Incidence Rate and Risk Factors for HCV Seroconversion Among Injecting Drug Users in an Area with Low HIV Seroprevalence

Abstract

We conducted a study on injecting drug users attending one of 3 drug treatment centres in Naples, to estimate HIV and hepatitis C virus (HCV) incidence rates and to identify risk factors for seroconversion. Incidence rates were estimated using as denominator the person-time of follow-up of participants who were negative for both HIV and HCV at enrollment and who were retested within 6-12 months. Information on risk factors was collected using a standardized questionnaire. A nested case-control analysis was performed comparing seroconverters with persistently HCV-negative individuals. None of the initially non-infected participants seroconverted for HIV, while the incidence rate for HCV infection was approximately 29 per 100 person-years. Analysis of risk factors showed that age > 28 years and injecting use of cocaine were associated with HCV seroconversion. The protective role of methadone treatment was also marginally significant. Our findings suggest that HCV infection may represent an important public health problem in areas with low HIV circulation. The identification of specific risk factors for HCV infection is needed to plan effective prevention strategies.

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

“…4,8,10,11 At the 2 sites in our study, the HCV infection prevalence was lower than was reported in these studies, and we found a longer time of injecting (>6 years) before reaching a peak prevalence of infection. Additionally, our reported prevalence was lower than the prevalence reported in young injection drug users in Baltimore.…”

“…4,[7][8][9] However, we did not find direct syringe sharing, which is an established risk factor for HCV infection among injection drug users, [8][9][10][11] to be associated with prevalent HCV infection. Nevertheless, several correlates of HCV infection in our sample may have served as markers for syringe sharing.…”

Assessing the impact and cost-effectiveness of needle and syringe provision and opioid substitution therapy on hepatitis C transmission among people who inject drugs in the UK: an analysis of pooled data sets and economic modelling

“…In total, we included 21 published studies 14,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] and seven unpublished studies [33][34][35][36][37]59,60 comprising 1827 HCV incident infections and 8789.7 person-years of follow-up. Overall HCV infection incidence ranged between 0.09 and 42 cases per 100 person-years across the studies.…”

“…Twenty-one of the included studies reported the impact of OST, 14,20,39,40,[45][46][47]49,[51][52][53]55,57,58 including seven unpublished estimates. [33][34][35][36][37]59,60 Seventeen studies reported the impact of NSPs, 14,20,[41][42][43][44]47,48,50,54,56,58 including five unpublished sources, [33][34][35]59,60 and four reported combined measures of NSPs with OST, 14,33,44,47 including one unpublished data source.…”

“…Of the 28 studies, we pooled data from a total of 17 studies to assess the impact of current OST use on HCV infection incidence, 14,39,40,[45][46][47]49,52,53,55,56,58 including five unpublished estimates. 33,36,37,59,60 Current use of OST was defined as reporting use of OST within the past 6 months (yes or no) 33,46,49,58,60 or as reporting use of OST either within 6 months or > 6 months ago, 36 use of methadone at the time of survey, 39,47,52,59 continuous use of OST throughout the follow-up period, 40,45,53 with one study defining continuous use as daily use of methadone (any dosage) in the past 6 months 14 or in the past month.…”