Global Genotype Distribution of Hepatitis C Viral Infection among People who Inject Drugs

The majority of hepatitis C virus (HCV) infection results in chronic infection, which can lead to liver cirrhosis and hepatocellular carcinoma. Global burden of hepatitis C virus (HCV) is estimated at 150 million individuals, or 3% of the world’s population. The distribution of the seven major genotypes of HCV varies with geographical regions. Since Asia has a high incidence of HCV, we assessed the distribution of HCV genotypes in Thailand and Southeast Asia. From 588 HCV-positive samples obtained throughout Thailand, we characterized the HCV 5’ untranslated region, Core, and NS5B regions by nested PCR. Nucleotide sequences obtained from both the Core and NS5B of these isolates were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes. Results were compared to the epidemiological data of HCV genotypes identified within Southeast Asian. Among the HCV subtypes characterized in the Thai samples, subtype 3a was the most predominant (36.4%), followed by 1a (19.9%), 1b (12.6%), 3b (9.7%) and 2a (0.5%). While genotype 1 was prevalent throughout Thailand (27–36%), genotype 3 was more common in the south. Genotype 6 (20.9%) constituted subtype 6f (7.8%), 6n (7.7%), 6i (3.4%), 6j and 6m (0.7% each), 6c (0.3%), 6v and 6xa (0.2% each) and its prevalence was significantly lower in southern Thailand compared to the north and northeast (p = 0.027 and p = 0.030, respectively). Within Southeast Asia, high prevalence of genotype 6 occurred in northern countries such as Myanmar, Laos, and Vietnam, while genotype 3 was prevalent in Thailand and Malaysia. Island nations of Singapore, Indonesia and Philippines demonstrated prevalence of genotype 1. This study further provides regional HCV genotype information that may be useful in fostering sound public health policy and tracking future patterns of HCV spread.

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Genotypic Distribution of Hepatitis C Virus in Thailand and Southeast Asia

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 multi-transfused 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.

Hepatitis C virus in Vietnam: high prevalence of infection in dialysis and multi-transfused patients involving diverse and novel virus variants.

Department of Internal Medicine, Faculty of Medicine, Dr. Sardjito Hospital, Gadjah Mada University,Yogyakarta, IndonesiaHepatitis virus-related liver disease increasessubstantially the mortality rate of patients withHIV on highly active antiretroviral therapy(HAART). Therefore, early diagnosis of hepatitisB virus (HBV) and hepatitis C virus (HCV) is im-portant. However, the prevalence of HBV andHCV infection in Indonesian patients infectedwith HIV is unknown. Therefore, this study ex-amined the molecular and clinical characteris-tics of HBV and HCV in 126 patients infectedwith HIV, mostly on HAART, at Dr. Sardjito Hos-pital, Yogyakarta, Indonesia. The rates of tripleinfection, HIV/HCV co-infection, HIV/HBV co-in-fection, and mono-infection were 4.8%, 34.1%,3.2%, and 57.9%, respectively. Seven HCV gen-otypes were detected, with genotypes 1a, 1b,1c, 3a, 3k, 4a, and 6n found in 23 (52%), 1 (2%),4 (9%), 5 (11%), 7 (16%), 3 (6%), and 1 (2%)patients, respectively, indicating multiplemodes of transmission. HBV-DNA was detectedin 2/10 patients with hepatitis B surface antigen;both patients were HAART naive. Univariateanalysis revealed that male sex, higher educa-tion level, injection drug use, sexual contact, al-anine aminotransferase 40 IU/L, and aspartateaminotransferase-to-platelet ratio index > 0.5were associated with HCV co-infection. In multi-variate analysis, injection drug use (OR: 26.52;95% CI: 3.52–199.54) and alanine aminotransfer-ase 40 IU/L (OR: 6.36; 95% CI: 1.23–32.89)were independently associated with HCVco-infection. HCV co-infection was commonamong Indonesian patients infected withHIV, particularly among injecting drug users,and was a risk factor for disease progressionof HIV. J. Med. Virol. 84:857–865, 2012.

Clinical and virological characteristics of hepatitis B or C virus co-infection with HIV in Indonesian patients

The genetic diversity and evolutionary history of hepatitis C virus in Vietnam.

To identify hepatitis C virus (HCV) transmission routes among injection drug users in Northern Vietnam, plasma samples were collected from 486 drug users in Hai Phong. Plasma viral RNA was extracted from 323 (66.5%) samples that were positive for anti-HCV antibodies. Portions of the HCV 5'-untranslated (5'UTR)-Core and NS5B genes were amplified by reverse-transcriptase polymerase chain reaction, sequenced directly, and genotyped in 194 and 195 specimens, respectively. Both regions were genotyped in 137 specimens. In the 5'UTR-Core region, genotype 6a was predominant (32.5%), followed by genotype 1a (23.7%), genotype 1b (20.6%), and genotype 6e (14.4%). In the NS5B region, genotype 1a was predominant (42.6%), followed by genotype 1b (24.1%), genotype 6a (14.4%), genotype 3b (7.2%), and genotype 6e (5.1%). Of the 137 specimens with both regions genotyped, 23 (16.8%) showed discordant genotyping results between the two regions, suggesting possible recombination and/or dual infection. Phylogenetic analysis revealed close associations between Hai Phong strains and strains from Southern China: the Yunnan province for genotype 3b; the Guangxi province for genotype 6e; the USA for genotype 1a; and Southern Vietnam for genotypes 1a and 6e. The human immunodeficiency virus (HIV) infection rate among HCV-infected injection drug users was 52.6-55.4% and did not differ significantly by HCV genotype. Most drug users infected with HIV-1 [98.8% (171/173)] were co-infected with HCV. These results suggest multiple routes of HCV transmission among injection drug users in Northern Vietnam that may also be HIV transmission routes.

Hoang Thi Thanh Huyen

Papers

Multiple routes of hepatitis C virus transmission among injection drug users in Hai Phong, Northern Vietnam