Hepatitis C Virus Seroconversion Research Articles

Incidence of hepatitis C infection among prisoners by routine laboratory values during a 20-year period.

BackgroundTo estimate the incidence of Hepatitis C virus (HCV) and the predictive factors through repeated routine laboratory analyses.MethodsAn observational cohort study was carried out in Quatre Camins Prison, Barcelona. The study included subjects with an initial negative HCV result and routine laboratory analyses containing HCV serology from 1992 to 2011. The incidence of infection was calculated for the study population and for sub-groups by 100 person-years of follow-up (100 py). The predictive factors were determined through Kaplan-Meier curves and a Cox regression. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated.ResultsA total of 2,377 prisoners were included with a median follow-up time of 1,540.9 days per patient. Among the total population, 117 HCV seroconversions were detected (incidence of 1.17/100 py). The incidence was higher between 1992 and 1995 (2.57/100 py), among cases with HIV co-infection (8.34/100 py) and among intravenous drug users (IDU) without methadone treatment (MT) during follow-up (6.66/100 py). The incidence rate of HCV seroconversion among cases with a history of IDU and current MT was 1.35/100 py, which is close to that of the total study population. The following variables had a positive predictive value for HCV infection: IDU (p<0.001; HR = 7,30; CI: 4.83–11.04), Spanish ethnicity (p = 0.009; HR = 2,03; CI: 1.93–3.44) and HIV infection (p = 0.015; HR = 1.97; CI: 1.14–3.39).ConclusionThe incidence of HCV infection among prisoners was higher during the first part of the study and among IDU during the entire study period. Preventative programs should be directed toward this sub-group of the prison population.

Incidence and Risk Factors for Incident Hepatitis C Infection Among Men Who Have Sex With Men With HIV-1 Infection in a Large Urban HIV Clinic in Tokyo

The epidemiology of hepatitis C virus (HCV) infection among HIV-infected men who have sex with men (MSM) who do not inject drugs in Asia remains unknown. The incidence and risk factors for incident HCV infection among HIV-infected MSM at a large HIV clinic in Tokyo were elucidated. Poisson regression compared the incidence of HCV seroconversion at different observation periods. Of 753 HIV-1 infected MSM patients negative for HCV antibody (HCVAb) at baseline and available follow-up HCVAb test, 21 patients (2.8%) seroconverted to HCVAb positive over 2246 person-years (PY), for an incidence of 9.35 per 1000 PY. The incidence increased over time from 0 per 1000 PY in 2005-2006, 3.0 per 1000 PY in 2007-2008, 7.7 per 1000 PY in 2009-2010, to 24.9 per 1000 PY in 2011-2012 (P = 0.012). Of 21 incident cases, only 4 (19%) were injection drug users, and sensitivity analysis that excluded injection drug users yielded similar findings. Multivariate analysis identified illicit drug use to be an independent risk for HCV infection (hazard ratio = 3.006; 95% confidence interval: 1.092 to 8.275; P = 0.033). Incident HCV infection is increasing among HIV-1-infected MSM noninjection drug users at resource-rich setting in Asia. Illicit drug use is an independent risk factor for incident HCV infection in this population.

Host and Viral Determinants of the Outcome of Exposure to HCV Infection Genotype 4: A Large Longitudinal Study

The objective of this study was to characterize the factors that influence the outcome of exposure to hepatitis C virus (HCV) genotype 4 (HCV-G4) and the course of recent infection. In this longitudinal study, we prospectively assessed the clinical, genetic, virological, and immunological parameters and retrospectively determined single-nucleotide polymorphisms at interleukin-28B (IL-28B) rs12979860 in a well-characterized large cohort recently exposed to HCV-G4. A total of 136 subjects with acute HCV (new viremia, seroconversion, and HCV-specific T-cell responses) were identified. Forty-eight subjects (35%) had spontaneous viral clearance and 88 subjects developed chronic HCV of which 42 subjects were treated with pegylated interferon monotherapy, with a sustained virologic response (SVR) rate of 88%. Twenty-six subjects developed HCV-specific T-cell immune responses without detectable viremia or seroconversion. IL-28B-CC (odds ratio (OR) 14.22; P<0.0001), multispecific T-cell responses (OR=11.66; P<0.0001), >300 IU/l alanine aminotransferase (ALT) decline within 4 weeks (OR=6.83; P<0.0001), jaundice (OR=3.54; P=0.001), female gender (OR=2.39; P=0.007), and >2.5 log10 HCV-RNA drop within 8 weeks (OR=2.48; P=0.016) were independently associated with spontaneous clearance. ALT normalization and undetectable HCV-RNA predicted SVR. Exposed apparently uninfected participants had a higher frequency of IL-28B-CC than patients with unresolved acute HCV (P<0.001). IL-28B-CC was associated with multispecific T-cell response (r(2)=0.0.835; P<0.001). IL-28B-CC genotype, multispecific HCV T-cell responses, rapid decline in ALT, and viral load predict spontaneous clearance and response to acute HCV-G 4 therapy. IL-28B-CC genotype correlates with developing early multispecific T-cell responses. These findings have important implications for predicting the outcome of HCV exposure and acute infection and identifying patients likely to benefit from therapy.

Hepatitis C virus seroconversion in hemodialysis units with a high prevalence of hepatitis C: do we need isolation?

ObjectiveThe objective of this study was to determine whether the isolation of hemodialysis patients with hepatitis C virus (HCV) in hemodialysis units with a high prevalence of hepatitis C is necessary or not.BackgroundHCV is one of the most common pathogens leading to serious morbidity and mortality in hemodialysis patients. Despite the quality control measures developed to reduce the risk of HCV transmission, HCV persists, and nosocomial virus transmission remains a concern.Patients and methodsThis study included 514 patients with end-stage renal disease on regular hemodialysis in Menoufia governorate, Egypt. Of them, 303 patients started dialysis with negative HCV, and 44 patients seroconverted to HCV positive during dialysis. Patients were divided into two groups: group 1, which included 259 patients who remained negative for HCV, and group 2, which included 44 patients who seroconverted to HCV positive during dialysis. Risk factors for seroconversion were compared between the two groups.ResultsThe duration of dialysis in months (33.72 in group 1 compared with 71.36 in group 2), a positive family history for HCV infection (6.4% in group 1 vs. 20.5% in group 2), and a low socioeconomic level (58.3% in group 1 vs. 72.7% in group 2) were found to be significant among the studied groups. Other factors such as blood transfusion, surgery, dentist visit, a history of bilharziasis and hepatitis B virus vaccination were found to be insignificant. The duration of dialysis was found to be a key predictor of HCV seroconversionConclusionPatients with a long duration of dialysis were more liable to HCV seroconversion in dialysis units with a high prevalence rate of HCV infection, especially in developing countries. Good training on infection control measures with strict supervision of the dialysis staff is required. A controlled randomized study is needed to compare the isolation policy with no isolation of HCV patients on regular hemodialysis in developing countries to determine whether there is any benefit of isolation.

Sustained Drug Use Changes After Hepatitis C Screening and Counseling Among Recently Infected Persons Who Inject Drugs: A Longitudinal Study

Notification of hepatitis C virus (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). It remains to be established whether postscreening behavioral changes extend over time for PWID and whether screening test notification has behavioral impacts among HCV-negative PWID. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWID. Initially HCV-seronegative PWID (n = 208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semiannual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable generalized estimating equation analyses were conducted to assess substance use and behavior changes over time and compare changes between HCV seroconverters and HCV-seronegative participants while adjusting for baseline characteristics. Of the 208 participants (83% male; mean age, 34.7 years, mean follow-up time, 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV and status notification, whereas a 10% decrease for each additional 3 months of follow-up was observed for injection cocaine and heroin use among HCV seroconverters but not among HCV-seronegative PWID (P < .05). No significant changes were observed in alcohol use. Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Among PWID deemed seronegative after screening, there is no sustained trend for change in risk behavior.

Editorial Commentary: Hepatitis C Virus Testing and Drug Use in North America; Is There More Than Meets the Eye?

Editorial Commentary: Hepatitis C Virus Testing and Drug Use in North America; Is There More Than Meets the Eye?

P5.022 Earlier HCV Diagnosis by the Introduction of Routine HCV Testing For HIV Positive MSM and MSM Opting Out For HIV in a Large STI Outpatient Clinic

BackgroundIn October 2007 at a large STI outpatient clinic (SOC), anti-HCV screening was introduced for HIV unaware MSM opting-out for HIV testing (MOH) and HIV-positive MSM. We evaluated whether this...

P3.201 Recent Syphilis Predicts Hepatitis C Virus (HCV) Seroconversion Among HIV-Positive Men Who Have Sex with Men (MSM)

BackgroundThere is evidence of sexual HCV transmission among HIV-positive MSM from the UK and Europe. We estimated HCV seroincidence and its risk factors in a North American population of HIV-positive...

Reduction in HCV Incidence Among Injection Drug Users Attending Needle and Syringe Programs in Australia: A Linkage Study

We examined trends in HCV incident infection among injection drug users (IDUs) attending needle and syringe programs (NSPs) in Australia in 1995 to 2010. We created a passive retrospective cohort of 724 IDUs who tested negative for HCV antibodies by a simple deterministic method linking partial identifiers to find repeat respondents in annual cross-sectional serosurveillance. We identified 180 HCV seroconversions over the study period, for a pooled incidence density of 17.0 per 100 person-years (95% confidence interval [CI] = 14.68, 19.66). Incidence density declined, from a high of 30.8 per 100 person-years (95% CI = 21.3, 44.6) in 2003 to a low of 4.0 (95% CI = 1.3, 12.3) in 2009. A decline in HCV incidence among Australian IDUs attending NSPs coincided with considerable expansion of harm reduction programs and a likely reduction in the number of IDUs, associated with significant changes in drug markets. Our results demonstrate the capacity of repeat cross-sectional serosurveillance to monitor trends in HCV incidence and provide a platform from which to assess the impact of prevention and treatment interventions.

1181 EVALUATION OF PROMETHEUS INDEX IN PATIENTS COINFECTED WITH HEPATITIS C VIRUS AND HUMAN IMMUNODEFICIENCY VIRUS

to calculate time to development and subsequent loss of HCV antibodies. Results: Among 48 MSM, 54 HCV (re-)infections were documented. Most frequent genotypes were 1a (71%) and 4d (20%). Median age was 42 years (IQR 36–47). Median time between the last negative and the first positive HCVRNA test was 114 days (IQR 80–137). The first positive HCVRNA sample had detectable HCV antibodies in 12/48 subjects; median time to HCV seroconversion was 60 days (IQR 0–112). HCV was spontaneously cleared in 3 subjects and 23 were treated during the acute phase of infection, resulting in a sustained virologic response (SVR) in 15/23 (65%). Interestingly, all subjects with viral clearance (n =18) showed a significant decrease of anti-HCV reactivity during follow-up (see figure 1; peak vs. subsequent nadir anti-HCV reactivity, p =0.001 (Wilcoxon’s ranksum test)). Among those with viral clearance, cumulative incidence of seroreversion was 17% (95%CI 7–40) after 4 years. During reinfection (n =6), anti-HCV reactivity did not significantly differ from reactivity during primary infection (p =0.17).

Increases in acute hepatitis C (HCV) incidence across Europe: which regions and patient groups are affected?

BackgroundIn the last decade, several outbreaks of sexually acquired acute HCV have been described in men who have sex with men (MSM) infected with HIV in Australia, Europe, and North America. The aims of this study were to determine the incidence of acute HCV within the large EuroSIDA cohort and to explore possible regional differences throughout Europe and in different HIV transmission risk groups.MethodsBaseline was defined as 1st Jan of 2002 or entry into EuroSIDA, whichever comes later. All patients from EuroSIDA who were HCV antibody‐negative at baseline and had at least 2 HCV antibody test results available were included into the study. HCV seroconversion was defined as change from negative to positive HCV‐antibody test within the observation period from 2002 onwards. Follow‐up was counted from baseline to HCV antibody positivity for seroconverters and to the last HCV antibody‐negative test result for those that did not seroconvert for HCV. Poisson regression analyses were performed to identify predictive factors for HCV seroconversion.ResultsA total of 150 HCV seroconversions (95 [63.3%] in MSM) occurred in 4295 patients during 18,928 person years of follow‐up (PYFU), overall incidence of 0.79 acute infections per 100 PYFU (95% CI: 0.67–0.92) (see figure). The incidence of HCV seroconversions increased from 0.47 (CI: 0.19–0.74) in 2002 to 2.34 (CI: 1.24–3.44) in 2010. Similar patterns were observed across all European regions (p=0.89, test for interaction). In multivariate analysis, IDU was associated with a higher incidence rate ratio (IRR) than MSM: 4.59 (2.40–8.80; p&lt;0.0001), South and East Europe both had higher IRR compared to Western Europe, respectively (1.98 [1.12–3.49]; p=0.018 and 2.41 [1.41–4.12]; p=0.0014). Calendar year per 2 years was also associated with a higher IRR (1.29 [1.19–1.39]; p&lt;0.0001).ConclusionThe incidence of acute HCV within EuroSIDA increased over time. Although, the incidence of seroconversion was 54% higher in MSM than in heterosexuals, IDUs had the highest incidence of HCV seroconversion. Rising incidences can be found in all European regions highlighting the need for increased prevention efforts in all European countries. image

Temporal changes and regional differences in treatment uptake of hepatitis C therapy in EuroSIDA

AbstractUp to 30% of European HIV‐positive patients tested for hepatitis C virus (HCV) are seropositive. All co‐infected patients with chronic HCV and ≥F2 fibrosis should be considered for HCV therapy given their increased risk of death from liver disease. Despite this the extent to which co‐infected patients initiate HCV treatment is not well described. The aims of this study were to determine the rate of HCV treatment uptake among co‐infected patients and to estimate the effect of treatment on all‐cause and liver‐related death. EuroSIDA patients positive for HCV antibody and HCV‐RNA were included in the study. Baseline was defined as the date of recruitment or HCV seroconversion, whichever occurred later. Poisson regression was used to identify temporal changes and regional differences in HCV treatment uptake (use of at least interferon‐α [peg‐IFN]± ribavirin) and to study the association between HCV treatment and progression to all‐cause and liver‐related death. 1947 patients were included, with a median follow‐up time of 107 months (IQR: 57–156). Overall 456 (23.4%) of HIV/HCV co‐infected patients have received HCV therapy so far. The incidence of HCV treatment rose from 0.29 (95% CI: 0.13–0.45) per 100 person‐years follow‐up in 1998 to 5.26 (95% CI: 3.87–65) in 2007, before falling to 3.73 (95% CI: 2.40–5.06) in 2009. There were considerable regional differences (Figure). In a multivariable model treatment incidence increased 11.0% (95% CI: 4.0–18.4; p=0.0016) per 2 calendar years. Patients with CD4 cell counts greater than 350 cell/mm3 (incidence rate ratio [IRR]: 1.75 [1.37–2.23; p &lt; 0.0001]), HIV‐RNA less than 500 copies/ml (IRR: 1.58 [1.18–2.12; p=0.0023]), with HCV genotype 3 (IRR: 1.55 [1.21–1.98; p=0.0006]) compared to genotype 1) and those from south (IRR: 1.99 (1.45–2.72; p&lt;0.0001) and east central Europe (IRR: 1.61 [1.11–2.34; p=0.011]) compared to west Europe, were more likely to initiate treatment. In a multivariable model treatment for HCV was not significantly associated with all‐cause death (355 deaths, IRR: 0.81 [95% CI: 0.54–1.19; p=0.28]) or liver‐related death (95 deaths, IRR: 1.0 [95% CI: 0.50–2.02; p=0.99]). The incidence of treatment for HCV among co‐infected patients increased from 1998 until 2007 and was common in those with higher CD4 cell counts and lower HIV‐RNA, consistent with HCV treatment guidelines. HCV treatment was not associated with all‐cause or liver‐related death in this population. image

Adherence with screening guidelines for hepatitis C testing among HIV‐infected patients

Purpose of the studyCo‐infection with HIV / hepatitis C virus (HCV) occurs commonly due to similar routes of transmission, mainly in MSM and IVDU patients. In 2009, EACS guidelines introduced the notion of systematic annual HCV screening among HIV‐infected patients. This study evaluated staff knowledge, adherence to HCV screening recommendations and seroconversion rates for HCV in our HIV Reference Centre.MethodsEight physicians (HIV specialists) were interviewed on recommendations and perceived adherence to EACS clinical guidelines on HCV screening [1]. We then reviewed medical records of our cohort of HIV‐infected patients on regular follow‐up in our centre each year, from 2008 to 2011. We considered a patient to be on regular follow‐up when records showed at least two clinical reviews and one HIV viral load testing during the year. Demographic features and HCV serology tests were collected from the operating software of our institution (Medical Explorer v3r9, 2008). Diagnosis of HCV was retained when serology became positive and HCV RNA was detected. Year Patients on regular f/un MSM‐Bisexual patients on regular f/un (%) HCV serology tests n (%) HCV tests among MSM‐Bisexual patients n (%) 2008 818 258 (31) 292 (35) 118 (45) 2009 869 290 (33) 314 (28) 132 (45) 2010 938 308 (33) 389 (41) 198 (56) 2011 963 335 (35) 425 (44) 193 (57) Summary of resultsThough knowledge of current guidelines was excellent (100%), staff claimed a 87.5% adherence rate to these recommendations. Rate of screening rose gradually between 2008 and 2011, especially after introduction of EACS guidelines in 2009 (Table 1 and Fig. 1). The maximal screening rate was in 2011, with 44% of patients tested among the general HIV population and 57% among MSM bisexual patients. This trend was statistically significant in both populations (p&lt;0.01). The year 2011 displayed a marked increase in diagnosis of HCV infection, with 8 new patients diagnosed in a 963‐patient‐large cohort (all were MSM).ConclusionIn our centre, knowledge of EACS guidelines on screening for HCV was good but adherence to these recommendations is poor, though it improves over time. It is consistent with published rates of compliance to clinical guidelines on screening policies for HCV among STD/HIV specialists (47–54%) [2]. However, it remains low compared to expected rates of 70–100%. Education of clinicians is warranted to increase awareness and further improve adherence to guidelines. Peer review and computer‐based algorithms / reminders could be used in order to increase systematic screening.Evolution of HCV Screening &amp; Acute HCV Hepatitis Diagnosis (2008–2011).image

Fed‐batch cultivation of Escherichia coli expressed designer hepatitis C virus diagnostic intermediate and its evaluation

The present study aimed for an enhanced induction strategy combined with high-level production of a capture antigen of hepatitis C virus (HCV) for use in diagnosis of HCV infection. We have expressed the synthetic gene encoding for HCV multiepitope protein in pET-28a(+) vector and investigated its production in Escherichia coli BL21(DE3) cells using high-cell-density fed-batch cultivation. A maximum cell dry mass of 30 g/L was obtained, and the culture was induced with 1, 5, and 10 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) for ∼4 H at 30°C; a maximum protein production of 1.5 g/L was observed in the case of induction with 10 mM IPTG. The enhanced induction strategy resulted in a ∼15-fold increase as compared to 1 mM IPTG. The protein was purified using a simple immobilized metal affinity chromatography procedure, yielding 16.6 mg/g dry cell weight of pure protein with more than 99% purity. Further, the protein was evaluated for its diagnostic potential by using the commercially available HCV Seroconversion Panel, Worldwide HCV Performance Panel, and Viral Coinfection Panel. The protein showed high sensitivity and specificity, which was comparable to the best performing commercially available enzyme immunoassay (EIA) kits.

Evaluation of an isolation program of hepatitis C virus infected hemodialysis patients in some hemodialysis centers in egypt.

Introduction. Hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality in hemodialysis (HD) patients. Several studies demonstrated nosocomial transmission of HCV among HD patients. Aim. We aimed to evaluate the isolation program of HCV seropositive patients among a group of Egyptian haemodialysis patients to decrease the incidence of HCV seroconversion. Methods. One hundred and fourteen HCV seronegative patients who were receiving regular haemodialysis in different four haemodialysis units in Egypt. The first group included forty six patients on regular hemodialysis in two centers following strict isolation of the HCV seropositive patients, and the second group included sixty eight patients on regular hemodialysis in the other two centers not following this strict isolation. All these patients were followed up over a period of 36 months. Results. There was a significantly higher incidence of HCV seroconversion of patients on hemodialysis in units not following strict isolation of HCV seropositive patients (42.9%) than those on regular hemodialysis in units following strict isolation (14.8%). Conclusions. In HD units with a high prevalence of HCV+ patients, strict isolation of HCV+ patients in combination with implementation of universal prevention measures can limit the spread of HCV infection in HD patients.

Hepatitis B and C infection in haemodialysis patients in Libya: prevalence, incidence and risk factors

BackgroundPatients receiving maintenance haemodialysis (HD) are at higher risk for acquiring Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infections than the general population. Strict infection control measures are essential to prevent nosocomial transmission. We aimed to investigate the incidence and prevalence of HBV and HCV infection in the HD population of Libya as well as risk factors for infection.MethodsAll adult patients receiving maintenance HD (n=2382) in Libyan dialysis centres (n=39) were studied between May 2009 and October 2010. Testing for Hepatitis B surface antigen (HBsAg) and anti-HCV antibodies was performed at initiation of dialysis and every 3–6 months thereafter. Patients who were sero-negative for HBV and HCV (n=1160) were followed up for 1 year to detect sero-conversions.ResultsParticipant median age was 49 years and 58% were male. 831 patients (34.9%) were sero-positive for HBV and/or HCV (anti-HCV positive 31.1%; HBsAg positive 2.6%; both positive 1.2%). Of the sero-positive patients 4.7% were known to be infected before the initiation of HD. The prevalence of HBV±HCV infection varied widely between HD centres from 0% to 75.9%. Sero-positive patients were younger, had longer time on dialysis and more previous blood transfusions. Prospective follow-up revealed an incidence of sero-conversion of 7.7% during 1 year (7.1% HCV; 0.6% HBV). Wide variation in rates of newly acquired infections was observed between dialysis centres. All new HBV cases were referred from centres already treating HBV infected patients. New HCV infections were reported in most centres but the rate of HCV sero-conversion varied widely from 1.5% to 31%. Duration of dialysis, history of previous renal transplant and history of receiving HD in another centre in Libya were significantly associated with sero-conversion.ConclusionPatients on maintenance HD in Libya have a high incidence and prevalence of HCV infection and lower rates of HBV infection. The factors associated with HBV and HCV infection are highly suggestive of nosocomial transmission within HD units. Urgent action is required to improve infection control measures in HD centres and to reduce dependence on blood transfusions for the treatment of anaemia.

Occupational hepatitis C seroconversions in a Brazilian hospital

There are six known cases of occupational human immunodeficiency virus (HIV) seroconversion in Brazil. However, there are neither published cases of occupational hepatitis C virus (HCV) seroconversion nor systematic studies of blood and body fluid exposures (BBFE) that could estimate the risk of HCV or HIV occupational seroconversion in Brazil. To describe the outcomes of BBFEs in a Brazilian hospital over 12 years and 2 months. Statistical analysis of a computerized database of exposure events recorded on printed forms. Incidence rates (IR) were calculated as the number of BBFE per 100 full-time equivalent worker-years. There were 1457 BBFE, 87% being percutaneous and 561 (38%) recurring in health care workers (HCWs) who reported having previous exposures. The highest IRs occurred in laboratory technicians (9.7), medical students (9.5), cleaning staff (9.5) and nursing aids (9.2). The IR in temporary employees was 13.0. Two HCWs, a nursing aid and a surgeon, seroconverted to hepatitis C after HCV exposures involving 13 G catheter needles. The risk of acquiring a HCV infection was 2 in 38 percutaneous HCV exposures, i.e. 5% (95% CI: 0.89-16.3). There were no seroconversions to HIV despite 80 percutaneous HIV exposures. HCV has a higher potential for occupational transmission than HIV. Measures to reduce the risks of BBFE and occupational transmission of blood-borne viral infections should be improved in Brazil.

Injection of drug residue as a potential risk factor for HCV acquisition among Montréal young injection drug users

BackgroundPreparing drugs or medications for injection may leave residues in containers and filters used by injection drug users (IDUs). Little is known about the specific practice of injecting someone else's drug residue as a possible route of HCV transmission. MethodsA prospective cohort study of street youth aged 14–23years old was carried out between July 2001 and December 2005. For this analysis, youth who injected in the six months prior to interview were selected if they were HCV-negative and had completed at least one follow-up visit. Semi-annual visits involved completing an interviewer-administered questionnaire and providing a blood sample for HCV antibody testing. “Sharing behaviors” (any injection preparation behavior that could entail IDUs using injection equipment used by others) including injecting someone else's drug residue were assessed at each interview. Predictors of HCV seroconversion were identified using Cox proportional hazards regression analyses. Two multivariate models were built, one considering sharing behaviors only, and one with cocaine injection forced into it. ResultsOf the 175 participants, 60% were male and their mean age was 20.7years old. In both models, residue injection was a predictor of HCV incidence, although with marginal statistical significance. The adjusted hazard ratio estimates were (2.15; 95% CI 0.99–4.67) and (2.11; 95% CI 0.97–4.62) respectively. ConclusionThis epidemiological study underscores the role injection of drug residue may play in HCV transmission among IDUs. In the current context of the worldwide HCV epidemics, this question deserves further investigation.

Quality control measures for lowering the seroconversion rate of hemodialysis patients with hepatitis B or C virus

Hemodialysis (HD) patients are at high risk of infection by hepatitis B virus (HBV) or hepatitis C virus (HCV). The present study was designed to determine the impact of quality control measures on the prevention of transmission of blood-borne viruses. A total of 6182 adult maintenance HD patients from all HD units in Zhejiang Province were recruited on January 1, 2007. The baseline demographic and clinical characteristics were recorded and all patients were followed up until death or survival at 4 years later. The Quality Control Standards of Hemodialysis were gradually implemented in HD units. The HBV or HCV seroconversion rates of the recruited patients were calculated and compared every year during the observation period. The prevalence of HBV was 8.3% at the beginning of the study, and 6.6% for HCV. With the implementation of the HD quality control measures, the HBV seroconversion rate tended to decrease year by year (X2=6.620, P=0.085), and the HCV seroconversion rate decreased significantly (X2=10.41, P=0.015). Compared with the data in 2007, the HBV seroconversion rate (X2=4.204, P=0.040, relative risk ratio 0.393, 95% CI 0.156-0.991) and the HCV seroconversion rate (X2=7.373, P=0.007, relative risk ratio 0.386, 95% CI 0.189-0.787) decreased significantly in 2010. Quality control measures for HD decreased the seroconversion rates of HBV or HCV in HD patients, showing that updated quality control measures reduce the risk for transmission of blood-borne viruses in the HD population.

Meta‐analysis of hepatitis C seroconversion in relation to shared syringes and drug preparation equipment

We conducted a systematic review of studies reporting seroincidence of hepatitis C infection (HCV) in relation to shared syringes and drug preparation equipment among injection drug users (IDUs). We identified published and unpublished studies that met inclusion criteria. We estimated the relative contributions of shared syringes and drug preparation equipment to HCV transmission using random-effects meta-analysis, and analyzed potential sources of heterogeneity of effects among studies. Syringe sharing was associated with HCV seroconversion [pooled risk ratio (PRR) = 1.94, 95% confidence interval (CI) 1.53, 2.46], as was sharing drug preparation containers (PRR = 2.42, 95% CI 1.89, 3.10), filters (PRR = 2.61, 95% CI 1.91, 3.56), rinse water (PRR = 1.98, 95% CI 1.54, 2.56), combinations of this equipment (PRR = 2.24, 95% CI 1.28, 3.93) and 'backloading', a syringe-mediated form of sharing prepared drugs (PRR = 1.86, 95% CI 1.41, 2.44). Meta-regression results showed that the association between syringe sharing and seroconversion was modified by HCV seroprevalence in the IDU populations. The risk of hepatitis C infection through shared syringes is dependent upon hepatitis C infection seroprevalence in the population. The risk of hepatitis C infection through shared drug preparation equipment is similar to that of shared syringes. Because the infection status of sharing partners is often unknown, it is important for injection drug users to consistently avoid sharing unsterile equipment used to prepare, divide or inject drugs and avoid backloading with an unsterile syringe.