Hepatitis C Virus Seropositivity Research Articles

Hepatitis C Virus Antibody Status and Survival After Renal Transplantation: Meta-Analysis of Observational Studies

The natural history of hepatitis C virus (HCV) among patients after renal transplantation (RT) remains incompletely defined. We conducted a systematic review of the published medical literature on the impact of hepatitis C antibody status on survival of patients who received RT. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the relative risk (RR) for mortality and graft loss with HCV seropositivity across the published studies. We identified eight clinical trials (6365 unique patients); six (75%) were cohort studies and two (2/8 = 25%) controlled trials, respectively. Pooling of study results demonstrated that presence of anti-HCV antibody was an independent and significant risk factor for death and graft failure after RT; the summary estimate for RR was 1.79 (95% CI, 1.57-2.03; homogeneity test, p = 0.0427) and 1.56 (95% CI, 1.35-1.80; homogeneity test, p = 0.0192), respectively. As a cause of death, hepatocellular carcinoma (HCC) and liver cirrhosis were significantly more frequent among anti-HCV positive than anti-HCV negative RT patients. This meta-analysis demonstrates that RT recipients with anti-HCV antibody have an increased risk of mortality and graft failure compared with HCV antibody negative patients.

Association of sex, hygiene and drug equipment sharing with hepatitis C virus infection among non-injecting drug users in New York City

Background: Hepatitis C virus (HCV) rates are higher in non-injecting drug users (NIDUs) than general population estimates. Whether this elevated HCV rate is due to drug use or other putative risk behaviors remains unclear. Methods: Recent non-injection drug users of heroin, crack and/or cocaine were street-recruited from 2000 to 2003 and underwent an interview and venipuncture for HCV antibody assays. Multiple logistic regression analyses were used to assess correlates for HCV infection. Results: Of 740 enrollees, 3.9% were HCV positive. The median age (intraquartile range) was 30 (35–24) years, 70% were male and 90% were Black or Hispanic. After adjustment, HCV seropositives were significantly more likely than seronegatives to be older than 30 [adjusted odds ratio (AOR) = 5.71], tattooed by a friend/relative/acquaintance [AOR = 3.61] and know someone with HCV [AOR = 4.29], but were less likely to have shared nail or hair clippers, razors or a toothbrush [AOR = 0.32]. Conclusions: Non-commercial tattooing may be a mode of HCV transmission among NIDUs and education on the potential risk in using non-sterile tattooing equipment should be targeted toward this population. While no evidence was found for HCV transmission through NIDU equipment sharing or sexual risk behavior, further research is still warranted.

Seroprevalence of hepatitis C virus and associated risk behaviours: a population-based study in San Juan, Puerto Rico

Limited information about the epidemiology of hepatitis C virus (HCV) infection is available in Puerto Rico, one of the areas hardest hit by the human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) epidemic. We estimated the prevalence of HCV infection and identified correlates of seropositivity in the municipality of San Juan, Puerto Rico. A probability cluster design was employed to select a sample of households representative of the population aged 21-64 years in San Juan during 2001-2002. All 964 subjects completed a face-to-face interview to gather data on demographics and self-reported risk behaviours followed by venipuncture for HCV antibody testing. Variables that were at least marginally associated with HCV seroprevalence (P < 0.10) in the bivariate analyses were considered for inclusion into the multiple logistic regression model to estimate the adjusted prevalence odds ratio (POR). Overall weighted prevalence of HCV infection was 6.3% (95% CI 3.6-10.9%). A significant (P < 0.05) higher prevalence was observed among subjects with the following characteristics: age 30-49 (9.5%), male sex (10.6%), < or =12 years of education (9.6%), no health coverage (12.6%), lifetime heroin use (39.2%), lifetime cocaine use (39.6%), tattooing practices (34.2%), history of imprisonment (32.8%), and self-reported histories of hepatitis B virus infection (30.4%) and HIV/AIDS (92.1%). Multivariate logistic regression revealed that tattooing practices (POR = 8.9; 95% CI 1.7-44.7), lifetime cocaine use (POR = 5.5; 95% CI 2.2-13.5), blood transfusions prior to 1992 (POR = 4.0; 95% CI 1.6-10.1), lifetime heroin use (POR = 3.3; 95% CI 1.4-7.8), and history of imprisonment (POR = 2.3; 95% CI 1.1-4.9) remained significantly associated with HCV seropositivity. The large prevalence of HCV infection observed in Puerto Rican adults residing in San Juan suggest that HCV infection is an emerging public health concern and merits further investigation.

Lichen planus and hepatitis C virus: a multicentre study of patients with oral lesions and a systematic review

An association between hepatitis C virus (HCV) infection and lichen planus (LP) has been investigated, but results have been inconsistent. To investigate the relationship between LP and HCV seropositivity. Methods In a cross-sectional study we tested the sera of 303 consecutive newly diagnosed patients with histologically proven LP referred to three Italian centres for the presence of anti-HCV IgG. A comparable control group was also tested. Next, in a systematic review, studies were identified by searching different databases in April 2004. Inclusion criteria were: (i) analytical study design; (ii) clinical and histological diagnosis of LP; and (iii) serological test for anti-HCV antibodies as main outcome. The risk of bias was assessed on the basis of characteristics of the study group, appropriateness of the control group and study design. Pooled data were analysed by calculating odds ratios (ORs), using a random effects model. In the cross-sectional study, nearly one in five (19.1%) of the LP group was HCV positive, while a much lower prevalence of infection was found in the control group (3.2%) [OR 7.08; 95% confidence interval (CI) 3.43-14.58]. The systematic review yielded 25 relevant studies, six of which had a low risk of bias. There was a statistically significant difference in the proportion of HCV-seropositive subjects among patients with LP, compared with controls (OR 4.80; 95% CI 3.25-7.09). Following subgroup analyses, the variability of HCV prevalence in patients with LP seemed to depend on geographical area, but not on age. Anti-HCV circulating antibodies are more common in patients with LP than in controls, although such an association may not be significant in some geographical areas.

Risk behaviors and antibody hepatitis B and C prevalence among injecting drug users in south-western Sydney, Australia.

Hepatitis C virus (HCV) infection is now the leading notifiable disease in Australia. The current study aimed to determine the prevalence of HCV and hepatitis B virus (HBV) infection and associated risk behaviors among injecting drug users (IDUs) screened in south-western Sydney as part of a multisite prospective cohort study. Using a combination of snowball sampling and word-of-mouth recruitment strategies, 377 IDUs were interviewed using a structured questionnaire and tested for exposure to HCV and HBV. Entry criteria were injecting drug use in the previous 6 months and antibody HCV serostatus not known to be positive. More than one-third (36.6%) tested HCV antibody positive and one-quarter (28%) had been exposed to HBV. Independent predictors of HCV seropositivity were HBV core antibody positive serostatus, incarceration in the past year, injecting in public, Asian ethnicity and duration of injecting. Individual risk behaviors, including sharing needles and syringes, sharing other injecting equipment and being injected by others, were not significant in either bivariate or multivariate models. Results indicate an urgent need for structural interventions designed to reduce the exposure of IDUs, particularly indigenous Australian and Asian injectors, to risk environments. Structural interventions, including population-based hepatitis B immunization, expanded access to needle and syringe programs and drug treatment, prison diversion programs and medically supervised injecting facilities, should be incorporated into existing blood-borne virus prevention efforts.

Hepatitis C virus seroprevalence among mothers delivering at the Korle-Bu Teaching Hospital, Ghana

To determine the Hepatitis C virus (HCV) carrier rate among mothers, and to determine if selected sociodemographic characteristics are associated with HCV seropositivity. Maternity Unit of the Korle-Bu Teaching Hospital (KBTH). A cross-sectional serological survey of mothers delivering at the KBTH. Women who had singleton live births and fresh stillbirths in the two labour wards of the KBTH were randomly selected for screening from 1st March to 30th September, 2001. A structured pre-tested questionnaire was used by trained research assistants to collect and record data on medical and sociodemographic characteristics of the subjects. Maternal blood samples were taken and stored at the Public Health Reference Laboratory. The second generation Murex diagnostics ELISA kit was used to test the maternal sera for HCV antibodies. Sixteen (2.5%, 95% CI, 1.5-4.1%) of the 638 subjects were HCV seropositive. None of the medical and sociodemographic characteristics examined showed any association with HCV seropositivity. No subject or her sexual partner was a drug injector. The carrier rate of 2.5% of HCV infection found in this study is near the top end of the range found in unselected pregnant populations from other parts of the world. Knowing the prevalence rate of HCV infection in our pregnant population will help policy-makers on the cost effectiveness of available intervention measures.

Hepatitis C virus infection as a likely etiology of intrahepatic cholangiocarcinoma.

Although hepatitis C virus (HCV)-related cirrhosis has been suggested as a risk factor for intrahepatic cholangiocarcinoma (ICC), few sizeable studies have tested this hypothesis. We investigated ICC risk factors, with special reference to HCV infection. We conducted a hospital-based case-control study including 50 ICC patients and 205 other surgical patients without primary liver cancer. HCV seropositivity was detected in 36% of ICC patients and 3% of controls. By univariate analysis, the odds ratio (OR) for association of anti-HCV antibodies with development was 16.87 (95% confidence interval (CI), 5.69 to 50.00). History of blood transfusion or diabetes mellitus, elevated serum total bilirubin, elevated aspartate aminotransferase and alanine aminotransferase, decreased serum albumin and decreased platelet count were identified as other possible ICC risk factors. By multivariate analysis, anti-HCV antibodies (adjusted OR, 6.02; 95% CI, 1.51 to 24.1), elevated alanine aminotransferase, decreased serum albumin, and decreased platelet count were found to be independent risk factors for ICC development. As liver status worsened, the adjusted OR for ICC tended to increase. HCV infection is a likely etiology of ICC in Japan.

Failure to diagnose recent hepatitis C virus infections in London injecting drug users.

Hepatitis C virus (HCV) infection results in chronic liver disease in a substantial proportion of those infected. Most new cases of HCV infection in the UK are associated with intravenous drug use. It is important to identify these infections because of the implications for the future health of the individuals concerned and for the control of further spread of infection. However, as hepatitis C infection is characterised by a relatively long asymptomatic period of seronegative viraemia, a laboratory diagnostic protocol that does not test HCV seronegative samples for the presence of HCV RNA may wrongly designate HCV viraemic seronegative individuals as uninfected. Amongst 424 injecting drug users whose serum was sent to our diagnostic laboratory for "HCV screening" over a 14-month period, the prevalence of HCV seropositivity was 48.4%. We retrospectively identified seven individuals for whom there was evidence of recent acquisition of HCV infection. Three of these infections were identified using our routine diagnostic protocol: testing for the presence of HCV-specific antibody and performing HCV RNA testing only on seropositive and seroindeterminate specimens. However, four cases were only identified by HCV RNA testing of HCV seronegative serum. On the basis of these observations, we estimate the incidence of HCV infection amongst London injecting drug users as being 14.3 per 100 person-years. We advocate that all HCV seronegative blood samples obtained from injecting drug users should be tested for the presence of HCV RNA, and suggest that this could be done efficiently by nucleic acid testing the specimens in small pools. .

Association of diabetes and hepatitis C infection: epidemiologic evidence and pathophysiologic insights.

Up to one third of patients with chronic hepatitis C virus (HCV) develop type 2 diabetes mellitus (DM). This prevalence is much higher than that observed in the general population, and in patients with other chronic liver diseases such as hepatitis B virus, alcoholic liver disease, and primary biliary cirrhosis. Further, HCV seropositivity in patients with DM appears to be higher than in the general population. Post- liver transplantation DM also appears to be higher among patients with HCV. In this article, we review the epidemiologic association between HCV and DM, highlighting the most recent pathophysiologic insights into the mechanisms underlying this association.

Sentinel surveillance of HIV and hepatitis C virus in two urban emergency departments

This study was designed to determine the prevalence of HIV and hepatitis C virus (HCV) in a specific population, and to distinguish between known and previously unrecognized infections in the emergency department (ED) setting. Consecutive patients aged 15 to 54 years who had presented to the EDs of 2 urban hospitals during a 6-week period were enrolled in a prospective cross-sectional study if a complete blood count had been obtained as part of their care. The study patients were initially cross-referenced against local databases of known HIV and HCV seropositive patients. After removal of all personal identifiers, the study patients' leftover blood was serotested for HIV and HCV, and seroprevalences were calculated. Univariate and multivariate analyses were performed to identify factors associated with HIV and HCV infection. Of 3057 individuals whose files were analyzed, 1457 (48%) were male and 7% (213) were Aboriginal. Overall, 302 patients (10%; 95% confidence interval [CI], 9%-11%) were seropositive for HCV and, of these, only 132 (44%) were previously known to be. HCV seropositivity was associated with Aboriginal status, age, male gender, hospital site and HIV infection (all p < 0.001). In contrast, 39 patients (1%; 95% CI, 1%-2%) were HIV seropositive. Of these, 32 (82%) were previously known to be HIV positive, and 27 (69%) were HCV seropositive. HIV seropositivity was only associated with HCV infection (p < 0.001). The rate of previously undetected infections was relatively low for HIV but high for HCV. Emergency physicians in urban settings will frequently encounter patients not known to be HCV positive and not identified as such. These results emphasize the need for more effective preventive measures in the community and the importance of observing standard (universal) precautions in ED practice.

HIV and Hepatitis C Virus Testing and Seropositivity Rates in Canadian Federal Penitentiaries: A Critical Opportunity for Care and Prevention

Incarcerated persons experience high rates of HIV and hepatitis C virus (HCV) infection, but little is known about the burden of these bloodborne viruses among federal penitentiary inmates in Canada. The present study investigates rates of testing and seropositivity for HIV and HCV among inmates in all 53 Canadian federal penitentiaries. A cross-sectional design using surveillance data on voluntary HIV and HCV antibody testing in 2002 were applied to estimate the rate of testing uptake and the rate of incident seropositive tests among new admissions to federal penitentiaries and resident inmates. Rates of testing and infection were further examined by sex and region. Seroprevalence of HIV and HCV was estimated from the number of cumulative positive tests to year-end. Of 7670 new admissions during 2002, 30% were tested for HIV and HCV. Test seropositivity rates in this group were 0.7% for HIV and 10% for HCV. Of the 12,426 resident inmates, 28% were tested for HIV and 27% for HCV. Seropositivity rates in this group were 0.3% for HIV and 7% for HCV. Seroprevalence rates at yearend for 2002 were 2.0% for HIV and 26% for HCV and were substantially higher among women offenders (HIV: 3.7% of women, 1.9% of men; HCV: 34% of women, 26% of men). Variations in testing uptake and test seropositivity were observed across regions. The present study underscores the value of continued monitoring and evaluation of trends in HIV and HCV infection, which remain prevalent in federal penitentiaries. Higher rates of testing are warranted for at-risk inmates to improve early detection of infection and provide infected inmates with timely care and treatment. For those who remain free of infection, testing can provide the additional benefits of exposing inmates to health counselling and for the reinforcement of prevention messages. The period of incarceration is also a critical opportunity to link inmates with outside resources in preparation for release to the community.

Initial steroid-free immunosuppression after liver transplantation in recipients with hepatitis C virus related cirrhosis.

Steroids can increase hepatitis C virus (HCV) replication. After liver transplantation (LTx), steroids are commonly used for immunosuppression and acute rejection is usually treated by high steroid dosages. Steroids can worsen the outcome of recurrent HCV infection. Therefore, we evaluated the outcome of HCV infected liver recipients receiving initial steroid-free immunosuppression. Thirty patients undergoing LTx received initial steroid-free immunosuppression. Indication for LTx included 7 patients with HCV related cirrhosis. Initial immunosuppression consisted of tacrolimus 2X0.05 mg/kg.d po and mycophenolate mofetil (MMF) 2X15 mg/kg.d po. The tacrolimus dosage was adjusted to trough levels in the target range of 10-15 microg/L during the first 3 mo and 5-10 microg/L thereafter. Manifestations of acute rejection were verified histologically. Patient and graft survival of 30 patients receiving initial steroid-free immunosuppression was 86% and 83% at 1 and 2 years. Acute rejection occurred in 8/30 patients, including 1 HCV infected recipient. All HCV-infected patients had HCV genotype II (1b). HCV seropositivity occurred within the first 4 mo after LTx. The virus load was not remarkably increased during the first year after LTx. Histologically, grafts had no severe recurrent hepatitis. From our experience, initial steroid-free immunosuppression does not increase the risk of acute rejection in HCV infected liver recipients. Furthermore, none of the HCV infected patients developed serious chronic liver diseases. It suggests that it may be beneficial to avoid steroids in this particular group of patients after LTx.

This month in Gastroenterology

This month in Gastroenterology

Hépatite chronique virale C

The hepatitis C virus (HCV) is a common cause of cirrhosis and hepatocellular carcinoma, as well as the most common reason for liver transplantation. HCV transmission occurs through exposure to infected blood (blood transfusion before 1990), injection drug users. Publications have implied that up to 40% of HCV seropositives do not have recognized parenteral risk factors. After contamination, 50 à 80% of patients do not clear virus, but develop chronic hepatitis C. HCV is a RNA virus; the rate of viral is high (10 12 virious per day) and the turnover of virus is rapid, the half-life of 2 to 3 hours. The diagnosis of chronic hepatitis C is based on both anti-HCV detection using enzyme immunoassays (EIA) and HCV RNA detection using a polymerase chain reaction (PCR) method. The HCV genotype (numbered 1 to 6) should be determined before treatment. The chronic sequelae of hepatitis C include progressive hepatic fibrosis, cirrhosis and hepatocellular carcinoma. In the majority of patients with chronic hepatitis C, the progression of fibrosis is insidious and slow. The factors associated with rapid progression of fibrosis are excessive alcohol consumption, older age, viral co-infection, immune deficiency, overweight. Liver biopsy provides a unique source of information on fibrosis, but significant progress has been made in the non invasive assessment of hepatitis fibrosis. Treatment is recommanded for patients with on risk of developing cirrhosis, characterized by bridging fibrosis. Combinaison therapy (peg interferon and ribavirine) should be used in the treatment of hepatitis C. Choise of duration of therapy and dose of ribavirin be based on HCV genotype. Patients with genotype 1 achieve sustained virological response of 45 à 50%, compared with rates of 80% with genotypes 2 or 3.

Hepatitis C virus (HCV): prevalence in a gynecological urgent care clinic population.

To determine the prevalence of hepatitis C virus (HCV) among women seeking urgent gynecological care. Women were asked to complete a short self-assessment screening of HCV risk. Those answering yes to any of the screening questions were offered HCV testing and were asked to complete a more detailed questionnaire. Among the 125 women who completed the screening questionnaire, 80% (100) answered yes to one or more of the screening questions. Of the 99 women who underwent testing, six (6.1%) were HCV seropositive; a history of injection drug use was the only finding associated with HCV seropositivity (R.R 9.7: 95% CI 1.90-49.40). Women seeking urgent outpatient gynecological care, particularly those who are injection drug users, are at a substantial risk of HCV infection. A careful risk assessment should be completed in order to identify women who should be offered HCV testing.

Cost-effectiveness of treatment for chronic hepatitis C infection in an evolving patient population.

Approximately 2.7 million US individuals are chronically infected with the hepatitis C virus (HCV). As public health campaigns are pursued, a growing number of treatment candidates are likely to have minimal evidence of liver damage. To examine the clinical benefits and cost-effectiveness of newer treatments for chronic hepatitis C infection in a population of asymptomatic, HCV sero-positive but otherwise healthy individuals. Cost-effectiveness analysis using a Markov model of the natural history of HCV infection and impact of treatment. We used an epidemiologic model to derive a range of natural history parameters that were empirically calibrated to provide a good fit to observed data on both prevalence of HCV seropositivity and time trends in outcomes related to HCV infection. Cohorts of 40-year-old men and women with elevated levels of alanine aminotransferase, positive results on quantitative HCV RNA assays and serologic tests for antibody to HCV, and no histological evidence of fibrosis on liver biopsy. Monotherapy with standard or pegylated interferon alfa-2b; combination therapy with standard or pegylated interferon plus ribavirin. Lifetime costs, life expectancy, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. The probability of patients with chronic HCV developing cirrhosis over a 30-year period ranged from 13% to 46% for men and from 1% to 29% for women. The incremental cost-effectiveness of combination therapy with pegylated interferon for men ranged from 26 000 dollars to 64 000 dollars per QALY for genotype 1 and from 10 000 dollars to 28 000 dollars per QALY for other genotypes; and for women ranged from 32 000 dollars to 90 000 dollars for genotype 1 and from 12 000 dollars to 42 000 dollars for other genotypes. Because the benefits of treatment were realized largely in the form of improvements in health-related quality of life, rather than prolonged survivorship, cost-effectiveness ratios expressed as dollars per year of life were substantially higher. Results were most sensitive to assumptions about the gains and decrements in health-related quality of life associated with treatment. While newer treatment options for hepatitis C appear to be reasonably cost-effective on average, these results vary widely across different patient subgroups and depend critically on quality-of-life assumptions. As the pool of persons eligible for treatment for HCV infection expands to the more general population, it will be imperative for patients and their physicians to consider these assumptions in making individual-level treatment decisions.

The association between hepatitis C virus and HIV-1 in preparatory cohorts for HIV vaccine trials in Thailand.

To study the association between hepatitis C virus (HCV) and HIV-1, and HCV seropositivity as an indicator of HIV-1 risk behavior for HIV vaccine preparatory cohorts in Thailand. Cross-sectional study of HIV-1-infected persons identified at screening for potential HIV vaccine trial cohort studies. Sera from HIV-1-infected and uninfected volunteers was matched by age, sex, and community, and tested for HCV reactivity. Logistic regression methods were used to measure associations between HIV-1, HCV and other risk factors for HIV infection. The prevalence of HCV among HIV-negative controls was 8.3% (6/72) for men and 4.2% (5/118) for women. Co-infection with HIV and occurred in 50.7% (37/73) of men and 3.4% (4/118) of women. Among men who reported injection drug use (IDU), 96.4% (27/28) were HCV seropositive. No women reported IDU. HCV was associated with HIV infection [odds ratio (OR), 11.3; 95% confidence interval (CI), 4.4-29.3] and IDU (OR, 12.0; 95% CI, 3.4-41.9) among men, but not women (OR, 0.8; 95% CI, 0.2-3.0). After adjustment for potential confounding, HCV, but not IDU, remained strongly associated with HIV-1 infection among men (OR, 9.4; 95% CI, 2.7-32.6). The strong associations between HCV seropositivity, HIV-1 infection, and IDU history suggest that IDU was reported accurately in this study. The surprisingly high prevalence of HCV among HIV-1-infected young men may assist health policy makers in the choice of behavioral interventions for this important subgroup of the population.

The tattooing paradox: are studies of acute hepatitis adequate to identify routes of transmission of subclinical hepatitis C infection?

The Hepatitis Branch of the Centers for Disease Control and Prevention does not recommend routine regulation and inspection of tattoo parlors because surveillance of hepatitis C virus (HCV)-positive acute hepatitis cases rarely identifies tattooing in the incubation period. However, the majority of seroepidemiological studies agree that tattooing is a strong, independent risk factor for subclinical HCV seropositivity. We postulated that this paradox might be explained if transmission of HCV by tattooing generally caused subclinical HCV seropositivity without the acute hepatitis syndrome. We reanalyzed data from a prior seroepidemiological study of 626 consecutive patients who were unaware of their HCV serologic status and whose risk factors were ascertained by interview of an internist. Separate multiple logistic regression models were developed to predict a history of the acute hepatitis syndrome and HCV seropositivity. A history of injection-drug use was strongly associated with both HCV seropositivity (adjusted odds ratio [AOR], 7.2; 95% confidence interval [CI], 3.1-16.5) and a history of acute hepatitis (AOR, 5.9; 95% CI, 2.5-13.8), whereas having a commercially applied tattoo was strongly associated with HCV seropositivity (AOR, 6.5; 95% CI, 2.9-14.4) but not with a history of acute hepatitis (AOR, 1.2; 95% CI, 0.5-3.3). Intravenous injection of relatively large quantities of innocula of HCV may be more likely to result in the relatively rare acute HCV hepatitis syndrome, whereas intradermal exposure to small quantities of innocula may cause only subclinical HCV infections. If so, public policy on regulation and inspection of tattoo parlors should be determined by seroepidemiological studies rather than by the Sentinel Counties Study of acute hepatitis cases.

Assessment of iatrogenic transmission of HCV in Southern Italy: was the cause the Salk polio vaccination?

Since the first studies on hepatitis C virus (HCV) prevalence were published, it has been evident that southern Italy is an area of hyperendemicity. A recent study conducted in southern Italy suggested that the high prevalence of HCV infection might be the result of past iatrogenic transmission. Polio vaccination with the parenteral Salk vaccine between 1956 and 1965 by multiple use of unsafe glass syringes may have been one of the major causes of the spread of HCV infection among southern Italian adults who are now older than 40 years of age. Persons born between the 1940s and early 1960s have a nearly 3-fold increased risk of HCV seropositivity than the younger age group. The findings are consistent with a cohort effect of exposure to the Salk parenteral vaccination.

Estimation of the number of injecting drug users attending an outreach syringe-exchange program and infection with human immunodeficiency virus (HIV) and hepatitis C virus: the AjUDE-Brasil project.

This study estimated the number of street injecting drug user (IDU) clients of a syringe-exchange program (SEP) who were infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). A two-sample capture-recapture method was carried out. The first capture listed all interviewed IDUs outreached for syringe exchange from April 1 to May 1, 1998; the second capture involved those outreached from May 2 to June 6, 1998. Blood spots were collected for HIV and HCV serologies. Analysis used captured probability model varying with time. We interviewed 55 IDUs in the first capture and 99 in the second; 17 participated in both samples. An estimate of 317 IDUs attending the SEP was obtained (95% confidence interval [CI] 235-467). Based on the overall seroprevalence rates for HIV (47.7%) and HCV (53.1%), it was estimated that 151 IDUs were HIV infected (95% CI 112-223) and 168 (95% CI 125-248) were HCV infected. Enumeration of IDUs associated with estimates of the total number of HIV and HCV seropositives provide a powerful tool for SEPs to help monitor the number of IDUs, to plan for provisions, and to organize the new demands on existing health facilities for HIV and HCV care.