Infected Injection Drug Users Research Articles

Lower Broadly Neutralizing Antibody Responses in Female Versus Male HIV-1 Infected Injecting Drug Users.

Understanding the factors involved in the development of broadly neutralizing antibody (bNAb) responses in natural infection can guide vaccine design aimed at eliciting protective bNAb responses. Most of the studies to identify and study the development of bNAb responses have been performed in individuals who had become infected via homo- or heterosexual HIV-1 transmission; however, the prevalence and characteristics of bNAb responses in injecting drug users (IDUs) have been underrepresented. We retrospectively studied the prevalence of bNAb responses in HIV-1 infected individuals in the Amsterdam Cohort, including 50 male and 35 female participants who reported injecting drug use as the only risk factor. Our study revealed a significantly lower prevalence of bNAb responses in females compared to males. Gender, transmission route and CD4+ count at set point, but not viral load, were independently associated with the development of bNAb responses in IDUs. To further explore the influences of gender in the setting of IDU, we also looked into the Swiss 4.5k Screen. There we observed lower bNAb responses in female IDUs as well. These results reveal that the emergence of bNAbs may be dependent on multiple factors, including gender. Therefore, the effect of gender on the development of bNAb responses is a factor that should be taken into account when designing vaccine efficacy trials.

Prevalence of antiretroviral drug resistance in treatment-naive injecting drug users infected with HIV-1 in Guangzhou, 2008-2015

Objective: To understand the prevalence of drug resistance in treatment-naive injecting drug users (IDUs) infected with HIV-1 in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the newly confirmed HIV-1 positive IDUs living in Guangzhou, being infected through injecting drug use and receiving no antiretroviral therapy at the time of confirmation during 2008-2015. Full sequence of pol protease (PR) gene and partial sequence of reverse transcriptase (RT) gene were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced. After that, data were submitted to the HIV resistance database of Stanford University for drug resistance analysis. Results: Among the 518 HIV-1 infected IDUs, HIV-1pol gene segments were successfully obtained from the serum samples of 407 HIV-1 infected IDUs (78.57%) aged 18-64 (37.44±8.14) years. Among them, males accounted for 89.68% (365/407), those of Han ethnic group accounted for 89.93% (366/407), the unmarried accounted for 55.28% (225/407), and those with education level of junior high school or below accounted for 83.78% (341/407). The distribution of subtypes was predominated by CRF07_BC (47.18%, 192/407), followed by CRF01_AE (23.83%, 97/407), CRF08_BC (22.85%, 93/407), and other subtypes (6.14%, 25/407). The overall prevalence of drug resistance was 3.44% (14/407). The prevalence of drug resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.47%(6/407), 0.25% (1/407) and 1.72% (7/407) respectively. The mutation rate was 12.29% (50/407). No major drug resistance mutation was detected in protease and nucleoside reverse transcriptase regions. Higher rate of V179E mutation in the non-nucleoside reverse transcriptase region was detected in other subtypes and subtype CRF07_BC. Mutation seemed to have occurred in all 8 cases of subtype CRF55_01B in other subtypes. The highest mutation rate of E138A was detected in subtype CRF08_BC (3.23%). Two cases were resistant to all four drugs of NNRTIs. Conclusions: The prevalence of drug resistance in treatment-naive HIV-1 positive IDUs remained at a relatively low level during 2008-2015, in Guangzhou. Most infections were sensitive to existing antiviral drugs. However, drug resistance surveillance in IDUs infected with HIV should be strengthened to prevent the prevalence of multi-drug resistance and cross drug resistance.

CHALLENGES AND PARTICULARITIES IN THE MANAGEMENT OF SEVERE BACTERIAL INFECTIONS IN HIV-INFECTED INJECTING DRUG USERS

Injecting drug use became during last decade a major health public issue, both in Romania and around the world. Incidence of HIV and viral hepatitis in injecting drug users (IDUs) has dramatically increased due to the appearance of new highly addictive drugs (called “ethnobotanicals”) with unknown effects and associated with increased use of unsterile injecting equipment. Severe bacterial infections with poor outcome often complicate the clinical evolution of these patients, especially in case of severe immunosuppression secondary to HIV. We will describe in this review the most common bacterial infections developed due to injecting drug use. Bacterial endocarditis in IDUs are usually right-sided, Staphylococcus aureus being the most common pathogen. These patients also develop skin/soft tissues and respiratory tract infections (due to altered local defense mechanisms), as well as sexually transmitted diseases due to high risk sexual behavior, usually determined by recreational drug use. This behavior is known as “ChemSEX” and is usually practiced by men having sex with men. There were also reported cases of wound botulism, tetanus and even anthrax epidemics among IDUs. HIV infected IDUs usually require complex management with multidisciplinary approach and sometimes surgical treatment.

A cross-sectional survey of receiving no methadone maintenance treatment in HIV infected injecting drug users in Dehong Dai and Jingpo autonomous prefecture, Yunnan province

Objective: To understand the current status of receiving no methadone maintenance treatment (MMT) and influencing factors in HIV infected injecting drug users (IDUs) in Dehong Dai and Jingpo autonomous prefectures, Yunnan province. Methods: Data of survival of IDUs with AIDS in Dehong were collected from " Chinese National Comprehensive HIV/AIDS and Care Information System" in December, 2014. Results: There were 987 IDUs who should receive MMT, the majority of them were males (94.6%, 934/987), aged 35-44 years (53.0%, 523/987) and farmers (77.2%, 762/987). Among the 987 IDUs, 60.2% (592/987) received no MMT. Multivariate logistic regression analysis showed that being female (OR=2.66, 95%CI: 1.21-5.87), in Jingpo ethnic group (OR=3.05, 95% CI: 1.97-4.71) were the major risk factors for receiving no MMT; not being farmers (OR=0.46, 95%CI: 0.31-0.70), in Dai ethnic group (OR=0.53, 95%CI: 0.36-0.79), diagnosed HIV infection history ≥10 years (OR=0.60, 95%CI: 0.45-0.81) were the major protective factors for receiving no MMT. The reasons for receiving no MMT included long distance journey (289, 48.8%), fear of exposure (124, 20.9%), poor daily medication compliance (59, 10.0%), fear of side effects (47, 7.9%), others (73, 12.3%). Conclusions: The proportion of receiving no MMT in IDUs with AIDS in Dehong was high. Being female and farmer, in Jingpo ethnic group, low educational level, short diagnosed HIV infection history were influencing factors for receiving no MMT. The effective intervention measures should be taken to further improve MMT coverage according to the different characteristics of the patients.

FRI-177 - Community pop-up clinic: a harm reduction strategy to engage hepatitis C virus infected injection drug users

FRI-177 - Community pop-up clinic: a harm reduction strategy to engage hepatitis C virus infected injection drug users

Characterization of Occult Hepatitis B Infection Among Injecting Drug Users in Tehran, Iran.

BackgroundHepatitis B virus (HBV) infection is a major health problem worldwide.ObjectivesThe aim of this study was to investigate the frequency of occult hepatitis B infection (OBI) and its associated risk factors, together with the molecular characterization of the virus in injecting drug users of Tehran.Patients and MethodsThe study consisted of 229 injecting drug users. Serum samples were collected and tested for the presence of hepatitis B core antibody (HBcAb) and hepatitis B surface antigen (HBsAg) by an enzyme-linked immunosorbent assay (ELISA). HBV B virus DNA was extracted from the serum samples, and a fragment of the S gene was amplified using the nested polymerase chain reaction. The genotype, subgenotypes, subtype, and S gene mutation of HBV were determined by direct sequencing. A phylogenetic tree was constructed using the neighbor-joining method.ResultsSixty-four (28%) participants were HBcAb positive, 59 cases were HBcAb positive and HBsAg negative, and 5 cases were HBsAg positive. Hepatitis B DNA was found in three HBsAg-positive cases. Thirteen of 59 (22%) individuals were hepatitis B DNA positive. The phylogenetic tree of hepatitis B DNA showed the existence of genotype D. The only significant correlation was between sharing a syringe and OBI.ConclusionsIn comparison with the rate of HBcAb positivity reported in other Iranian studies, the rate was higher in the present study. There were a few variations, genotypes, and subtypes among the infected injecting drug users. Further investigations are needed to unravel the molecular characterization of OBI.

Factors influencing access to methadone maintenance treatment among injecting drug users attending antiretroviral treatment clinics in two counties, Yunnan province

To understand the demographic characteristics of HIV infected injecting drug users (IDUs) with access to antiretroviral therapy (ART) and to identify the factors influencing their access to methadone maintenance treatment (MMT). Outpatients infected with HIV through injecting drug use were selected from the ART clinics in 2 counties in Yunnan province. They were divided into 2 groups, MMT group and non MMT group. Descriptive epidemiologic analysis was conducted on their demographic characteristics, disease history and high risk behaviors and logistic regression analysis was done to identify the factors associated with the access to MMT. Among 635 IDUs (536 males, 99 females) surveyed, 247 received MMT (38.9%), 388 received no MMT(61.1%). The median age was 40.33 years and the median diagnosed HIV infection time was 6.08 years. Multivariate logistic regression indicated that being female (OR=2.40, 95%CI:1.00-5.74), educational level of junior high school (OR=3.28, 95%CI:1.75-6.14), educational level of senior high school or above (OR=7.10, 95%CI:1.90-26.62), more than 6 years of diagnosed HIV infection history (OR=3.84, 95% CI:2.11-6.98) and HCV positive (OR=6.21, 95% CI:3.06-12.58) were the positive factors influencing IDUs' access to MMT. However, being married (OR=0.38, 95%CI:0.20-0.72) or being employed (OR=0.01, 95%CI:0.00-0.02) were the negative factors influencing IDUs' access to MMT. The proportion of HIV infected IDUs who received MMT in ART clinics was still very low in the two counties, targeted intervention measures should be taken to increase the MMT coverage, especially among those who are married or employed.

Diverse origins of hepatitis C virus in HIV co-infected men who have sex with men in Hong Kong.

BackgroundWorldwide, Hepatitis C (HCV) infection has been increasingly recognized in HIV-positive men who have sex with men (MSM). The objective of this study was to characterize the transmission dynamics of acute HCV infection in HIV-positive MSM in Hong Kong using a molecular approach.FindingsWe retrospectively examined 24 HIV-positive MSM with acute HCV infection diagnosed between 2009 and 2014 in Hong Kong. Detection and molecular characterization of HCV was successfully performed in 22 (91.7 %) patients. Genotype 3a was the most prevalent as identified in 14 (63.6 %) MSM, followed by 1a in 4 (18.2 %), 6a in 2 (9.1 %), and 1each (4.5 %) for 1b and 2a. The high prevalence of genotype 3a in MSM was in stark contrast to its rarity among HCV infected injection drug users (IDU) in Hong Kong. Phylogenetic analyses revealed a monophyletic HCV-3a cluster composing of MSM without injection history, and a homologous pair with HCV-6a genotype. There was otherwise no temporal or genetic clustering of the corresponding HIV sequences.ConclusionsThe origin of sexually acquired acute HCV infections in HIV-positive MSM was diverse and not directly linked with local IDU. The transmission dynamics of HIV and HCV infections in MSM in Hong Kong were evidently unrelated.

Hepatitis B virus sero-profiles and genotypes in HIV-1 infected and uninfected injection and Non-injection drug users from coastal Kenya.

BackgroundInformation about HBV sero-markers, infection stages and genotypes in HIV-1 infected and uninfected injection and non-injection drug users (IDUs) in Kenya remains elusive.MethodsA cross-sectional study examining HBV sero-marker, infection stages and genotypes was conducted among HIV-1 infected and uninfected, respectively, IDUs (n = 157 and n = 214) and non-IDUs (n = 139 and n = 48), and HIV-1 uninfected non-drug using controls (n = 194) from coastal, Kenya. HBV sero-marker and infection stages were based on HBV 5-panel rapid test plasma sero-reactivity. DNA was extracted from acute and chronic plasma samples and genotypes established by nested-PCR and direct sequencing.ResultsHBsAg positivity was higher in HIV-1 infected IDUs (9.6 %) relative to HIV-1 uninfected IDUs (2.3 %), HIV-1 infected non-IDUs (3.6 %), HIV-1 uninfected non-IDUs (0.0 %) and non-drug users (2.6 %; P = 0.002). Contrastingly, HBsAb positivity was higher in HIV-1 uninfected IDUs (14.6 %) and non-IDUs (16.8) in comparison to HIV-1 infected IDUs (8.3 %), and non-IDUs (8.6 %), and non-drug users (8.2 %; P = 0.023). HBcAb positivity was higher in HIV-1 infected IDUs (10.2 %) compared to HIV-1 uninfected IDUs (3.3 %), HIV-1 infected non-IDUs (6.5 %), HIV-1 uninfected non-IDUs (2.1 %) and non-drug users (4.6 %; P = 0.038). Acute (5.7 %, 1.4 %, 0.0 %, 0.0 % and 1.5 %) and chronic (5.1 %, 0.9 %, 3.6 %, 0.0 % and 1.5 %) stages were higher in HIV-1 infected IDUs, compared to HIV-1 uninfected IDUs, HIV-1 infected and uninfected non-IDUs and non-drug users, respectively. However, vaccine type response stage was higher in HIV-1 uninfected IDUs (15.4 %) relative to HIV-1 infected IDUs (6.4 %), and HIV-1 infected (6.5 %), and uninfected (10.4 %) non-IDUs, and non-drug users (5.7 %; P = 0.003). Higher resolved infection rates were also recorded in HIV-1 uninfected IDUs (11.2 %) compared to HIV-1 infected IDUs (8.3 %), and HIV-1 infected (7.2 %), uninfected (6.3 %) non-IDUs, and non-drug users (6.7 %; P = 0.479), respectively. Only A1 genotype showing minimal diversity was detected among the study participants.ConclusionHBV sero-markers and infection staging are valuable in diagnosis and genotyping of HBV infections. Among IDUs, higher HBsAg and HBcAb positivity in HIV-1 infected and higher HBsAb positivity in HIV-1 negative IDUs suggests frequent exposure. Additionally, HBV genotype A is the dominant circulating genotype in both high and low risk populations of Kenya.

Transmitted Drug Resistance Mutations in Antiretroviral-Naïve Injection Drug Users with Chronic HIV-1 Infection in Iran.

The growing incidence and transmission of drug resistant HIV-1 strains due to widespread use of antiretroviral therapy (ART) can jeopardize the success of first-line ART. While there is a known moderate prevalence of transmitted drug resistance (TDR) among newly infected Iranians, no data exist about the rate of these primary resistance mutations among the ART-naïve, chronically infected individuals who are, in fact, the main candidates for ART initiation. To address this issue, we collected blood samples from 40 ART-naïve injection drug-users (IDUs) with chronic HIV-1 infection (seroconversion time ranging from 2 to 9 years) living in Sanandaj, Iran, followed by sequencing of the protease and reverse-transcriptase regions from their HIV-1 genome. Phylogenetic analyses of the sequenced regions revealed that all samples were CRF35_AD. Transmitted resistance mutations were interpreted as surveillance drug-resistant mutations (SDRMs) based on the world health organization (WHO) algorithm. The frequency of SDRMs to any class of antiretroviral drugs was 15%, which included mutations to nucleoside reverse transcriptase inhibitors (NRTIs, 10%), with M41L and M184V as the most common (5%), and non-nucleoside reverse transcriptase inhibitors (NNRTIs, 5%), with K103N as the only detected mutation (5%). Although not in the WHO SDRMs list, several minor protease inhibitor resistant mutations listed in the International Antiviral Society-USA panel were identified, of which M36I, H69K, L89M/V/I (each one 100%) and K20R/T (92.5%) can be considered as polymorphic signatures for CRF35_AD.The relatively high rate of TDR mutations in our study raises concerns about the risk of treatment failure in chronically infected IDUs of Sanandaj city. These results suggest that routine resistance testing should be considered before the therapy initiation in this area. Additional surveillance studies are required to generalize this deduction to other cities of Iran.

Hepatitis B virus and hepatitis C virus infection among HIV-1-infected injection drug users in Dali, China: prevalence and infection status in a cross-sectional study.

To assess the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and to investigate their mutual influences on infection status among human immunodeficiency virus type 1 (HIV-1)-seropositive injection drug users (IDUs). A cross-sectional study was conducted among HIV infected IDUs in Dali, China. The participants were tested for serological markers of HBV and HCV infection, alanine transaminase (ALT) activity and CD4(+) T cell count. HCV genotype was determined by sequencing. Of 529 patients, 498 (94.1 %) HIV infected IDUs agreed to participate. The overall prevalence of HCV infection (anti-HCV antibody positive) and spontaneous HCV clearance were 90.8 % (452/498) and 21.5 % (97/452), respectively. Of 411 subjects who had not received HBV vaccine, 296 (72.0 %) were positive for antibody against HBV core antigen (HBcAb), while 274 (66.7 %) were positive for both HCV antibody and HBcAb. HBV antigens were detected in 52 of the HBV-infected subjects (17.6 %). HCV clearance was associated with HBV antigenemia (p = 0.0002) and higher CD4(+) T cell count (p = 0.0294). Resolved HBV infection was associated with HCV genotype 3 (p = 0.0365). HBV and HCV infection are highly prevalent and mutually influence infection status in HIV-1 infected IDUs in Dali, China.

Characterization of HIV-1 envelopes in acutely and chronically infected injection drug users.

BackgroundMucosally acquired human immunodeficiency virus type 1 (HIV-1) infection results from a limited number of variants, and these infecting strains potentially have unique properties, such as increased susceptibility to entry blockers, relative interferon-alpha (IFN-α) resistance, and replication differences in some primary cells. There is no data about the phenotypic properties of HIV-1 envelope variants found early after acquisition among subjects infected through injection drug use (IDU). For the first time, we compared the characteristics of virus envelopes among injection drug users sampled prior to seroconversion (HIV RNA+/Ab-), within 1 year (early), and more than 2 years (chronic) after estimated acquisition.ResultsVirus envelopes from 7 HIV RNA+/Ab- subjects possessed lower genetic diversity and divergence compared to 7 unrelated individuals sampled during the chronic phase of disease. Replication competent recombinant viruses incorporating the HIV RNA+/Ab- as compared to the chronic phase envelopes were significantly more sensitive to a CCR5 receptor inhibitor and IFN-α and showed a statistical trend toward greater sensitivity to a fusion blocker. The early as compared to chronic infection envelopes also demonstrated a statistical trend or significantly greater sensitivity to CCR5 and fusion inhibitor and IFN- α. The HIV RNA+/Ab- as compared to chronic envelope viruses replicated to a lower extent in mature monocyte derived dendritic cells – CD4+ T cell co-cultures, but there were no significant replication differences in other primary cells among the viruses with envelopes from the 3 different stages of infection.ConclusionsSimilar to mucosal acquisition, HIV-1 envelope quasispecies present in injection drug users prior to seroconversion have unique phenotypic properties compared to those circulating during the chronic phase of disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-014-0106-8) contains supplementary material, which is available to authorized users.

Current situation related to antiretroviral therapy and related influential factors on HIV infected injection drug users in the methadone maintenance treatment clinics

To find out the current coverage of antiretroviral therapy (ART) among HIV positive subjects and to identify the major influential factors associated with the participation in ART among them. 291 HIV positive subjects from 6 methadone maintenance treatment (MMT) clinics in Guangxi and Yunnan province were surveyed by questionnaires. 217 males (74.6%) and 74 females (25.4%) were under investigation, with the average age of 38.4 +/- 5.9. Most of them received less than senior high school education, married and unemployed. Results from the single factor logistic regression analysis showed that: working status, living alone, self-reported history of drinking alcohol in the last month, negative attitude towards MMT among family members,poor self-reported compliance to MMT in the last month,lack of incentives in the MMT clinics, reluctance on disclosure of their own HIV status, good self-perception on their health status, lack of communication on ART related topics among family members in the last 6 months, lack of correct attitude and knowledge on ART etc. appeared as the main factors that influencing the participation in ART program among the patients. Data from the multivariate logistic regression analysis showed that factors as: living alone, unwilling to tell others about the status of HIV infection, poor self-perception on HIV infection, lack of discussion of ART related topics within family members in the last 6 months and poor awareness towards ART among the family members etc., were associated with the low participation rate of ART. Conclusion Strengthening the publicity and education programs on HIV positive patients and their family members at the MMT clinics seemed to be effective in extending the ART coverage. Attention should also be paid to increase the family support to the patients.

P3.225 HSV-2 Seroprevalence Among Current Injection Drug Users in Estonia

BackgroundSTI prevalence or incidence data among HIV infected can help to distinguish populations with different levels of sexual HIV transmission risk. Herpes simplex virus type 2 (HSV-2) is considered useful...

Distribution of Hepatitis C Virus Genotypes Among Chronic Infected Injecting Drug Users in Tehran, Iran

Background: Hepatitis C virus (HCV) is the main cause of infection that has the potential to cause chronic liver disease. Injecting drug users (IDUs) have a key role in HCV transmission in Iran. Knowledge of the distribution of various genotypes is essential for successful future research and control strategies. Objectives: The aim of this study was to identify HCV genotypes among chronic infected injecting drug users (IDUs) in Tehran, Iran. Patients and Methods: In this cross sectional study, we investigated HCV genotypes among 36 plasma samples from HCV infected IDUs (35 male and 1female, mean age: 33.67, and age range 20-62 years), referred to Research Center of Iranian Blood Transfusion Organization(IBTO) in Tehran from December 2008 to March 2009.HCV Genotyping was performed using type-specific primers. Results: Genotypes 3a, 1a and 1b were found in 58.3 %, 25% and 16.7 % patients, respectively. Conclusions: Our study demonstrated the high prevalence of genotype 3a among injecting drug users, which is also found in Europe and United states.

Diversity of HIV Type 1 and Drug Resistance Mutations Among Injecting Drug Users in Kenya

Drug use in Kenya dates back to the precolonial period but research among drug users in relation to human immunodeficiency virus (HIV)-associated risk and intervention strategies has been low. To evaluate HIV-1 diversity and drug resistance among injecting drug users (IDUs), a cross-sectional study involving 58 patients was carried out in Mombasa between February and March 2010. HIV-1 RNA was extracted from plasma and polymerase chain reaction using specific primers for HIV-1 reverse transcriptase was done. Population sequencing was done and subtypes were determined phylogenetically. The prevalent HIV-1 subtypes were A1 (52/58), D (5/58), and C (2/58). The prevalence of drug resistance was 13.8% (8/58) with detection of nucleoside reverse transcriptase inhibitor (NRTI) mutations, T215F (n=5), K219Q (n=3), M184V (n=1), and nonnucleoside RTI mutation, K103N (n=1). Antiretroviral therapy (ART) and its monitoring among infected Kenyan IDUs is feasible. Policymakers and service providers in HIV prevention initiatives should improve service delivery so as to measure ART coverage among IDUs to prevent further transmission of drug-resistant variants.

Cross-reactive neutralizing activity in HIV-1 infected injecting drug users

Background Vaccine elicited HIV-1 specific cross-reactive neutralizing humoral immunity may provide protection against acquisition of HIV-1. Several studies have focussed on a better understanding of cross-reactive neutralizing activity (CrNA) in natural infection, but only in homosexual and heterosexual HIV-1 transmission cases. Methods To analyze the prevalence and characteristics of CrNA in HIV-1 infected individuals who reported injecting drug use as the only risk factor, we screened serum samples from 50 male and 35 female participants of the Amsterdam Cohort Studies (ACS) on injecting drug users (IDU) for CrNA across a heterologous 6-viral panel. For comparison, similar data from the ACS on men who have sex with men (MSM) were available. Results HIV-1 infected IDU showed significantly lower geometric mean IC50 values and a lower proportion of individuals that was capable of neutralizing the majority of viruses in the panel as compared to MSM. This difference was however no longer observed when women were excluded from the IDU group. Interestingly, three out of 50 in the male IDU population qualified as elite neutralizer as compared to 1 out of 299 among MSM. Multivariate analysis with viral load at setpoint, CD4+ count at setpoint, gender and transmission route as co-variates revealed only CD4+ count at setpoint as independently associated with CrNA in serum. Conclusion CrNA prevalence and potency in HIV-1 infected IDU was lower than in MSM. This could be attributed to the presence of women in the cohort, rather than the route of exposure, which could be explained by the fact that women had a higher CD4+ T cell count at setpoint, which was the only independent predictor for the presence of CrNA. Our data may implicate that the ability of an HIV-1 vaccine to elicit CrNA may be lower in women and testing for gender dependent future vaccine efficacy may be recommended.

Improved adherence to modern antiretroviral therapy among HIV‐infected injecting drug users

Adherence to antiretroviral therapy (ART) among injecting drug users (IDUs) is often suboptimal, yet little is known about changes in patterns of adherence since the advent of highly active antiretroviral therapy in 1996. We sought to assess levels of optimal adherence to ART among IDUs in a setting of free and universal HIV care. Data were collected through a prospective cohort study of HIV-positive IDUs in Vancouver, British Columbia. We calculated the proportion of individuals achieving at least 95% adherence in the year following initiation of ART from 1996 to 2009. Among 682 individuals who initiated ART, the median age was 37 years (interquartile range 31-44 years) and 248 participants (36.4%) were female. The proportion achieving at least 95% adherence increased over time, from 19.3% in 1996 to 65.9% in 2009 (Cochrane-Armitage test for trend: P < 0.001). In a logistic regression model examining factors associated with 95% adherence, initiation year was statistically significant (odds ratio 1.08; 95% confidence interval 1.03-1.13; P < 0.001 per year after 1996) after adjustment for a range of drug use variables and other potential confounders. The proportion of IDUs achieving at least 95% adherence during the first year of ART has consistently increased over a 13-year period. Although improved tolerability and convenience of modern ART regimens probably explain these positive trends, by the end of the study period a substantial proportion of IDUs still had suboptimal adherence, demonstrating the need for additional adherence support strategies.

P21 Actively injecting drug users can be successfully treated with antiviral therapy for HCV, are unlikely to be re-infected, and significantly reduce their illicit drug use

IntroductionCurrently the predominant mode of transmission of hepatitis C virus (HCV) in the developed world is injection drug use (IDU) and HCV antibody prevalence rates reach 60–90% in those who...

Serodiagnosis of Primary Infections with Human Parvovirus 4, Finland

To determine the prevalence of parvovirus 4 infection and its clinical and sociodemographic correlations in Finland, we used virus-like particle–based serodiagnostic procedures (immunoglobulin [Ig] G, IgM, and IgG avidity) and PCR. We found 2 persons with parvovirus 4 primary infection who had mild or asymptomatic clinical features among hepatitis C virus–infected injection drug users.