Publications by Year: 2019

2019
Williams LD, Korobchuk A, Pavlitina E, Nikolopoulos GK, Skaathun B, Schneider J, Kostaki EG, Smyrnov P, Vasylyeva TI, Psichogiou M, et al. Experiences of Stigma and Support Reported by Participants in a Network Intervention to Reduce HIV Transmission in Athens, Greece; Odessa, Ukraine; and Chicago, Illinois. AIDS BehavAIDS BehavAIDS Behav. 2019;23:1210-1224.Abstract
A growing body of evidence suggests that network-based interventions to reduce HIV transmission and/or improve HIV-related health outcomes have an important place in public health efforts to move towards 90-90-90 goals. However, the social processes involved in network-based recruitment may pose a risk to participants of increasing HIV-related stigma if network recruitment causes HIV status to be assumed, inferred, or disclosed. On the other hand, the social processes involved in network-based recruitment to HIV testing may also encourage HIV-related social support. Yet despite the relevance of these processes to both network-based interventions and to other more common interventions (e.g., partner services), there is a dearth of literature that directly examines them among participants of such interventions. Furthermore, both HIV-related stigma and social support may influence participants' willingness and ability to recruit their network members to the study. This paper examines (1) the extent to which stigma and support were experienced by participants in the Transmission Reduction Intervention Project (TRIP), a risk network-tracing intervention aimed at locating recently HIV-infected and/or undiagnosed HIV-infected people and linking them to care in Athens, Greece; Odessa, Ukraine; and Chicago, Illinois; and (2) whether stigma and support predicted participant engagement in the intervention. Overall, experiences of stigma were infrequent and experiences of support frequent, with significant variation between study sites. Experiences and perceptions of HIV-related stigma did not change significantly between baseline and six-month follow-up for the full TRIP sample, and significantly decreased during the course of the study at the Chicago site. Experiences of HIV-related support significantly increased among recently-HIV-infected participants at all sites, and among all participants at the Odessa site. Both stigma and support were found to predict participants' recruitment of network members to the study at the Athens site, and to predict participants' interviewer-rated enthusiasm for naming and recruiting their network members at both the Athens and Odessa sites. These findings suggest that network-based interventions like TRIP which aim to reduce HIV transmission likely do not increase stigma-related risks to participants, and may even encourage increased social support among network members. However, the present study is limited by its associational design and by some variation in implementation by study site. Future research should directly assess contextual differences to improve understanding of the implications of site-level variation in stigma and support for the implementation of network-based interventions, given the finding that these constructs predict participants' recruitment of network members and engagement in the intervention, and thereby could limit network-based interventions' abilities to reach those most in need of HIV testing and care.
Psichogiou M, Giallouros G, Pantavou K, Pavlitina E, Papadopoulou M, Williams LD, Hadjikou A, Kakalou E, Skoutelis A, Protopapas K, et al. Identifying, linking, and treating people who inject drugs and were recently infected with HIV in the context of a network-based intervention. AIDS CareAIDS CareAIDS Care. 2019;31:1376-1383.Abstract
Identifying and linking people to care soon after HIV infection could limit viral transmission and protect their health. This work aims at describing the continuum of care among recently HIV-infected people who inject drugs (PWID) and participated in an intervention in the context of an HIV outbreak in Athens, Greece. The Transmission Reduction Intervention Project (TRIP) conducted risk network-based contact tracing and screened people for recent HIV infection. A comprehensive approach with a case management component that aimed to remove barriers to accessing care was adopted. Follow-up data on antiretroviral treatment (ART) and HIV-RNA levels were obtained from HIV clinics. TRIP enrolled 45 recently HIV-infected PWID (80% male) with a median viral load at recruitment of 5.43 log(10) copies/mL. Of the recently infected persons in TRIP, 87% were linked to care; of these, 77% started ART; and of those on ART, 89% achieved viral load <200 copies/mL. TRIP and its public health allies managed to get most of the recently HIV-infected PWID who were identified by the program into care and many of them onto ART. This resulted in very low HIV-RNA levels. Treatment as prevention can work if individuals are aided in overcoming difficulties in entry to, or attrition from care.
Revill PA, Chisari FV, Block JM, Dandri M, Gehring AJ, Guo H, Hu J, Kramvis A, Lampertico P, Janssen HLA, et al. A global scientific strategy to cure hepatitis B. Lancet Gastroenterol HepatolLancet Gastroenterol HepatolLancet Gastroenterol Hepatol. 2019;4:545-558.Abstract
Chronic hepatitis B virus (HBV) infection is a global public health challenge on the same scale as tuberculosis, HIV, and malaria. The International Coalition to Eliminate HBV (ICE-HBV) is a coalition of experts dedicated to accelerating the discovery of a cure for chronic hepatitis B. Following extensive consultation with more than 50 scientists from across the globe, as well as key stakeholders including people affected by HBV, we have identified gaps in our current knowledge and new strategies and tools that are required to achieve HBV cure. We believe that research must focus on the discovery of interventional strategies that will permanently reduce the number of productively infected cells or permanently silence the covalently closed circular DNA in those cells, and that will stimulate HBV-specific host immune responses which mimic spontaneous resolution of HBV infection. There is also a pressing need for the establishment of repositories of standardised HBV reagents and protocols that can be accessed by all HBV researchers throughout the world. The HBV cure research agenda outlined in this position paper will contribute markedly to the goal of eliminating HBV infection worldwide.
Schueler K, Ferreira M, Nikolopoulos G, Skaathun B, Paraskevis D, Hatzakis A, Friedman SR, Schneider JA. Pre-exposure Prophylaxis (PrEP) Awareness and Use Within High HIV Transmission Networks. AIDS BehavAIDS BehavAIDS Behav. 2019;23:1893-1903.Abstract
Improved implementation of pre-exposure prophylaxis (PrEP) should be a valuable tool within communities experiencing high HIV incidence, such as black men who have sex with men (MSM). Using baseline data from the Chicago arm of the Transmission Reduction Intervention Project (TRIP), we examined awareness and use of PrEP within HIV potential transmission networks. Transmission Reduction Intervention Project recruited participants ages 18-69 (N = 218) during 2014-2016 from networks originating from recently and chronically HIV-infected MSM and transgender persons. In total, 53.2% of participants had heard of PrEP, while 8 (6.5%) HIV-negative participants reported ever using PrEP. In multivariable regression, PrEP awareness was associated with identifying as gay, attending some college or higher, having an HIV test in the previous 6 months, and experiencing HIV-related social support. PrEP awareness was not associated with experiencing or observing HIV-related stigma. PrEP use was associated with participants knowing two or more other PrEP-users. These findings demonstrate moderate awareness, but low uptake of PrEP within HIV potential transmission networks in Chicago. Future research should explore how to increase PrEP use in these networks and investigate the social dynamics behind our finding that PrEP users are more likely to know other PrEP users.
Serdari D, Kostaki EG, Paraskevis D, Stamatakis A, Kapli P. Automated, phylogeny-based genotype delimitation of the Hepatitis Viruses HBV and HCV. PeerJPeerJPeerJ. 2019;7:e7754.Abstract
BACKGROUND: The classification of hepatitis viruses still predominantly relies on ad hoc criteria, i.e., phenotypic traits and arbitrary genetic distance thresholds. Given the subjectivity of such practices coupled with the constant sequencing of samples and discovery of new strains, this manual approach to virus classification becomes cumbersome and impossible to generalize. METHODS: Using two well-studied hepatitis virus datasets, HBV and HCV, we assess if computational methods for molecular species delimitation that are typically applied to barcoding biodiversity studies can also be successfully deployed for hepatitis virus classification. For comparison, we also used ABGD, a tool that in contrast to other distance methods attempts to automatically identify the barcoding gap using pairwise genetic distances for a set of aligned input sequences. RESULTS—DISCUSSION: We found that the mPTP species delimitation tool identified even without adapting its default parameters taxonomic clusters that either correspond to the currently acknowledged genotypes or to known subdivision of genotypes (subtypes or subgenotypes). In the cases where the delimited cluster corresponded to subtype or subgenotype, there were previous concerns that their status may be underestimated. The clusters obtained from the ABGD analysis differed depending on the parameters used. However, under certain values the results were very similar to the taxonomy and mPTP which indicates the usefulness of distance based methods in virus taxonomy under appropriate parameter settings. The overlap of predicted clusters with taxonomically acknowledged genotypes implies that virus classification can be successfully automated.
Soulie C, Santoro MM, Charpentier C, Storto A, Paraskevis D, Di Carlo D, Gennari W, Sterrantino G, Zazzi M, Perno CF, et al. Rare occurrence of doravirine resistance-associated mutations in HIV-1-infected treatment-naive patients. J Antimicrob ChemotherJ Antimicrob ChemotherJ Antimicrob Chemother. 2019;74:614-617.Abstract
BACKGROUND: Doravirine is a novel HIV-1 NNRTI recently shown to be non-inferior to both darunavir/ritonavir and efavirenz in combination therapy with two NRTIs in treatment-naive patients. Doravirine has an in vitro resistance profile that is distinct from other NNRTIs and retains activity against viruses containing the most frequently transmitted NNRTI mutations. OBJECTIVES: The aim of this study was to examine the prevalence of doravirine resistance-associated mutations in HIV-1-infected treatment-naive patients in Europe. METHODS: From 2010 to 2016, 9764 treatment-naive patients were tested for NNRTI antiretroviral drug resistance by bulk sequencing in Greece, Italy and France. We studied the prevalence of doravirine resistance-associated mutations previously identified in vitro: V106A/M, V108I, Y188L, V190S, H221Y, F227C/L/V, M230I/L, L234I, P236L, Y318F and K103N/Y181C. RESULTS: Among 9764 sequences, 53.0% and 47.0% of patients had B and non-B subtypes, respectively. Overall, the presence of at least one doravirine resistance-associated mutation (n = 137; 1.4%) or the K103N/Y181C mutations (n = 5; 0.05%) was very rare. The most prevalent mutations were V108I (n = 62; 0.6%), Y188L (n = 18; 0.2%), H221Y (n = 18; 0.2%) and Y318F (n = 23; 0.2%). The frequency of doravirine resistance-associated mutations was similar between B and non-B subtypes. In comparison, the prevalence of rilpivirine, etravirine, nevirapine and efavirenz resistance was higher whatever algorithm was used (ANRS: 8.5%, 8.1%, 8.3% and 3.9%, respectively; Stanford: 9.9%, 10.0%, 7.5% and 9.4%, respectively). CONCLUSIONS: The prevalence of doravirine resistance-associated mutations is very low in antiretroviral-naive patients. These results are very reassuring for doravirine use in naive patients.
Souliotis K, Saridi M, Banou K, Golna C, Paraskevis D, Hatzakis A, Smith A. Health and health needs of migrants in detention in Greece: shedding light to an unknown reality. Global HealthGlobal HealthGlobal Health. 2019;15:4.Abstract
BACKGROUND: Population movements have been increasing over the past years in Europe due to socioeconomic factors, global turbulence and conflicts, especially in the area of Middle East. The presence of migrant populations in Europe challenges health systems due to increased requirements for health care provision. However, to date there is limited published data on the burden of disease among this population (in Greece and elsewhere). Our objective was to record burden of disease of undocumented migrants hosted in a Detention Center and therefore generate data for migrant and public health planning. METHODS: Epidemiological data have been collected for 4756 male migrants hosted in a Detention Center from mid 2013 to mid 2015. Of them, 1427 have used health services in the Center, which maintained a detailed record of their medical history and tests. RESULTS: The majority of the study population was aged between 18 and 40 years old. Among those who used health services, most suffered from respiratory (45.6%) and digestive (30.1%) diseases. Injury, poisoning and other external causes accounted for 19.6% of service use, diseases of the skin and subcutaneous tissue for 18.7%, and factors affecting health status and contact with health services for 16.7%. Prevalence of communicable diseases was 15.9% amongst migrants randomly tested. CONCLUSION: Systematic screening and monitoring of diseases and use of health services by migrants in detention centers allows for an evidence based understanding of the burden of disease related to these populations and the investment required to effectively manage it, thus providing critical input to appropriate health planning. Surveillance for communicable diseases amongst migrants in detention centers would also allow for a true picture of the impact of their presence on public health indicators and help address related prejudices and stigma.
Morgan E, Skaathun B, Nikolopoulos GK, Paraskevis D, Williams LD, Smyrnov P, Friedman SR, Schneider JA. A Network Intervention to Locate Newly HIV Infected Persons Within MSM Networks in Chicago. AIDS BehavAIDS BehavAIDS Behav. 2019;23:15-20.Abstract
Individuals with recent/acute HIV-infection have an increased likelihood of disease transmission. To evaluate effectiveness of identifying recent infections, we compared networks of recently and long-term HIV-infected individuals. The Transmission Reduction Intervention Project included two separate arms of recruitment, networks of recently HIV-infected individuals and networks of long-term HIV-infected individuals. Networks of each were recruited and tested for HIV and syphilis infection. The per-seed yield ratios of recruitment were compared between arms. Overall, 84 (41.6%) of 202 participants were identified as HIV-positive. HIV prevalence was higher (p < 0.001) among networks of recent seeds (33/96, 34.4%) compared to long-term seeds (6/31, 19.4%). More individuals were identified with active syphilis infection (p = 0.007) among networks of recent seeds (15/96, 15.6%), compared to networks of long-term seeds (3/31, 9.7%). Network-based recruitment of recently HIV-infected individuals was more effective at identifying HIV and syphilis infection. Allocation of public health resources may be improved by targeting interventions toward networks of recently HIV-infected individuals.
Paraskevis D, Beloukas A, Stasinos K, Pantazis N, de Mendoza C, Bannert N, Meyer L, Zangerle R, Gill J, Prins M, et al. HIV-1 molecular transmission clusters in nine European countries and Canada: association with demographic and clinical factors. BMC MedBMC MedBMC Med. 2019;17:4.Abstract
BACKGROUND: Knowledge of HIV-1 molecular transmission clusters (MTCs) is important, especially in large-scale datasets, for designing prevention programmes and public health intervention strategies. We used a large-scale HIV-1 sequence dataset from nine European HIV cohorts and one Canadian, to identify MTCs and investigate factors associated with the probability of belonging to MTCs. METHODS: To identify MTCs, we applied maximum likelihood inferences on partial pol sequences from 8955 HIV-positive individuals linked to demographic and clinical data. MTCs were defined using two different criteria: clusters with bootstrap support >75% (phylogenetic confidence criterion) and clusters consisting of sequences from a specific region at a proportion of >75% (geographic criterion) compared to the total number of sequences within the network. Multivariable logistic regression analysis was used to assess factors associated with MTC clustering. RESULTS: Although 3700 (41%) sequences belonged to MTCs, proportions differed substantially by country and subtype, ranging from 7% among UK subtype C sequences to 63% among German subtype B sequences. The probability of belonging to an MTC was independently less likely for women than men (OR = 0.66; P < 0.001), older individuals (OR = 0.79 per 10-year increase in age; P < 0.001) and people of non-white ethnicity (OR = 0.44; P < 0.001 and OR = 0.70; P = 0.002 for black and 'other' versus white, respectively). It was also more likely among men who have sex with men (MSM) than other risk groups (OR = 0.62; P < 0.001 and OR = 0.69; P = 0.002 for people who inject drugs, and sex between men and women, respectively), subtype B (ORs 0.36-0.70 for A, C, CRF01 and CRF02 versus B; all P < 0.05), having a well-estimated date of seroconversion (OR = 1.44; P < 0.001), a later calendar year of sampling (ORs 2.01-2.61 for all post-2002 periods versus pre-2002; all P < 0.01), and being naïve to antiretroviral therapy at sampling (OR = 1.19; P = 0.010). CONCLUSIONS: A high proportion (>40%) of individuals belonged to MTCs. Notably, the HIV epidemic dispersal appears to be driven by subtype B viruses spread within MSM networks. Expansion of regional epidemics seems mainly associated with recent MTCs, rather than the growth of older, established ones. This information is important for designing prevention and public health intervention strategies.
Paraskevis D, Hatzakis A. Global molecular epidemiology of HIV-1: the chameleon challenge. Lancet Infect DisLancet Infect DisLancet Infect Dis. 2019;19:114-115.
Paraskevis D, Stylianou DC, Hezka J, Stern Z, Oikonomopoulou M, Mamais I, Kostrikis LG. HCV Phylogeography of the General Population and High-Risk Groups in Cyprus Identifies the Island as a Global Sink for and Source of Infection. Sci RepSci RepSci Rep. 2019;9:10077.Abstract
Hepatitis C virus (HCV) genotype and subtype distribution differs according to geographic origin and transmission risk category. Previous molecular epidemiology studies suggest the presence of multiple subtypes among Cypriot subjects. To investigate HCV genotype- and subtype-specific dissemination patterns, origins, and transmission in Cyprus, we analyzed HCV sequences encoding partial Core-E1 and NS5B regions. Analyzed populations comprised the general population and high-risk cohorts in Cyprus and a globally sampled dataset. Maximum-likelihood phylogeny reconstruction with bootstrap evaluation, character reconstruction using parsimony, and bootstrap trees estimated by ML were performed to identify the geographic origin of HCV subtypes and statistically significant dispersal pathways among geographic regions. Phylogeographic analyses traced the origin of subtypes in the general population and among PWID in Cyprus to unique and overlapping globally distributed regions. Phylogenetic analysis in Core-E1 revealed that most sequences from incarcerated populations in Cyprus clustered with the general population and PWID. We estimate that HCV infections in Cyprus originate from multiple global sources while most HCV transmissions among incarcerated individuals occur locally. This analysis is one of a few studies tracing HCV dispersal patterns using global datasets, and these practices and findings should inform how HCV epidemics are targeted by future prevention policies.
Korobchuk A, Davtyan H, Denisiuk O, Zachariah R, Nikolopoulos GK, Paraskevis D, Skaathun B, Schneider J, Vasylyeva TI, Williams LD, et al. People with high HIV viral load within risk networks: who are these people and who refers them best?. J Infect Dev CtriesJ Infect Dev CtriesJ Infect Dev Ctries. 2019;13:103s-110s.Abstract
INTRODUCTION: Viral load is one of the most important determinants for HIV transmission. Identification of people with high viral load (PHVL) can be effective in limiting onward HIV transmission. In order to improve the identification of these individuals within risk networks, we determined a) the number of PHVL recruited through risk networks b) their socio-demographic, behavioural and clinical characteristics and c) the characteristics of individuals who referred these PHVL to the study. METHODOLOGY: From November 2013 to March 2016, in Odessa, Ukraine, Transmission Reduction Intervention Project (TRIP) was implemented to identify people recently infected with HIV within the risk networks of "seeds" and "venues" where they engaged in risk behaviour. RESULTS: TRIP identified 53 PHVL, of whom 32 (60%) injected drugs; 42 (79%) were unaware of their HIV status; 25 (47%) had more than one sex partner, and only 14 (26%) were using condoms. There were 164 people who referred individuals into the study; 33 of them (20%) referred PHVL. In terms of referrers, those with lower than secondary level of education, not living with a sex partner, and reporting regular condom use were significantly more likely (p < 0.05) to refer PHVL. Most PHVL (38, 72%) and their referrers (27, 82%) were found through venues. CONCLUSIONS: In Odessa city, PHVL are at high risk of transmitting HIV as the majority inject drugs, do not know their HIV status, and have unprotected sex and/or multiple partners. Targeting these individuals for HIV prevention, harm reduction and initiation of antiretroviral treatment (ART) is urgent.
Kostaki EG, Flampouris A, Karamitros T, Chueca N, Alvarez M, Casas P, Alejos B, Hatzakis A, Garcia F, Paraskevis D. Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions. Front MicrobiolFront MicrobiolFront Microbiol. 2019;10:370.Abstract
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41-6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain. Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000-2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively. Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2-79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (t(MRCA)) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999-2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin. Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics.
Lodi S, Günthard HF, Gill J, Phillips AN, Dunn D, Vu Q, Siemieniuk R, Garcia F, Logan R, Jose S, et al. Effectiveness of Transmitted Drug Resistance Testing Before Initiation of Antiretroviral Therapy in HIV-Positive Individuals. J Acquir Immune Defic SyndrJ Acquir Immune Defic SyndrJ Acquir Immune Defic Syndr. 2019;82:314-320.Abstract
BACKGROUND: For people living with HIV, major guidelines in high-income countries recommend testing for transmitted drug resistance (TDR) to guide the choice of first-line antiretroviral therapy (ART). However, individuals who fail a first-line regimen can now be switched to one of several effective regimens. Therefore, the virological and clinical benefit of TDR testing needs to be evaluated. METHODS: We included individuals from the HIV-CAUSAL Collaboration who enrolled <6 months of HIV diagnosis between 2006 and 2015, were ART-naive, and had measured CD4 count and HIV-RNA. Follow-up started at the date when all inclusion criteria were first met (baseline). We compared 2 strategies: (1) TDR testing within 3 months of baseline versus (2) no TDR testing. We used inverse probability weighting to estimate the 5-year proportion and hazard ratios (HRs) of virological suppression (confirmed HIV-RNA <50 copies/mL), and of AIDS or death under both strategies. RESULTS: Of 25,672 eligible individuals (82% males, 52% diagnosed in 2010 or later), 17,189 (67%) were tested for TDR within 3 months of baseline. Of these, 6% had intermediate- or high-level TDR to any antiretroviral drug. The estimated 5-year proportion virologically suppressed was 77% under TDR testing and 74% under no TDR testing; HR 1.06 (95% confidence interval: 1.03 to 1.19). The estimated 5-year risk of AIDS or death was 6% under both strategies; HR 1.03 (95% confidence interval: 0.95 to 1.12). CONCLUSIONS: TDR prevalence was low. Although TDR testing improved virological response, we found no evidence that it reduced the incidence of AIDS or death in first 5 years after diagnosis.
Gountas I, Sypsa V, Papatheodoridis G, Paraskevis D, Kalamitsis G, Anagnostou O, Antaraki A, Fotiou A, Hatzakis A. A hepatitis C outbreak preceded the HIV outbreak among persons who inject drugs in Athens, Greece: Insights from a mathematical modelling study. J Viral HepatJ Viral HepatJ Viral Hepat. 2019;26:1311-1317.Abstract
People who inject drugs (PWID) comprise one of the major transmission risk groups for human immunodeficiency virus (HIV) and hepatitis C virus (HCV). In 2011, Athens experienced a large HIV outbreak among PWID. Significant public health interventions were implemented in response to the HIV outbreak. The aims of this study were to estimate the indirect effects of the HIV interventions on HCV infection and to evaluate the concept of the association between HCV and HIV infections in the case of Athens. A dynamic, stochastic, individual-based model was developed to simulate HCV transmission among PWID. We calibrated the model to reproduce the observed HCV prevalence among PWID in Greece. Two years prior to the HIV outbreak, an undetected HCV outbreak has occurred. In 2009, the incidence of HCV infection increased from 640 (495, 842) cases in 2008 to 1260 (1060, 1500). The mean time from initiation of injecting drug use to HCV acquisition decreased from 29 months in 2008 to 13 months in 2009. After HIV interventions, HCV incidence declined by 64.8% in 2012, compared to 2009. The averted HCV incidence cases attributed to the HIV-implemented interventions were 2200 (1950, 2480), during 2012-2015. The cumulative number incident HCV cases in Athens during 2002-2015 was about 9900 (7800, 12 100). Our results highlight that before the 2011 HIV outbreak in Athens, an HCV outbreak occurred in 2009. Prevention measures for HIV that took place in the Athens metropolitan area in 2012 reduced significantly the incidence of HCV.