The risk of HIV transmission at each step of the HIV care continuum among people who inject drugs: a modeling study

Abstract

BackgroundPeople who inject drugs (PWID) are at continued risk for HIV in the U.S., and experience disparities across the HIV care continuum compared to other high-risk groups. Estimates of the risk of HIV transmission at each stage of the care continuum may assist in identifying public health priorities for averting incident infections among PWID, in addition to transmissions to sexual partners of PWID.MethodsWe created an agent-based model simulating HIV transmission and the HIV care continuum for PWID in New York City (NYC) in 2012. To account for sexual transmission arising from PWID to non-PWID, the simulation included the entire adult NYC population. Using surveillance data and estimates from the National HIV Behavioral Surveillance system, we simulated a dynamic sexual and injecting network. We estimated the proportion of HIV transmission events attributable to PWID in the following categories, those: without an HIV diagnosis (‘Undiagnosed’); diagnosed but not on antiretroviral therapy (ART) (‘Diagnosed − not on ART’); those who initiated ART but were not virally suppressed (‘Unsuppressed’); and, those who achieved viral suppression (‘Suppressed’).ResultsWe estimated HIV incidence among PWID to be 113 per 100,000 person-years in 2012, with an overall incidence rate for the entire adult NYC population of 33 per 100,000 person-years. Despite accounting for only 33% of the HIV-infected PWID population, the Undiagnosed were associated with 52.6% (95% simulation interval [95% SI]: 47.1–57.0%) of total transmission events. The Diagnosed − not on ART population contributed the second-largest proportion of HIV transmissions, with 36.6% (95% SI: 32.2–41.5%). The Unsuppressed population contributed 8.7% (95% SI: 5.6–11.8%), and Suppressed 2.1% (95% SI: 1.1–3.9%), relatively little of overall transmission.ConclusionsAmong PWID in NYC, more than half (53%) of transmissions were from those who were unaware of their infection status and more than 36% were due to PWID who knew their status, but were not on treatment. Our results indicate the importance of early diagnosis and interventions to engage diagnosed PWID on treatment to further suppress population-level HIV transmission. Future HIV prevention research should focus on the elimination of identified and potential barriers to the testing, diagnosis, and retention of PWID on HIV treatment.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-017-4528-9) contains supplementary material, which is available to authorized users.

Viral load testing to monitor the HIV epidemic among PWID in Vietnam

“…The pilot survey has measured VL among male PWID, including those who were aware of their HIV status and those who did not know their status before. Findings indicate that a significant proportion of PWID do not have their VL suppressed leading to high-risk of HIV transmission from PWID to their sexual partners [3] in the community although level of unsuppressed viral load is not a direct measure of HIV viral transmission in itself. This pilot indicated that it was feasible to add VL testing into HSS and Vietnam government can add it as a routine practice in HSS and can be expanded in the coming years.…”

Modelling microbial infection to address global health challenges

“…Individual-based models. Whereas the unit of interest for withinhost modelling is an infected cell, the analogous unit for individualbased models is an infected person (Table 1) 5,17,18 . Individual-based models are often used to explore the interplay between disease transmission and individual-level risk factors, such as comorbidities, sexual behaviours and age.…”

“…Individual-based models are uniquely suited for representing overlap in individual-level risk factors and translating the implications of this overlap for public health policy. For example, an individual-based model was recently used to demonstrate that the majority of HIV transmission among people who inject drugs in New York City is attributable to undiagnosed infections 18 . These modelling results underscore the urgency for the city to invest in more comprehensive screening and improved diagnostic practices.…”

The Role of Mental Disorders in the Distribution and Treatment of Hiv Infection

“…Проблемы со здоровьем могут быть факторами риска ВИЧ или возникать в результате ВИЧ-инфекции и ее осложнений [1][2][3][4][5][6][7][8] Однако, в целом, женщины с ПАВ имеют тенденцию к более высокому уровню коморбидности, особенно посттравматическом стрессе [5,6]. Список литературы…”

“…Две основные проблемы для ВИЧ+-повышенное рискованное поведение и влияние расстройств на приверженность к лечению. Среди потребителей опиатов ПР связаны с более высокой частотой совместного использования игл и шприцев и меньшим использованием презервативов при сексуальных контактах[7].Антиретровирусные препараты обладают высокой гепатоксичностью вследствие регулярного и в течение длительного времени (пожизненного) употребления, к тому же абакавир и невирапин (верамун) вызывают аллергические реакции и усиливают воспаление, что приводит к разрушению клеток печени. Тяжелая гепатотоксичность у 5-8,2% больных (женщины и люди старше 50 лет, страдающие гепатитами С).…”