. Although the highest infection risk was in school-aged children, there were important heterogeneities in the age of infection by subtype and season. These heterogeneities could influence the impact of school closure and childhood vaccination on influenza transmission in tropical areas, such as Vietnam.
5. Powell TJ, Fox A, Peng Y, Lê Quỳnh Mai, Lien VT, Hang NL, Wang L, Lee LY, Simmons CP, McMichael AJ, Farrar JJ, Askonas BA, Trần Như Dương, Phạm Quang Thái, Nguyễn Thị Thu Yến, Rowland-Jones SL, Nguyễn Trần Hiển, Horby P, Dong T. Identification of H5N1-specific T-cell responses in a high-risk cohort in vietnam indicates the existence of potential asymptomatic infections. J Infect Dis. 2012 Jan;205(1):20-7. Epub 2011 Nov 11.
Identification of H5N1-specific T-cell responses in a high-risk cohort in vietnam indicates the existence of potential asymptomatic infections
Powell TJ, Fox A, Peng Y, Quynh Mai le T, Lien VT, Hang NL, Wang L, Lee LY, Simmons CP, McMichael AJ, Farrar JJ, Askonas BA, Duong TN, Thai PQ, Thu Yen NT, Rowland-Jones SL, Hien NT, Horby P, Dong T.
BACKGROUND: Most reported human H5N1 viral infections have been severe and were detected after hospital admission. A case ascertainment bias may therefore exist, with mild cases or asymptomatic infections going undetected. We sought evidence of mild or asymptomatic H5N1 infection by examining H5N1-specific T-cell and antibody responses in a high-risk cohort in Vietnam.
METHODS: Peripheral blood mononuclear cells were tested using interferon-γ enzyme-linked immunospot T assays measuring the response to peptides of influenza H5, H3, and H1 hemagglutinin (HA), N1 and N2 neuraminidase, and the internal proteins of H3N2. Horse erythrocyte hemagglutination inhibition assay was performed to detect antibodies against H5N1.
RESULTS: Twenty-four of 747 individuals demonstrated H5-specific T-cell responses but little or no cross-reactivity with H3 or H1 HA peptides. H5N1 peptide-specific T-cell lines that did not cross-react with H1 or H3 influenza virus HA peptides were generated. Four individuals also had antibodies against H5N1.
CONCLUSIONS: This is the first report of ex vivo H5 HA-specific T-cell responses in a healthy but H5N1-exposed population. Our results indicate that the presence of H5N1-specific T cells could be an additional diagnostic tool for asymptomatic H5N1 infection.
6. Lauber C, Ziebuhr J, Junglen S, Drosten C, Zirkel F, Phan Thị Ngà, Morita K, Snijder EJ, Gorbalenya AE. Mesoniviridae: a proposed new family in the order Nidovirales formed by a single species of mosquito-borne viruses. Arch Virol. 2012 Apr 24. [Epub ahead of print].
Mesoniviridae: a proposed new family in the order Nidovirales formed by a single species of mosquito-borne viruses
Recently, two independent surveillance studies in Côte d'Ivoire and Vietnam, respectively, led to the discovery of two mosquito-borne viruses, Cavally virus and Nam Dinh virus, with genome and proteome properties typical for viruses of the order Nidovirales. Using a state-of-the-art approach, we show that the two insect nidoviruses are (i) sufficiently different from other nidoviruses to represent a new virus family, and (ii) related to each other closely enough to be placed in the same virus species. We propose to name this new family Mesoniviridae. Meso is derived from the Greek word "mesos" (in English "in the middle") and refers to the distinctive genome size of these insect nidoviruses, which is intermediate between that of the families Arteriviridae and Coronaviridae, while ni is an abbreviation for "nido". A taxonomic proposal to establish the new family Mesoniviridae, genus Alphamesonivirus, and species Alphamesonivirus 1 has been approved for consideration by the Executive Committee of the ICTV.
Exposure to second-hand smoke at home and its associated factors: findings from the Global Adult Tobacco Use survey in Vietnam, 2010
OBJECTIVE: The paper describes the pattern of exposure to second-hand smoke (SHS) at home among the adult population of Vietnam and examines associated socio-demographic factors..
METHODS: A total of 11,142 households were selected for this survey using a two-phase sampling design analogous with three-stage stratified cluster sampling. The dependent variable was the status of exposure to SHS at home. Independent variables included gender, age, occupation, asset-based wealth quintile, ethnicity, marital status, residence. Logistic regression modelling was performed to examine the association with relevant factors of patterns of exposure to second-hand smoke among non-smokers.
RESULTS: Of adults aged 15 years and above (representing approximately 47 million people) 73.1% reported they were exposed to SHS at home at least monthly. Considering non-smokers only, the prevalence of exposure to SHS at home was 67.6% (equivalent to approximately 33 million non-smokers). The significant correlates of the status of exposure to SHS at home among non-smokers were female gender, ethnic minority, low education, and lack of smoking restriction at home.
CONCLUSIONS: The study showed that a high percentage of people are exposed to second-hand smoke at home. Disadvantaged people were more likely than the better-off to be exposed to SHS at home.
Analyses of health outcomes from the 5 sites participating in the Africa and Asia clinical efficacy trials of the oral pentavalent rotavirus vaccine
BACKGROUND: Efficacy of the pentavalent rotavirus vaccine (PRV), RotaTeq(®), against severe rotavirus gastroenteritis (RVGE) was evaluated in two double-blind, placebo-controlled, multicenter Phase III clinical trials conducted in GAVI-eligible countries in Africa (Ghana, Kenya, and Mali) and in Asia (Bangladesh and Vietnam) from March 2007 through March 2009. The findings from each continent have been analyzed and presented separately, according to a single identical protocol. Ad hoc analyses combining data from the five sites were performed to further assess the impact of PRV.
METHODS: 6674 infants (4705 infants from Africa and 1969 infants from Asia), randomized 1:1 to receive 3 doses of PRV/placebo at approximately 6-, 10-, and 14-weeks of age according to each country's EPI schedule, were included in the per protocol efficacy analysis. Breastfeeding and concomitant administration of EPI vaccines, including OPV, were allowed. Episodes of gastroenteritis (GE) in infants who presented to study facilities were captured and scored using the 20-point Vesikari scale. Stool samples were analyzed by rotavirus-specific EIA to detect presence of rotavirus antigen and RT-PCR to determine the G/P genotypes. We assessed efficacy to prevent all-cause GE and RVGE at a variety of cut-off points (score≥11, severe; score≥15, very severe).
RESULTS: Vaccine efficacy (VE) against RVGE, regardless of serotype, through the entire follow-up period for any severity, severe (score≥11), and very severe (score≥15) was 33.9%, 95% CI (22.7, 43.5), 42.5%, 95% CI (27.4, 54.6), and 51.2%, 95% CI (26.3, 68.2), respectively. Through the first year of life, VE against severe RVGE was 58.9%, 95% CI (40.0, 72.3) and against all-cause severe GE was 23.0%, 95% CI (5.4, 37.3). VE against severe RVGE caused by non-vaccine G serotypes, G8 and G9, through the entire follow-up period was 87.5%, 95% CI (6.8, 99.7) and 48.0%, 95% CI (-5.5, 75.6), respectively. All G8 strains were associated with P2A (a P-type not contained in PRV), while the majority of the G9 strains were associated with P1A (a P-type contained in PRV).
CONCLUSIONS: Combining data from the 5 sites strengthens the precision of VE estimates and reveals rising VE with increased RVGE severity. Extrapolating data from VE against severe GE and RVGE suggest that 39% of severe GE episodes during the first year of life were due to rotavirus, highlighting substantial, potentially preventable, public health burden of RVGE. PRV provides protection against non-vaccine serotypes (G8P2A).
9. Shin S, Đặng Đức Anh, Zaman K, Yunus M, Mai le TP, Vũ Đình Thiểm, Azim T, Victor JC, Dallas MJ, Steele AD, Neuzil KM, Ciarlet M.Immunogenicity of the pentavalent rotavirus vaccine among infants in two developing countries in Asia, Bangladesh and Vietnam. Vaccine. 2012 Apr 27;30 Suppl 1:A106-13.
Immunogenicity of the pentavalent rotavirus vaccine among infants in two developing countries in Asia, Bangladesh and Vietnam
Shin S, Anh DD, Zaman K, Yunus M, Mai le TP, Thiem VD, Azim T, Victor JC, Dallas MJ, Steele AD, Neuzil KM, Ciarlet M.
BACKGROUND: We evaluated the immunogenicity of the pentavalent rotavirus vaccine (PRV) in two GAVI-eligible Asian countries, Bangladesh and Vietnam, nested in a larger randomized, double-blind, placebo-controlled efficacy trial conducted over a two-year period from 2007 through 2009.
METHODS: 2036 infants were randomly assigned, in a 1:1 ratio, to receive three oral doses of PRV or placebo approximately at 6, 10, and 14 weeks of age. Concomitant use of EPI vaccines, including oral poliovirus vaccine (OPV) and diphtheria-tetanus-whole cell pertussis (DTwP) vaccine, was encouraged in accordance to the local EPI schedule. A total of 303 infants were evaluated for immunogenicity and blood samples were collected before the first dose (pD1) and approximately 14 days following the third dose (PD3). The seroresponse rates (≥3-fold rise from pD1 to PD3) and geometric mean titers (GMTs) were measured for anti-rotavirus immunoglobulin A (IgA) and serum neutralizing antibody (SNA) to human rotavirus serotypes G1, G2, G3, G4, and P1A, respectively.
RESULTS: Nearly 88% of the subjects showed a ≥3-fold increase in serum anti-rotavirus IgA response in the analysis of the two countries combined. When analyzed separately, the IgA response was lower in Bangladeshi children (78.1% [95% CI: 66.0, 87.5]) than in Vietnamese children (97.0% [95% CI: 89.6, 99.6]), with a PD3 GMT of 29.1 (units/mL) and 158.5 (units/mL), respectively. In the combined population, the SNA responses to the individual serotypes tested ranged from 10 (G3) to 50 (G1) percentage points lower than the responses shown in the developed countries. However, the SNA response to G3 in Vietnamese subjects was 37.3% (95% CI: 25.8, 50.0), which was similar to the G3 response rate in developed countries.
CONCLUSIONS: Three oral doses of PRV were immunogenic in two GAVI-eligible Asian countries: Bangladesh and Vietnam. The GMTs of both the serum anti-rotavirus IgA and SNA responses were generally higher in Vietnamese than in Bangladeshi children. The SNA responses varied by individual serotypes and were lower than the results from developed countries. The clinical significance of these observations is not understood because an immune correlate of protection has not been established.
10. Nguyễn Vân Trang, Yamashiro T, Lê Thị Kim Anh, Vũ Thị Hậu, Luan le T, Đặng Đức Anh. Genetic variation in the VP7 gene of rotavirus G1P strains isolated in Vietnam, 1998-2009.Virus Res. 2012 May;165(2):190-6. Epub 2012 Feb 25.
Genetic variation in the VP7 gene of rotavirus G1P strains isolated in Vietnam, 1998-2009
Group A rotavirus genotype G1P is the most common strain affecting humans around the world over the past few decades. In this study, we examined genetic variation in the VP7 gene of rotavirus G1P strains, detected in children of four major cities of Vietnam during three different rotavirus seasons: 1998-1999, 2007-2008 and 2008-2009 in order to assess the evolution of the virus over 11 years. Fecal samples (n=73) from children hospitalized for gastroenteritis caused by G1P rotavirus were analyzed by DNA sequencing of gene 9 encoding the VP7 capsid protein. Phylogenetic analyses indicated that VP7 gene of the G1 strains from 1999 contained a lineage I, while rotaviruses from 2009 clustered in lineage II. Both of these lineages were found co-circulating in 2007-2008 season. While different sublineages of lineage I and II co-circulated in the 1998-1999 and 2007-2008 seasons, almost all strains in 2009 belonged to sub-lineage II-C. In the analysis using selected 10 strains, the VP4 genes of these 2 VP7-G1 lineages were all grouped in F45-like cluster. Deduced amino acid analyses indicated that there were thirteen amino acid substitutions between strains of two lineages. Of those, two were found in antigenic regions A and C, implying possible antigenic differences between these two lineages. The G1P strains in Vietnam are very genetically diverse and dynamic, implying the frequent monitoring on evolution of rotavirus will be important to assess efficacy of rotavirus vaccine in Vietnam.
11. Linda Dunford, Michael J. Carr, Jonathan Dean, Nguyễn Thùy Linh, Tạ Thị Thu Hồng, Nguyễn Thanh Bình, Jeff Connell, Suzie Coughlan, Nguyễn Trần Hiển, William W. Hall, Nguyễn Thị Lan Anh.A Multicentre Molecular Analysis of Hepatitis B and Blood-Borne Virus Coinfections in Viet Nam.Plos One. June 2012; Vol 7 (6). e39027.
A Multicentre Molecular Analysis of Hepatitis B and Blood-Borne Virus Coinfections in Viet Nam
Linda Dunford, Michael J. Carr, Jonathan Dean, Linh Thuy Nguyen, Thu Hong Ta Thi, Binh Thanh Nguyen, Jeff Connell, Suzie Coughlan, Hien Tran Nguyen, William W. Hall, Lan Anh Nguyen Thi.
Hepatitis B (HBV) infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654) were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs) (17.4%, n = 174/1000) and dialysis patients (14.3%, n = 82/575) than in lower-risk groups (9.4%; p<0.001). Coinfection with HIV was seen in 28% of HBV-infected IDUs (n = 49/174) and 15.2% of commercial sex workers (CSWs; n = 15/99). HCV infection was present in 89.8% of the HBV-HIV coinfected IDUs (n = 44/49) and 40% of HBV-HIV coinfected CSWs (n = 16/40). Anti-HDV was detected in 10.7% (n = 34/318) of HBsAg positive individuals. Phylogenetic analysis of HBV S gene (n = 187) showed a predominance of genotype B4 (82.6%); genotypes C1 (14.6%), B2 (2.7%) and C5 (0.5%) were also identified. The precore mutation G1896A was identified in 35% of all specimens, and was more frequently observed in genotype B (41%) than genotype C (3%; p<0.0001). In the immunodominant ‘a’ region of the surface gene, point mutations were identified in 31% (n = 58/187) of sequences, and 2.2% (n = 4/187) and 5.3% (n = 10/187) specimens contained the major vaccine escape mutations G145A/R and P120L/Q/S/T, respectively. 368 HBsAg positive individuals were genotyped for the IL28B SNP rs12979860 and no significant association between the IL28B SNP and clearance of HBsAg, HBV viral load or HBeAg was observed. This study confirms the high prevalence of HBV infection in Viet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective management strategies.
12. Nguyễn Lê Hải, Ruxrungtham K, Delaugerre C.Genetic Barrier to the Development of Resistance to Integrase Inhibitors in HIV-1 Subtypes CRF01_AE and B.Intervirology. 2012;55(4):287-95. Epub 2012 Mar 23.
Genetic Barrier to the Development of Resistance to Integrase Inhibitors in HIV-1 Subtypes CRF01_AE and B.
Nguyen HL, Ruxrungtham K, Delaugerre C.
Objective: The genetic barrier for the evolution of integrase inhibitors (INIs) including raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG) resistance was compared between HIV-1 subtypes CRF01_AE and B. Methods: Analysis of 66 substitutions associated with INI resistance at 41 amino acid positions in 144 nucleotide sequences (109 HIV-1 subtype CRF01_AE and 35 HIV-1 subtype B) of integrase-coding region of polymerase gene derived from INI-naive patients. Results: 28/41 studied amino acid positions were conserved, leading to a similar genetic barrier between the two subtypes. At six codon positions with different genetic barriers, six mutations (V72I, L101I, A124T, T125K, and G140C/S) displayed a higher genetic barrier and one mutation (V201I) showed a lower genetic barrier in subtype CRF01_AE than subtype B. Conclusions: Most studied amino acid positions including all corresponding to RAL and EVG primary mutations show a high level of conservation, indicating the same genetic barrier between subtypes CRF01_AE and B. Nevertheless, different genetic barriers were observed in two mutations described to be associated with DTG resistance (L101I, A124T) and other five RAL and EVG secondary mutations (V72I, T125K, G140C/S, V201I), which could have an impact on the development of resistance to RAL, EVG, and DTG.
13. Nguyễn Lê Hải, Pitakpolrat P, Sirivichayakul S, Delaugerre C, Ruxrungtham K. Minority HIV-1 resistant variants in recent infection and in patients who failed first-line antiretroviral therapy with no detectable resistance-associated mutations in Thailand.J Med Virol. 2012 May;84(5):713-20. doi: 10.1002/jmv.23235J.
Minority HIV-1 resistant variants in recent infection and in patients who failed first-line antiretroviral therapy with no detectable resistance-associated mutations in Thailand
Le Nguyen H, Pitakpolrat P, Sirivichayakul S, Delaugerre C, Ruxrungtham K.
Through the Thai National AIDS Program, approximately 200,000 patients infected with HIV are on antiretroviral (ARV) therapy. Although studies have shown low prevalence of primary HIV-1 resistance transmission in Thailand and in Southeast Asia where subtype CRF01_AE is predominant, minority HIV-1 drug resistance has not been studied. Two groups of patients, whose conventional genotyping results showed no drug resistance-associated mutations, were investigated: 104 homosexual men recently infected with HIV-1, naïve to ARV treatment and 22 first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based failure patients. Pyrosequencing (PSQ) assay was developed to detect and quantify minority Y181C and M184V variants from the patients' plasma samples. The sensitivity of PSQ to detect minority Y181C and M184V variants was approximately 1%. 1/104 (0.5%) and 3/101 (3%) samples were found harboring Y181C and M184V in the group of homosexual men recently infected with HIV-1. In patients with first-line treatment failure, one had a minority M184V mutation (4.5%). The prevalence of Y181C and M184V minority variants in homosexual men recently infected and naïve to treatment was low in Thailand. Systematic monitoring of primary resistance transmission in Thailand and this region is essential to guide whether genotypic resistance test is required prior to commencing the first-line highly active antiretroviral therapy (HAART).
14. Trần Quang Huy, Nguyễn Thị Hồng Hạnh, Mai Anh Tuan, Nguyen Thi Thuy, Vu Quang Khue, Phan Thị Ngà. Development of electrochemical immunosensors based on different serum antibody immobilization methods for detection of Japanese encephalitis virus.Adv. Nat. Sci.: Nanosci. Nanotechnol. Vol 3 (1); 3 (2012), 015012, doi:10.1088/2043-6262/3/1/015012 (IOP).
Development of electrochemical immunosensors based on different serum antibody immobilization methods for detection of Japanese encephalitis virus
Quang Huy Tran, Thi Hong Hanh Nguyen, Anh Tuan Mai, Thi Thuy Nguyen, Quang Khue Vu and Thi Nga Phan
This paper describes the development of electrochemical immunosensors based on human serum antibodies with different immobilization methods for detection of Japanese encephalitis virus (JEV). Human serum containing anti-JEV antibodies was used to immobilize onto the surface of silanized interdigitated electrodes by four methods: direct adsorption (APTES-serum), covalent binding with a cross linker of glutaraldehyde (APTES-GA-serum), covalent binding with a cross linker of glutaraldehyde combined with anti-human IgG (APTES-GA-anti-HIgG-serum) and covalent binding with a cross linker of glutaraldehyde combined with a bioaffinity of protein A (APTES-GA-PrA-serum). Atomic force microscopy was used to verify surface characteristics of the interdigitated electrodes before and after treatment with serum antibodies. The output signal of the immunosensors was measured by the change of conductivity resulting from the specific binding of JEV antigens and serum antibodies immobilized on the electrodes, with the help of horseradish peroxidase (HRP)-labeled secondary antibody against JEV. The results showed that the APTES-GA-PrA-serum method provided the highest signal of the electrochemical immunosensor for detection of JEV antigens, with the linear range from 25 ng ml−1 to 1 μg ml−1, and the limit of detection was about 10 ng ml−1. This study shows a potential development of novel electrochemical immunosensors applied for virus detection in clinical samples in case of possible outbreaks.
15. Trần Quang Huy, Mai Anh Tuan, Nguyễn Thanh Thủy, Phạm Văn Chung, Nguyễn Thị Hồng Hạnh. Towards the use of protein A-tagged gold nanoparticles for signal amplification of electrochemical immunosensors in virus detection.Adv. Nat. Sci.: Nanosci. Nanotechnol. Vol 3 (2); 3 (2012) 025013, doi:10.1088/2043-6262/3/2/025013 (IOP).
Towards the use of protein A-tagged gold nanoparticles for signal amplification of electrochemical immunosensors in virus detection
Quang Huy Tran, Anh Tuan Mai, Thanh Thuy Nguyen, Van Chung Pham and Thi Hong Hanh Nguyen
In this paper we represent a study on the potential use of protein A-tagged gold nanoparticles applied for signal amplification of electrochemical immunosensors. Gold nanoparticles (GNPs) were synthesized by the chemical reduction of tetrachloroauric (III) acid trihydrate using sodium ascorbate, and then tagged with protein A (PrA) via ultracentrifugation. UV-Vis spectroscopy and transmission electron microscopy were used to verify the characteristics of formed GNPs/PrA complex. The analyzed results indicate that GNPs were found spherically, homogeneously, and with an average diameter of about 10 nm. Immunoelectron microscopy was then used to investigate the bioactivity of the GNPs/PrA complex in solution by the effective binding of GNPs to viral particles. Scanning electron and fluorescence microscopies were also used to investigate the distribution and the bioactivity of the GNPs/PrA complex on the surface of the interdigitated sensor. Consequently, this study provided some assumptions of the potential application of protein A-tagged gold nanoparticles for signal amplification of electrochemical immunosensors in virus detection from clinical samples.
16. Yvan Bettarel, Nguyễn Thanh Thủy, Trần Quang Huy, Phan Kim Hoang and Thierry Bouvier. Observation of virus-like particles in thin sections of the bleaching scleractinian coral Acropora cytherea. Journal of the Marine Biological Association of the United Kingdom, Available on CJO doi:10.1017/S0025315411002062.FirstView Article : pp 1-4.
Observation of virus-like particles in thin sections of the bleaching scleractinian coral Acropora cytherea
Yvan Bettarel, Nguyen Thanh Thuy, Tran Quang Huy, Phan Kim Hoang and Thierry Bouvier
Virus-like particles were observed in thin sections of partially bleaching colonies of the scleractinian Acropora cytherea, collected in the Hon Mun Marine Protected Area (Vietnam). The most common particles were found in the cytoplasm of epidermal cells, exhibiting icosahedral symmetry and measuring 90–140 nm in diameter. Some had a tail-like structure resembling that of certain Hepadnaviridae such as the hepatitis B virus. Some others were tailless with a virion size. Overall, less than 10% of the cells showed obvious signs of infection. Images of virally-parasitized tissues of A. cytherea provide further evidence that corals are a target for viral infection. However, more research is required into their pathogenicity and involvement in bleaching events.
17. Linda Dunford, Michael J. Carr, Jonathan Dean, Allison Waters, Nguyễn Thùy Linh, Tạ Thị Thu Hồng, Bùi Thị Lan Anh, Đỗ Huy Dương, Thu Thị Thùy Dương, Nguyễn Thu Hà, Đỗ Thị Diễm Trinh, Lưu Phương Quỳnh, Jeff Connell, Suzie Coughlan, Nguyễn Trần Hiển, William W. Hall, Nguyễn Thị Lan Anh. Hepatitis C Virus in Vietnam: High Prevalence of Infection in Dialysis and Multi-Transfused Patients Involving Diverse and Novel Virus Variants. PLoS ONE, 2012 August, Vol 7 (Issue 8): e41266. doi:10.1371/journal.pone.0041266.
Hepatitis C Virus in Vietnam: High Prevalence of Infection in Dialysis and Multi-Transfused Patients Involving Diverse and Novel Virus Variants
Linda Dunford, Michael J. Carr, Jonathan Dean, Allison Waters, Linh Thuy Nguyen, Thu Hong Ta Thi, Lan Anh Bui Thi, Huy Duong Do, Thu Thuy Duong Thi, Ha Thu Nguyen, Trinh Thi Diem Do, Quynh Phuong Luu, Jeff Connell, Suzie Coughlan, Hien Tran Nguyen, William W. Hall, Lan Anh Nguyen Thi
Hepatitis C virus (HCV) is a genetically diverse pathogen infecting approximately 2–3% of the world’s population. Herein, we describe results of a large, multicentre serological and molecular epidemiological study cataloguing the prevalence and genetic diversity of HCV in five regions of Vietnam; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. Individuals (n = 8654) with varying risk factors for infection were analysed for the presence of HCV Ab/Ag and, in a subset of positive specimens, for HCV RNA levels (n = 475) and genotype (n = 282). In lower risk individuals, including voluntary blood donors, military recruits and pregnant women, the prevalence of infection was 0.5% (n = 26/5250). Prevalence rates were significantly higher (p,0.001) in intravenous drug users (IDUs; 55.6%, n = 556/1000), dialysis patients (26.6%, n = 153/575) commercial sex workers (CSWs; 8.7%, n = 87/1000), and recipients of multiple blood transfusions (6.0%, n = 32/529). The prevalence of HCV in dialysis patients varied but remained high in all regions (11–43%) and was associated with the receipt of blood transfusions [OR: 2.08 (1.85–2.34), p = 0.001], time from first transfusion [OR: 1.07 (1.01–1.13), p = 0.023], duration of dialysis [OR: 1.31 (1.19–1.43), p,0.001] and male gender [OR: 1.60 (1.06–2.41), p = 0.026]. Phylogenetic analysis revealed high genetic diversity, particularly amongst dialysis and multi-transfused patients, identifying subtypes 1a (33%), 1b (27%), 2a (0.4%), 3a (0.7%), 3b (1.1%), 6a (18.8%), 6e (6.0%), 6h (4.6%), 6l (6.4%) and 2 clusters of novel genotype 6 variants (2.1%). HCV genotype 1 predominated in Vietnam (60%, n = 169/282) but the proportion of infections attributable to genotype 1 varied between regions and risk groups and, in the Southern part of Vietnam, genotype 6 viruses dominated in dialysis and multitransfused patients (73.9%). This study confirms a high prevalence of HCV infection in Vietnamese IDUs and, notably, reveals high levels of HCV infection associated with dialysis and blood transfusion.
Longitudinal analysis of integrase N155H variants in heavily treated patients failing raltegravir-based regimens
Nguyen H, Charpentier C, Nguyen N, de Truchis P, Molina JM, Ruxrungtham K, Delaugerre C
OBJECTIVES: The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping.
METHODS: Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype.
RESULTS: No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA.
CONCLUSIONS: The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.
19. Le Tuan Anh, Le Thi Tam, Nguyen Van Quy, Trần Huy Hoàng, Đặng Đức Anh, Trần Quang Huy, Vu Dinh Lam. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections. Adv. Nat. Sci.: Nanosci. Nanotechnol. 3 (4) (2012) 045007. Doi: 10.1088/2043-6262/3/4/045007
Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections
Anh-Tuan Le*, Thi Tam Le, Van Quy Nguyen, Huy Hoang Tran, Duc Anh Dang, Quang Huy Tran* and Dinh Lam Vu
In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ~ 3 mgl−1. More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases.
20. Trần Quang Bình, Phạm Trần Phương, Bui Thi Nhung, Dang Dinh Thoang, Pham Van Thang, Tran Khanh Long and Dương Văn Thanh. Prevalence and correlates of hyperglycemia in a rural population, Vietnam: implications from a cross-sectional study. BMC Public Health, November 2012, 12:939 doi:10.1186/1471-2458-12-939.
Prevalence and correlates of hyperglycemia in a rural population, Vietnam: implications from a cross--sectional study
Tran Quang Binh, Pham Tran Phuong, Bui Thi Nhung, Dang Dinh Thoang, Pham Van Thang, Tran Khanh Longand Duong Van Thanh
Despite the increasing prevalence of type 2 diabetes in urban areas, relatively little has been known about its actual prevalence and its associations in rural areas, Vietnam. The purpose of this study was to evaluate the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), diabetes and their risk factors in a rural province, Vietnam.
A cross--sectional study with a representative sample was designed to estimate the hyperglycemia prevalence, using 75-g oral glucose tolerance test. Potential risk factors for hyperglycemia were analyzed using multinomial logistic regression, taken into account influences of socio--economic status, anthropometric measures, and lifestyle--related factors.
The age and sex-adjusted prevalence rates (95% CI) of isolated IFG, isolated IGT, combined IFG-IGT, and diabetes were 8.7 (7.0-10.5), 4.3 (3.2-5.4), 1.6 (0.9-2.3), and 3.7% (2.7-4.7%), respectively. There were still 73% of diabetic subjects without knowing the condition. Blood pressure, family history of diabetes, obesity-related measures (waist circumference, waist-hip ratio, body fat percentage, and abdominal obesity) were the independent risk factors for hyperglycemia (IFG, IGT, and diabetes).
The prevalence of hyperglycemia in rural areas has not been as sharply increased as that reported in urban cities, Vietnam. Blood pressure and obesity-related measures were the most significant predictors for hyperglycemia level and they can be taken into account in building prognosis models to early detection of diabetes in rural Vietnamese populations.
21. Trần Quang Bình, Phạm Trần Phương, Bui Thi Nhung, Dang Dinh Thoang, Hà Thị Liên, Dương Văn Thanh. Association of the common FTO-rs9939609 polymorphism with type 2 diabetes, independent of obesity–related traits in Vietnamese population. Gene 513:31-35., 8 November 2012, Doi: 10.1016/j.gene.2012.10.082.
Association of the common FTO-rs9939609 polymorphism with type 2 diabetes, independent of obesity-related traits in a Vietnamese population
Type 2 diabetes (T2D) is a complex disorder resulting from both genetic and environmental factors in its pathogenesis. A case−control study was designed with subjects recruited from a general population to investigate whether the association between T2D and the common T>A polymorphism (rs9939609) in fat mass and obesity associated (FTO) gene is mediated by obesity–related measurements, considering the contribution of socio–economic status and lifestyle factors. The significant association between the FTO− rs9939609 polymorphism and T2D was first observed in the model unadjusted (OR per A allele = 1.61, 95%CI = 1.06–2.44, P = 0.024). It remained consistently replicated in the final model after adjustments for sex, age, systolic blood pressure, socio–economic status, lifestyle factors, and obesity–related measurements (body mass index, waist–hip ratio, body fat percentage, and body adiposity index), showing an increased T2D risk with an additive effect of the alleles (ORs per A allele = 1.80–1.92, 95% CI = 1.09–3.19, P < 0.05). The FTO− rs9939609 polymorphism, systolic blood pressure, and waist−hip ratio were the most significant independent predictors for T2D, in which the power of the adjusted prediction model was 0.769. In conclusion, the study suggested that the FTO− rs9939609 polymorphism was significantly associated with the increased risk of T2D, independent of obesity–related measurements in Vietnamese population.
22. Nguyễn Thị Vân Anh, Marc Choisy, Duy Hung Nguyen, Trần Thị Thanh Hoa, Phạm Thị Kim Liên, Đinh Thị Phương Thảo, Jules Philippe, Thai Son Nguyen, Hồ Minh Lý, Sang Van Tran, Anne-Laure Bañuls and Đặng Đức Anh. High prevalence of Beijing and EAI4-VNM genotypes among M. tuberculosis isolates in northern Vietnam: sampling effect, rural and urban disparities.PLoS One, 2012; 7(9): e45553. doi: 10.1371/journal.pone.0045553.
High Prevalence of Beijing and EAI4-VNM Genotypes among M. tuberculosis Isolates in Northern Vietnam: Sampling Effect, Rural and Urban Disparities
Nguyen VA, Choisy M, Nguyen DH, Tran TH, Pham KL, Thi Dinh PT, Philippe J, Nguyen TS, Ho ML, Van Tran S, Bañuls AL, Dang DA
A total of 221 isolates of M. tuberculosis were sampled from hospitals and the general population in the northern plain of Vietnam, one of the most populated region of the country. Genotypic composition and diversity were characterized, and we investigated how they are affected by sampling (hospital vs. general population), correcting for potential confounding effects (location, age and gender of the patients). Spoligotyping and 12 MIRU-VNTR typing were used as first line. Then 15 MIRU-VNTR standard set was used, making 21 MIRU-VNTR typing for the clustered isolates. Result showed that 8 lineages and 13 sub-lineages were circulating in the region. The most predominant lineages were Beijing (38.5%) and EAI (38.5%). Others appeared with small proportions H (1.4%), LAM (1.8%), T (8.1%), X (0.9%), MANU (2.3%), and Zero (0.4%). Higher clustering rate was found in the hospital samples (17.9% in urban and 19.2% in rural areas) compared to the population ones (0%). The typical Vietnamese EAI4-VNM sub-lineage of EAI lineage accounted for 67% of EAI strains and was associated with older ages. Beijing genotypes were associated with younger, urban population and were characterized by high clustering rates. These characteristics strongly suggest that Beijing strains are invading the population, replacing the local EAI-VNM4, thus predicting a more serious tuberculosis situation in the future in the absence of more effective control strategies.