Antiretroviral treatment of primary HIV infection to reduce onward transmission

Nucleic acid testing and molecular characterization of HIV infections

Significant advances have been made in the molecular assays used for the detection of human immunodeficiency virus (HIV), which are crucial in preventing HIV transmission and monitoring disease progression. Molecular assays for HIV diagnosis have now reached a high degree of specificity, sensitivity and reproducibility, and have less operator involvement to minimize risk of contamination. Furthermore, analyses have been developed for the characterization of host gene polymorphisms and host responses to better identify and monitor HIV-1 infections in the clinic. Currently, molecular technologies including HIV quantitative and qualitative assays are mainly based on the polymerase chain reaction (PCR), transcription-mediated amplification (TMA), nucleic acid sequence-based amplification (NASBA), and branched chain (b) DNA methods and widely used for HIV detection and characterization, such as blood screening, point-of-care testing (POCT), pediatric diagnosis, acute HIV infection (AHI), HIV drug resistance testing, antiretroviral (AR) susceptibility testing, host genome polymorphism testing, and host response analysis. This review summarizes the development and the potential utility of molecular assays used to detect and characterize HIV infections.

Evaluation of the virtues and pitfalls in an HIV screening algorithm based on two fourth generation assays - A step towards an improved national algorithm

BACKGROUND

Fourth-generation immunoassays used for HIV screening, simultaneously detect anti-HIV antibodies and HIV-1 P24 antigen, but are prone to false-positive results. Usually, they are followed by highly specific third-generation assay, able to differentiate between HIV-1/2 infections. In Israel, screening algorithm is based on consecutive testing by two fourth-generation assays and confirmation by a third-generation test.

OBJECTIVES

To evaluate the performance of this algorithm.

STUDY DESIGN

Architect HIV1/2 Combo (Combo) reactive results were tested by Vidas HIV Duo Ultra (VD). Confirmation was by INNO-LIA HIV 1/2 or Geenius assays. Five-year results were retrospectively analyzed. HIV true positives (TPs), acute infected (AI), false-positives (FPs) and HIV negatives, were as defined by the algorithm.

RESULTS

501,338 individuals were screened, of which 956 were TPs, 64 AI and 30 F Ps. Specificity was almost 100% and positive predictive value 97%. VD was negative in 94% of confirmed Combo false-reactive individuals. The Combo results in the first tested sample differed substantially between TPs, AI and FPs, enabling the determination of a cutoff value that distinguished 94% of TPs and AI from FPs.

CONCLUSIONS

An algorithm is suggested that will use a single sample collection. HIV negative diagnosis will be based on Combo unreactive or Combo reactive/VD negative results. HIV positive diagnosis will be based on Combo reactive/ VD positive results, given a Combo value above a designated cutoff. Below this cutoff samples will be tested by a molecular assay. Since HIV-2 rarely occurs in Israel, the use of a third-generation confirmation assay should be discussed.

Molecular investigation of HIV-1 cross-group transmissions during an outbreak among people who inject drugs (2011-2014) in Athens, Greece

New diagnoses of HIV-1 infection among people who inject drugs (PWID) rocketed in Athens, Greece between 2011 and 2014 (HIV-1 outbreak). Our aim was to identify, during that period, potential cross-group transmissions between the within-Greece PWID and other risk or national groups using molecular methods. Sequences from 33 PWID were outside the PWID-outbreak networks in Greece (PWID-imported transmissions). Phylogenetic analyses on 28 of these sequences (subtypes A and B) showed that 11 subtype B infections originated from Greece, whereas 8 and 7 subtype A strains were from former Soviet Union countries (A_FSU) and Greece, respectively. The putative source in half of the PWID-imported transmissions with Greek origin was an individual who acquired HIV via sexual contact. During four years of an HIV-1 outbreak among PWID in Athens, Greece, 33 individuals in this group (4.6% of all diagnoses with phylogenetic analyses) are likely to represent infections, sexually or injection-acquired, outside the within-Greece-PWID-outbreak networks. Combined molecular and traditional HIV surveillance to monitor introductions of new strains, and interventions that aim at reducing the rate of both injection and sexual risky practices are needed during drug injection-related HIV outbreaks.

Evaluation of the Architect HIV Ag/Ab Combo Assay in a low-prevalence setting: The role of samples with a low S/CO ratio

BACKGROUND

The Architect HIV Ag/Ab Combo Assay, a fourth-generation ELISA, has proven to be highly reliable for the diagnosis of HIV infection. However, its high sensitivity may lead to false-positive results.

OBJECTIVES

To evaluate the diagnostic performance of Architect in a low-prevalence population and to assess the role of the sample-to-cutoff ratio (S/CO) in reducing the frequency of false-positive results.

STUDY DESIGN

We conducted a retrospective study of samples analyzed by Architect between January 2015 and June 2017. Positive samples were confirmed by immunoblot (RIBA) or nucleic acid amplification tests (NAATs). Different S/CO thresholds (1, 2.5, 10, 25, and 100) were analyzed to determine sensitivity, specificity, and negative and positive predictive values (NPV, PPV). ROC analysis was used to determine the optimal S/CO.

RESULTS

A total of 69,471 samples were analyzed. 709 (1.02%) were positive by Architect. Of these, 63 (8.89%) were false-positive results. Most of them (93.65%) were in samples with S/CO < 100. However, most confirmations by NAATs (12 out of 19 cases) were also recorded for these samples. The optimal S/CO was 2.5, which provided the highest area under the ROC curve (0.9998) and no false-negative results. With this S/CO, sensitivity and specificity were 100.0%, and PPV and NPV were 95.8% and 100.0%, respectively. In addition, the frequency of false-positive results decreased significantly to 4.15%.

CONCLUSIONS

Although Architect generates a relatively high number of false-positive results, raising the S/CO limit too much to increase specificity can lead to false-negative results, especially in newly infected individuals.

Relevance of cutoff on a 4th generation ELISA performance in the false positive rate during HIV diagnostic in a low HIV prevalence setting

BACKGROUND

Despite the high specificity of fourth-generation enzyme immunoassays (4th-gen-EIA) for screening during HIV diagnosis, their positive predictive value is low in populations with low HIV prevalence. Thus, screening should be optimized to reduce false positive results.

OBJECTIVES

The influence of sample cutoff (S/CO) values by a 4th-gen-EIA with the false positive rate during the routine HIV diagnosis in a low HIV prevalence population was evaluated.

STUDY DESIGN

A total of 30,201 sera were tested for HIV diagnosis using Abbott Architect^® HIV-Ag/Ab-Combo 4th-gen-EIA at a hospital in Spain during 17 months. Architect S/CO values were recorded, comparing the HIV-1 positive results following Architect interpretation (S/CO≥1) with the final HIV-1 diagnosis by confirmatory tests (line immunoassay, LIA and/or nucleic acid test, NAT). ROC curve was also performed.

RESULTS

Among the 30,201 HIV performed tests, 256 (0.85%) were positive according to Architect interpretation (S/CO≥1) but only 229 (0.76%) were definitively HIV-1 positive after LIA and/or NAT. Thus, 27 (10.5%) of 256 samples with S/CO≥1 by Architect were false positive diagnose. The false positive rate decreased when the S/CO ratio increased. All 19 samples with S/CO ≤10 were false positives and all 220 with S/CO>50 true HIV-positives. The optimal S/CO cutoff value provided by ROC curves was 32.7. No false negative results were found.

CONCLUSIONS

We show that very low S/CO values during HIV-1 screening using Architect can result HIV negative after confirmation by LIA and NAT. The false positive rate is reduced when S/CO increases.

What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland

OBJECTIVES

Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare.

DESIGN

Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate.

SETTING

This study was conducted in primary care units in selected provinces in Poland.

PARTICIPANTS

A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected.

RESULTS

Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect.

CONCLUSIONS

Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed.

The impact of transient combination antiretroviral treatment in early HIV infection on viral suppression and immunologic response in later treatment

Objective:

Effects of transient combination antiretroviral treatment (cART) initiated during early HIV infection (EHI) remain unclear. We investigate whether this intervention affects viral suppression and CD4⁺ cell count increase following its reinitiation in chronic infection (CHI).

Design:

Longitudinal observational study.

Methods:

We identified adult patients from Concerted Action of Seroconversion to AIDS and Death in Europe who seroconverted after 1/1/2000, had a 12 months or less HIV test interval and initiated cART from naive. We classified individuals as ‘pretreated in EHI’ if treated within 6 months of seroconversion, interrupted for at least 12 weeks, and reinitiated during CHI. Statistical analysis was performed using survival analysis methods and mixed models.

Results:

Pretreated and initiated in CHI groups comprised 202 and 4263 individuals, with median follow-up after CHI treatment 4.5 and 3 years, respectively. Both groups had similar virologic response and relapse rates (P = 0.585 and P = 0.206) but pretreated individuals restarted treatment with higher baseline CD4⁺ cell count (∼80 cells/μl; P < 0.001) and retained significantly higher CD4⁺ cell count for more than 3 years after treatment (re)initiation. Assuming common baseline CD4⁺ cell count, differences in CD4⁺ cell count slopes were nonsignificant. Immunovirologic response to CHI treatment was not associated with timing or duration of the transient treatment.

Conclusion:

Although treatment interruptions are not recommended, stopping cART initiated in EHI does not seem to reduce the chance of a successful outcome of treatment in CHI.

HIV testing updates and challenges: when regulatory caution and public health imperatives collide

Numerous improvements in HIV testing technology led recently to the first revision of recommendations for diagnostic laboratory testing in the USA in 25 years. Developments in HIV testing continue to produce tests that identify HIV infection earlier with faster turnaround times for test results. These play an important role in identifying HIV infection during the highly infectious acute phase, which has implication for both patient management and public health interventions to control the spread of HIV. Access to these developments, however, is often delayed by the regulatory apparatus for approval and oversight of HIV testing in the USA. This article summarizes recent developments in HIV diagnostic testing technology, outlines their implications for clinical management and public health, describes current systems of regulatory oversight for HIV testing in the USA, and proposes alternatives that could expedite access to improved tests as they become available.

Individualized diagnosis interventions can add significant effectiveness in reducing human immunodeficiency virus incidence among men who have sex with men: insights from Southern California

PURPOSE

In this article, we examine the effectiveness of a variety of HIV diagnosis interventions in recently HIV-diagnosed men who have sex with men (MSM). These interventions use the preventive potential of postdiagnosis behavior change (PDBC), as measured by the reduction in the number of new infections. Empirical evidence for PDBC was presented in the behavioral substudy of the Southern California Acute Infection and Early Disease Research Program. In previous modeling work, we demonstrated the existing preventive effects of PDBC. However, a large proportion of new infections among MSM are either undiagnosed or diagnosed late, and the preventive potential of PDBC is not fully utilized.

METHODS

We derive empirical, stochastic, network-based models to examine the effectiveness of several diagnosis interventions that account for PDBC among MSM over a 10-year period. These interventions involve tests with shorter detection windows, more frequent testing, and individualized testing regimens.

RESULTS

We find that individualized testing interventions (i.e., testing individuals every three partners or 3 months, whichever is first, or every six partners or 6 months, whichever is first) result in significantly fewer new HIV infections than the generalized interventions we consider.

CONCLUSIONS

This work highlights the potential of individualized interventions for new public health policies in HIV prevention.

Predictors of virologic response in persons who start antiretroviral therapy during recent HIV infection

OBJECTIVE

Despite evidence supporting antiretroviral therapy (ART) in recent HIV infection, little is known about factors that are associated with successful ART. We assessed demographic, virologic, and immunologic parameters to identify predictors of virologic response.

DESIGN

A 24-week observational study of ART on persons enrolled within 6 months of their estimated date of infection (EDI) evaluated baseline demographics and the collection of blood and gut specimens.

METHODS

Flow cytometry analyses of blood and gut lymphocytes allowed characterization of CD4 and CD8 T cells at study entry and end. Additional assessments included soluble CD14 (sCD14), lipopolysaccharide, CD4 T-cell counts, and HIV RNA levels.

RESULTS

Twenty-nine participants initiated ART, and 17 achieved undetectable HIV RNA by study end. A longer time from EDI to ART, older age, higher sCD14, lower proportions of central memory CD4 T cells, and higher proportions of activated CD8 T cells were associated with detectable viremia. Multivariable logistic regression found only older age and elevated sCD14 were independently associated with persistent viremia. Additionally, we observed that ART in recent infection did not result in discernible recovery of CD4 T cells in the gut.

CONCLUSION

In persons who started ART within 3-33 weeks from EDI, age and microbial translocation were associated with detectable HIV RNA. As observed in other cohorts, ART in recent infection did not improve proportions of total CD4 T cells in gut-associated lymphoid tissue (GALT). This lends support to further evaluate the use of more potent ART or regimens that protect the GALT in recent HIV infection.

HIV criminal prosecutions and public health: an examination of the empirical research

OBJECTIVES

To review the extant literature on HIV criminal laws, and to determine the impact of these laws on public health practice.

METHODS

The available research on this topic was obtained and reviewed.

RESULTS

The extant literature addressed three main topics: people's awareness of HIV criminal laws; people's perceptions of HIV criminal laws; and the potential effects of HIV criminal laws on people's sexual, HIV-status disclosure and healthcare-seeking practices. Within these categories, the literature demonstrated a high level of awareness of HIV criminal laws, but a poor comprehension of these laws. For perceptions, on the whole, the quantitative research identified support for, while the qualitative literature indicated opposition to, these laws. Lastly, the behavioural effects of HIV criminal laws appear to be complex and non-linear.

CONCLUSIONS

A review of the extant literature from a public health perspective leads to the conclusion that HIV criminal laws undermine public health.

HIV care in the Swedish-Danish HIV cohort 1995-2010, closing the gaps

Background

Successful treatment reduces morbidity, mortality and transmission of HIV. We evaluated trends in the treatment status of HIV infected individuals enrolled in care in Sweden and Denmark during the years 1995-2010. Our aim was to assess the proportion of HIV-infected individuals who received services along the continuum of care in Denmark in 2010, and to discuss the findings in relation to the organization of the health care system.

Methods

We analyzed CD4 counts and viral loads (VL) among all HIV patients enrolled in the cohort. For each month of the study period we estimated the proportions of patients who 1) had initiated highly active antiretroviral treatment (HAART) and had VL<500 copies/mL, 2) were not eligible for HAART, 3) had initiated HAART but had VL≥500 copies/mL, 4) were eligible for, but had not initiated HAART and 5) had initiated HAART but no VL monitoring for >13 months or 6) no HAART or monitoring of CD4 for >13 months. Patients fulfilling criteria 1 or 2 were considered successfully managed.

Results

The proportion of successfully managed patients continued to increase throughout the study period and reached 83% in 2010, 92% of Swedish/Danish men who have sex with men and heterosexual patients, but only 74% of immigrants and 78% of injection drug users were successfully managed due to higher rates of inadequate monitoring in the latter two groups. In 2010, 70% of all individuals diagnosed with HIV in Denmark were virally suppressed.

Conclusion

In a public health care system with free access to specialized care, successful management of the majority of HIV patients is achievable. Interventions tailored to retain immigrants and injection drug users in care are needed to further reduce the proportion of sub-optimally treated HIV patients.

Clinical uncertainties, health service challenges, and ethical complexities of HIV "test-and-treat": a systematic review

Despite the HIV "test-and-treat" strategy's promise, questions about its clinical rationale, operational feasibility, and ethical appropriateness have led to vigorous debate in the global HIV community. We performed a systematic review of the literature published between January 2009 and May 2012 using PubMed, SCOPUS, Global Health, Web of Science, BIOSIS, Cochrane CENTRAL, EBSCO Africa-Wide Information, and EBSCO CINAHL Plus databases to summarize clinical uncertainties, health service challenges, and ethical complexities that may affect the test-and-treat strategy's success. A thoughtful approach to research and implementation to address clinical and health service questions and meaningful community engagement regarding ethical complexities may bring us closer to safe, feasible, and effective test-and-treat implementation.

Nondisclosure prosecutions and population health outcomes: examining HIV testing, HIV diagnoses, and the attitudes of men who have sex with men following nondisclosure prosecution media releases in Ottawa, Canada

BACKGROUND

During the past decade, the intersection of HIV and criminal law has become increasingly discussed. The majority of studies to date have approached this topic from a sociological or legal perspective. As a result, the potential effect of nondisclosure prosecutions on population health and HIV prevention work remains mostly unknown.

METHODS

A descriptive quantitative-qualitative study was undertaken to examine HIV testing, HIV diagnoses, and the attitudes of men who have sex with men following regional media releases about a local nondisclosure prosecution. As part of this study, first, we reviewed the trends in HIV testing and HIV diagnoses from 2008 through 2011 in Ottawa, Canada. Second, we explored the attitudes and beliefs of local MSM about HIV, HIV prevention, HIV serostatus disclosure, nondisclosure prosecutions, and public health.

RESULTS

Quantitatively, the findings of this study revealed that, in comparison to the period preceding the media releases about a local nondisclosure prosecution, HIV testing and HIV diagnoses among men who have sex with men did not significantly change after the media releases of interest. Qualitatively, a subgroup of 27 men who have sex with men (12 HIV-positive, 15 HIV-negative) noted their beliefs that the local public health department openly shares information about people living with HIV with the police. Moreover, some HIV-positive participants stated that this perceived association between the local public health department and police services caused them to not access public health department services, notwithstanding their desires to seek assistance in maintaining safer sexual practices.

CONCLUSIONS

Nondisclosure prosecutions likely undermine HIV prevention efforts.

Include, differentiate and manage: gay male youth, stigma and healthcare utilization

In Canada, there has been a recent increase in HIV incidence among young men who have sex with men. However, gay male youth (GMY) may forego HIV testing due to fear of stigmatization. Therefore, the aim of this research was to explore the perceptions of stigma in health care within this population. The research was conducted through a series of semi-structured interviews with eight GMY aged 20-29, who frequented a gay-friendly clinic in downtown Ottawa, Canada. In a sub-analysis of the interviews utilizing the work of Hardt and Negri's three-part sequence - inclusion, differentiation and management - we found that homosexuality-related stigmatization affects the interaction between GMY and health professionals. Interview participants perceived HIV-related risk counselling as a manifestation of stigma. These findings reveal that the experience of stigma and stigmatization is not necessarily based on health professionals' intentions, but rather, on patients' perceptions of the interactions they have with health professionals. Specific modifications to the delivery of health care may help to overcome stigmatization.

Plasma HIV viral rebound following protocol-indicated cessation of ART commenced in primary and chronic HIV infection

Objectives

The magnitude of HIV viral rebound following ART cessation has consequences for clinical outcome and onward transmission. We compared plasma viral load (pVL) rebound after stopping ART initiated in primary (PHI) and chronic HIV infection (CHI).

Design

Two populations with protocol-indicated ART cessation from SPARTAC (PHI, n = 182) and SMART (CHI, n = 1450) trials.

Methods

Time for pVL to reach pre-ART levels after stopping ART was assessed in PHI using survival analysis. Differences in pVL between PHI and CHI populations 4 weeks after stopping ART were examined using linear and logistic regression. Differences in pVL slopes up to 48 weeks were examined using linear mixed models and viral burden was estimated through a time-averaged area-under-pVL curve. CHI participants were categorised by nadir CD4 at ART stop.

Results

Of 171 PHI participants, 71 (41.5%) rebounded to pre-ART pVL levels, at a median of 50 (95% CI 48–51) weeks after stopping ART. Four weeks after stopping treatment, although the proportion with pVL≥400 copies/ml was similar (78% PHI versus 79% CHI), levels were 0.45 (95% CI 0.26–0.64) log₁₀ copies/ml lower for PHI versus CHI, and remained lower up to 48 weeks. Lower CD4 nadir in CHI was associated with higher pVL after ART stop. Rebound for CHI participants with CD4 nadir >500 cells/mm³ was comparable to that experienced by PHI participants.

Conclusions

Stopping ART initiated in PHI and CHI was associated with viral rebound to levels conferring increased transmission risk, although the level of rebound was significantly lower and sustained in PHI compared to CHI.

Reaping the prevention benefits of highly active antiretroviral treatment: policy implications of HIV Prevention Trials Network 052

PURPOSE OF REVIEW

This review explores the policy implications of findings from the HIV Prevention Trials Network (HPTN 052) treatment as prevention (TasP) study.

RECENT FINDINGS

To date, the potential of antiretrovirals to prevent sexual transmission of HIV by infected persons has been grounded in observational cohort, ecological, mathematical modeling, and meta-analytic studies. HPTN 052 represents the first randomized controlled trial to test the secondary prevention benefit of HIV transmission using antiretroviral treatment in largely asymptomatic persons with high CD4 cell counts.

SUMMARY

The US National HIV/AIDS Strategy has among its key goals the reduction of incident HIV infections, improved access to quality care and associated outcomes, and the reduction in HIV-associated health disparities and inequities. HPTN 052 demonstrates that providing TasP, in combination with other effective prevention strategies offers the promise of achieving these life-saving goals. But HPTN 052 also highlights the need for cautious optimism and underscores the importance of addressing current gaps in the HIV prevention, treatment, and care continuum in order for 'TasP' strategies to achieve their full potential. Among these are necessary improvements in the capacity to expand HIV testing, facilitate effective linkage and retention in care, and improve treatment initiation, maintenance, and virus suppression.

No treatment versus 24 or 60 weeks of antiretroviral treatment during primary HIV infection: the randomized Primo-SHM trial

BACKGROUND

The objective of this study was to assess the benefit of temporary combination antiretroviral therapy (cART) during primary HIV infection (PHI).

METHODS AND FINDINGS

Adult patients with laboratory evidence of PHI were recruited in 13 HIV treatment centers in the Netherlands and randomly assigned to receive no treatment or 24 or 60 wk of cART (allocation in a 1∶1∶1 ratio); if therapy was clinically indicated, participants were randomized over the two treatment arms (allocation in a 1∶1 ratio). Primary end points were (1) viral set point, defined as the plasma viral load 36 wk after randomization in the no treatment arm and 36 wk after treatment interruption in the treatment arms, and (2) the total time that patients were off therapy, defined as the time between randomization and start of cART in the no treatment arm, and the time between treatment interruption and restart of cART in the treatment arms. cART was (re)started in case of confirmed CD4 cell count < 350 cells/mm(3) or symptomatic HIV disease. In total, 173 participants were randomized. The modified intention-to-treat analysis comprised 168 patients: 115 were randomized over the three study arms, and 53 randomized over the two treatment arms. Of the 115 patients randomized over the three study arms, mean viral set point was 4.8 (standard deviation 0.6) log(10) copies/ml in the no treatment arm, and 4.0 (1.0) and 4.3 (0.9) log(10) copies/ml in the 24- and 60-wk treatment arms (between groups: p < 0.001). The median total time off therapy in the no treatment arm was 0.7 (95% CI 0.0-1.8) y compared to 3.0 (1.9-4.2) and 1.8 (0.5-3.0) y in the 24- and 60-wk treatment arms (log rank test, p < 0.001). In the adjusted Cox analysis, both 24 wk (hazard ratio 0.42 [95% CI 0.25-0.73]) and 60 wk of early treatment (hazard ratio 0.55 [0.32-0.95]) were associated with time to (re)start of cART.

CONCLUSIONS

In this trial, temporary cART during PHI was found to transiently lower the viral set point and defer the restart of cART during chronic HIV infection.

HIV prevention in the context of care: HIV testing and public health practice

In this article, an argument is put forth that clinic-based HIV testing can function as an important aspect of public health HIV prevention. This assertion is not an outright declaration that all HIV testing is beneficial. Instead, it is the conclusion that the individual-focused initiative of HIV testing could, if structured properly, induce population-level HIV prevention benefits. This analysis was informed using the impact fraction model, the Anderson-May equation, current epidemiological information about HIV from Canada, the United States, and England, and the extant literature on the dynamics of HIV transmission. This conclusion could help inform the development of public and population health HIV testing and HIV prevention policies/practices.

Transmission clustering drives the onward spread of the HIV epidemic among men who have sex with men in Quebec

Phylodynamic analysis and epidemiologic data identified 3 patterns of spread of primary human immunodeficiency virus type 1 infection (PHI) among men who have sex with men (2001-2009): 420 unique PHIs, 102 small clusters (2-4 PHIs per cluster, n = 280), and 46 large clusters (5-31 PHIs per cluster, n = 450). Large clusters disproportionately increased from 25.2% of PHIs in 2005 to 39.1% in 2009 (χ(2) = 33.9, P < .001). Scalar expansion of large clusters over 11 months (interquartile range, 3.5-25.5 months) correlated with cluster membership size (r(2) = 0.174, F = 4.424, P = .047). PHI cohort data revealed variations in social networks and risk behaviors among the 3 groups, suggesting the need for tailored prevention measures.

A community-based study of barriers to HIV care initiation

Timely treatment of HIV infection is a public health priority, yet many HIV-positive persons delay treatment initiation. We conducted a community-based study comparing HIV-positive persons who received an HIV diagnosis at least 3 months ago but had not initiated care (n=100) with a reference population of HIV-positive persons currently in care (n=115) to identify potential barriers to treatment initiation. Study participants were mostly male (78.0%), and persons of color (54.9% Latino, 26.3% black), with median age 37.8 years. Median time since HIV diagnosis was 3.7 years. Univariate analysis revealed that those never in care differed substantially from those currently in care with regard to sociodemographics; HIV testing and counseling experiences; perceived barriers to care; and knowledge, attitudes, and beliefs regarding HIV. Factors independently associated with never initiating HIV care were younger age (adjusted odds ratio [AOR]=0.93; 95% confidence interval [CI]: 0.88, 0.99), shorter time since diagnosis (AOR=0.87; 95% CI: 0.77, 0.98), lacking insurance (AOR=0.11; 95% CI: 0.03, 0.35), not knowing someone with HIV/AIDS (AOR=0.09; 95% CI: 0.03, 0.30) not disclosing HIV status (AOR=0.13; 95% CI: 0.02, 0.70), not receiving help making an HIV care appointment after diagnosis (AOR=0.04; 95% CI: 0.01, 0.14), and not wanting to think about being HIV positive (AOR=3.57; 95% CI: 1.22, 10.46). Our findings suggest that isolation and stigma remain significant barriers to initiating HIV care in populations consisting primarily of persons of color, and that direct linkages to HIV care at the time of diagnosis are critical to promoting timely care initiation in these populations.

The potential public health effects of a police announcement about HIV nondisclosure: a case scenario analysis

In May 2010, a local police force released the details of an HIV-transmission-related criminal investigation. This involved the publication of the name and photograph of, and charges against a man who the police allege did not disclose his HIV status prior to engaging in sexual activities that pose a "significant risk" for HIV transmission. Presently, however, there are no public health analyses of this situation. Consequently, the available literature on Canadian criminal laws, HIV transmission within this jurisdiction, and HIV prevention are presented and discussed herein. The outcome of this analysis is the conclusion that the act of publicizing an HIV-related criminal investigation more likely inhibits than encourages STI/HIV testing among HIV-negative and HIV-positive men who have sex with men. It is the assertion here that this undertaking thus conflicts with the overall public health goals of HIV prevention, and should likely not occur in the future.