We examined the association of individual demographic and behavioral attributes, partnership (dyad) and social network characteristics with unprotected sex in the heterosexual dyads of IDUs in St Petersburg, Russia. Of the individual-level characteristics female gender and younger age; and of the dyad-level characteristics sharing injecting equipment, social exposure to the sex partner (“hanging out with” or seeing each other daily), and both partners self-reporting being HIV infected were associated with unprotected sex. Although self-reported HIV discordant couples were less likely to engage in unprotected sex, it was reported in over half of self-reported HIV discordant relationships. This study highlights the intertwining of sexual risk and injecting risk, and the importance of sero-sorting based on perceived HIV status among IDU sexual partnerships in St Petersburg, Russia. A combination of social network and dyad interventions may be appropriate for this population of IDUs, especially for IDUs who are both injecting and sex partners, supported by free and confidential rapid HIV testing and counseling services to provide a comprehensive response to the wide-spread HIV epidemic among IDUs in St Petersburg.
Injecting drug users; Risk networks; Sexual risk; HIV infection risk; Dyad analysis; Russia
In this study, we investigated how individual attributes, dyad characteristics and social network characteristics may influence engaging in receptive syringe sharing, distributive syringe sharing and sharing cookers in injecting partnerships of IDUs in St Petersburg, Russia. We found that all three levels were associated with injecting equipment sharing, and that dyad characteristics were modified by characteristics of the social network. Self-reported HIV discordance and male gender concordance played a role in the risk of equipment sharing. Dyad interventions may not be sufficient to reduce injecting risk in IDU partnerships, but a combination of dyad and network interventions that target both IDU partnerships and the entire IDU population may be more appropriate to address injecting risk among IDUs.
Injecting drug users; Risk networks; Injecting risk; Dyad analysis; Russia
To assess among injecting drug users (IDUs) in St Petersburg, Russia, the urban environmental, social norms, and individual correlates of unsafe injecting.
Between December 2004 and January 2007 IDUs (N=446) were interviewed in St. Petersburg, Russia.
Prevalence of HCV was 96% and HIV 44%; 17% reported receptive syringe sharing after an HIV infected IDU (RSS); 49% distributive syringe sharing (DSS); 76% sharing cookers, 73% sharing filters and 71% syringe mediated drug sharing (SMS) when not all syringes were new. Urban environmental characteristics correlated with sharing cookers and SMS; and social norms correlated with RSS, DSS and sharing cookers. Individual correlates included cleaning used syringes (all five dependent variables) and self-report of HIV infection (RSS and DSS).
HIV status disclosure is an unreliable but frequently used HIV prevention method among IDUs in St. Petersburg, who reported alarmingly high levels of injecting equipment sharing. Voluntary counseling and testing should be widely available for this population. Ethnography is needed to assess the effectiveness of the syringe cleaning process. Prevention interventions need to be ongoing among IDUs in St. Petersburg, and should incorporate urban environmental factors and social norms, which may involve peer education and social network interventions.
Russia; Injecting drug users; Injecting equipment sharing; HIV infection; Hepatitis infections
We evaluated the efficacy of a peer-educator network intervention as a
strategy to reduce HIV acquisition among injection drug users (IDUs) and their
drug and/or sexual networks. A randomized controlled trial was conducted in St.
Petersburg, Russia among IDU index participants and their risk network
participants. Network units were randomized to the control or experimental
intervention. Only the experimental index participants received training
sessions to communicate risk reduction techniques to their network members.
Analysis includes 76 index and 84 network participants who were HIV uninfected.
The main outcome measure was HIV sero-conversion. The incidence rates in the
control and experimental groups were 19.57 (95 % CI 10.74–35.65)
and 7.76 (95 % CI 3.51–17.19) cases per 100 p/y, respectively.
The IRR was 0.41 (95 % CI 0.15–1.08) without a statistically
significant difference between the two groups (log rank test statistic
X2 = 2.73, permutation p value = 0.16).
Retention rate was 67 % with a third of the loss due to incarceration or
death. The results show a promising trend that this strategy would be successful
in reducing the acquisition of HIV among IDUs.
Injection drug users; Russia; HIV prevention; Network
Cultural adaptation is an important step in the process of implementing health promotion interventions that, having been proven to be effective in one culture, are being applied in another. This study describes the results of a formative investigation to culturally adapt a STI/HIV risk reduction intervention for use in St. Petersburg, Russia. Analyses of data from brief elicitation interviews, focus groups, community experts, and a pilot test of the adapted intervention identified environmental, cognitive-information processing, and affect-motivation factors that needed to be addressed during the adaptation process. The participant/counselor relationship was adapted to reflect a hierarchical (cf collaborative) relationship in order to accommodate Russian expectations about patient interactions with healthcare experts. Key skills building activities (e.g., identification of personal risk behaviors, role-playing) were approached gradually or indirectly in order to maintain participants’ engagement in the intervention, and close-ended questions were added to assist participants in understanding unfamiliar concepts such as “triggers” and self-efficacy. Information about the prevalence of HIV/STI infections and alcohol use included data specific to St. Petersburg to increase the personal relevance of these materials and messages. Intervention components were tailored to participants’ risk reduction and informational needs. No gender differences that would have justified adaptation of the intervention approach or content were noted. Examples of specific adaptations and the key issues to attend to when adapting behavioral interventions for use in Russian clinical settings are discussed.
cultural adaptation; sexual risk behavior; HIV; STI; alcohol
To assess risk for unintended pregnancy, this study describes the correlates of unprotected sexual intercourse (UPSI) among women who inject illicit drugs or who have sexual partners who inject drugs in St Petersburg, Russia.
Data from a cross-sectional survey and biological test results collected between 2005 and 2008 from 202 Russian women (143 drug injectors and 59 non-drug injectors) were analysed. Multivariate regression was used to investigate the correlates of UPSI occurring at the women’s last sexual act. Independent variables included socio-demographics, age at sexual debut, first sexual encounter perceived as involuntary, number of pregnancies and number of children for which the participant is the primary caretaker, heavy sporadic drinking (i.e. consuming more than five drinks in 2 hours at least twice a month), at-risk drinking per the Alcohol Use Disorder Identification Test (AUDIT-C) score, and sexually transmitted infections (HIV-1, syphilis serology, Chlamydia trachomatis and Neisseria gonorrheae).
Sixty-seven percent of women reported UPSI at last intercourse. UPSI was independently associated with heavy sporadic drinking [odds ratio (OR) 2.8, 95% CI 1.2–6.6] and having been pregnant (OR 2.25, 95% CI 1.1–4.6).
Despite the high risk for HIV acquisition or transmission and unintended pregnancy, condom use among the study population is low. Programmes to investigate and improve contraceptive use, including condom use, among this vulnerable group of women are needed. Such programmes may require identifying and targeting female reproductive health concerns and problem drinking, particularly heavy sporadic drinking, rather than conventional measures of alcohol misuse.
Whether intimate partner violence (IPV) perpetration and victimization are associated with human immunodeficiency virus (HIV) risk behaviors is seldom investigated in Russia. The present study hypothesized that patients from a sexually transmitted infection center in Russia who perpetrated IPV or were victims of IPV would be more likely to have HIV risk behaviors including injection drug use, multiple partners, and inconsistent condom use than those who were not involved with IPV. We used a self-administered questionnaire to collect information from 381 patients on demographics, health status, drug injection, sexual behaviors, and violence involving sexual partners between 2008 and 2009. After adjusting for sociodemographics, lifetime IPV perpetration was significantly associated with having had multiple sexual partners among male patients (odds ratio [OR] = 2.61, p < .05). Intimate partner violence victimization was significantly associated with injection drug use among male and female patients (OR = 5.22, p < .05) and with inconsistent condom use among female patients (OR = 8.93, p < .05). Intimate partner violence perpetration and victimization were common among male and female study participants and were associated with greater HIV risk behaviors. Human immunodeficiency virus prevention programs in Russia should address the risks associated with IPV among people at risk for HIV.
The study examined the efficacy of a brief theory-based counseling intervention to reduce sexual HIV risk behaviors among STI clinic patients in St. Petersburg, Russia. Men and women (n=307) were recruited to receive either: (1) a 60-minute motivational/skills-building counseling session dealing with sexual HIV risk reduction, or (2) written HIV prevention information material. Participants completed baseline and three- and six-month assessments in the period between July 2009 and May 2011. Compared to the control group, the face-to-face counseling intervention showed significant increases in the percentage of condom use and consistent condom use, and significant decreases in the number of unprotected sexual acts and frequency of drug use before sex at three-months follow-up. Intervention effects dissipated by six months. The brief counseling intervention may effectively reduce HIV sexual risk behaviors and enhance protective behaviors among STI clinic patients in Russia. Short-term positive effects were achieved with a single one hour counseling session.
STI clinic patients; sexual HIV prevention intervention; randomized controlled trial; brief counseling intervention; sexual risk reduction; HIV risk reduction
Human gene LOC100505644 uncharacterized LOC100505644 [Homo sapiens] (Entrez Gene ID 100505644) is abundantly expressed in tumors but weakly expressed in few normal tissues. Till now the function of this gene remains unknown. Here we identified the chromosomal borders of the transcribed region and the major splice form of the LOC100505644-specific transcript. We characterised the major regulatory motifs of the gene and its splice sites. Analysis of the secondary structure of the major transcript variant revealed a hairpin-like structure characteristic for precursor microRNAs. Comparative genomic analysis of the locus showed that it originated in primates de novo. Taken together, our data indicate that human gene LOC100505644 encodes some non-protein coding RNA, likely a microRNA. It was assigned a gene symbol ELFN1-AS1 (ELFN1 antisense RNA 1 (non-protein coding)). This gene combines features of evolutionary novelty and predominant expression in tumors.
The majority of HIV-infected individuals requiring antiretroviral therapy (ART) in Russia are Injection Drug Users (IDU). Substitution therapy used as part of a comprehensive harm reduction program is unavailable in Russia. Past data shows that only 16% of IDU receiving substance abuse treatment completed the course without relapse, and only 40% of IDU on ART remained on treatment at 6 months. Our goal was to determine if it was feasible to improve these historic outcomes by adding intensive case management (ICM) to the substance abuse and ART treatment programs for IDU.
IDU starting ART and able to involve a “supporter” who would assist in their treatment plan were enrolled. ICM included opiate detoxification, bi-monthly contact and counseling with the case, weekly group sessions, monthly contact with the “supporter” and home visits as needed. Full follow- up (FFU) was 8 months. Stata v10 (College Station, TX) was used for all analysis. Descriptive statistics were calculated for all baseline demographic variables, baseline and follow-up CD4 count, and viral load. Median baseline and follow-up CD4 counts and RNA levels were compared using the Kruskal-Wallis test. The proportion of participants with RNA < 1000 copies mL at baseline and follow-up was compared using Fisher’s Exact test. McNemar’s test for paired proportions was used to compare the change in proportion of participants with RNA < 1000 copies mL from baseline to follow-up.
Between November 2007 and December 2008, 60 IDU were enrolled. 34 (56.7%) were male. 54/60 (90.0%) remained in FFU. Overall, 31/60 (52%) were active IDU at enrollment and 27 (45%) were active at their last follow-up visit. 40/60 (66.7%) attended all of their ART clinic visits, 13/60 (21.7%) missed one or more visit but remained on ART, and 7/60 (11.7%) stopped ART before the end of FFU. Overall, 39/53 (74%) had a final 6–8 month HIV RNA viral load (VL) < 1000 copies/mL.
Despite no substitution therapy to assist IDU in substance abuse and ART treatment programs, ICM was feasible, and the retention and adherence of IDU on ART in St. Petersburg could be greatly enhanced by adding ICM to the existing treatment programs.
Injection drug users; Russia; HIV/AIDS; Antiretroviral therapy; Case management
IDU exposure remains a primary driver of the Russian HIV epidemic, and recent incidence data provide little evidence that this epidemic is slowing. While there are multiple important challenges that need to be further explored before starting vaccine trials, most importantly access to evidence-based drug treatment services for trial participants, the current context of high HIV incidence and low genetic diversity of HIV strains, suggests the need for intensified prevention strategies and supports the feasibility of mounting efficacy trials of HIV vaccines among IDUs in the Russian Federation.
HIV; Injection Drug use; St. Petersburg; Molecular Epidemiology; Vaccines
Growing evidence indicates that emotional distress such as depression may have the potential to increase the risk for HIV and other sexually transmitted infections (STIs). This study investigated the association between depressive symptoms and unprotected sex among STI clinic patients in Russia.
We used pre-intervention data collected between 2009 and 2010 among 307 participants who were enrolled in a randomized intervention trial conducted in a STI clinic in St. Petersburg, Russia. The 10-item Center for Epidemiological Studies Depression Scale was used to identify depressive symptoms and two indicators were used to measure unprotected sex. Logistic regression models were applied for the analysis and controlled for the following potential confounders: demographic characteristics, being a commercial sex worker, history of drug injection and alcohol misuse.
Of the participants, 20.2% were classified as having depressive symptoms. About 59.6% of the participants did not use a condom during the last sexual intercourse and 24.4% never used condoms in the past three months. Depressive symptoms were significantly associated with both indicators of unprotected sex in two different models: odds ratio (OR) = 2.36, 95% confidence interval (CI), 1.24–4.48 for unprotected sex in the last sexual intercourse; and OR = 2.71, 95% CI, 1.43–5.11 for unprotected sex in the past three months.
Depressive symptoms were common and were strongly associated with unprotected sex among study participants in St. Petersburg, Russia. Efforts to promote condom use should address lack of condom use due to depressive symptoms.
Condom; Depression; Depressive symptoms; Russia; Unprotected sex; STI clinic patients; alcohol misuse; drug injection; commercial sex work
We conducted a cross-sectional study to determine whether the time between two consecutive sexual partnerships (gap) is associated with sexually transmitted infections (STIs) in Russia. A self-administered questionnaire was administered to STI clinic patients in St. Petersburg and participant’s STI data at the time of enrollment in the study was collected from medical charts. The length of the gap between partnerships was divided into four categories: overlapping (0 or negative gap), short gaps (1–90 days), mid-length gaps (91–365 days), and long gaps (366 days or more). Among the 659 respondents, 22.6% had overlapping partnerships, and 13.7, 4.2, and 59.5% had short, mid-length and long gaps, respectively. Short gaps (OR 2.34; 95% CI 1.38–3.95), but not overlapping relationships, were independently associated with STIs when contrasted against long term gaps. HIV prevention programs for Russian STI clinic patients should therefore focus also on prolonging the gap between consecutive, monogamous sexual partnerships.
Gap between sexual partnerships; Consecutive sexual relationships; Serial monogamous relationships; Partner concurrency; STI; Russia
Gender differences in the relationship between alcohol use and depressive symptoms are inconsistent, and few studies have addressed this issue in Russia. Because this finding may have important implications for interventions to reduce alcohol misuse or alcohol related problems in Russia, we conducted a study to investigate whether the association between alcohol use and depressive symptoms differs by gender at high risk for HIV.
We used the Alcohol Use Disorders Identification Test (AUDIT) and the 10-item Center for Epidemiological Studies Depression Scale to measure alcohol use and depressive symptoms among 307 patients who attended a clinic for sexually transmitted infections in St. Petersburg, Russia. Logistic regression models were applied for the analysis.
The comparison of data between men and women revealed a significant quadratic term of alcohol use and significant interactions between alcohol use and gender on depressive symptoms. Men with an AUDIT score in the first and fourth quartiles were more likely to report depressive symptoms in comparison to men in the second quartile. Their odds ratios (ORs) and 95% confidence intervals (CIs) were 7.54 (2.00–28.51) and 5.06 (1.31–19.63), respectively. Among women, a linear trend was observed such that those who misused alcohol were three times more likely to have depressive symptoms than those who did not misuse alcohol (OR = 3.03, 95% CI, 1.05–8.80).
The association between alcohol use and depressive symptoms differed by gender. Additional research is needed to investigate this relationship in Russia. Strategies to reduce alcohol-related problems in Russia may need to consider these differences.
alcohol; depression; depressive symptoms; gender differences; Russia
This study investigates whether age at first alcoholic drink is associated with sexual risk behaviors among injection drug users (IDUs) and non-IDUs who are sexual partners of IDUs in St. Petersburg, Russia. A path analysis was used to test a model of age at first drink, age at sexual debut, age at first drug use, current substance use patterns and current sexual risk behaviors among 558 participants. Results revealed that age at first drink had an effect on multiple sex partners through age at sexual debut and injection drug use, but no effect on unprotected sex. Age at first drug use was not related to sexual risk behaviors. Investigation of age of drinking onset may provide useful information for programs to reduce sexual risk behaviors and injection drug use. Different paths leading to unprotected sex and multiple sexual partners call for different approaches to reduce sexual risk behaviors among this population.
Age at first alcoholic drink; HIV sexual risks; IDU; Russia; Age at first drug use; Sexual debut
Sexual concurrency is associated with higher prevalence of sexually transmitted diseases (STDs) including HIV. However, most studies have focused only on the concurrency of the individual participant (individual concurrency) and not on concurrency of their sexual partners (partner concurrency). Furthermore, limited concurrency information is available in Russia where HIV epidemic is growing rapidly. We therefore examine the prevalence and correlates of individual and partner concurrency, and determine whether either type of concurrency is associated with diagnosed STDs among STD clinic attendees in St. Petersburg, Russia.
In total, 799 attendees were recruited into a cross-sectional study between 2006 and 2008. A questionnaire collected information on demographics, medical history, sexual behaviors, and up to 3 sexual partners during the preceding year.
The prevalence of individual and partner concurrency was 24.7% and 45.4%, respectively. Both were correlated with marital status, weekly alcohol consumption, age at first sex, and number of lifetime sexual partners. Partner concurrency was significantly associated with diagnosed STDs (odds ratio = 2.06; 95% confidence interval = 1.35–3.15). No significant association between individual concurrency and STDs was observed.
Partner concurrency, not individual concurrency, is independently associated with increased odds of having an STD in the studied population.
The detection of sound begins when energy derived from an acoustic stimulus deflects the hair bundles atop hair cells1. As hair bundles move, the viscous friction between stereocilia and the surrounding liquid poses a fundamental physical challenge to the ear’fs high sensitivity and sharp frequency selectivity. Part of the solution to this problem lies in the active process that uses energy for frequency-selective sound amplification2,3. Here we demonstrate that a complementary part of the solution involves the fluid-structure interaction between stereocilia and the liquid within the hair bundle. Using force measurement on a dynamically scaled model, finite-element analysis, analytical estimation of hydrodynamic forces, stochastic simulation, and high-resolution interferometric measurement of hair bundles, we characterize the origin and magnitude of the forces between individual stereocilia during small hair-bundle deflections. We find that the close apposition of stereocilia effectively immobilizes the liquid between them, which reduces the drag and suppresses the relative squeezing but not the sliding mode of stereociliary motion. The obliquely oriented tip links couple the mechanotransduction channels to this least dissipative coherent mode, whereas the elastic horizontal top connectors that stabilize the structure further reduce the drag. As measured from the distortion products associated with channel gating at physiological stimulation amplitudes of tens of nanometres, the balance of viscous and elastic forces in a hair bundle permits a relative mode of motion between adjacent stereocilia that encompasses only a fraction of a nanometre. A combination of high-resolution experiments and detailed numerical modelling of fluid-structure interactions reveals the physical principles behind the basic structural features of hair bundles and shows quantitatively how these organelles are adapted to the needs of sensitive mechanotransduction.
We investigated whether inebriation was associated with having non-main partners and unprotected sex with non-main partners and whether drinking motivations were associated with sexual risk behaviors among patients attending an STD clinic in St Petersburg, Russia. A cross-sectional behavior survey was applied to 362 participants between 2008 and 2009. Multivariate logistic regression was used for analysis. At-risk drinking per Alcohol Use Disorders Identification Test (AUDIT-C) criteria (OR 2.5, 95% CI 1.4–4.4) was independently associated with having non-main sexual partners. Inebriation (OR 3.2, 95% CI 1.3–8.1) but not at-risk drinking or drinking prior to sex was associated with unprotected sex with non-main partners. Among drinkers, the consumption of alcohol to facilitate sexual encounters (OR 2.7, 95% CI 1.6–4.5) was associated with having non-main sexual partners. HIV prevention programs in Russia must address inebriation in addition to conventional patterns of problem drinking such as those measured by AUDIT-C and consider individuals’ motivations to drink that lead to sexual risk taking.
Sexual risk behaviors; STD clinic; Russia; Drinking motivation; Inebriation; AUDIT-C
Many women in Russia rely on abortion as a primary birth control method. Although refusal to use contraceptives, including condoms, may undermine public health efforts to decrease HIV sexual risk behaviors, few studies have investigated the risk factors associated with abortion among women at high risk for HIV. This study sought to identify the correlates of abortions and of lack of condom use among high risk STD clinic patients in St Petersburg Russia.
Cross-sectional analysis of data collected between 2009 and 2010 from women who had casual or multiple sexual partners in the previous three months was analyzed. Multivariate logistic regression assessed the independent correlates of abortion(s) and no condom use in the prior three months. Independent variables included socio-demographics, at risk drinking per alcohol use disorder identification test (AUDIT-C) criteria, having sex after drinking alcohol, having a sexual partner who injects illicit drugs, and parity.
Of 87 participants, 45% had an abortion in their lifetime and 26% did not use condoms in the prior three months. Abortion was independently associated with low income (OR, 3.33, 95%CI, 1.13-9.78) and at risk drinking (OR, 3.52, 95%CI, 1.24-10.05). Lack of condom use was independently associated with being more likely to have sex after drinking (OR, 3.37, 95%CI, 1.10-10.28) and parity (OR, 3.69, 95%CI, 1.25-10.89).
Programs to increase contraceptive use including condom use among women at high risk for STD/HIV in Russia are needed. Programs to reduce sexual HIV risk and abortion rates must address alcohol misuse and target women with limited income.
abortion; condom use; Russia; HIV risk; high risk women; alcohol misuse; AUDIT-C
Alcohol misuse has been linked to intimate partner violence (IPV). However, this association is not usually examined in Russia. Moreover, more investigation is required as to whether specific drinking contexts are also associated with IPV. The objectives of this study are: to investigate whether alcohol misuse is associated with IPV and to further examine whether specific drinking contexts among drinkers are associated with IPV.
A questionnaire was used to collect information on demographics, health status, alcohol use, and violence involving sexual partners among 440 participants who were recruited from an STI (sexually transmitted infection) clinic center in St. Petersburg, Russia for a cross-sectional study from 2008 to 2009. Multivariate logistic regression was used for analysis.
Overall, 47.0% participants were classified as misusing alcohol and 7.2% participants perpetrated IPV in the past three months. Participants with alcohol misuse were 3.28 times (OR: 3.28; 95% CI: 1.34-8.04) as likely as those without alcohol misuse to perpetrate IPV. Among participants who had consumed alcohol in the past three months, those who usually drank on the streets or in parks (OR: 5.62; 95% CI: 1.67-18.90) were more likely to perpetrate IPV.
Both alcohol misuse and certain drinking contexts (e.g., drinking on the streets or at parks) were associated with IPV. The association between drinking contexts and IPV needs further investigation, as do the underlying mechanisms for this association. IPV prevention initiatives might benefit from reducing alcohol misuse. Drinking contexts such as drinking on the streets or at parks as well as the factors related to the use of alcohol in these contexts may also need to be addressed.
The purpose of this analysis was to estimate human immunodeficiency virus (HIV) prevalence and testing patterns among injection drug users (IDUs) in St. Petersburg, Russia. HIV prevalence among 387 IDUs in the sample was 50%. Correlates of HIV-positive serostatus included unemployment, recent unsafe injections, and history/current sexually transmitted infection. Seventy-six percent had been HIV tested, but only 22% of those who did not report HIV-positive serostatus had been tested in the past 12 months and received their test result. Correlates of this measure included recent doctor visit and having been in prison or jail among men. Among the 193 HIV-infected participants, 36% were aware of their HIV-positive serostatus. HIV prevalence is high and continuing to increase in this population. Adequate coverage of HIV testing has not been achieved, resulting in poor knowledge of positive serostatus. Efforts are needed to better understand motivating and deterring factors for HIV testing in this setting.
Russia; Injection drug users; HIV prevalence; HIV testing; HIV serostatus; Knowledge
The frequency sensitivity of auditory hair cells in the inner ear varies with their longitudinal position in the sensory epithelium. Among the factors that determine the differential cellular response to sound is the resonance of a hair cell's transmembrane electrical potential, whose frequency correlates with the kinetic properties of the high-conductance Ca2+-activated K+ (BK) channels encoded by a Slo (kcnma1) gene. It has been proposed that the inclusion of specific alternative axons in the Slo transcripts along the cochlea underlies the gradient of BK-channel kinetics. By analyzing the complete sequences of chicken Slo gene (cSlo) cDNAs from the chicken's cochlea, we show that most transcripts lack alternative exons. Transcripts with more than one alternative exon constitute only 10% of the total. Although the fraction of transcripts containing alternative exons increases from the cochlear base to the apex, the combination of alternative exons is not regulated. There is also a clear increase in the expression of BK transcripts with long carboxyl termini toward the apex. When long and short BK transcripts are expressed in HEK-293 cells, the kinetics of single-channel currents differ only slightly, but they are substantially slowed when the channels are coexpressed with the auxiliary β subunit that occurs more widely at the apex. These results argue that the tonotopic gradient is not established by the selective inclusion of highly specific cSlo exons. Instead, a gradient in the expression of β subunits slows BK channels toward the low-frequency apex of the cochlea.
To date, the great majority of Russian HIV infections have been diagnosed among IDUs and concerns about the potential for a sexual transmission of HIV beyond the IDU population have increased. This study investigated differences in the prevalence of sexual risk behaviors between IDUs and non-IDUs in St. Petersburg, Russia and assessed associations between substance use patterns and sexual risks within and between those two groups.
Cross-sectional survey data and biological test results from 331 IDUs and 65 non-IDUs who have IDU sex partners were analyzed. Multivariate regression was employed to calculate measures of associations.
IDUs were less likely than non-IDUs to report multiple sexual partners and unprotected sex with casual partners. The quantity, frequency and intensity of alcohol use did not differ between IDUs and non-IDUs, but non-IDUs were more likely to engage in alcohol use categorized as risky per the alcohol use disorders identification test (AUDIT-C). Risky sexual practices were independently associated with monthly methamphetamine injection among IDUs and with risky alcohol use among non-IDUs. Having sex when high on alcohol or drugs was associated with unprotected sex only among IDUs.
Greater prevalence of sexual risk among non-IDUs who have IDU sex partners compared to IDUs suggests the potential for sexual transmission of HIV from the high-prevalence IDU population into the general population. HIV prevention programs among IDUs in St. Petersburg owe special attention to risky alcohol use among non-IDUs who have IDU sex partners and the propensity of IDUs to have sex when high on alcohol or drugs and forgo condoms.
To understand the epidemiology and transmission patterns of hepatitis C virus (HCV), the predominant blood borne-pathogen infecting drug injectors (IDUs), in a part of the former Soviet Union.
Cross-sectional respondent driven sample of IDUs.
St. Petersburg, RF
387 IDUs were recruited in late 2005 and throughout 2006.
Participants were surveyed to collect demographic, medical, and both general and dyad specific drug injection and sexual behaviors. A blood sample was collected to detect antibodies to hepatitis C and to amplify viral RNA for molecular analysis. The molecular data, including genotypes, were analyzed spatially and linkage patterns were compared to the social linkages obtained by respondent driven sampling (RDS) for chains of respondents and among the injection dyads.
HCV infection was all but ubiquitous: 94.6% of IDUs were HCV-seropositive. Among the 208 viral sequences amplified, genotype 3a predominated (n=119, 56.9%) followed by 1b (n=61, 29.2%), and 1a (n=25, 11.9%). There was no significant clustering of genotypes spatially. Neither genotypes nor closely related sequences were clustered within RDS chains. Analysis of HCV sequences from dyads failed to find associations of genotype or sequence homology within pairs.
Genotyping reveals that there have been at least five unique introductions of HCV genotypes into the IDU community in St. Petersburg. Analysis of prevalent infections does not appear to correlate with the social networks of IDUs, suggesting that simple approaches to link these networks to prevalent infections, rather than incident transmission, will not prove meaningful. On a more positive note, the majority of IDUs are infected with 3a genotype that is associated with sustained virologic response to antiviral therapy.
HCV; genotyping; Injection drug users; Respondent Driven Sampling; Russia
Background: Russia has one of the world’s fastest growing HIV epidemics and it has been largely concentrated among injection drug users (IDU). St Petersburg, Russia’s second largest city, is one of the country’s regions that has been most affected by the HIV epidemic. To monitor the current epidemic situation, we sought to estimate recent HIV incidence among IDU in St Petersburg. Methods: In a cross-sectional study of 691 IDU recruited during 2005–08, HIV incidence was estimated by two methods: a retrospective cohort analysis and BED capture enzyme immunoassay (EIA) results. Socio-demographic and behavioural correlates of incident infections and spatial patterns were examined. Results: In the retrospective cohort analysis, the incidence rate was estimated to be 14.1/100 person-years [95% confidence interval (CI) 10.7–17.6]. Using results of BED EIA and two correction formulas for known misclassification, incidence estimates were 23.9 (95% CI 17.8–30.1) and 25.5 (95% CI 18.9–32.0) per 100 person-years. Independent correlates of being recently infected included current unemployment (P = 0.004) and not having injected drugs in the past 30 days (P = 0.03). HIV incident cases were detected in all but one district in the city, with focal areas of transmission observed to be expanding. Conclusions: High HIV incidence among IDU in St Petersburg attests to continued growth of the epidemic. The need for expansion of HIV prevention interventions targeted to vulnerable populations throughout the city is urgent. These results also suggest that the BED EIA may over-estimate incidence even after correction for low specificity.
human immunodeficiency virus; HIV; incidence; injection drug users; Russia