Introduction

In order to determine the impact of HIV prevention and care programs, it is essential to look at both HIV incidence and prevalence estimates and trends over time. We estimated the HIV incidence and prevalence and assessed the trend using data from three cross-sectional surveys of men who have sex with men (MSM) in two cities in Georgia.

Methods

Using respondent-driven sampling strategy, a total of 796 eligible MSM (18 years or older men with self-reported oral or anal sex with another man in past 12 months) were recruited in Tbilisi in 2010, 2012 and 2015 and 115 in Batumi 2015 into behavioral surveys and HIV testing. To estimate the HIV incidence, we divided the number MSM tested positive for HIV to the time at risk. We calculated the time at risk as years since age at first anal intercourse to the age at last HIV-negative test or the age at first HIV-positive test, accounted for the interval censorship. We calculated the respondent-driven sampling adjusted estimates for HIV prevalence and assessed the trend in Tbilisi by Chi2 test for trend. For HIV incidence rate, we used Kaplan Meier method to estimate the rates and assessed the subgroup differences by log-rank test.

Results

The HIV prevalence was 14.9% in Batumi in 2015; it significantly increased in Tbilisi from 6.2% in 2010 to 14.1% in 2012, and to 19.6% in 2015 (p-value for trend < 0.001). Likewise, the HIV incidence rate in Tbilisi significantly increased form 0.45 per 100 person-years (PY) in 2010 to 0.98 per 100 PY in 2012 (p-value 0.01), and to 1.63 per 100 PY in 2015 (p-value < 0.001). HIV incidence rate was 1.37 per 100 PY in Batumi in 2015. In 2015, young MSM (Tbilisi: 3.71, Batumi: 3.92 per 100 PY, p-value< 0.008), single MSM (Tbilisi: 1.99, per 100 PY, p-value 0.03) and less educated MSM (Batumi: 1.86 per 100 PY, p-value 0.03) had higher HIV incidence than other MSM.

Conclusion

Our findings suggest the continuous transmission of HIV among MSM in Tbilisi and a high prevalence of HIV among MSM in Batumi and the critical need for scaling up the coverage and accessibility of combination prevention packages including rapid HIV diagnosis and treatment.

Given globalization and other social phenomena, controlling the spread of infectious diseases has become an imperative public health priority. A plethora of interventions that in theory can mitigate the spread of pathogens have been proposed and applied. Evaluating the effectiveness of such interventions is costly and in many circumstances unrealistic. Most important, the community effect (i.e., the ability of the intervention to minimize the spread of the pathogen from people who received the intervention to other community members) can rarely be evaluated. Here we propose a study design that can build and evaluate evidence in support of the community effect of an intervention. The approach exploits molecular evolutionary dynamics of pathogens in order to track new infections as having arisen from either a control or an intervention group. It enables us to evaluate whether an intervention reduces the number and length of new transmission chains in comparison with a control condition, and thus lets us estimate the relative decrease in new infections in the community due to the intervention. We provide as an example one working scenario of a way the approach can be applied with a simulation study and associated power calculations.

BACKGROUND:Globally, four out of ten individuals living with HIV have not been tested for HIV. Testing is especially important for men who have sex with men (MSM), among whom an increasing HIV epidemic has been identified in many regions of the world. As a supplement to site-based HIV testing services, HIV self-testing (HIVST) provides a promising approach to promote HIV testing. However, evidence is scattered and not well-summarized on the effect of HIVST to improve HIV testing behaviors, especially for MSM. METHODS:Seven databases (PubMed, Web of Science, Cochrane Library, PsycINFO, CINAHL Plus, WanFang, and China National Knowledge Internet) and conference abstracts from six HIV/sexually transmitted infections conferences were searched from January 2000-April 2017. RESULTS:Of 1,694 records retrieved, 23 studies were identified, 9 conducted in resource-limited countries and 14 in high-income countries. The pooled results showed that HIVST increased HIV test frequency for MSM by one additional test in a 6-month period (mean difference = 0.88 [95% CI 0.52-1.24]). The pooled proportion of first-time testers among those who took HIVST was 18.7% (95% CI: 9.9-32.4) globally, with a rate 3.32 times higher in resource-limited country settings (32.9% [95% CI: 21.3-47.6]) than in high-income countries (9.9% [95% CI: 7.4-13.8]). The pooled proportions included non-recent testers, 32.9% (95% CI: 28.1-38.3); ever or currently married MSM, 16.7% (95% CI: 14.5-19.4); and HIV positive men, 3.8% (95% CI: 2.0-5.7) globally; 6.5% [95% CI: 0.38-12.3] in resource-limited country settings; and 2.9% [95% CI: 2.0-5.0] in high-income countries). The rates reported for linkage to care ranged from 31.3% to 100%. CONCLUSIONS:HIVST could increase HIV testing frequency and potentially have capacity equivalent to that of site-based HIV testing services to reach first-time, delayed, married, and HIV-infected testers among MSM and link them to medical care. However, more rigorous study designs are needed to explore the specific self-testing approach (oral-fluid based or finger-prick based) on improving HIV testing for MSM in different social and economic settings.

Prompt initiation of combination antiretroviral therapy (ART) is important to reduce comorbidity and mortality among people living with HIV, especially for those with a low CD4 cell count. However there is evidence that not everyone receives prompt initiation of ART after enrolling into HIV care. The current study investigated factors associated with failure to initiate ART within two years of entering into care among those with a CD4 count at or below 350 cells/mm3. The sample included 4,907 ART-naive patients with a CD4 count at or below 350 cells/mm3 enrolled between January 1, 2003 and December 31, 2012 at any of eight clinical sites in the Center for AIDS Research Network of Integrated Clinical Systems (CNICS). The two-year risk of delayed ART initiation was estimated using a log-binomial regression model with stabilized inverse probability of censoring weights for those lost to follow-up. Adjusting for other factors, an earlier enrollment date was the sole demographic characteristic associated with an increased risk of delayed ART initiation. Higher CD4 count, lower viral load, and a prevalent AIDS diagnosis were clinical characteristics associated with delayed ART initiation. Gender, age, race/ethnicity and HIV risk factors such as reported male-to-male sexual contact and injection drug use were not associated with delayed ART initiation. This study identified characteristics of patients for whom treatment was strongly to moderately recommended but who did not initiate ART within two years of entering care. Despite the known benefits of early antiretroviral therapy initiation, a lower viral load measurement may continue to be an important clinical characteristic in the more recent era with current ART initiation guidelines. These findings provide a target for closer monitoring and intervention to reduce disparities in HIV care.

Introduction

At the individual level, there is clear evidence that Human Immunodeficiency Virus (HIV) transmission can be substantially reduced by lowering viral load. However there are few data describing population-level HIV viremia especially in high-burden settings with substantial under-diagnosis of HIV infection. The 2nd Kenya AIDS Indicator Survey (KAIS 2012) provided a unique opportunity to evaluate the impact of antiretroviral therapy (ART) coverage on viremia and to examine the risks for failure to suppress viral replication. We report population-level HIV viral load suppression using data from KAIS 2012.

Methods

Between October 2012 to February 2013, KAIS 2012 surveyed household members, administered questionnaires and drew serum samples to test for HIV and, for those found to be infected with HIV, plasma viral load (PVL) was measured. Our principal outcome was unsuppressed HIV viremia, defined as a PVL ≥ 550 copies/mL. The exposure variables included current treatment with ART, prior history of an HIV diagnosis, and engagement in HIV care. All point estimates were adjusted to account for the KAIS 2012 cluster sampling design and survey non-response.

Results

Overall, 61·2% (95% CI: 56·4-66·1) of HIV-infected Kenyans aged 15-64 years had not achieved virological suppression. The base10 median (interquartile range [IQR]) and mean (95% CI) VL was 4,633 copies/mL (0-51,596) and 81,750 copies/mL (59,366-104,134), respectively. Among 266 persons taking ART, 26.1% (95% CI: 20.0-32.1) had detectable viremia. Non-ART use, younger age, and lack of awareness of HIV status were independently associated with significantly higher odds of detectable viral load. In multivariate analysis for the sub-sample of patients on ART, detectable viremia was independently associated with younger age and sub-optimal adherence to ART.

Discussion

This report adds to the limited data of nationally-representative surveys to report population- level virological suppression. We established heterogeneity across the ten administrative and HIV programmatic regions on levels of detectable viral load. Timely initiation of ART and retention in care are crucial for the elimination of transmission of HIV through sex, needle and syringe use or from mother to child. Further refinement of geospatial mapping of populations with highest risk of transmission is necessary.

Current ideas about HIV prevention include a mixture of primarily biomedical interventions, socio-mechanical interventions such as sterile syringe and condom distribution, and behavioral interventions. This article presents a framework for socially-integrated transdisciplinary HIV prevention that may improve current prevention efforts. It first describes one socially-integrated transdisciplinary intervention project, the Transmission Reduction Intervention Project. We focus on how social aspects of the intervention integrate its component parts across disciplines and processes at different levels of analysis. We then present socially-integrated perspectives about how to improve combination antiretroviral treatment (cART) processes at the population level in order to solve the problems of the treatment cascade and make treatment as prevention more effective. Finally, we discuss some remaining problems and issues in such a social transdisciplinary intervention in the hope that other researchers and public health agents will develop additional socially-integrated interventions for HIV and other diseases.

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.

OBJECTIVE: Although our understanding of viral transmission among people who inject drugs (PWID) has improved, we still know little about when and how many times each injector transmits HIV throughout the duration of infection. We describe HIV dynamics in PWID to evaluate which preventive strategies can be efficient. DESIGN: Due to the notably scarce interventions, HIV-1 spread explosively in Russia and Ukraine in 1990s. By studying this epidemic between 1995 and 2005, we characterized naturally occurring transmission dynamics of HIV among PWID. METHOD: We combined publicly available HIV pol and env sequences with prevalence estimates from Russia and Ukraine under an evolutionary epidemiology framework to characterize HIV transmissibility between PWID. We then constructed compartmental models to simulate HIV spread among PWID. RESULTS: In the absence of interventions, each injector transmits on average to 10 others. Half of the transmissions take place within 1 month after primary infection, suggesting that the epidemic will expand even after blocking all the post-first month transmissions. Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID. Treating acutely infected on top of primary prevention is notably effective. CONCLUSION: As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID. Growing PWID populations in the developing world, where primary prevention is scarce, constitutes a public health time bomb.

Assessment of the long-term population-level effects of HIV interventions is an ongoing public health challenge. Following the implementation of a Transmission Reduction Intervention Project (TRIP) in Odessa, Ukraine, in 2013-2016, we obtained HIV pol gene sequences and used phylogenetics to identify HIV transmission clusters. We further applied the birth-death skyline model to the sequences from Odessa (n = 275) and Kyiv (n = 92) in order to estimate changes in the epidemic's effective reproductive number (R_e) and rate of becoming uninfectious (δ). We identified 12 transmission clusters in Odessa; phylogenetic clustering was correlated with younger age and higher average viral load at the time of sampling. Estimated R_e were similar in Odessa and Kyiv before the initiation of TRIP; R_e started to decline in 2013 and is now below R_e = 1 in Odessa (R_e = 0.4, 95%HPD 0.06-0.75), but not in Kyiv (R_e = 2.3, 95%HPD 0.2-5.4). Similarly, estimates of δ increased in Odessa after the initiation of TRIP. Given that both cities shared the same HIV prevention programs in 2013-2019, apart from TRIP, the observed changes in transmission parameters are likely attributable to the TRIP intervention. We propose that molecular epidemiology analysis can be used as a post-intervention effectiveness assessment tool.