Partner Notification for Reduction of HIV-1 Transmission and Related Costs among Men Who Have Sex with Men: A Mathematical Modeling Study

Effects of improved partner notification on the transmission of HIV and N. gonorrhoea among men who have sex with men: a modelling study

Objectives Men who have sex with men (MSM) are disproportionally affected by HIV in the Netherlands. Partner notification (PN) is an important element in controlling the transmission of sexually transmitted infections (STIs) and HIV. We investigated the effects of improving PN on the transmission of HIV and Neisseria gonorrhoeae (NG) among MSM in the Netherlands. Methods We developed an agent-based model that describes the transmission of HIV and NG among MSM. In the baseline scenario, 14.3% and 29.8% of casual and steady partners of the index case get notified and tested for HIV/STI after 3 weeks (percentage notified and tested (PNT)). We examined the following scenarios: (1) increase PNT to 41% for both partner types; (2) decrease the time between the index and the partners tested to 1 week and (3) combine scenarios 1 and 2. Effects are expressed as cumulative change from the baseline simulation over 15 years. Results Increasing PNT could lead to a decrease in gonorrhoea cases of 45% (IQR 39.9% to 49.9%), with an increase in the number of HIV/STI tests of 4.4% (IQR 1.6% to 7.3%), but no change in HIV infections (-5.4%; IQR -21% to 7.9%). Decreasing the time between tests could lead to a change in new NG infections of -14.2% (IQR -17.2% to -10%), no change in HIV infections (8.2%; IQR -1.3% to 20%) or in the number of HIV/STI tests performed (-0.4%; IQR -1.5 to 0.6%). Scenario 3 led to a change in NG infections of -56.8% (IQR -63.8% to -47.4%), no change in HIV infections (11.5%; IQR -11.1% to 33.9%) or in the number of HIV/STI tests (-0.5%; IQR: -4.9% to 4.3%). Conclusions Increasing the percentage of sexual partners notified and tested for HIV/STI may have only a small effect on HIV but could reduce the number of new NG infections substantially. However, it could lead to an increase in the number of HIV/STI tests performed.

Spatio-temporal forecasting of COVID-19 cases in the Netherlands for source and contact tracing

Source and contact tracing (SCT) is a core public health measure that is used to contain the spread of infectious diseases. It aims to identify a source of infection, and to advise those who have been exposed to this source. Due to the rapid increases in incidence of COVID-19 in the Netherlands, the capacity to conduct a full SCT quickly became insufficient. Therefore, the public health services (PHS) might benefit from a restricted strategy targeted to geographical regions where (predicted) case-to-case transmission is high. In this study, we set out to develop a prediction model for the number of COVID-19 cases per postal code within the Netherlands using geographic and demographic features. The study population consists of individuals residing in one of the participating nine Dutch PHS regions who tested positive for SARS-CoV-2 between 1 June 2020 and 27 February 2021. Using a machine learning random forest regression model, we predicted the top 100 postal codes with the highest number of cases with an accuracy of 49% for the current week, 42% for next week, and 44% for two weeks from present. In addition, the age groups of 20-39 and 40-64 years had a higher prediction accuracy than groups outside these age ranges. The developed model provides a starting point for targeted preventive SCT efforts that incorporate geospatial and demographic characteristics of a neighbourhood. It should nonetheless be noted that during the early stages of the outbreak, the number of available datapoints needed to inform such models are likely insufficient. Given the accuracy and data requirements of the developed model, it is unlikely that this class of models can play a pivotal role in informing policy during the early phases of a future epidemic.

Characteristics and short- and long-term direct medical costs among adults with timely and delayed presentation for HIV care in the Netherlands

INTRODUCTION

In Europe, half of people living with HIV (PLWH) present late to care, with associated higher morbidity and mortality. This study aims to assess short- and long-term costs of HIV-care based on time of presentation and identify other factors contributing to higher costs in the first and fifth year after antiretroviral therapy (ART) initiation.

MATERIAL AND METHODS

We included ATHENA cohort data which prospectively includes 98% of PLWH in the Netherlands. PLWH who initiated ART in 2013 were included and followed over five years. PLWH were divided in three categories based on CD4 cell-count at time of ART initiation: timely presentation (CD4>350cells/μL), late presentation (CD4 200-350cells/μL or >350cells/μL with AIDS-defining illness) and very late presentation (CD4<200cells/μL). The total HIV-care cost was calculated distinguishing ART medication and non-ART medication costs (hospitalization, outpatient clinic visits, co-medications, and HIV-laboratory tests).

RESULTS

From 1,296 PLWH, 273 (21%) presented late and 179 (14%) very late. Nearly half of those who entered HIV-care in a very late stage were of non-Dutch origin, with 21% originating from sub-Saharan Africa. The mean cost per patient in the first year was €12,902 (SD€11,098), of which about two-thirds due to ART (€8,250 (SD€3,142)). ART costs in the first and fifth year were comparable regardless of time of presentation. During the first year on treatment, non-ART medication costs were substantially higher among those with late presentation (€4,749 (SD€8,009)) and very late presentation (€15,886 (SD€ 21,834)), compared with timely presentation (€2,407(SD€4,511)). Higher non-ART costs were attributable to hospitalization and co-medication. The total non-ART costs incurred across five years on treatment were 56% and 246% higher for late and very late presentation respectively as compared to timely presentation.

CONCLUSION

Very late presentation is associated with substantial costs, with non-ART costs nearly seven times higher than for those presenting timely. Hospitalization and co-medication costs are likely to continue to drive higher costs for individuals with late presentation into the future. Programs that identify individuals earlier will therefore likely provide significant short- and long-term health cost savings.

The Role of HIV Partner Services in the Modern Biomedical HIV Prevention Era: A Network Modeling Study

BACKGROUND

HIV partner services can accelerate the use of antiretroviral-based HIV prevention tools (antiretroviral therapy [ART] and preexposure prophylaxis [PrEP]), but its population impact on long-term HIV incidence reduction is challenging to quantify with traditional partner services metrics of partner identified or HIV screened. Understanding the role of partner services within the portfolio of HIV prevention interventions, including using it to efficiently deliver antiretrovirals, is needed to achieve HIV prevention targets.

METHODS

We used a stochastic network model of HIV/sexually transmitted infection transmission for men who have sex with men, calibrated to surveillance-based estimates in the Atlanta area, a jurisdiction with high HIV burden and suboptimal partner services uptake. Model scenarios varied successful delivery of partner services cascade steps (newly diagnosed "index" patient and partner identification, partner HIV screening, and linkage or reengagement of partners in PrEP or ART care) individually and jointly.

RESULTS

At current levels observed in Atlanta, removal of HIV partner services had minimal impact on 10-year cumulative HIV incidence, as did improving a single partner services step while holding the others constant. These changes did not sufficiently impact overall PrEP or ART coverage to reduce HIV transmission. If all index patients and partners were identified, maximizing partner HIV screening, partner PrEP provision, partner ART linkage, and partner ART reengagement would avert 6%, 11%, 5%, and 18% of infections, respectively. Realistic improvements in partner identification and service delivery were estimated to avert 2% to 8% of infections, depending on the combination of improvements.

CONCLUSIONS

Achieving optimal HIV prevention with partner services depends on pairing improvements in index patient and partner identification with maximal delivery of HIV screening, ART, and PrEP to partners if indicated. Improving the identification steps without improvement to antiretroviral service delivery steps, or vice versa, is projected to result in negligible population HIV prevention benefit.

The Cost-Effectiveness of HIV/STI Prevention in High-Income Countries with Concentrated Epidemic Settings: A Scoping Review

The purpose of this scoping review is to establish the state of the art on economic evaluations in the field of HIV/STI prevention in high-income countries with concentrated epidemic settings and to assess what we know about the cost-effectiveness of different measures. We reviewed economic evaluations of HIV/STI prevention measures published in the Web of Science and Cost-Effectiveness Registry databases. We included a total of 157 studies focusing on structural, behavioural, and biomedical interventions, covering a variety of contexts, target populations and approaches. The majority of studies are based on mathematical modelling and demonstrate that the preventive measures under scrutiny are cost-effective. Interventions targeted at high-risk populations yield the most favourable results. The generalisability and transferability of the study results are limited due to the heterogeneity of the populations, settings and methods involved. Furthermore, the results depend heavily on modelling assumptions. Since evidence is unequally distributed, we discuss implications for future research.

HIV Response Interventions that Integrate HIV Molecular Cluster and Social Network Analysis: A Systematic Review

Due to improved efficiency and reduced cost of viral sequencing, molecular cluster analysis can be feasibly utilized alongside existing human immunodeficiency virus (HIV) prevention strategies. The goal of this paper is to elucidate how HIV molecular cluster and social network analyses are being integrated to implement HIV response interventions. We searched PubMed, Scopus, PsycINFO, and Cochrane Library databases for studies incorporating both HIV molecular cluster and social network data. We identified 32 articles that combined analyses of HIV molecular sequences and social or sexual networks. All studies were descriptive. Six studies described network interventions informed by molecular and social data but did not fully evaluate their efficacy. There is no current standard for incorporating molecular and social network analyses to inform interventions or data demonstrating its utility. More research must be conducted to delineate benefits and best practices for leveraging molecular data for network-based interventions.

Health Worker Perspectives on Barriers and Facilitators of Assisted Partner Notification for HIV for Refugees and Ugandan Nationals: A Mixed Methods Study in West Nile Uganda

Assisted partner notification (APN) is recommended by the World Health Organization to notify sexual partners of HIV exposure. Since 2018, APN has been offered in Uganda to Ugandan nationals and refugees. Distinct challenges faced by individuals in refugee settlements may influence APN utilization and effectiveness. To explore APN barriers and facilitators, we extracted index client and sexual partner data from APN registers at 11 health centers providing care to refugees and Ugandan nationals in West Nile Uganda and conducted qualitative interviews with health workers (N = 32). Since APN started, 882 index clients participated in APN identifying 1126 sexual partners. Following notification, 95% (1025/1126) of partners tested for HIV; 22% (230/1025) were diagnosed with HIV with 14% (139/1025) of tested partners newly diagnosed. Fear of stigma and disclosure-related violence limit APN utilization and effectiveness. Prospective research involving index clients and sexual partners is needed to facilitate safe APN optimization in refugee settlements.

Peer Mobilization and Human Immunodeficiency Virus (HIV) Partner Notification Services Among Gay, Bisexual, and Other Men Who Have Sex With Men and Transgender Women in Coastal Kenya Identified a High Number of Undiagnosed HIV Infections

Background

Human immunodeficiency virus (HIV) partner notification services (HPN), peer mobilization with HIV self-testing, and acute and early HIV infection (AEHI) screening among gay, bisexual, and other men who have sex with men (GBMSM) and transgender women (TGW) were assessed for acceptability, feasibility, and linkage to antiretroviral therapy (ART) and preexposure prophylaxis (PrEP) services.

Methods

Between April and August 2019, peer mobilizers mobilized clients by offering HIV oral self-tests and immediate clinic referral for clients with AEHI symptoms. Mobilized participants received clinic-based rapid antibody testing and point-of-care HIV RNA testing. Newly diagnosed participants including those derived from HIV testing services were offered immediate ART and HPN. Partners were recruited through HPN.

Results

Of 772 mobilized clients, 452 (58.5%) enrolled in the study as mobilized participants. Of these, 16 (3.5%) were HIV newly diagnosed, including 2 (0.4%) with AEHI. All but 2 (14/16 [87.5%]) initiated ART. Thirty-five GBMSM and TGW were offered HPN and 27 (77.1%) accepted it. Provider referral identified a higher proportion of partners tested (39/64 [60.9%] vs 5/14 [35.7%]) and partners with HIV (27/39 [69.2%] vs 2/5 [40.0%]) than index referral. Of 44 enrolled partners, 10 (22.7%) were newly diagnosed, including 3 (6.8%) with AEHI. All 10 (100%) initiated ART. PrEP was initiated among 24.0% (103/429) mobilized participants and 28.6% (4/14) partners without HIV.

Conclusions

HPN, combined with a peer mobilization-led self-testing strategy and AEHI screening for GBMSM and TGW, appears to be acceptable and feasible. These strategies, especially HPN provider referral, effectively identified undiagnosed HIV infections and linked individuals to ART and PrEP services.

Comparison of effectiveness and cost for different HIV screening strategies implemented at large urban medical centre in the United States

INTRODUCTION

Incident HIV infections persist in the United States (U.S.) among marginalized populations. Targeted and cost-efficient testing strategies can help in reaching HIV elimination. This analysis compares the effectiveness and cost of three HIV testing strategies in a high HIV burden area in the U.S. in identifying new HIV infections.

METHODS

We performed a cost analysis comparing three HIV testing strategies in Chicago: (1) routine screening (RS) in an inpatient and outpatient setting, (2) modified partner services (MPS) among networks of the recently HIV infected and diagnosed, and (3) a respondent drive sampling (RDS)-based social network (SN) approach targeting young African-American men who have sex with men. All occurred at the same academic medical centre during the following times: routine testing, 2011 to 2016; MPS, 2013 to 2016; SN: 2013 to 2014. Costs were in 2016 dollars and included personnel, HIV testing, training, materials, overhead. Outcomes included cost per test, HIV-positive test and new diagnosis. Sensitivity analyses were performed to assess the impact of population demographics.

RESULTS

The RS programme completed 57,308 HIV tests resulting in 360 (0.6%) HIV-positive tests and 165 new HIV diagnoses (0.28%). The MPS completed 146 HIV tests, resulting in 79 (54%) HIV-positive tests and eight new HIV diagnoses (5%). The SN strategy completed 508 HIV tests, resulting in 210 (41%) HIV-positive tests and 37 new HIV diagnoses (7.2%). Labour accounted for the majority of costs in all strategies. The estimated cost per new HIV diagnosis was $16,773 for the RS programme, $61,418 for the MPS programme and $15,683 for the SN testing programme. These costs were reduced for the RS and MPS strategies in sensitivity analyses limiting testing efficacy to the highest prevalence patient populations ($2,841 and $33,233 respectively).

CONCLUSIONS

The SN strategy yielded the highest proportion of new diagnoses, followed closely by the MPS programme. Both the SN strategy and RS programme were comparable in the cost per new diagnosis. A simultaneous approach that consists of RS in combination with SN testing may be most effective for identifying new HIV infections in settings with heterogeneous epidemics with both high rates of HIV prevalence and HIV testing.

Development of a Question Prompt List for Patients Living With HIV and Assessment of Their Information Needs

A question prompt list (QPL) is an efficient method to facilitate patient active participation and communication by providing patients with questions to ask their health care providers. We developed a QPL based on the information needs of patients living with HIV in Korea. A mixed method study design was used, involving five sequential steps: literature review, focus group interview with experienced nurses, in-depth interviews with patients, expert reviews, and a survey of 170 patients. A QPL with 27 questions was developed through literature reviews and expert reviews, and 12 questions were identified based on the Borich needs assessment model. Questions included items regarding diagnosis and prognosis, medication, depressive symptoms, sexual relationships, and family and social life. Our findings suggest that a QPL should be used as a tool to encourage effective communication for patients living with HIV.

Health System Factors Influencing Partner Notification for STIs and HIV in Lilongwe Malawi. A Pre-intervention Phase Assessment for a Quality Improvement Project

Introduction

Despite its wide use, passive partner notification (PN) has a low yield of sexual partners influenced by patient-related and health system (HS) factors.

Methods

We conducted a qualitative study and clinic observations during a pre-intervention phase of a quality improvement (QI) project to identify HS factors that influenced passive PN at Bwaila STI unit (BSU) in Lilongwe Malawi from January to February 2016. We conducted 15 in-depth interviews with health workers and clinic observations for six clinic flow and PN processes at the clinic.

Results

The majority of health workers felt that the lack of incentives for sexual partners or couples who presented to the clinic was the most important negative HS factor that influenced passive PN. We observed an average clinic start time of 09:02 hours. The average duration of the group health talk was 56 minutes and there was no difference in the time spent at the clinic between index cases and partners (1 hour 41 minutes versus 1 hour 36 minutes respectively).

Discussion

Lack of incentives for sexual partners or couples was the most important HS factors that impacted the yield of sexual partners. Interventions focusing on designing simple non-monetary incentives and QI of passive PN should be encouraged.

Sociodemographic Differences in Clients Preferring Video-Call Over In-person Interview: A Pilot Study of HIV Tele-partner Services

The New York City Department of Health Disease Intervention Specialists (DIS) routinely contact newly HIV-diagnosed persons via telephone calls and in-person meetings to conduct partner services (PS) interviews in order to elicit the names and contact information of the HIV-exposed partners for notification and HIV-testing, and to assist clients with linkage to care. From October 2013 to December 2015, we offered PS interviews conducted via video-call alongside voice-call and in-person modes in a selected geographic area of NYC. PS interviews were conducted according to the clients' preferred mode (in-person, voice- or video-call) and location (health care facility, clients' residences, or other NYC locations). At the conclusion of the PS interviews, DIS elicited responses from persons interviewed via video-call on their perception, satisfaction and personal experiences using video-call for public health and personal purposes. Acceptance and satisfaction with PS interviews via video-call were high among clients aged <30 years, men who have sex with men, or with education above high school; while PS yields were similar across modes. These results provide evidence of the potential effectiveness of video-call interviews for specific populations.

Cost-effectiveness analysis of pre-exposure prophylaxis for HIV-1 prevention in the Netherlands: a mathematical modelling study

BACKGROUND

Pre-exposure prophylaxis (PrEP) with tenofovir and emtricitabine prevents HIV infections among men who have sex with men (MSM). PrEP can be given on a daily or intermittent basis. Unfortunately, PrEP is not reimbursed in most European countries. Cost-effectiveness analyses of PrEP among MSM in Europe are absent but are key for decision makers to decide upon PrEP implementation.

METHODS

We developed a deterministic mathematical model, calibrated to the well defined Dutch HIV epidemic among MSM, to predict the effect and cost-effectiveness of PrEP. PrEP was targeted to 10% of highly sexually active Dutch MSM over the coming 40 years. Cost-effectiveness ratios were calculated to predict the cost-effectiveness of daily and on-demand PrEP. Cost-effectiveness ratios below €20 000 were considered to be cost-effective in this analysis.

FINDINGS

Within the context of a stable HIV epidemic, at 80% effectiveness and current PrEP pricing, PrEP can cost as much as €11 000 (IQR 9400-14 100) per quality-adjusted life-year (QALY) gained when used daily, or as little as €2000 (IQR 1300-3000) per QALY gained when used on demand. At 80% effectiveness, daily PrEP can be considered cost-saving if the price of PrEP is reduced by 70%, and on-demand PrEP can be considered cost-saving if the price is reduced by 30-40%.

INTERPRETATION

PrEP for HIV prevention among MSM in the Netherlands is cost-effective. The use of PrEP is most cost-effective when the price of PrEP is reduced through on-demand use or through availability of generic PrEP, and can quickly be considered cost-saving.

FUNDING

None.