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Berto A, Day J, Van Vinh Chau N, Thwaites GE, My NN, Baker S, Darton TC. Current challenges and possible solutions to improve access to care and treatment for hepatitis C infection in Vietnam: a systematic review. BMC Infect Dis 2017; 17:260. [PMID: 28399806 PMCID: PMC5387342 DOI: 10.1186/s12879-017-2360-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/29/2017] [Indexed: 12/24/2022] Open
Abstract
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.
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Affiliation(s)
- Alessandra Berto
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
| | - Jeremy Day
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | | | - Guy E Thwaites
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Ngoc Nghiem My
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam
| | - Stephen Baker
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.,The London School of Hygiene and Tropical Medicine, London, UK
| | - Thomas C Darton
- Oxford University Clinical Research Unit, Vietnam Wellcome Trust Major Overseas Programme, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
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Krekulova L, Rehak V, Killoran P, Madrigal N, Riley LW. Genotypic distribution of TT virus (TTV) in a Czech population: evidence for sexual transmission of the virus. J Clin Virol 2001; 23:31-41. [PMID: 11595582 DOI: 10.1016/s1386-6532(01)00185-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND TTV is a new DNA virus distinguished by its high degree of strain heterogeneity. The geographic clustering of viral genotypes suggests frequent community transmission. While no specific human disease has yet been linked to it, a transmission mechanism that facilitates strain diversity may eventually select for a strain that will become pathogenic. OBJECTIVE This study was performed to examine the prevalence, genotypic distribution, and mode of transmission of TTV in detail. STUDY DESIGN Three groups of study subjects were recruited between October 1998 and January 2000 in Prague, Czech Republic. Group 1 included 152 injection drug users with liver disease; group 2 included 102 persons with liver disease who denied ever using injection drugs; group 3 included 111 prospective blood donors. TTV DNA was detected from blood by a semi-nested PCR assay, and a selected set of PCR products was genotyped by direct sequencing. Factors associated with TTV prevalence in groups 1 and 2 subjects were compared. RESULTS TTV was detected in 15.8, 13.7, and 13.5% of Groups 1, 2, and 3 subjects, respectively (P>0.05). The most common genotype was 2 (54%), followed by 1 (13%). The prevalence of TTV viremia was nearly three times higher in persons with a present or past history of hepatitis B compared to those without (P<0.05). TTV prevalence increased proportionately with the number of lifetime sex partners in both groups (P<0.05); it was highest (32%) among non-users of injection drugs who had five or more lifetime sex partners. CONCLUSION TTV prevalence in the Czech population is similar among blood donors, persons with liver disease, as well as in a high-risk population of injection drug users. TTV appears to be sexually transmitted.
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Affiliation(s)
- L Krekulova
- Division of Infectious Diseases, School of Public Health, University of California, Berkeley, 140 Warren Hall, Berkeley, CA 94720, USA
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Lin CL, Kyono W, Tongson J, Chua PK, Easa D, Yanagihara R, Nerurkar VR. Fecal excretion of a novel human circovirus, TT virus, in healthy children. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2000; 7:960-3. [PMID: 11063506 PMCID: PMC95993 DOI: 10.1128/cdli.7.6.960-963.2000] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The role of TT virus (TTV) as a human pathogen is unclear, as is the mode of TTV transmission. To determine the prevalence of TTV infection and the possible fecal-oral route of transmission, we analyzed fecal specimens from 67 healthy, nontransfused children for TTV DNA sequences by heminested PCR, using the NG and T primer sets. The overall prevalence of TTV fecal excretion was 22.4% (15 of 67), with the T primer set (19.4%) being more sensitive than the NG primer set (10.4%). TTV prevalence based on gender or ethnicity showed no significant differences. None of seven children in the 0- to 6-month age group had detectable TTV in feces. Of three sets of siblings, two unrelated sets of twins, ages 33 and 37 months, were negative for fecal TTV DNA, while the third set of siblings, ages 99 and 35 months, was positive. The absence of TTV in the feces of children younger than 6 months and the high prevalence (40%) in children 7 to 12 months of age is consistent with age-specific acquisition of TTV infection by the nonparenteral route. TTV genotypes 1, 3, 4, and 5 were represented in our study population. TTV-positive siblings had TTV genotypes 1 and 4, suggesting unrelated environmental sources of TTV infection. This observation suggests a possible time frame for TTV acquisition in children which coincides with increased interaction with their environment and increased susceptibility to infectious agents.
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Affiliation(s)
- C L Lin
- Retrovirology Research Laboratory, Pacific Biomedical Research Center, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
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