Derivation and Validation of an HIV Risk Prediction Score Among Gay, Bisexual, and Other Men Who Have Sex With Men to Inform PrEP Initiation in an STD Clinic Setting

Data mining and machine learning in HIV infection risk research: An overview and recommendations

In the contemporary era, the applications of data mining and machine learning have permeated extensively into medical research, significantly contributing to areas such as HIV studies. By reviewing 38 articles published in the past 15 years, the study presents a roadmap based on seven different aspects, utilizing various machine learning techniques for both novice researchers and experienced researchers seeking to comprehend the current state of the art in this area. While traditional regression modeling techniques have been commonly used, researchers are increasingly adopting more advanced fully supervised machine learning and deep learning techniques, which often outperform the traditional methods in predictive performance. Additionally, the study identifies nine new open research issues and outlines possible future research plans to enhance the outcomes of HIV infection risk research. This review is expected to be an insightful guide for researchers, illuminating current practices and suggesting advancements in the field.

Evaluating the Screening and Enrollment of People at Risk of HIV in Mexico's Preexposure Prophylaxis Demonstration Project, 2018-2020

OBJECTIVES

Screening tools in which participants self-report sexual behaviors can identify people at risk of HIV acquisition for enrollment in preexposure prophylaxis (PrEP). We compared enrollment outcomes (ie, receiving PrEP vs being excluded by a counselor or declining PrEP) in Mexico's PrEP demonstration project and evaluated the validity of a 4-criteria PrEP eligibility tool in which participants self-reported risk behavior-having condomless anal sex, transactional sex, a partner living with HIV, or a sexually transmitted infection-as compared with PrEP eligibility assessed by a counselor.

METHODS

We recruited men who have sex with men and transwomen who were offered PrEP services in Mexico. We characterized participants according to enrollment outcome and identified underlying factors through logistic regression analyses. We calculated the sensitivity and specificity of the self-reported risk criteria, using the counselor's risk assessment as the point of reference.

RESULTS

Of 2460 participants, 2323 (94%) had risk criteria of HIV acquisition according to the 4-criteria tool; 1701 (73%) received PrEP, 247 (11%) were excluded by a counselor, and 351 (15%) declined PrEP despite being considered eligible by the counselor. Participants who were excluded or who declined PrEP were less likely to report HIV risk behaviors than those who received PrEP, and participants who declined PrEP were more likely to be transwomen (vs men who have sex with men) and aged ≤25 years (vs >25 y). The 4-criteria risk tool had high sensitivity (98.6%) and low specificity (29.8%).

CONCLUSION

The screening tool identified most participants at risk of HIV acquisition, but counselors' assessment helped refine the decision for enrollment in PrEP by excluding those with low risk. Public health strategies are needed to enhance enrollment in PrEP among some groups.

Effectiveness of the Modified Vaccinia Ankara Vaccine Against Mpox in Men Who Have Sex With Men: A Retrospective Cohort Analysis, Seattle, Washington

Background

Data on modified Vaccinia Ankara (MVA) vaccine effectiveness against mpox in real-world settings are limited.

Methods

We performed a retrospective cohort analysis using Cox proportional hazards regression to estimate the association between vaccination and laboratory-confirmed mpox incidence. Study subjects included all men who have sex with men seen in a sexual health clinic in Seattle, Washington, between 1 January 2020 and 31 December 2022. Subjects' receipt of vaccine and diagnosis with mpox were ascertained from public health vaccine registry and surveillance data. Analyses were adjusted for demographic factors, human immunodeficiency virus (HIV) status, and sexual risk behaviors.

Results

The incidence of mpox per 100 person-years was 8.83 among patients with 0 doses, 3.32 among patients with 1 dose, and 0.78 among patients with 2 doses of MVA vaccine. Mpox diagnosis was significantly associated with age category 30-39 and 40-51 years, HIV positivity, syphilis diagnosis in the prior year, >10 sex partners in the last year, and having a clinic visit in the last year. In the multivariate model adjusting for these factors, vaccine effectiveness was 81% for 1 dose and 83% for 2 doses.

Conclusions

These data support the effectiveness of the MVA vaccine-including a single dose of the vaccine-in preventing mpox disease and highlight the appropriateness of risk factor-based prioritization of immunization early in the epidemic. The durability of MVA vaccine-induced immunity is unknown, and at-risk persons should receive 2 doses of MVA.

Preexposure Prophylaxis for the Prevention of HIV: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

A 2019 review for the US Preventive Services Task Force (USPSTF) found oral preexposure prophylaxis (PrEP) associated with decreased HIV infection risk vs placebo or no PrEP in adults at increased HIV acquisition risk. Newer PrEP regimens are available.

Objective

To update the 2019 review on PrEP, to inform the USPSTF.

Data Sources

Ovid MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Embase (January 2018 to May 16, 2022); surveillance through March 24, 2023.

Study Selection

Randomized clinical trials of PrEP vs placebo or no PrEP or newer vs older PrEP regimens and diagnostic accuracy studies of instruments for predicting incident HIV infection.

Data Extraction and Synthesis

Dual review of titles and abstracts, full-text articles, study quality, and data abstraction. Data were pooled using the DerSimonian and Laird random-effects model.

Main Outcomes and Measures

HIV acquisition, mortality, and harms; and diagnostic test accuracy.

Results

Thirty-two studies were included in the review (20 randomized clinical trials [N = 36 543] and 12 studies of diagnostic accuracy [N = 5 544 500]). Eleven trials in the 2019 review found oral PrEP associated with decreased HIV infection risk vs placebo or no PrEP (n = 18 172; relative risk [RR], 0.46 [95% CI, 0.33-0.66]). Higher adherence was associated with greater efficacy. One new trial (n = 5335) found oral tenofovir alafenamide/emtricitabine (TAF/FTC) to be noninferior to tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in men who have sex with men (RR, 0.47 [95% CI, 0.19-1.14]). Two new trials found long-acting injectable cabotegravir associated with decreased risk of HIV infection vs oral TDF/FTC (RR, 0.33 [95% CI, 0.18-0.62] in cisgender men who have sex with men and transgender women [n = 4490] and RR, 0.11 [95% CI, 0.04-0.31] in cisgender women [n = 3178]). Discrimination of instruments for predicting incident HIV infection was moderate in men who have sex with men (5 studies; n = 25 488) and moderate to high in general populations of persons without HIV (2 studies; n = 5 477 291).

Conclusions and Relevance

In adults at increased HIV acquisition risk, oral PrEP was associated with decreased risk of acquiring HIV infection compared with placebo or no PrEP. Oral TAF/FTC was noninferior to oral TDF/FTC, and injectable cabotegravir reduced the risk of HIV infection compared with oral TDF/FTC in the populations studied.

Performance of HIV Infection Prediction Models in Men Who Have Sex with Men: A Systematic Review and Meta-Analysis

Effective ways to identify and predict men who have sex with men (MSM) at substantial risk for HIV is a global priority. HIV risk assessment tools can improve individual risk awareness and subsequent health-seeking actions. We sought to identify and characterize the performance of HIV infection risk prediction models in MSM through systematic review and meta-analysis. PubMed, Embase, and The Cochrane Library were searched. Eighteen HIV infection risk assessment models with a total of 151,422 participants and 3643 HIV cases were identified, eight of which have been externally validated by at least one study (HIRI-MSM, Menza Score, SDET Score, Li Model, DHRS, Amsterdam Score, SexPro model, and UMRSS). The number of predictor variables in each model ranged from three to 12, age, the number of male sexual partners, unprotected receptive anal intercourse, recreational drug usage (amphetamines, poppers), and sexually transmitted infections were critical scoring variables. All eight externally validated models performed well in terms of discrimination, with the pooled area under the receiver operating characteristic curve (AUC) ranging from 0.62 (95%CI: 0.51 to 0.73, SDET Score) to 0.83 (95%CI: 0.48 to 0.99, Amsterdam Score). Calibration performance was only reported in 10 studies (35.7%, 10/28). The HIV infection risk prediction models showed moderate-to-good discrimination performance. Validation of prediction models across different geographic and ethnic environments is needed to ensure their real-world application.

Dynamic immune markers predict HIV acquisition and augment associations with sociobehavioral factors for HIV exposure

Prior studies attempting to link biomarkers of immune activation with risk of acquiring HIV have relied on cross sectional samples, most without proximity to HIV acquisition. We created a nested case-control study within the Sabes study in Peru, and assessed a panel of plasma immune biomarkers at enrollment and longitudinally, including within a month of diagnosis of primary HIV or matched timepoint in controls. We used machine learning to select biomarkers and sociobehavioral covariates predictive of HIV acquisition. Most biomarkers were indistinguishable between cases and controls one month before HIV diagnosis. However, levels differed between cases and controls at study entry, months to years earlier. Dynamic changes in IL-2, IL-7, IL-10, IP-10 and IL-12, rather than absolute levels, jointly predicted HIV risk when added to traditional risk factors, and there was modest effect modification of biomarkers on association between sociobehavioral risk factors and HIV acquisition.

Developing a symptoms-based risk score for infectious syphilis among men who have sex with men

Background

Syphilis incidence is rising among men who have sex with men (MSM). An online tool based on a risk score identifying men with higher risk of infectious syphilis could motivate MSM to seek care. We aimed therefore to develop a symptoms-based risk score for infectious syphilis.

Methods

We included data from all consultations by MSM attending the Amsterdam Centre for Sexual Health in 2018–2019. Infectious syphilis (ie, primary, secondary or early latent syphilis) was diagnosed according to the centre’s routine protocol. Associations between symptoms and infectious syphilis were expressed as odds ratios (OR), with 95% confidence intervals (CI). Based on multivariable logistic regression models, we created risk scores, combining various symptoms. We assessed the area under the curve (AUC) and cut-off based on the Youden Index. We estimated which percentage of MSM should be tested based on a positive risk score and which percentage of infectious syphilis cases would then be missed.

Results

We included 21,646 consultations with 11,594 unique persons. The median age was 34 years (IQR 27–45), and 14% were HIV positive (93% on antiretroviral treatment). We diagnosed 538 cases of infectious syphilis. Associations with syphilis symptoms/signs were strong and highly significant, for example, OR for a painless penile ulcer was 35.0 (CI 24.9 to 49.2) and OR for non-itching rash 57.8 (CI 36.8 to 90.9). Yet, none of the individual symptoms or signs had an AUC >0.55. The AUC of risk scores combining various symptoms varied from 0.68 to 0.69. For all risk scores using cut-offs based on Youden Index, syphilis screening would be recommended in 6% of MSM, and 59% of infectious syphilis cases would be missed.

Conclusion

Symptoms-based risk scores for infectious syphilis perform poorly and cannot be recommended to select MSM for syphilis screening. All MSM with relevant sexual exposure should be regularly tested for syphilis.

A Demedicalized Model to Provide PrEP in a Sexual Health Clinic

BACKGROUND

Sexual health clinics (SHCs) serve large numbers of patients who might benefit from preexposure prophylaxis (PrEP). Integrating longitudinal PrEP care into SHCs can overburden clinics. We implemented an SHC PrEP program that task shifted most PrEP operations to nonmedical staff, disease intervention specialists (DIS).

METHODS

We conducted a retrospective cohort analysis of PrEP patients in an SHC in Seattle, WA, from 2014 to 2020 to assess the number of patients served and factors associated with PrEP discontinuation. Clinicians provide same-day PrEP prescriptions, whereas DIS coordinate the program, act as navigators, and provide most follow-up care.

RESULTS

Between 2014 and 2019, 1387 patients attended an initial PrEP visit, 93% of whom were men who have sex with men. The number of patients initiating PrEP per quarter year increased from 20 to 81. The number of PrEP starts doubled when the clinic shifted from PrEP initiation at scheduled visits to initiation integrated into routine walk-in visits. The percentage of visits performed by DIS increased from 3% in 2014 to 45% in 2019. Median duration on PrEP use was 11 months. PrEP discontinuation was associated with non-Hispanic black race/ethnicity [hazard ratio (HR) 1.34, 95% confidence interval (CI) 1.02 to 1.76], age <20 years (HR 2.17, 95% CI: 1.26 to 3.75), age between 20 and 29 years (HR 1.55, 95% CI: 1.06 to 2.28), and methamphetamine use (HR 1.98, 95% CI: 1.57 to 2.49). The clinic had 750 patients on PrEP in the final quarter of 2019.

CONCLUSIONS

A demedicalized SHC PrEP model that task shifts most operations to DIS can provide PrEP at scale to high priority populations.

Characteristics of HIV Seroconverters Identified in an Emergency Department HIV Screening Program

The emergency department (ED) may represent a missed opportunity to proactively intervene upon patients at "high risk" for HIV. We sought to describe characteristics of ED HIV seroconverters (individuals who screened positive in the ED for HIV who had either (1) a previous prior negative HIV test in the electronic health record (EHR) or who (2) self-reported a prior negative HIV test) to identify a "high-risk" phenotype for pre-infection engagement. A retrospective chart-review was performed of HIV seroconverters at an academic, urban ED. General demographics, mental health illness comorbidities, and Centers for Disease Control and Prevention (CDC)-identified "high risk" factors, including intravenous drug use (IVDU) and history of sexually transmitted infection (STI) were noted. One hundred thirty total patients were identified, 48 (36.9%) with prior HER-negative test and 82 (63.1%) with self-reported previous negative test. Of total seroconverters: 100 (76.9%) were male and 77 (59.2%) were between the ages of 13-34, comparable to national rates of new HIV diagnoses. Ninety-two patients (70.8%) were Black and 16 (12.3%) had a history of IVDU, significantly increased compared with regional and national new HIV rates (p < 0.05). Fifty-two patients (40%) had an STI within 1 year before HIV-positive screen, 67 (51.5%) had a history of mental health illness, and 77 (59.2%) were uninsured. This review revealed an HIV seroconversion population disproportionately affected by race, IVDU, mental health comorbidities, and additional social factors. The ED may represent a unique opportunity for at-risk, pre-HIV exposure intervention, particularly for vulnerable populations.