Assessment of HCV genotypes in Yunnan Province of Southwest China

Recently, we reported that the frequency of hepatitis C virus (HCV) genotypes and subtypes has rapidly changed among intravenous drug users (IDUs) in Yunnan Province over the last 5 years; this is especially true for subtype 6a which has increased in frequency from 5 to 15%. Here, we assessed 120 HCV-positive plasma samples from the general population (GP). HCV NS5B fragments were amplified and sequenced by PCR. We identified four HCV genotypes (1, 2, 3 and 6) and seven HCV subtypes (1b, 2a, 3a, 3b, 6a, 6n, and 6k) in this population. Genotype 3 was predominant, with a distribution frequency of 0.484, followed by genotype 1 (0.283), genotype 6 (0.133) and genotype 2 (0.100). HCV subtypes 3b (frequency 0.292) and 1b (frequency 0.283) were the most common subtypes. A comparison of the current data with previous results reported for IDUs showed that the distribution frequencies of genotypes 1, 2 and 6 were significantly different between patients in the GP and IDUs (P < 0.05). Among the HCV subtypes, the distribution frequencies of 1b, 2a, 6a, and 6n were significantly different between patients in the GP and IDU groups (P < 0.05). Moreover, Phylogenetic analyses showed that HCV subtype 6a strains isolated from IDUs and the GP were intermixed and not separately clustered. HCV subtype 6a was predominant not only among IDUs but also among those in the GP in the Guangdong Province and Vietnam. However, HCV subtype 6a was predominant only among IDUs and not among those in the GP in the Yunnan and Guangxi Provinces. Our results indicate that the HCV subtype 6a could rapidly spread across China.     

Molecular epidemiology of hepatitis C virus among injection drug users in Iran: a slight change in prevalence of HCV genotypes over time

Injecting drug users (IDUs) are the main at-risk population for hepatitis C virus (HCV) transmission. We studied HCV infection, risk factors, and genotype distribution in relation to the year of first injection among Iranian IDUs. Of a total of 126 specimens positive for HCV antibody, 93 (74?%) had detectible HCV RNA, and the NS5B gene was sequenced for 83, with genotype 3a (n?=?48, 58?%) being predominant, followed by 1a (n?=?35, 42?%). Tattooing was an independent predictor for HCV infection. No significant difference was found between HCV genotypes and IDU characteristics. Although there was no change in the distribution of prevalent genotypes before and after 1997, a slight variation in the prevalence was observed (p?=?0.71). The difference in the prevalence of subtypes 1a and 3a (9.1?% in the period 1984-1996 and 18.2?% in the period 1997-2009) during 25?years was 9.1?%. These findings indicate a high prevalence of HCV infection among Iranian IDUs and highlights HCV-3a as the most prevalent subtype for the past 25?years. Harm-reduction strategies appear to be the most important measures to reduce the transmission of HCV in Iran.     

The unique HCV genotype distribution and the discovery of a novel subtype 6u among IDUs co-infected with HIV-1 in Yunnan, China

The Yunnan province is the epicenter of HIV-1 epidemics in China and a center for drug trafficking to the other parts of the world. In six prefectures of this province, a total of 132 IDUs were recruited to determine the sero-prevalence of HCV and HIV-1 and the positive rates were 93.94% and 68.18%, respectively (P<0.001). Co-infection with HCV and HIV-1 was found among 89 IDUs, of whom several HCV fragments were amplified and sequenced. Sequences of the HCV 5'NCR-C and NS5B region were determined from 82 IDUs. Phylogenetic analyses showed consistent genotyping among 80 IDUs. Among them HCV genotypes 1a, 1b, 3a, 3b, 6a, 6n, and a tentatively assigned novel 6u subtype were found in 1 (1.25%), 16 (20%), 19 (23.75%), 24 (30%), 4 (5%), 9 (11.25%) and 7 (8.75%) individuals, respectively. In two IDUs, genotyping results were discordant, suggesting mixed HCV infections or recombination. The proportion of patients with HCV 1b tended to decrease from the north to south and from the east to west in this province. Genotype 3 and 6 strains were more frequent in the southern prefectures. The novel subtype 6u strains were only detected in Dehong which borders Myanmar. Our findings showed a unique pattern of HCV genotype distribution, which is similar to that in the southeastern Asian countries but distinct from that among the general population in China. Routes of drug trafficking and the resulting high prevalence of HIV-1 infection may have contributed to this pattern of HCV genotype distribution.     

Temporal trends in the HIV-1 epidemic in Russia: predominance of subtype A

During the period 1996-1997, three highly homogeneous variants of HIV-1 were identified, circulating among injecting drug users (IDUs) in the former Soviet Union republics. One of these belonged to HIV-1 genetic subtype A (IDU-A), another belonged to HIV-1 genetic subtype B (IDU-B) and the third was a recombinant between the first two variants (CRF03_AB). However, since 1997, the HIV-1 epidemic has affected an increasing number of geographic regions in Russia. This study was undertaken to survey the prevailing genetic variants and to estimate the current proportions of these three HIV-1 genetic subtypes in Russia. Blood samples were taken in 1999-2003 from 1090 HIV-infected individuals and analysed by gag/env HMA. The IDU-A variant was found to be the majority variant (89.7-100%) in 44 of 45 regions of the Russian Federation studied. The IDU-A variant was also found to spreading rapidly through heterosexual transmission in 1999-2003 (30/34, 88%). CRF03_AB predominates in the Kaliningrad region only (28/29, 96.6%). The IDU-B variant is currently of minor importance in the IDU epidemic but other European subtype B variants predominate among men having sex with men (18/18, 100%). Sequence analysis of the env V3 encoding regions derived from HIV-1 infected individuals in Yekaterinburg (the main centre of the HIV-1 epidemic in Russia in 2002-2003) showed that the IDU-A variant is still highly homogeneous. The mean pairwise nucleotide distance (n = 9) was 2.89 +/- 1.14 (range 1.36-6.14). However, the mean genetic distance between each sequence within the samples collected from the Yekaterinburg IDU-A variant subset and the IDU-A consensus is 2.51 +/- 1.06 (range 1.36-4.66) and considerably higher than in South Russia in 1996 (0.79 +/- 0.51, range 0.38-1.90). The current HIV-1 epidemic in Russia is almost entirely caused by a highly homogeneous A-subtype strain, which will influence vaccine development strategies and must be taken into account in the quality control of molecular tests for the diagnosis of HIV-1.     

High prevalence of HIV-1 and hepatitis C virus coinfection among injection drug users in the southeastern region of Yunnan, China

The southeastern region of Yunnan province is a key site for drug trafficking and HIV-1 infection spread from the west of Yunnan and Laos to southeastern China. To investigate the prevalence of HIV-1 infection and hepatitis C virus (HCV) coinfection among injection drug users (IDUs) in southeastern Yunnan, three cohorts of 285 addicts, including 242 IDUs and 43 oral drug users, living in the cities of Gejiu and Kaiyuan and the county of Yanshan were studied. HIV-1 and HCV infections were detected by enzyme-linked immunosorbent assay and/or polymerase chain reaction. Data on the age, sex, risk behavior, drug use history, employment, ethnic background, and marriage status were obtained by interview. The overall prevalence of HIV-1 infection was 71.9%. The rate of HCV coinfection among 138 HIV-1-infected IDUs was 99.3%. Most HIV-infected IDUs were 20 to 35 years old (86.7%) and were ethnic Han (75.9%), suggesting that the epidemic in Yunnan is no longer confined to non-Han ethnic minorities. HIV prevalence in female IDUs (81.2%) was significantly higher than in male IDUs (68.2%) ( p <.05). The prevalence of HIV infection reached 68.4% after 1 year of injection drug use. Needle/syringe sharing is the major high risk factor for the spread of HIV-1 and HCV infections. Large-scale educational campaigns are urgently needed to reduce the spread of HIV and HCV infection in these regions.     

Complete genome sequencing and phylogenetic analysis of HCV isolates from China reveals a new subtype, designated 6u

Full length genome sequences were characterized for three novel hepatitis C virus (HCV) isolates (here named DH012, DH014, and DH028). The complete genomes were all isolated from injecting drug users (IDUs) who were co-infected with HIV-1 and lived in Dehong prefecture, Yunnan Province, China, which neighbors Myanmar. The three genomes are 9,443-9,470 nt in length and each contains a single open reading frame (ORF) of 9,069 nt long. Pairwise comparisons indicated nucleotide similarities of 97.9-98.6% among the three isolates, and similarities of 72.4-75.0% between the three isolates and 20 reference strains (representing HCV subtypes 6a-6q and 6t plus two unassigned genotype 6 isolates km41 and gz52557). Phylogenetic analyses demostrated that the three isolates formed a tight and well-supported monophyletic cluster in the genotype 6 clade. No evidence of viral recombination was found using similarity plots and bootscanning analyses. Based on the current HCV classification criteria, we have assigned the three isolates to a new subtype, 6u. Although another "6u" isolate D83 has been reported very recently, it is subtypically distinct from the three isolates we described here. Because its designation does not meet the criteria described in the updated HCV nomenclature proposal, this "6u" isolate should be reclassified.     

High prevalence of HIV, HIV/hepatitis C virus coinfection, and risk behaviors among injection drug users in Chennai, India: a cause for concern

OBJECTIVE: To estimate the prevalence of HIV and hepatitis C virus (HCV) and hepatitis B virus (HBV) coinfections and current risk behaviors among HIV-positive and -negative injection drug users (IDUs) in Chennai, India. METHODS: Cross-sectional analysis of a convenience sample of 912 IDUs recruited between March 2004 and April 2005. Specimens were tested for HIV, HBV, and HCV. Adjusted prevalence ratios (PRs) were estimated using Poisson regression with robust variance estimates. RESULTS: The prevalence of HIV, hepatitis B surface antigen, and anti-HCV were 29.8%, 11.1%, and 62.1%, respectively. Among HIV-infected IDUs, prevalence of coinfection with anti-HCV and hepatitis B surface antigen/anti-HCV were 86% and 9.2%, respectively. In multivariate analysis, injecting at a dealer's place (PR: 1.57) and duration of injection drug use >or=11 years (PR: 3.02) were positively associated with prevalent HIV infection. Contrastingly, alcohol consumption >or=1 per week (PR: 0.55) was negatively associated with HIV. HIV-positive IDUs were as or more likely compared with HIV-negative IDUs to report recent high-risk injection-related behaviors. CONCLUSIONS: There is a high burden of HIV, HCV, and HBV among IDUs that needs to be addressed by improving access to therapies for these infections; furthermore, preventive measures are urgently needed to prevent further spread of HIV, HBV, and HCV in this vulnerable population.     

Presence of multiple HIV subtypes and a high frequency of subtype chimeric viruses in heterosexually infected women

The HIV-1 subtype distribution was determined in 41 HIV-positive women (-8% of all HIV-infected women in Denmark) belonging to different risk groups. HIV p17 gag and env gene subtypes were determined by DNA sequence analysis. Five different HIV subtypes were detected across all patients. Most HIV-1-positive women of Danish origin carried subtype B viruses, and a minority had virus belonging to subtypes A or C. All injecting drug users (IDUs) were infected with HIV subtype B viruses, whereas all non-B subtypes were present in cases linked to heterosexual transmission. In contrast, all women of African origin carried non-B HIV subtypes (subtypes A, C, D, or G) regardless of transmission mode. Of these women, 21% infected with non-B HIV subtypes appeared to be infected by subtype chimeric viruses and 7% were jointly infected with viruses belonging to two different subtypes (A and C). Data demonstrate a preferential representation of non-B HIV subtypes in women infected through heterosexual contact, as well as a high degree of recombination between viruses derived from endemic areas in which several HIV subtypes predominate. Combined with the increased incidence of heterosexual transmission of HIV, the results imply that an increased subtype diversity can be anticipated in newly infected individuals.     

Genetic variations of hepatitis C virus circulating in the Ural region

A study of distributions of different genetic variations (subtypes) of hepatitis C virus (HCV), circulating in the territories of Yekaterinburg and Chelyabinsk among infected population categories of different social statuses and age, is reported in the paper. The predominance of 1b subtype was shown in the HCV-infected patients at the hemodialysis center (HDC) and at the pediatric oncohematology center (OHC), 83.3% and 84.6% respectively. The summarized results of examinations of patients conducted at HCV-infection departments (97 persons) did not reveal any essential differences between the data, obtained for Moscow and Saint-Petersburg, concerning the distributions of HCV subtypes. However, according to an analysis made in cities of the Urals region, the prevalence of 1b subtype in Chelyabinsk was 2-fold higher than that of 3a subtype, whereas in Yekaterinburg there was an equal ratio (1:1) between the above subtypes. Besides, unequal distributions of HCV subtypes were registered in different age groups. 3a subtype was found to be predominant in patients aged 15 to 27, and prevalence of 1b subtype persisted in persons aged below 15 and above 27. The conclusion is that the redistributed occurrence rates of separate HCV subtypes, with their spectrum in mentioned territories being preserved, is associated with a growing number of young drug-addicts who are more often get infected with 3a subtype.     

Hepatitis C virus (HCV) 5'NC sequence variants and their association with hepatitis C risk groups.

BACKGROUND: Genotype distribution of hepatitis C virus (HCV) is relatively uniform in Prague, Czech Republic. Unlike the other developed countries where HCV genotype 3 is increasingly associated with injection drug users (IDU), subtype 1b remains the most prevalent HCV subtype in Prague, regardless of risk factors. OBJECTIVE: We wished to determine if subtype 1b strains could be further differentiated by comparing the conserved 5'NC sequences of the strains infecting IDU and non-IDU populations. STUDY DESIGN: All prospectively collected serum samples that were HCV RNA positive were genotyped according to the 5'NC and NS5b regions. All 5'NC sequences were further analyzed for new mutations and these data were compared to patient epidemiologic information. RESULTS: We found eight 5'NC sequence variants among 96 specimens tested. Further analysis of subtype 1b strains showed that a variant with a nucleotide insertion at -138 positions was found only among non-IDU subjects, while the variant with T-->C substitution at -94 was found only among the IDUs. CONCLUSIONS: These observations suggest that the current HCV transmission between the IDU and non-IDU populations is uncommon, and may reflect the beginning of divergence of HCV genotypes in the IDU population in Prague.     

Hepatitis C virus (HCV) genotypes and the influence of HCV subtype 1b on the progression of chronic hepatitis C in Korea: a single center experience

Background/Aims

There is some controversy regarding whether or not hepatitis C virus (HCV) subtype 1b is more influential than non-1b subtypes on the progression of chronic hepatitis (CH) C to liver cirrhosis (LC) and hepatocellular carcinoma (HCC).

Methods

We retrospectively analyzed 823 patients with chronic HCV infection, including 443 CH patients, 264 LC patients, and 116 HCC patients, who were HCV RNA positive and HBsAg negative. These patients had not received any prior treatment with either interferon alone or a combination of interferon and ribavirin.

Results

HCV subtypes 1b (51.6%) and 2a/2c (39.5%) were the two most common genotypes. The proportions of genotypes 2 (2a/2c, 2b, and 2) and 3 were 45.8% and 1.1%, respectively. One case of genotype 4 was found. HCV subtype 1b (47.3%) was less common than the non-1b subtypes (52.7%) in non-LC patients, but its proportion (56.9%) was higher than that of non-1b subtypes (43.1%) in LC patients (P=0.006). The proportions of patients with HCV subtype 1b did not differ significantly between the LC (55.3%) and HCC (60.3%) groups. Older age, male gender, and the relative progression of liver damage (non-LC vs. compensated LC vs. decompensated LC) were significant risk factors for HCC, with odds ratios of 1.081 (95% confidence interval [CI], 1.056-1.106), 5.749 (95% CI, 3.329-9.930), and 2.895 (95% CI, 2.183-3.840), respectively. HCV subtype 1b was not a significant risk factor for HCC (odds ratio, 1.423; 95% CI, 0.895-2.262).

Conclusions

HCV subtypes 1b and 2a/2c were the two most common HCV genotypes. HCV subtype 1b seemed to be more influential than non-1b subtypes on the progression of CH to LC, but not on the development of HCC from LC.     

HIV-1 subtyping in Salvador, Bahia, Brazil: a city with African sociodemographic characteristics

To investigate the prevalence of the HIV-1 subtypes in different populations from Salvador, Bahia, Brazil, blood samples from 72 HIV-1-seropositive injecting drug users (IDUs) and 62 individuals infected sexually were analyzed using the heteroduplex mobility assay (HMA). In the IDU group, 89.5% were classified as subtype B, 3% as subtype F, and 7.5% showed a B/F HMA profile. In the sexual transmission (ST) group, 95% were identified as B subtype, 3.4% showed a B/F profile, and 1.6% a B/C/E HMA profile. All Brazilian samples that showed multiple reactivities in the HMA analysis clustered on sequencing with B North American/ European HIV-1 isolates in the phylogenetic analysis, whereas the F subtypes clustered with F Brazilian HIV-I isolates. Serologic reactivities of IDU's sera were examined using a panel of synthetic V3 loop peptides representative of the different HIV-1 subtypes. No difference in serologic reactivity between F and B subtype plasma could be observed. Predominance of HIV-I subtype B was identified in both study groups, whereas subtype F was detected only among IDUs in a frequency lower than described for other Brazilian regions.     

Molecular characterization of hepatitis C virus genotype 4 sequences in HIV-coinfected patients from Argentina

The prevalence of hepatitis C virus genotype 4 (HCV-4) is increasing in different parts of the World but in Latin America the data are still scarce. We aimed to characterize HCV-4 isolates from 383 HIV-coinfected patients in Argentina. Sequence analyses were based on the non-structural 5B region of HCV. Results from 18 patients indicated a genetic heterogeneity that involved three genotype 4 subtypes. Sequences were ascribed to subtype 4d (67%), 4a (22%), and 4m (11%). In spite of different sources of transmission were defined among patients, no statistical association was found with the genotype 4 subtype. The scenario is also compatible with multiple importation of the epidemic and there is no evidence for transmission-specific clusters or network-like transmission of HCV-4. This HCV-4 does not represent a recent introduction in Argentina, it circulates in all transmission groups and its presence is increasing among HIV-infected patients.     

Distribution of genotypes and response to alpha-interferon in patients with hepatitis C virus infection in Germany

To determine the distribution of hepatitis C virus (HCV) genotypes in German isolates, nucleotide sequences of the viral nonstructural 5 (NS5) genome domains were analyzed in isolates from 107 chronically HCV-infected patients. Of these 107 patients, 46 (43.0% were infected with subtype 1a and 47 (43.9%) with subtype 1 b. Six patients (5.6%) with a history of intravenous drug abuse were infected with subtype 3a. Eight patients (7.5%) who had acquired their HCV infection in Egypt carried subtype 4a. Forty-three of the 107 patients were treated with -interferon. Of these 43 patients, 16 (37.2%) were infected with subtype 1a and 27 patients (62.8%) with subtype 1b. Three patients infected with HCV-subtype 1a (18.7%) and four patients infected with subtype 1b (14.8%) showed a sustained complete response after interferon therapy. The HCV genotype 1 with its subtypes 1a and 1 b was the most common source of HCV infection in this group of patients. There was no significant difference in response to -interferon treatment of HCV infection with the subtypes 1a or 1b.     

The spread of HIV-1 subtypes B and CRF01_AE among injecting drug users in Bangkok, Thailand

The HIV epidemic among injecting drug users (IDUs) in Bangkok was initially dominated by HIV subtype B and later by the recombinant CRF01_AE. The present study investigates the distribution of the 2 variants in time and how it is affected by changes in injecting risk behavior and treatment. A mathematic model describing the spread of HIV subtype B and CRF01_AE among IDUs was developed, and data from the AIDSVAX B/E cohort of IDUs in Bangkok were used. From the model, it was calculated that during 1999 to 2003, the annual incidence of HIV was around 0.6 and 2.7 to 3.9 infections per 100 person-years for subtype B and CRF01_AE, respectively. Of the new infections, 18% and 72% are first infections with subtype B and CRF01_AE, respectively, and 9% are superinfections. With increases in risk behavior, the fraction of superinfections rises. If treatment reduces the infectivity of CRF01_AE more than that of subtype B, the fraction of subtype B infections should increase. Subtype B should remain prevalent in a small but considerable fraction of the population for a long time. Changes in risk behavior and the introduction of treatment may alter the distribution of subtypes, but CRF01_AE should remain dominant.     

Genotype distribution and molecular epidemiology of hepatitis C virus in blood donors from southeast France

The genotype distribution of hepatitis C virus (HCV) in blood donors from southeast France was tracked for a period of 13 years (1991 to 2003). Virus genomes from 321 samples were analyzed by amplification and sequencing of the NS5b and E1 regions. The most frequent genotypes were 1b (30.2%), 1a (27.7%), and 3a (22.4%). Although it was less common, genotype 2 was characterized by the presence of strains belonging to 11 different subtypes, including 5 that had never been characterized. Genotypes 1a, 1b, 3a, and 4a presented typical "epidemic" profiles, with a large number of isolates per subtype and short mean genetic distances between isolates. Type 2 isolates displayed a typical "endemic" profile, with a large number of subtypes and very few isolates in each subtype. The epidemiology of HCV infection in southeast France changed radically during the study period in relation to modifications in the etiology of infection. We observed the emergence of new epidemic subtypes (subtypes 1a and 3) linked to intravenous drug use and a decrease in the types linked to blood transfusion and nosocomial infection (epidemic subtype 1b and endemic type 2). Comparison of strains from blood donors with strains from a cohort of inpatients in the same region during 2001 and 2002 demonstrated for the first time that the monitoring of blood donors is a generally valid indicator of HCV epidemiology in terms of genotype distribution.     

High-Resolution Hepatitis C Virus Subtyping Using NS5B Deep Sequencing and Phylogeny,an Alternative to Current Methods

Hepatitis C virus (HCV) is classified into seven major genotypes and 67 subtypes. Recent studies have shown that in HCV genotype 1-infected patients, response rates to regimens containing direct-acting antivirals (DAAs) are subtype dependent. Currently available genotyping methods have limited subtyping accuracy. We have evaluated the performance of a deep-sequencing-based HCV subtyping assay, developed for the 454/GS-Junior platform, in comparison with those of two commercial assays (Versant HCV genotype 2.0 and Abbott Real-time HCV Genotype II) and using direct NS5B sequencing as a gold standard (direct sequencing), in 114 clinical specimens previously tested by first-generation hybridization assay (82 genotype 1 and 32 with uninterpretable results). Phylogenetic analysis of deep-sequencing reads matched subtype 1 calling by population Sanger sequencing (69% 1b, 31% 1a) in 81 specimens and identified a mixed-subtype infection (1b/3a/1a) in one sample. Similarly, among the 32 previously indeterminate specimens, identical genotype and subtype results were obtained by direct and deep sequencing in all but four samples with dual infection. In contrast, both Versant HCV Genotype 2.0 and Abbott Real-time HCV Genotype II failed subtype 1 calling in 13 (16%) samples each and were unable to identify the HCV genotype and/or subtype in more than half of the non-genotype 1 samples. We concluded that deep sequencing is more efficient for HCV subtyping than currently available methods and allows qualitative identification of mixed infections and may be more helpful with respect to informing treatment strategies with new DAA-containing regimens across all HCV subtypes.     

The effects of widespread methadone treatment on the molecular epidemiology of hepatitis C virus infection among injection drug users in Hong Kong

The distribution of HCV genotypes among injection drug users in Hong Kong was assessed in context of methadone treatment availability. Three time periods were defined by the year of initiating injection-on or before 1980, 1981-1994, and 1995-2006-with methadone becoming widely available since the second period. Of the 273 HCV RNA-positive cases, the most prevalent subtype was HCV 6a (52.4%), followed by HCV 1b (38.5%). The new variants of HCV subtypes 6e and 6h were detected. Both subtypes 1b and 6a were prevalent among older injectors, while subtype 3a was more common in young injectors and those initiating injection recently during the third time period. Age (P < 0.05) and recent injection frequency (P < 0.01) were independently associated with HCV 6a infection. Subtype 1b was predominant in the first period, whereas 6a was more common in the second and third. Subtype 1b sequences appeared to have originated at two positions on the phylogenetic tree, while 6a showed a more disperse distribution suggestive of multiple introductions. Phylogenetic analysis on the NS5B region did not reveal specific clustering of any subtype/genotype. Overall, there was no suggestion of outbreaks of HCV. The extensive use of methadone may have protected Hong Kong from the emergence of HCV clusters among injection drug users.     

Retrovirus infections in a sample of injecting drug users in Rio de Janeiro City, Brazil: prevalence of HIV-1 subtypes, and co-infection with HTLV-I/II.

BACKGROUND: Retrovirus infections among injecting drug users (IDUs), a core at-risk population for both HIV-1 and HTLV-I/II infections in Brazil, were assessed within an ongoing cooperative research. OBJECTIVE: The study assessed the seroprevalences of HIV-1 and HTLV-I/II infections, as well as the prevalence of HIV-1 subtypes in a sample of IDUs from Rio de Janeiro, Brazil. An attempt to evaluate HIV incidence was carried out using a dual 'sensitive/less sensitive' testing strategy. STUDY DESIGN: Cross-sectional evaluation of 175 IDUs. Serostatus for HIV-1 and HTLV-I/II were established by enzyme-linked immunosorbent assays, and confirmed by western blot. The dual testing strategy aimed to estimate HIV-1 incidence rates. Differentiation between HTLV-I and -II was performed by western blot. DNA samples were polymerase chain reaction amplified by a nested protocol, and HIV-1 subtyping was determined by heteroduplex mobility assay. RESULTS: Forty-six and 29 samples were found to be, respectively, positive for HIV-1 and HTLV-I/II, 15 of them co-infected by both viruses. Among HTLV-I/II-infected patients, 75.9% were infected by HTLV-I. Thirty-one HIV samples were identified as B subtype, with seven of them showing the typical "Brazilian B" pattern in the gp120 V3 loop, and ten were identified as F subtype. The use of less sensitive assays for HIV infection wrongly identified a deeply immunocompromised patient as an incident case. CONCLUSION: Moderately high seroprevalences were found for both HIV-1 and HTLV-I/II infections, HIV-1/HTLV-I co-infections being of special concern. A non-statistically significant higher prevalence of F subtype was observed, when compared with the distribution of F/B subtypes among Brazilian patients from other exposure categories. No recent HIV-1 infections were detected, but a limitation of the "sensitive/less-sensitive" testing strategy was made evident.     

Molecular and epidemiological profiles of hepatitis C virus genotype 4 in Denmark

The prevalence of hepatitis C virus (HCV) genotype 4 has increased throughout Europe. This is an epidemiological study of patients infected chronically with HCV genotype 4 in Denmark. The HCV strains analyzed originated from patient samples collected between 1999 and 2007 as part of the national Danish hepatitis B and C network, DANHEP. Sequence analyses were based on the envelope 1 region of HCV. Results from a total of 72 patients indicated a high degree of genetic heterogeneity. Fifty‐six patients (78%) were infected with one of the three dominating subtypes: 4d, 4a, or 4r. The remaining 16 patients (22%) were infected with subtypes 4h, 4k, 4l, 4n, 4o, or 4Unclassified. Three epidemiological profiles were identified: (1) patients infected with HCV by intravenous drug use were infected solely with subtype 4d. They were all of European origin, and 15 of the 16 patients were ethnic Danes. No single transmission event could be confirmed, but the pairwise nucleotide identity within the patients of Danish origin was relatively high (～95%), suggesting a recent introduction into Denmark. (2) The 21 patients infected with subtype 4a all came from Northern Africa, Egypt, Pakistan, or the Middle East. (3) Patients from Southern Africa dominated among patients infected with subtype 4r (10 of 12 patients). This study demonstrates that HCV genotype 4d has been introduced in and spread among Danish intravenous drug users. The remaining subtypes show restricted distribution, infecting almost exclusively patients from geographical areas with a relatively high prevalence of HCV genotype 4 infections. J. Med. Virol. 82:1869–1877, 2010. © 2010 Wiley‐Liss, Inc.