The feasibility of HIV vaccine efficacy trials among Russian injection drug users

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

BACKGROUND

Mucosally 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.

RESULTS

Virus 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.

CONCLUSIONS

Similar 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.

Consensus HIV-1 subtype A integrase and its raltegravir-resistant variants: design and characterization of the enzymatic properties

Model studies of the subtype B and non-subtype B integrases are still required to compare their susceptibility to antiretroviral drugs, evaluate the significance of resistance mutations and identify the impact of natural polymorphisms on the level of enzymatic reactivity. We have therefore designed the consensus integrase of the HIV-1 subtype A strain circulating in the former Soviet Union territory (FSU-A) and two of its variants with mutations of resistance to the strand transfer inhibitor raltegravir. Their genes were synthesized, and expressed in E coli; corresponding His-tagged proteins were purified using the affinity chromatography. The enzymatic properties of the consensus integrases and their sensitivity to raltegravir were examined in a series of standard in vitro reactions and compared to the properties of the integrase of HIV-1 subtype B strain HXB2. The consensus enzyme demonstrated similar DNA-binding properties, but was significantly more active than HXB-2 integrase in the reactions of DNA cleavage and integration. All integrases were equally susceptible to inhibition by raltegravir and elvitegravir, indicating that the sporadic polymorphisms inherent to the HXB-2 enzyme have little effect on its susceptibility to drugs. Insensitivity of the mutated enzymes to the inhibitors of strand transfer occurred at a cost of a 30-90% loss of the efficacies of both 3'-processing and strand transfer. This is the first study to describe the enzymatic properties of the consensus integrase of HIV-1 clade A and the effects of the resistance mutations when the complex actions of sporadic sequence polymorphisms are excluded.

New evidence on the HIV epidemic in Libya: why countries must implement prevention programs among people who inject drugs

BACKGROUND

Libya had one of the world's largest nosocomial HIV outbreaks in the late 1990 s leading to the detention of 6 foreign medical workers. They were released in 2007 after the Libyan Government and the European Union agreed to humanitarian cooperation that included the development of Libya's first National HIV Strategy and the research reported in this article. Despite the absence of sound evidence on the status and dynamics of Libya's HIV epidemic, some officials posited that injecting drug use was the main mode of transmission. We therefore sought to assess HIV prevalence and related risk factors among people who inject drugs (PWID) in Tripoli.

METHODS

We conducted a cross-sectional survey among 328 PWID in Tripoli using respondent-driven sampling. We collected behavioral data and blood samples for HIV, hepatitis C virus, and hepatitis B virus testing.

RESULTS

We estimate an HIV prevalence of 87%, hepatitis C virus prevalence of 94%, and hepatitis B virus prevalence of 5%. We detected injecting drug use-related and sexual risk factors in the context of poor access to comprehensive services for HIV prevention and mitigation. For example, most respondents (85%) reported having shared needles.

CONCLUSIONS

In this first biobehavioral survey among PWID in Libya, we detected one of the highest (or even the highest) levels of HIV infection worldwide in the absence of a comprehensive harm-reduction program. There is an urgent need to implement an effective National HIV Strategy informed by the results of this research, especially because recent military events and related sociopolitical disruption and migration might lead to a further expansion of the epidemic.

Estimates of HIV incidence among drug users in St. Petersburg, Russia: continued growth of a rapidly expanding epidemic

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.

Contraception use and unplanned pregnancies among injection drug-using women in St Petersburg, Russia

BACKGROUND

This cross-sectional study estimated the prevalence of contraceptive methods and investigated whether abortion rates influence contraceptive behaviour among injection drug-using (IDU) women in St Petersburg, Russia.

METHODOLOGY

A self-administered questionnaire of behaviour in the last 3 months was applied to a convenient sample of IDU women.

RESULTS

Of 80 sexually active participants, 67% had had an abortion. No participant reported using hormonal contraceptives or intrauterine devices (IUDs). The only valid method of contraception used was condoms, which was reported by half of the participants. Consistent condom use was reported by 22% of participants and was no more likely among those who had an abortion. Condom use was significantly associated with having multiple or casual sex partners [prevalence ratio (PR) 1.75, 95% (confidence interval) CI 1.11-2.78, p = 0.01], having an IDU sex partner (PR 0.55, 95% CI 0.36-0.85, p = 0.029) and with a negative attitude toward condoms (PR 0.53, 95% CI 0.33-0.84, p = 0.01). Abortions were less likely among those who had multiple or casual sex partners (PR 0.69, 95% CI 0.49-0.97, p = 0.03).

CONCLUSIONS

Despite the high prevalence of abortions among IDU women, none reported the use of hormonal contraception or IUDs. Having had an abortion was not associated with greater likelihood of using condoms. Participants mostly used condoms with casual or multiple sex partners, suggesting that condoms were used mainly to prevent HIV/sexually transmitted infection transmission and not to prevent pregnancy. Programmes to prevent unwanted pregnancies and reduce abortion-related health risks among this understudied vulnerable group are needed.

Time to act: a call for comprehensive responses to HIV in people who use drugs

The published work on HIV in people who use drugs shows that the global burden of HIV infection in this group can be reduced. Concerted action by governments, multilateral organisations, health systems, and individuals could lead to enormous benefits for families, communities, and societies. We review the evidence and identify synergies between biomedical science, public health, and human rights. Cost-effective interventions, including needle and syringe exchange programmes, opioid substitution therapy, and expanded access to HIV treatment and care, are supported on public health and human rights grounds; however, only around 10% of people who use drugs worldwide are being reached, and far too many are imprisoned for minor offences or detained without trial. To change this situation will take commitment, advocacy, and political courage to advance the action agenda. Failure to do so will exacerbate the spread of HIV infection, undermine treatment programmes, and continue to expand prison populations with patients in need of care.