Hepatitis C virus transmission dynamics in injection drug users

Hepatitis C Virus Infection Among Injection Drug Users

BACKGROUND

Time to hepatitis C virus (HCV) seroconversion in initially seronegative injection drug users has not been directly measured, and public health planning would benefit from specifying the window of opportunity for prevention of infection, and factors that affect timing of infection.

METHODS

Four hundred eighty-four HCV antibody-negative injection drug users in Seattle, Washington were followed a median of 2.1 years to observe seroconversion. We examined time to HCV seroconversion in relation to subject characteristics using the Kaplan-Meier method and Cox proportional hazards regression. A weighted-average time to HCV seroconversion was calculated among new injectors (injecting < or = 2 years) using seroprevalence and seroincidence data.

RESULTS

There were 134 HCV seroconversions (11.6 per 100 person-years at risk; the 25th percentile of time to seroconversion was 26.2 months). Injection with a syringe used by another injector (adjusted hazards ratio = 1.8; 95% confidence interval = 1.3-3.0) and sharing a cooker or cotton (1.8; 1.0-3.1) were associated with time to HCV seroconversion. Using the estimate of the mean time to seroconversion from first injection in new injectors who were HCV antibody-negative at enrollment (5.4 years), and the midpoint between first injection and study enrollment in new injectors who were HCV antibody-positive at enrollment (0.6 years), the weighted-average time to seroconversion after beginning to inject was estimated to be 3.4 years.

CONCLUSION

The period of susceptibility to HCV infection in the majority of drug injectors appears to be long enough to justify the allocation of substantial resources toward interventions to reduce injection-related risk behavior in these individuals.

Injection drug use and the hepatitis C virus: considerations for a targeted treatment approach--the case study of Canada

Infection with the hepatitis C virus (HCV) is a major public health burden in Canada and globally. The literature shows that injection drug use is currently the primary transmission route for HCV, and that a majority of injection drug users (IDUs) are currently infected with HCV in Canada. This article first reviews the burden of HCV within IDU populations and the transmission risks and the treatment implications specific to IDUs. Traditionally, IDUs have been excluded from HCV treatment unless abstaining from illicit drug use. However, recent research suggests that categorical exclusion is not medically necessary. A series of key questions about the feasibility of offering HCV treatment to IDUs in the specific Canadian context are considered, including concerns related to the motivation of treatment for IDUs, treatment delivery, treatment side effects, HCV reinfection, and the social environment. The article concludes that treatment of HCV-infected illicit drug users is both feasible and may be necessary to reduce transmission and adverse outcomes in this high-risk population.

Hepatitis C: what every case manager should know

Over the next decade, case managers can anticipate encountering increasing numbers of clients with hepatitis C. This article provides a sociopolitical and medical overview of hepatitis C, diagnosis, risk and transmission factors, co-infection of HIV and hepatitis C treatment issues. The article identifies and analyzes policy and practice implications for case managers in health care.

Case-reporting of acute hepatitis B and C among injection drug users

Although public health surveillance system data are widely used to describe the epidemiology of communicable disease, occurrence of hepatitis B and C virus (HBV and HCV, respectively) infections may be misrepresented by under-reporting in injection drug users (IDUs). This study was carried out to examine the relationship between HBV and HCV incidence and case-reporting of hepatitis B and C in Seattle IDUs. Names of participants in a Seattle IDU cohort study who acquired HBV or HCV infection over a 12-month follow-up period were compared to a database of persons with acute hepatitis B and C reported to the health department surveillance unit over the same period. Of 2,208 IDUs enrolled in the cohort who completed a follow-up visit, 63/759 acquired HBV infection, 53/317 acquired HCV infection, and 3 subjects acquired both HBV and HCV. Of 113 cohort subjects who acquired HBV or HCV, only 2 (1.5%) cases were reported; both had acute hepatitis B. The upper 95% confidence limit for case-reporting of hepatitis C in the cohort was 5.7%, and for hepatitis B, it was 7.5%. In this study, reporting of acute hepatitis in IDUs was extremely low, raising questions regarding the use of community surveillance data to estimate underlying incidence in that population group.

Does bleach disinfection of syringes protect against hepatitis C infection among young adult injection drug users?

BACKGROUND

Hepatitis C virus (HCV) has emerged as a major public health problem among injection drug users. In this analysis we examine whether disinfection of syringes with bleach has a potentially protective effect on anti-HCV seroconversion.

METHODS

We conducted a nested case-control study comparing 78 anti-HCV seroconverters with 390 persistently anti-HCV seronegative injection drug users. These data come from the Second Collaborative Injection Drug Users Study, a prospective cohort study that recruited injection drug users from five U.S. cities between 1997 and 1999. We used conditional logistic regression to determine the effect of bleach disinfection of syringes on anti-HCV seroconversion.

RESULTS

Participants who reported using bleach all the time had an odds ratio (OR) for anti-HCV seroconversion of 0.35 (95% confidence interval = 0.08-1.62), whereas those reporting bleach use only some of the time had an odds ratio of 0.76 (0.21-2.70), when compared with those reporting no bleach use.

CONCLUSIONS

These results suggest that bleach disinfection of syringes, although not a substitute for use of sterile needles or cessation of injection, may help to prevent HCV infection among injection drug users.

The association between knowledge of hepatitis C virus status and risk behaviors in injection drug users

AIMS

The three primary objectives of this study were (1) to document the prevalence of the hepatitis C virus (HCV) and awareness of one's status in a sample of street-recruited injection drug users (IDUs); (2) to compare the drug use and HCV risk behaviors of IDUs who reported that they were HCV infected with those who were unaware of their status and subsequently tested positive for HCV antibodies; and (3) to assess associations between risk factors and HCV status by comparing those who tested positive with those who tested negative.

DESIGN

IDUs responded to structured interview questions assessing HCV risk behaviors and were offered a free HCV test.

SETTING

Subjects were recruited through street outreach in Denver, CO, USA.

PARTICIPANTS

Participants were current, out-of-treatment IDUs.

MEASUREMENTS

A modified version of the Risk Behavior Assessment (RBA) and HCV test results were used.

FINDINGS

Of the 197 participants, 20% had been diagnosed previously with HCV. Of those who did not know their status, 61% tested positive for HCV antibodies. Those who knew they were positive had been injecting longer but engaged in fewer HCV risk behaviors than those who did not know their status. Compared to those who tested negative, those who tested positive were more likely to be male, non-white and older. They also had been injecting longer, were more likely to use heroin and/or crack cocaine and consumed more alcohol.

CONCLUSIONS

In this study, a very large proportion of injection drug users who had hepatitis C were unaware of it, and they were engaging in more risk behaviors than those who were aware of their positive status. Risk factors associated with positive HCV status were identified so that those who are most at-risk for HCV might be targeted for testing and subsequent prevention or care.

Psychiatric comorbidity among hepatitis C-positive patients

This study assessed the prevalence of psychiatric disorders among hepatitis C patients at a Veterans Affairs Medical Center. Medical records of 306 randomly selected hepatitis C-positive patients were reviewed for past and present DSM-IV-based psychiatric disorders. Each psychiatric diagnosis was independently confirmed with DSM-IV criteria using symptoms recorded in the chart. Only independently confirmed diagnoses were included for analysis. Mood disorders were present in 38% of patients; personality disorders in 30%; PTSD in 19%; other anxiety disorders in 9%; and psychotic disorders in 17%. Although alcohol use disorders were found in 86% of this patient population, intravenous drug use disorders were present in only 28%. Our data indicate that prevalence rates of a variety of psychiatric disorders are higher in veterans with hepatitis C than in the general population. Mood, anxiety, personality, and psychotic disorders were all relatively common in these patients. Psychiatric disorders may influence the course and treatment of hepatitis C infection, and psychiatrists as well as internists should be aware of the substantial psychiatric comorbidity in patients with this infection.

Factors associated with prevalent hepatitis C: differences among young adult injection drug users in lower and upper Manhattan, New York City

OBJECTIVES

This study examined correlates of prevalent hepatitis C virus (HCV) infection among young adult injection drug users in 2 neighborhoods in New York City.

METHODS

Injection drug users aged 18 to 29 years were street recruited from the Lower East Side and Harlem. Participants were interviewed about drug use and sex practices; venipuncture was performed for hepatitis B virus (HBV), HCV, and HIV serologies.

RESULTS

In both sites, testing positive for HCV antibody (anti-HCV) was associated with having injected for more than 3 years. Additionally, HCV infection was positively associated with injecting with someone known to have had hepatitis (but the association was significant only in the Lower East Side) and with sharing cotton (but the association was statistically significant only in Harlem). Being in drug treatment and older than 24 years were associated with HCV in the Lower East Side but not in Harlem. Receiving money for sex was associated with anti-HCV positivity in Harlem but not in the Lower East Side.

CONCLUSIONS

Several differences in factors associated with prevalent HCV infection existed among 2 populations of young injection drug users from the same city. Indirect transmission of HCV may occur.

Prevalence of hepatitis C and G virus infections among intravenous drug users in Slovenia and Croatia

The prevalence of hepatitis C virus (HCV) and hepatitis G virus (HGV) infections was assessed in 115 Slovenian and 102 Croatian intravenous drug users (IVDUs). HCV and HGV infections were detected in 60 (52.2%) and 61 (53.0%) Slovenian IVDUs and in 70 (68.6%) and 39 (38.2%) Croatian IVDUs, respectively. The established prevalence of both HCV and HGV infection in Croatian IVDUs are the lowest found to date among IVDUs. HCV positive Slovenian and Croatian IVDUs were significantly older and reported longer duration of the intravenous drug use in comparison with HCV negative IVDUs. In contrast, no significant differences in both parameters were found among HGV-positive and -negative IVDUs.