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Around 80% of hepatitis C virus (HCV) infections in England are among injecting drug users (IDUs). The HCV Action Plan launched in 2004 includes targets to reduce HCV prevalence in recent initiates (those starting injecting in the preceding 3 years), and to increase HCV voluntary confidential testing (VCT). The Action Plan's impact is examined using surveillance data from recent initiates participating in an annual survey of IDUs in contact with specialist services across England, 2000-2008. Participants provided an oral fluid sample (tested for anti-HCV) and completed a short questionnaire (including HCV VCT and result of last test). Overall, anti-HCV prevalence among the recent initiates was 18% (619/3463); in 2004, it was 20% (59/291), other than being lower in 2000 [11%, 73/672, adjusted odds ratio (AOR) = 0.63 95%CI 0.42-0.93] there was no change over time. Prevalence increased with age; was higher among those ever imprisoned, using a needle exchange, and having a HCV VCT; and varied by region. Overall, 42% (1460) had ever had a HCV VCT; in 2004 uptake was 45% (130/291) having increased from 26% (175/672, AOR = 0.57 95%CI 0.42-0.77) in 2000, and it rose to 62% (197/320, AOR = 2.12 95%CI 1.50-2.99) in 2008. The proportion of anti-HCV-positive IDUs aware of their infection was higher in 2006-2008 than in earlier years. The HCV Action Plan has probably helped increase recent initiates' uptake of HCV VCT and the proportion of those diagnosed with HCV infection. However, its impact on HCV transmission is unclear. There is a need to reinvigorate, and improve coverage of, interventions to prevent HCV transmission., (© 2011 Blackwell Publishing Ltd.)

Monitoring hepatitis C virus (HCV) infection among injecting drug users (IDUs) in the community is complicated by difficulties in obtaining biological specimens and biases in recruitment and follow-up. This study examined the utility of dried blood spot (DBS) specimens from IDUs recruited using respondent-driven sampling (RDS). Active IDUs underwent a computer-assisted interview and provided a DBS sample, tested for HCV antibody (anti-HCV) and HCV-RNA. HCV incidence was estimated from the proportion of anti-HCV-negative subjects found HCV-RNA-positive and estimates of the duration of this state. Results were adjusted according to RDS derived sample weights. HCV-RNA testing was performed on 288 DBS samples; 173 were anti-HCV-positive (54% weighted), of which 70 (42%, 95%CI 34-50% weighted) were RNA-negative indicating cleared infection. Among the 115 anti-HCV-negatives, 14 were RNA-positive suggesting an incidence of 38-47 per 100pyrs. Incident infections were younger than anti-HCV-negative and prevalent infections: 25 vs. 29 and 34, respectively. Incidence was highest among individuals with poor needle exchange coverage. One hundred and fourteen were genotyped (60 1a, 46 3a): a cluster of 14 had homology of >98.5% including 10 incident infections. Public health surveillance of HCV among IDUs could be enhanced through the collection of DBS samples with appropriate recruitment approaches. DBS allow differentiation between individuals with cleared infections, ongoing infection and those recently infected. They also enable virus characterization at genotype and nucleotide level. This would allow surveillance to inform development of harm reduction interventions, and the international evidence base for these., (© 2010 Blackwell Publishing Ltd.)

Summary: The aim of this study was to assess the performance of HIV screening kits introduced over a 12-year period. HIV kits used by the National Blood Service (NBS) were assessed in the context of other HIV kits employed by diagnostic and reference laboratories. Thirty-three HIV screening kits were assessed and 13 had the potential to be used by the NBS. Specimens applied to NBS evaluations included 2000 HIV-negative specimens collected from blood donors, 200 HIV-positive specimens and 21 seroconversion panels, with larger numbers applied to the latter two categories prior to implementation of Communauté Européennes (CE) marking. The 33 HIV kits gave repeat reactive rates, based on HIV-negative specimens, of between 0% and 0.8% (and between 0% and 0.2% for kits relevant to the NBS). When examined for diagnostic sensitivity, the 33 kits gave sensitivities between 99.78% and 100%. Kits relevant to NBS gave sensitivities of 100% except one kit, which failed to detect one anti-HIV-2-positive specimen. Twenty-six kits were compared for detection of primary HIV infection. Of these, the 10 combined HIV antigen/antibody kits examined were more sensitive than other formats and have been exclusively adopted by NBS where operational considerations allow. Their added seroconversion sensitivity makes them the screening method of choice for populations at increased risk, e.g. in sexually transmitted infection (STI) clinics. The regular review of evaluation results has demonstrated a continuing improvement over time in the performance of HIV screening kits and contributed to advances in blood safety.

The objective of this study was to assess whether introducing dried blood spot testing can increase hepatitis C virus (HCV) diagnostic testing. A cluster randomized controlled trial was conducted. Sites were matched into pairs, with one site in each pair randomly allocated to receive the intervention (training and use of dried blood spot). Data were collected from all sites for 6 months before and 6 months after the start of the intervention. The participants were 22 specialist drug clinics and six prisons in England and Wales. The main outcome measure of this study was percentage point difference in individuals tested for HCV (the difference between the percentage of patients tested 6 months after and 6 months before the introduction of dried blood spot tests). Before the trial, 8% of patients at control and intervention sites had been tested for HCV, with 16 sites testing less than 5% of their caseload. The average percentage point difference between intervention and control sites was 14.5% (95% CI 1.3-28%, paired t-test, P = 0.03); with 13 of the 14 pairs contributing to the positive effect of the intervention (Wilcoxon matched-pairs signed-rank-test, P = 0.002). The size of the difference between intervention and control sites varied considerably. The study provides preliminary supporting evidence that dried blood spot testing may increase the uptake of HCV diagnostic testing, by increasing the opportunity for patients to be offered testing. Additional trials with a larger number of sites are justified, ideally in the context of drug and treatment policies that gave clearer priority (and targets) to infection control and testing.

Objective: To determine the specificity of the Abbott Murex HIV antigen/antibody combination enzyme immunoassay (EIA) for the diagnosis of HIV infection in Tanzania., Methods: A cross-sectional survey of 7333 Tanzanian adolescents and young adults was carried out. Sera testing positive by the Murex assay were further evaluated using a battery of other EIA which detect either antibody to HIV-1 or p24 antigen, and by PCR using pol primers., Results: Of the 674 sera testing positive by the Murex assay, only 53 (7.9%) were confirmed. The specificity of the Murex assay was 91.5%., Conclusions: Serological tests for HIV may perform differently in different populations. New diagnostic tests should not be introduced into populations in which they have not been evaluated.

In 1999, the Department of Health allocated additional funding to Health Authorities in England to expand hepatitis B immunization among injecting drug users (IDUs), with the aim of increasing coverage by 20%. In 2001, a vaccination programme for prison inmates in England was also instigated. Between 1998 and 2004 current IDUs participated in a series of annual unlinked anonymous surveys that recorded vaccine uptake (n = 11 383). The proportion self-reporting vaccine uptake rose significantly from 27% in 1998 to 59% in 2004 [adjusted odds ratio: 3.7 (95% CI 3.2-4.3); increase in uptake of 25% per annum (95% CI 22-27%)]. A second survey, which recruited 852 current IDUs from community settings in 2003/04, found that prisons were the most common source (38%) of vaccine doses, followed by drug services (28%) and general practitioners (17%), with only 14% receiving doses through needle exchanges. These data suggest that the 20% target of improving vaccination coverage has been met, with the prison vaccination programme likely to have made a substantive contribution in recent years. However, prevalence of antibodies to the hepatitis B core antigen was stable (21%) and is currently similar among the vaccinated and unvaccinated. Consideration needs to be given to improving community vaccination provision for IDUs, targeting recent initiates, and determining when surveillance data should indicate reductions in infection so that the effectiveness of the targeted strategy can be assessed.

Injection drug use is a common route of infection for the hepatitis B virus (HBV) in the UK. The aim of this study was to establish the prevalence and force of infection for HBV among injecting drug users (IDUs) recruited from multiple community and drug agency settings in England and Wales between 1990 and 2004. Cross-sectional studies of IDUs in and out of contact with drug agencies were conducted throughout the 15-year period. Oral fluid samples were tested for antibodies to the hepatitis B core antigen (anti-HBc). Logistic regression was used to investigate associations between risk factors and anti-HBc positivity and force of infection models were explored. In total, 2527 injectors were recruited from community settings, and 29 386 from drug agencies. Anti-HBc prevalence was 31% (95% CI 30.7-31.8%). It declined in the early 1990s from around 50% in 1992 to 25% in 1999, after which it increased slightly. It was also higher in those who had injected for longer, older IDUs, those recruited in London and North West England, and those reporting having a previous voluntary confidential HIV test. The force of infection models suggested that the incidence of infection increased in 1999-2004 compared with 1993-1998, and was higher in new injectors compared with those injecting for > or =1 year. In conclusion, findings suggest ongoing HBV transmission in recent years despite an overall decline in prevalence in the early and mid-1990s, and highlight the importance of targeting vaccination programmes at new IDUs who have high incidence rates of infection.

Our aim was to compare the prevalence of antibody to hepatitis C virus (anti-HCV) among recently initiated injecting drug users (IDUs) in London and Glasgow, and to identify risk factors which could explain differences in prevalence between the cities. Complementary studies of community recruited IDUs who had initiated injection drug use since 1996 were conducted during 2001-2002. Data on HCV risk behaviours were gathered using structured questionnaires with identical core questions and respondents were asked to provide an oral fluid specimen which was tested anonymously for anti-HCV but was linked to the questionnaire. Sensitivities of the anti-HCV assays for oral fluid were 92-96%. Prevalence of anti-HCV was 35% (122/354) in London and 57% (207/366) in Glasgow (P < 0.001). Multifactorially, factors significantly associated with raised odds of anti-HCV positivity were increasing length of injecting career, daily injection, polydrug use, having had a needlestick injury, and having served a prison sentence. In addition lower odds of anti-HCV positivity were associated with non-injection use of crack cocaine and recruitment from drug agencies. After adjustment for these factors, the increased odds of anti-HCV associated with being a Glasgow IDU were diminished but remained significant. HCV continues to be transmitted among the IDU population of both cities at high rates despite the availability of syringe exchange and methadone maintenance. Effectiveness of harm reduction interventions may be compromised by inadequate coverage and failure to reduce sufficiently the frequency of sharing different types of injecting equipment, as well as the high background prevalence of HCV, and its high infectivity. Comprehensive action is urgently required to reduce the incidence of HCV among injectors.

Fifteen HBsAg kits from 14 manufacturers were assessed. Their sensitivity was evaluated by testing 150 HBsAg-positive sera, sera from four donors who were low-level HBsAg carriers, and sequential specimens from 22 seroconverting individuals together with dilutions of six of these specimens. The British HBsAg Working Standard (0.5 IU mL-1) and the NIBSC/UKBTS HBsAg Monitor Sample (0.125 IU mL-1) were also tested. Five assays failed to detect one of the 150 routine HBsAg-positive sera. Four assays (Auszyme Monoclonal; Monolisa Ag HBs 2nd generation; Murex HBsAg; Ortho HBsAg Test Systems 3) were able to detect HBsAg in all but one of the six sera from low-level carriers, whereas one assay (MicroTrak II HBsAg) detected only one of the six. The most sensitive kit (Monolisa Ag HBs 2nd generation) detected HBsAg in 79 specimens from the seroconversion panels; four other kits detected HBsAg in at least 70 specimens, seven in 60-69, two in 50-59 and the least sensitive in 31. Further analysis of the findings on seroconverters indicated a median reduction in the duration of HBsAg detection of 5 days or more for four assays when compared with the most sensitive assay. One kit (Auszyme Monoclonal) detected HBsAg in 15 of the 18 dilutions prepared from the seroconversion specimens, whereas three kits detected HBsAg in fewer than 10 dilutions. Two kits gave negative reactions with the British HBsAg Working Standard on all of five occasions and six were consistently unreactive with the NIBSC/UKBTS HBsAg Monitor Sample; only three kits (Bioelisa, Enzygnost, Murex) were always reactive. There is therefore substantial variation in sensitivity among the HBsAg kits currently available.