Last data update: Jun 24, 2024. (Total: 47078 publications since 2009)
Records 1-30 (of 45 Records) |
Query Trace: Sansom S [original query] |
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Rapid environmental contamination with candida auris and multidrug-resistant bacterial pathogens near colonized patients
Sansom SE , Gussin GM , Schoeny M , Singh RD , Adil H , Bell P , Benson EC , Bittencourt CE , Black S , Del Mar Villanueva Guzman M , Froilan MC , Fukuda C , Barsegyan K , Gough E , Lyman M , Makhija J , Marron S , Mikhail L , Noble-Wang J , Pacilli M , Pedroza R , Saavedra R , Sexton DJ , Shimabukuro J , Thotapalli L , Zahn M , Huang SS , Hayden MK . Clin Infect Dis 2023 BACKGROUND: Environmental contamination is suspected to play an important role in Candida auris transmission. Understanding speed and risks of contamination after room disinfection could inform environmental cleaning recommendations. METHODS: We conducted a prospective multicenter study of environmental contamination associated with C. auris colonization at six ventilator-capable skilled nursing facilities and one acute-care hospital in Illinois and California. Known C. auris carriers were sampled at five body-sites followed by sampling of nearby room surfaces before disinfection and at 0, 4, 8, and 12-hours post-disinfection. Samples were cultured for C. auris and bacterial multidrug-resistant organisms (MDROs). Odds of surface contamination after disinfection were analyzed using multilevel generalized estimating equations. RESULTS: Among 41 known C. auris carriers, colonization was detected most frequently on palms/fingertips (76%) and nares (71%). C. auris contamination was detected on 32.2% (66/205) of room surfaces pre-disinfection and 20.5% (39/190) of room surfaces by 4-hours post-disinfection. A higher number of C. auris-colonized body sites was associated with higher odds of environmental contamination at every time point following disinfection, adjusting for facility of residence. In the rooms of 38 (93%) C. auris carriers co-colonized with a bacterial MDRO, 2%-24% of surfaces were additionally contaminated with the same MDRO by 4-hours post-disinfection. CONCLUSIONS: C. auris can contaminate the healthcare environment rapidly after disinfection, highlighting the challenges associated with environmental disinfection. Future research should investigate long-acting disinfectants, antimicrobial surfaces, and more effective patient skin antisepsis to reduce the environmental reservoir of C. auris and bacterial MDROs in healthcare settings. |
Assessing the individual benefits of reducing HIV diagnosis delay and increasing adherence to HIV care and treatment
UzunJacobson E , Li Z , Bingham A , Farnham PG , Sansom SL . AIDS Care 2022 1-7 We used an agent-based simulation model (Progression and Transmission of HIV) to follow for 20 years a cohort of persons in the United States infected with HIV in 2015. We assessed the benefits of reducing the delay between HIV infection and diagnosis and increasing adherence to HIV care and treatment on the percent of persons surviving 20 years after infection, average annual HIV transmission rates, and time spent virally suppressed. We examined average diagnosis delays of 1.0-7.0 years, monthly care drop-out rates of 5% to 0.1%, and combinations of these strategies. The percent of the cohort surviving the first 20 years of infection varied from 70.8% to 77.5%, and the annual transmission risk, from 1.5 to 5.2 HIV transmissions per 100 person-years. Thus, individuals can enhance their survival and reduce their risk of transmission to partners by frequent testing for HIV and adhering to care and treatment. |
Estimating the HIV Effective Reproduction Number in the United States and Evaluating HIV Elimination Strategies
Chen YH , Farnham PG , Hicks KA , Sansom SL . J Public Health Manag Pract 2021 28 (2) 152-161 CONTEXT: The reproduction number is a fundamental epidemiologic concept used to assess the potential spread of infectious diseases and whether they can be eliminated. OBJECTIVE: We estimated the 2017 United States HIV effective reproduction number, Re, the average number of secondary infections from an infected person in a partially infected population. We analyzed the potential effects on Re of interventions aimed at improving patient flow rates along different stages of the HIV care continuum. We also examined these effects by individual transmission groups. DESIGN: We used the HIV Optimization and Prevention Economics (HOPE) model, a compartmental model of disease progression and transmission, and the next-generation matrix method to estimate Re. We then projected the impact of changes in HIV continuum-of-care interventions on the continuum-of-care flow rates and the estimated Re in 2020. SETTING: United States. PARTICIPANTS: The HOPE model simulated the sexually active US population and persons who inject drugs, aged 13 to 64 years, which was stratified into 195 subpopulations by transmission group, sex, race/ethnicity, age, male circumcision status, and HIV risk level. MAIN OUTCOME MEASURES: The estimated value of Re in 2017 and changes in Re in 2020 from interventions affecting the continuum-of-care flow rates. RESULTS: Our estimated HIV Re in 2017 was 0.92 [0.82, 0.94] (base case [min, max across calibration sets]). Among the interventions considered, the most effective way to reduce Re substantially below 1.0 in 2020 was to maintain viral suppression among those receiving HIV treatment. The greatest impact on Re resulted from changing the flow rates for men who have sex with men (MSM). CONCLUSIONS: Our results suggest that current prevention and treatment efforts may not be sufficient to move the country toward HIV elimination. Reducing Re to substantially below 1.0 may be achieved by an ongoing focus on early diagnosis, linkage to care, and sustained viral suppression especially for MSM. |
Optimal allocation of societal HIV prevention resources to reduce HIV incidence in the United States
Sansom SL , Hicks KA , Carrico J , Jacobson EU , Shrestha RK , Green TA , Purcell DW . Am J Public Health 2020 111 (1) e1-e8 Objectives. To optimize combined public and private spending on HIV prevention to achieve maximum reductions in incidence.Methods. We used a national HIV model to estimate new infections from 2018 to 2027 in the United States. We estimated current spending on HIV screening, interventions that move persons with diagnosed HIV along the HIV care continuum, pre-exposure prophylaxis, and syringe services programs. We compared the current funding allocation with 2 optimal scenarios: (1) a limited-reach scenario with expanded efforts to serve eligible persons and (2) an ideal, unlimited-reach scenario in which all eligible persons could be served.Results. A continuation of the current allocation projects 331 000 new HIV cases over the next 10 years. The limited-reach scenario reduces that number by 69%, and the unlimited reach scenario by 94%. The most efficient funding allocations resulted in prompt diagnosis and sustained viral suppression through improved screening of high-risk persons and treatment adherence support for those infected.Conclusions. Optimal allocations of public and private funds for HIV prevention can achieve substantial reductions in new infections. Achieving reductions of more than 90% under current funding will require that virtually all infected receive sustained treatment. (Am J Public Health. Published online ahead of print November 19, 2020: e1-e8. https://doi.org/10.2105/AJPH.2020.305965). |
Health utility estimates and their application to HIV prevention in the United States: Implications for cost-effectiveness modeling and future research needs
Whitham HK , Hutchinson AB , Shrestha RK , Kuppermann M , Grund B , Shouse RL , Sansom SL . MDM Policy Pract 2020 5 (2) 2381468320936219 Objectives. Health utility estimates from the current era of HIV treatment, critical for cost-effectiveness analyses (CEA) informing HIV health policy, are limited. We examined peer-reviewed literature to assess the appropriateness of commonly referenced utilities, present previously unreported quality-of-life data from two studies, and discuss future implications for HIV-related CEA. Methods. We searched a database of cost-effectiveness analyses specific to HIV prevention efforts from 1999 to 2016 to identify the most commonly referenced sources for health utilities and to examine practices around using and reporting health utility data. Additionally, we present new utility estimates from the Centers of Disease Control and Prevention's Medical Monitoring Project (MMP) and the INSIGHT Strategies for Management of Anti-Retroviral Therapy (SMART) trial. We compare data collection time frames, sample characteristics, assessment methods, and key estimates. Results. Data collection for the most frequently cited utility estimates ranged from 1985 to 1997, predating modern HIV treatment. Reporting practices around utility weights are poor and lack details on participant characteristics, which may be important stratifying factors for CEA. More recent utility estimates derived from MMP and SMART were similar across CD4+ count strata and had a narrower range than pre-antiretroviral therapy (ART) utilities. Conclusions. Despite the widespread use of ART, cost-effectiveness analysis of HIV prevention interventions frequently apply pre-ART health utility weights. Use of utility weights reflecting the current state of the US epidemic are needed to best inform HIV research and public policy decisions. Improved practices around the selection, application, and reporting of health utility data used in HIV prevention CEA are needed to improve transparency. |
A mathematical model to estimate the state-specific impact of the Health Resources and Services Administration's Ryan White HIV/AIDS Program
Klein PW , Cohen SM , Uzun Jacobson E , Li Z , Clark G , Fanning M , Sterling R , Young SR , Sansom S , Hauck H . PLoS One 2020 15 (6) e0234652 BACKGROUND: Access to and engagement in high-quality HIV medical care and treatment is essential for ending the HIV epidemic. The Health Resources and Services Administration's (HRSA) Ryan White HIV/AIDS Program (RWHAP) plays a critical role in ensuring that people living with diagnosed HIV (PLWH) are linked to and consistently engaged in high quality care and receive HIV medication in a timely manner. State variation in HIV prevalence, the proportion of PLWH served by the RWHAP, and local health care environments could influence the state-specific impact of the RWHAP. This analysis sought to measure the state-specific impact of the RWHAP on the HIV service delivery system and health outcomes for PLWH, and presents template language to communicate this impact for state planning and stakeholder engagement. METHODS AND FINDINGS: The HRSA's HIV/AIDS Bureau (HAB) and the Centers for Disease Control and Prevention's Division of HIV/AIDS Prevention (CDC DHAP) have developed a mathematical model to estimate the state-specific impact of the RWHAP. This model was parameterized using RWHAP data, HIV surveillance data, an existing CDC model of HIV transmission and disease progression, and parameters from the literature. In this study, the model was used to analyze the hypothetical scenario of an absence of the RWHAP and to calculate the projected impact of this scenario on RWHAP clients, RWHAP-funded providers, mortality, new HIV cases, and costs compared with the current state inclusive of the RWHAP. To demonstrate the results of the model, we selected two states, representing high HIV prevalence and low HIV prevalence areas. These states serve to demonstrate the functionality of the model and how state-specific results can be translated into a state-specific impact statement using template language. CONCLUSIONS: In the example states presented, the RWHAP provides HIV care, treatment, and support services to a large proportion of PLWH in each state. The absence of the RWHAP in these states could result in substantially more deaths and HIV cases than currently observed, resulting in considerable lifetime HIV care and treatment costs associated with additional HIV cases. State-specific impact statements may be valuable in the development of state-level HIV prevention and care plans or for communications with planning bodies, state health department leadership, and other stakeholders. State-specific impact statements will be available to RWHAP Part B recipients upon request from HRSA's HIV/AIDS Bureau. |
Estimating the costs and cost-effectiveness of HIV self-testing among men who have sex with men, United States
Shrestha RK , Chavez PR , Noble M , Sansom SL , Sullivan PS , Mermin JH , MacGowan RJ . J Int AIDS Soc 2020 23 (1) e25445 INTRODUCTION: HIV testing is an essential prerequisite for accessing treatment with antiretroviral therapy or prevention using pre-exposure prophylaxis. Internet distribution of HIV self-tests is a novel approach, and data on the programmatic cost of this approach are limited. We analyse the costs and cost-effectiveness of a self-testing programme. METHODS: Men who have sex with men (MSM) reporting unknown or negative HIV status were enrolled from March to August 2015 into a 12-month trial of HIV self-testing in the United States. Participants were randomly assigned either to the self-testing arm or the control arm. All participants received information on HIV testing services and locations in their community. Self-testing participants received up to four self-tests each quarter, which they could use themselves or distribute to their social network associates. Quarterly follow-up surveys collected testing outcomes, including number of tests used and new HIV diagnoses. Using trial expenditure data, we estimated the cost of implementing a self-testing programme. Primary outcomes of this analysis included total programme implementation costs, cost per self-test completed, cost per person tested, cost per new HIV diagnosis among those self-tested and cost per quality adjusted life year (QALY) saved. RESULTS: A total of 2665 men were assigned either to the self-testing arm (n = 1325) or the control arm (n = 1340). HIV testing was reported by 971 self-testing participants who completed a total of 5368 tests. In the control arm, 619 participants completed 1463 HIV tests. The self-testing participants additionally distributed 2864 self-tests to 2152 social network associates. Testing during the trial identified 59 participants and social network associates with newly diagnosed HIV infection in the self-testing arm; 11 control participants were newly diagnosed with HIV. The implementation cost of the HIV self-testing programme was $449,510. The cost per self-test completed, cost per person tested at least once, and incremental cost per new HIV diagnosis was $61, $145 and $9365 respectively. We estimated that self-testing programme potentially averted 3.34 transmissions, saved 14.86 QALYs and nearly $1.6 million lifetime HIV treatment costs. CONCLUSIONS: The HIV self-testing programme identified persons with newly diagnosed HIV infection at low cost, and the programme is cost saving. |
Vital signs: HIV transmission along the continuum of care - United States, 2016
Li Z , Purcell DW , Sansom SL , Hayes D , Hall HI . MMWR Morb Mortal Wkly Rep 2018 68 (11) 267-272 BACKGROUND: In 2016, an estimated 1.1 million persons had human immunodeficiency virus (HIV) infection in the United States; 38,700 were new infections. Knowledge of HIV infection status, behavior change, and antiretroviral therapy (ART) all prevent HIV transmission. Persons who achieve and maintain viral suppression (achieved by most persons within 6 months of starting ART) can live long, healthy lives and pose effectively no risk of HIV transmission to their sexual partners. METHODS: A model was used to estimate transmission rates in 2016 along the HIV continuum of care. Data for sexual and needle-sharing behaviors were obtained from National HIV Behavioral Surveillance. Estimated HIV prevalence, incidence, receipt of care, and viral suppression were obtained from National HIV Surveillance System data. RESULTS: Overall, the HIV transmission rate was 3.5 per 100 person-years in 2016. Along the HIV continuum of care, the transmission rates from persons who were 1) acutely infected and unaware of their infection, 2) non-acutely infected and unaware, 3) aware of HIV infection but not in care, 4) receiving HIV care but not virally suppressed, and 5) taking ART and virally suppressed were 16.1, 8.4, 6.6, 6.1, and 0 per 100 person-years, respectively. The percentages of all transmissions generated by each group were 4.0%, 33.6%, 42.6%, 19.8%, and 0%, respectively. CONCLUSION: Approximately 80% of new HIV transmissions are from persons who do not know they have HIV infection or are not receiving regular care. Going forward, increasing the percentage of persons with HIV infection who have achieved viral suppression and do not transmit HIV will be critical for ending the HIV epidemic in the United States. |
Quantifying the risk of undetected HIV, hepatitis B virus, or hepatitis C virus infection in Public Health Service increased risk donors.
Jones JM , Gurbaxani BM , Asher A , Sansom S , Annambhotla P , Moorman AC , Brooks JT , Basavaraju SV . Am J Transplant 2019 19 (9) 2583-2593 To reduce the risk of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) transmission through organ transplantation, donors are universally screened for these infections by nucleic acid tests (NAT). Deceased organ donors are classified as "increased risk" if they engaged in specific behaviors during the 12 months before death. We developed a model to estimate the risk of undetected infection for HIV, HBV, and HCV among NAT-negative donors specific to the type and timing of donors' potential risk behavior to guide revisions to the 12-month timeline. Model parameters were estimated, including risk of disease acquisition for increased-risk groups, number of virions that multiply to establish infection, virus doubling time, and limit of detection by NAT. Monte Carlo simulation was performed. The risk of undetected infection was <1/1,000,000 for HIV after 14 days, for HBV after 35 days, and for HCV after 7 days from the time of most recent potential exposure to the day of a negative NAT. The period during which reported donor risk behaviors result in an "increased risk" designation can be safely shortened. This article is protected by copyright. All rights reserved. |
Optimal allocation of HIV prevention funds for state health departments
Yaylali E , Farnham PG , Cohen S , Purcell DW , Hauck H , Sansom SL . PLoS One 2018 13 (5) e0197421 OBJECTIVE: To estimate the optimal allocation of Centers for Disease Control and Prevention (CDC) HIV prevention funds for health departments in 52 jurisdictions, incorporating Health Resources and Services Administration (HRSA) Ryan White HIV/AIDS Program funds, to improve outcomes along the HIV care continuum and prevent infections. METHODS: Using surveillance data from 2010 to 2012 and budgetary data from 2012, we divided the 52 health departments into 5 groups varying by number of persons living with diagnosed HIV (PLWDH), median annual CDC HIV prevention budget, and median annual HRSA expenditures supporting linkage to care, retention in care, and adherence to antiretroviral therapy. Using an optimization and a Bernoulli process model, we solved for the optimal CDC prevention budget allocation for each health department group. The optimal allocation distributed the funds across prevention interventions and populations at risk for HIV to prevent the greatest number of new HIV cases annually. RESULTS: Both the HIV prevention interventions funded by the optimal allocation of CDC HIV prevention funds and the proportions of the budget allocated were similar across health department groups, particularly those representing the large majority of PLWDH. Consistently funded interventions included testing, partner services and linkage to care and interventions for men who have sex with men (MSM). Sensitivity analyses showed that the optimal allocation shifted when there were differences in transmission category proportions and progress along the HIV care continuum. CONCLUSION: The robustness of the results suggests that most health departments can use these analyses to guide the investment of CDC HIV prevention funds into strategies to prevent the most new cases of HIV. |
Impact of improved HIV care and treatment on PrEP effectivenesss in the United States, 2016-2020
Khurana N , Yaylali E , Farnham PG , Hicks KA , Allaire BT , Jacobson E , Sansom SL . J Acquir Immune Defic Syndr 2018 78 (4) 399-405 BACKGROUND: The effect of improving diagnosis, care, and treatment of persons living with HIV (PLWH) on PrEP effectiveness in the United States has not be well established. METHODS: We used a dynamic, compartmental model that simulates the sexually active US population. We investigated the change in cumulative HIV incidence from 2016 to 2020 for three HIV care continuum levels, and the marginal benefit of PrEP compared with each. We also explored the marginal benefit of PrEP for individual risk groups, and as PrEP adherence, coverage and dropout rates varied. RESULTS: Delivering PrEP in 2016 to persons at high risk of acquiring HIV resulted in an 18.1% reduction in new HIV infections from 2016 to 2020 under current care continuum levels. Achieving HIV national goals of 90% of PLWH with diagnosed infection, 85% of newly diagnosed PLWH linked to care at diagnosis, and 80% of diagnosed PLWH virally suppressed reduced cumulative incidence by 34.4%. Delivery of PrEP in addition to this scenario resulted in a marginal benefit of 11.1% additional infections prevented. When national goals were reached, PrEP prevented an additional 15.2% cases among men who have sex with men (MSM), 3.9% among heterosexuals, and 3.8% among persons who inject drugs. CONCLUSIONS: The marginal benefit of PrEP was larger when current HIV care continuum percentages were maintained, but continued to be substantial even when national care goals were met. The high-risk MSM population was the chief beneficiary of PrEP. |
Effects of reaching national goals on HIV incidence, by race and ethnicity, in the United States
Uzun Jacobson E , Hicks KA , Tucker EL , Farnham PG , Sansom SL . J Public Health Manag Pract 2017 24 (4) E1-E8 CONTEXT: Human immunodeficiency virus (HIV) incidence and prevalence in the United States are characterized by significant disparities by race/ethnicity. National HIV care goals, such as boosting to 90% the proportion of persons whose HIV is diagnosed and increasing to 80% the proportion of persons living with diagnosed HIV who are virally suppressed, will likely reduce HIV incidence, but their effects on HIV-related disparities are uncertain. OBJECTIVE: We sought to understand by race/ethnicity how current HIV care varies, the level of effort required to achieve national HIV care goals, and the effects of reaching those goals on HIV incidence and disparities. DESIGN: Using a dynamic model of HIV transmission, we identified 2016 progress along the HIV care continuum among blacks, Hispanics, and whites/others compared with national 2020 goals. We examined disparities over time. SETTING: United States. PARTICIPANTS: Beginning in 2006, our dynamic compartmental model simulated the sexually active US population 13 to 64 years of age, which was stratified into 195 subpopulations by transmission group, sex, race/ethnicity, age, male circumcision status, and HIV risk level. MAIN OUTCOME MEASURE: We compared HIV cumulative incidence from 2016 to 2020 when goals were reached compared with base case assumptions about progression along the HIV care continuum. RESULTS: The 2016 proportion of persons with diagnosed HIV who were on treatment and virally suppressed was 50% among blacks, 56% among Hispanics, and 61% among whites/others, compared with a national goal of 80%. When diagnosis, linkage, and viral suppression goals were reached in 2020, cumulative HIV incidence fell by 32% (uncertainty range: 18%-37%) for blacks, 25% (22%-31%) for Hispanics, and 25% (21%-28%) for whites/others. Disparity measures changed little. CONCLUSIONS: Achieving national HIV care goals will require different levels of effort by race/ethnicity but likely will result in substantial declines in cumulative HIV incidence. HIV-related disparities in incidence and prevalence may be difficult to resolve. |
Sex practices by HIV awareness and engagement in the continuum of care among MSM: A National HIV Behavioral Surveillance Analysis in 21 U.S. cities
Whitham HK , Sansom SL , Wejnert C , Finlayson T , Huang YA , An Q , Paz-Bailey G . AIDS Behav 2017 22 (3) 840-847 Using National HIV Behavioral Surveillance (NHBS) cross-sectional survey and HIV testing data in 21 U.S. metropolitan areas, we identify sex practices among sexually active men who have sex with men (MSM) associated with: (1) awareness of HIV status, and (2) engagement in the HIV care continuum. Data from 2008, 2011, and 2014 were aggregated, yielding a sample of 5079 sexually active MSM living with HIV (MLWH). Participants were classified into HIV status categories: (1) unaware; (2) aware and out of care; (3) aware and in care without antiretroviral therapy (ART); and (4) aware and on ART. Analyses were conducted examining sex practices (e.g. condomless sex, discordant condomless sex, and number of sex partners) by HIV status. Approximately 30, 5, 10 and 55% of the sample was classified as unaware, aware and out of care, aware and in care without ART, and aware and on ART, respectively. Unaware MLWH were more likely to report condomless anal sex with a last male partner of discordant or unknown HIV status (25.9%) than aware MLWH (18.0%, p value < 0.0001). Unaware MLWH were 3 times as likely to report a female sex partner in the prior 12 months as aware MLWH (17.3 and 5.6%, p-value < 0.0001). When examining trends across the continuum of care, reports of any condomless anal sex with a male partner in the past year (ranging from 65.0 to 70.0%), condomless anal sex with a male partner of discordant or unknown HIV status (ranging from 17.7 to 21.3%), and median number of both male and female sex partners were similar. In conclusion, awareness of HIV and engagement in care was not consistently associated with protective sex practices, highlighting the need for continued prevention efforts. |
Combinations of interventions to achieve a national HIV incidence reduction goal: insights from the agent-based PATH 2.0 model
Gopalappa C , Sansom SL , Farnham PG , Chen YH . AIDS 2017 31 (18) 2533-2539 OBJECTIVE: Analyzing HIV care service targets for achieving a national goal of a 25% reduction in annual HIV incidence and evaluating the use of annual HIV diagnoses to measure progress in incidence reduction. DESIGN: Because there are considerable interactions among HIV care services, we model the dynamics of combinations of increases in HIV care continuum targets to identify those that would achieve 25% reductions in annual incidence and diagnoses. METHODS: We used Progression and Transmission of HIV/AIDS (PATH 2.0), an agent-based dynamic stochastic simulation of HIV in the United States. RESULTS: A 25% reduction in annual incidence could be achieved by multiple alternative combinations of percentages of persons with diagnosed infection and persons with viral suppression including 85% and 68%, respectively, and 90% and 59%, respectively. The first combination corresponded to an 18% reduction in annual diagnoses, and infections being diagnosed at a median CD4 count of 372 cells/muL or approximately 3.8 years from time of infection. The corresponding values on the second combination are 4%, 462 cells/muL, and 2.0 years, respectively. CONCLUSIONS: Our analysis provides policy makers with specific targets and alternative choices to achieve the goal of a 25% reduction in HIV incidence. Reducing annual diagnoses does not equate to reducing annual incidence. Instead, progress toward reducing incidence can be measured by monitoring HIV surveillance data trends in CD4 count at diagnosis along with the proportion who have achieved viral suppression to determine where to focus local programmatic efforts. |
Assessing HIV acquisition risks among men who have sex with men in the United States of America
Shrestha RK , Sansom SL , Purcell DW . Rev Panam Salud Publica 2016 40 (6) 474-478 Men who have sex with men (MSM) can reduce their risk of acquiring human immunodeficiency virus (HIV) by using various prevention strategies and by understanding the effectiveness of each option over the short- and long-term. Strategies examined were: circumcision; insertive anal sex only; consistent, 100% self-reported condom use; and pre-exposure prophylaxis (PrEP). PrEP efficacy was based on three levels of adherence. The cumulative HIV acquisition risk among MSM over periods of 1 year and 10 years were estimated with and without single and combinations of prevention strategies. A Bernoulli process model was used to estimate risk. In the base case with no prevention strategies, the 1-year risk of HIV acquisition among MSM was 8.8%. In contrast, the 1-year risk associated with circumcision alone was 6.9%; with insertive sex only, 5.5%; with 100% self-reported condom use, 2.7%; and with average, high, and very high PrEP adherence, 5.1%, 2.5%, and 0.7%, respectively. The 10-year risk of HIV acquisition among MSM with no prevention strategy was 60.3%. In contrast, that associated with circumcision alone was 51.1%; with insertive sex only, 43.1%; with 100% self-reported condom use, 24.0%; and with average, high, and very high PrEP adherence, 40.5%, 22.2%, and 7.2%, respectively. While MSM face substantial risk of HIV, there are now a number of prevention strategies that reduce risk. Very high adherence to PrEP alone or with other strategies appears to be the most powerful tool for HIV prevention. |
Contribution of anal sex to HIV prevalence among heterosexuals: A modeling analysis
O'Leary A , DiNenno E , Honeycutt A , Allaire B , Neuwahl S , Hicks K , Sansom S . AIDS Behav 2017 21 (10) 2895-2903 Anal intercourse is reported by many heterosexuals, and evidence suggests that its practice may be increasing. We estimated the proportion of the HIV burden attributable to anal sex in 2015 among heterosexual women and men in the United States. The HIV Optimization and Prevention Economics model was developed using parameter inputs from the literature for the sexually active U.S. population aged 13-64. The model uses differential equations to represent the progression of the population between compartments defined by HIV disease status and continuum-of-care stages from 2007 to 2015. For heterosexual women of all ages (who do not inject drugs), almost 28% of infections were associated with anal sex, whereas for women aged 18-34, nearly 40% of HIV infections were associated with anal sex. For heterosexual men, 20% of HIV infections were associated with insertive anal sex with women. Sensitivity analyses showed that varying any of 63 inputs by +/-20% resulted in no more than a 13% change in the projected number of heterosexual infections in 2015, including those attributed to anal sex. Despite uncertainties in model inputs, a substantial portion of the HIV burden among heterosexuals appears to be attributable to anal sex. Providing information about the relative risk of anal sex compared with vaginal sex may help reduce HIV incidence in heterosexuals. |
Progression and Transmission of HIV/AIDS (PATH 2.0).
Gopalappa C , Farnham PG , Chen YH , Sansom SL . Med Decis Making 2016 37 (2) 224-233 BACKGROUND: HIV transmission is the result of complex dynamics in the risk behaviors, partnership choices, disease stage and position along the HIV care continuum-individual characteristics that themselves can change over time. Capturing these dynamics and simulating transmissions to understand the chief sources of transmission remain important for prevention. METHODS: The Progression and Transmission of HIV/AIDS (PATH 2.0) is an agent-based model of a sample of 10,000 people living with HIV (PLWH), who represent all men who have sex with men (MSM) and heterosexuals living with HIV in the U.S.A. Persons uninfected were modeled as populations, stratified by risk and gender. The model included detailed individual-level data from several large national surveillance databases. The outcomes focused on average annual transmission rates from 2008 through 2011 by disease stage, HIV care continuum, and sexual risk group. RESULTS: The relative risk of transmission of those in the acute phase was nine-times [5th and 95th percentile simulation interval (SI): 7, 12] that of those in the non-acute phase, although, on average, those with acute infections comprised 1% of all PLWH. The relative risk of transmission was 24- to 50-times as high for those in the non-acute phase who had not achieved viral load suppression as compared with those who had. The relative risk of transmission among MSM was 3.2-times [SI: 2.7, 4.0] that of heterosexuals. Men who have sex with men and women generated 46% of sexually acquired transmissions among heterosexuals. CONCLUSIONS: The model results support a continued focus on early diagnosis, treatment and adherence to ART, with an emphasis on prevention efforts for MSM, a subgroup of whom appear to play a role in transmission to heterosexuals. |
Challenges in estimating effectiveness of condom distribution campaigns to prevent HIV Transmission
Shrestha RK , Farnham PG , Whitham HK , Sansom SL . J Acquir Immune Defic Syndr 2016 73 (2) e35-8 An estimated 1.2 million people aged 13 years and older are living with human immunodeficiency virus (HIV) infection in the United States1, and approximately 45,000 people are newly diagnosed with the virus each year.2 Over the last 30 years, condom use has been a key element of comprehensive approaches to HIV prevention.3–9 For instance, the National HIV/AIDS Strategy for the United States 2010 (updated in 2015) calls for promotion of condom use in combination with other prevention approaches.10 Condom distribution campaigns, a frequently used public health intervention, make condoms freely available in settings frequented by people believed to be at high risk of transmitting or acquiring HIV. However, data regarding the effectiveness of condom distribution campaigns remain limited due to several methodological challenges. Knowledge of the strength of evidence of condom distribution campaign effectiveness is important for priority setting and the efficient allocation of HIV prevention resources among competing interventions.11–13 This paper examines limitations in the literature regarding condom distribution campaigns and the difficulties in estimating the effectiveness of campaigns through observational studies and mathematical modeling. |
Cost effectiveness of HIV prevention interventions in the U.S
Lin F , Farnham PG , Shrestha RK , Mermin J , Sansom SL . Am J Prev Med 2016 50 (6) 699-708 INTRODUCTION: The purpose of this study was to assess and compare the cost effectiveness of current HIV prevention interventions in the U.S. using a consistent, standardized methodology. METHODS: The cost effectiveness of common and emerging HIV biomedical and behavioral prevention interventions as delivered to men who have sex with men, injection drug users, and sexually active heterosexuals was estimated. Data on program costs, intervention efficacy, risk behaviors, and per contact transmission probabilities were collected from peer-reviewed papers and health department reports. These data were combined with 2010 national HIV incidence and prevalence surveillance data in a Bernoulli process model to estimate the reduced annual risk of HIV transmission or acquisition associated with these interventions. The cost per prevented case of HIV and the cost per saved quality-adjusted life year were then calculated. Analyses were conducted between 2014 and 2015. RESULTS: Interventions to diagnose HIV and provide ongoing care and treatment had the lowest cost per prevented case. Among interventions targeted at specific risk groups, interventions for men who have sex with men were the most cost effective. The least cost-effective interventions typically addressed people at risk of acquiring HIV rather than those at risk of transmitting the disease. CONCLUSIONS: HIV prevention interventions targeted at high-risk populations, those associated with the care continuum, and those that reduce the transmission risk of HIV-infected people are typically the most cost effective. Decision makers can consider these results in planning an efficient allocation of HIV prevention resources. |
Nearly half of US adults living with HIV received federal disability benefits in 2009
Huang YL , Frazier EL , Sansom SL , Farnham PG , Shrestha RK , Hutchinson AB , Fagan JL , Viall AH , Skarbinski J . Health Aff (Millwood) 2015 34 (10) 1657-65 The effects of HIV infection on national labor-force participation have not been rigorously evaluated. Using data from the Medical Monitoring Project and the National Health Interview Survey, we present nationally representative estimates of the receipt of disability benefits by adults living with HIV receiving care compared with the general US adult population. We found that in 2009, adults living with HIV were nine times more likely than adults in the general population to receive disability benefits. The risk of being on disability is also greater for younger and more educated adults living with HIV compared to the general population, which suggests that productivity losses can result from HIV infection. To prevent disability, early diagnosis and treatment of HIV are essential. This study offers a baseline against which to measure the impacts of recently proposed or enacted changes to Medicaid and private insurance markets, including the Affordable Care Act and proposed revisions to the Social Security Administration's HIV Infection Listings. |
Notification following new positive HIV test results
Huang YA , Hutchinson AB , Hollis ND , Sansom SL . Int J STD AIDS 2015 27 (10) 868-72 Client notification of a new HIV diagnosis is critical for timely access to treatment and reduction in behaviours associated with HIV infection. It is also an important input in HIV transmission and disease progression models. We used national, Centers for Disease Control and Prevention-funded HIV testing events data collected through the National HIV Prevention Program Monitoring and Evaluation system to update estimates of the proportion of newly identified HIV-positives notified of their status. We compared estimates from 2008 to 2010 across test technologies, settings, and HIV risk groups. In 2010, notification following a positive rapid test was 99.6% compared with 99.3% in 2008. Notification following a positive conventional test was 81.5% in 2010 compared with 80.8% in 2008. To realise the full promise of early HIV diagnosis and treatment for the prevention of additional HIV cases, efforts to ensure prompt notification following a new HIV diagnosis will be crucial. |
Cost-effectiveness of frequent HIV testing of high risk populations in the United States
Hutchinson AB , Farnham PG , Sansom SL , Yaylali E , Mermin JH . J Acquir Immune Defic Syndr 2015 71 (3) 323-30 PURPOSE: Data showing a high incidence of HIV infection among men who have sex with men (MSM) who had annual testing suggest that more frequent HIV testing may be warranted. Testing technology is also a consideration given the availability of sensitive testing modalities as well as the increased use of less sensitive rapid, point-of-care antibody tests. We assessed the cost-effectiveness of HIV testing of MSM and injection drug users (IDUs) at 3- and 6-month intervals using fourth-generation and rapid tests. METHODS: We used a published mathematical model of HIV transmission to evaluate testing intervals for each population using cohorts of 10,000 MSM and IDU. We incorporated HIV transmissions averted due to serostatus awareness and viral suppression. We included costs for HIV testing and treatment initiation, as well as treatment costs saved from averted transmissions. RESULTS: For MSM, HIV testing was cost-saving or cost-effective over a 1-year time period for both 6-month compared to annual testing, and quarterly compared to 6-month testing using either test. Testing IDU every 6 months compared to annually was moderately cost-effective over a 1-year time period with a fourth-generation test, while testing with rapid, point-of care tests or quarterly was not cost-effective. MSM results remained robust in sensitivity analysis, while IDU results were sensitive to changes in HIV incidence and continuum-of-care parameters. Threshold analyses on costs suggested additional implementation costs could be incurred for more frequent testing for MSM while remaining cost-effective. CONCLUSION: HIV testing of MSM as frequently as quarterly is cost-effective compared to annual testing, but testing IDU more frequently than annually is generally not cost-effective. |
From theory to practice: Implementation of a resource allocation model in health departments
Yaylali E , Farnham PG , Schneider KL , Landers SJ , Kouzouian O , Lasry A , Purcell DW , Green TA , Sansom SL . J Public Health Manag Pract 2015 22 (6) 567-75 OBJECTIVE: To develop a resource allocation model to optimize health departments' Centers for Disease Control and Prevention (CDC)-funded HIV prevention budgets to prevent the most new cases of HIV infection and to evaluate the model's implementation in 4 health departments. DESIGN, SETTINGS, AND PARTICIPANTS: We developed a linear programming model combined with a Bernoulli process model that allocated a fixed budget among HIV prevention interventions and risk subpopulations to maximize the number of new infections prevented. The model, which required epidemiologic, behavioral, budgetary, and programmatic data, was implemented in health departments in Philadelphia, Chicago, Alabama, and Nebraska. MAIN OUTCOME MEASURES: The optimal allocation of funds, the site-specific cost per case of HIV infection prevented rankings by intervention, and the expected number of HIV cases prevented. RESULTS: The model suggested allocating funds to HIV testing and continuum-of-care interventions in all 4 health departments. The most cost-effective intervention for all sites was HIV testing in nonclinical settings for men who have sex with men, and the least cost-effective interventions were behavioral interventions for HIV-negative persons. The pilot sites required 3 to 4 months of technical assistance to develop data inputs and generate and interpret the results. Although the sites found the model easy to use in providing quantitative evidence for allocating HIV prevention resources, they criticized the exclusion of structural interventions and the use of the model to allocate only CDC funds. CONCLUSIONS: Resource allocation models have the potential to improve the allocation of limited HIV prevention resources and can be used as a decision-making guide for state and local health departments. Using such models may require substantial staff time and technical assistance. These model results emphasize the allocation of CDC funds toward testing and continuum-of-care interventions and populations at highest risk of HIV transmission. |
A systematic review on cost effectiveness of HIV prevention interventions in the United States
Huang YA , Lasry A , Hutchinson AB , Sansom SL . Appl Health Econ Health Policy 2014 13 (2) 149-56 BACKGROUND: The Centers for Disease Control and Prevention (CDC) focus on funding HIV prevention interventions likely to have high impact on the HIV epidemic. In its most recent funding announcement to state and local health department grantees, CDC required that health departments allocate the majority of funds to four HIV prevention interventions: HIV testing, prevention with HIV-positives and their partners, condom distribution and policy initiatives. OBJECTIVE: We conducted a systematic review of the published literature to determine the extent of the cost-effectiveness evidence for each of those interventions. METHODOLOGY: We searched for US-based studies published through October 2012. The studies that qualified for inclusion contained original analyses that reported costs per quality-adjusted life-year saved, life-year saved, HIV infection averted, or new HIV diagnosis. For each study, paired reviewers performed a detailed review and data extraction. We reported the number of studies related to each intervention and summarized key cost-effectiveness findings according to intervention type. Costs were converted to 2011 US dollars. RESULTS: Of the 50 articles that met the inclusion criteria, 33 related to HIV testing, 15 assessed prevention with HIV-positives and partners, three reported on condom distribution, and one reported on policy initiatives. Methodologies and cost-effectiveness metrics varied across studies and interventions, making them difficult to compare. CONCLUSION: Our review provides an updated summary of the published evidence of cost effectiveness of four key HIV prevention interventions recommended by CDC. With the exception of testing-related interventions, including partner services, where economic evaluations suggest that testing often can be cost effective, more cost-effectiveness research is needed to help guide the most efficient use of HIV prevention funds. |
Estimating the cost to U.S. health departments to conduct HIV surveillance
Shrestha RK , Sansom SL , Laffoon BT , Farnham PG , Shouse RL , MacMaster K , Hall HI . Public Health Rep 2014 129 (6) 496-504 OBJECTIVES: HIV case surveillance is a primary source of information for monitoring HIV burden in the United States and guiding the allocation of prevention and treatment funds. While the number of people living with HIV and the need for surveillance data have increased, little is known about the cost of surveillance. We estimated the economic cost to health departments of conducting high-quality HIV case surveillance. METHODS: We collected primary data on the unit cost and quantity of resources used to operate the HIV case surveillance program in Michigan, where HIV burden (i.e., the number of HIV cases) is moderate to high (n=14,864 cases). Based on Michigan's data, we projected the expected annual HIV surveillance cost for U.S., state, local, and territorial health departments. We based our cost projection on the variation in the number of new and established cases, area-specific wages, and potential economies of scale. RESULTS: We estimated the annual total HIV surveillance cost to the Michigan health department to be $1,286,524 ($87/case), the annual total cost of new cases to be $108,657 ($133/case), and the annual total cost of established cases to be $1,177,867 ($84/case). Our projected median annual HIV surveillance cost per health department ranged from $210,600 in low-HIV burden sites to $1,835,000 in high-HIV burden sites. CONCLUSIONS: Our analysis shows that a systematic approach to costing HIV surveillance at the health department level is feasible. For HIV surveillance, a substantial portion of total surveillance costs is attributable to maintaining established cases. |
HIV sexual transmission risk among serodiscordant couples: assessing the effects of combining prevention strategies
Lasry A , Sansom SL , Wolitski RJ , Green TA , Borkowf CB , Patel P , Mermin J . AIDS 2014 28 (10) 1521-9 BACKGROUND: The number of strategies to prevent HIV transmission has increased following trials evaluating antiretroviral therapy (ART), preexposure prophylaxis (PrEP) and male circumcision. Serodiscordant couples need guidance on the effects of these strategies alone, and in combination with each other, on HIV transmission. METHODS: We estimated the sexual risk of HIV transmission over 1-year and 10-year periods among male-male and male-female serodiscordant couples. We assumed the following reductions in transmission: 80% from consistent condom use; 54% from circumcision in the negative male partner of a heterosexual couple; 73% from circumcision in the negative partner of a male-male couple; 71% from PrEP in heterosexual couples; 44% from PrEP in male-male couples; and 96% from ART use by the HIV-infected partner. FINDINGS: For couples using any single prevention strategy, a substantial cumulative risk of HIV transmission remained. For a male-female couple using only condoms, estimated risk over 10 years was 11%; for a male-male couple using only condoms, estimated risk was 76%. ART use by the HIV-infected partner was the most effective single strategy in reducing risk; among male-male couples, adding consistent condom use was necessary to keep the 10-year risk below 10%. CONCLUSION: Focusing on 1-year and longer term transmission probabilities gives couples a better understanding of risk than those illustrated by data for a single sexual act. Long-term transmission probabilities to the negative partner in serodiscordant couples can be high, though these can be substantially reduced with the strategic use of preventive methods, especially those that include ART. |
Updates of lifetime costs of care and quality of life estimates for HIV-infected persons in the United States: late versus early diagnosis and entry into care
Farnham PG , Gopalappa C , Sansom SL , Hutchinson AB , Brooks JT , Weidle PJ , Marconi VC , Rimland D . J Acquir Immune Defic Syndr 2013 64 (2) 183-9 BACKGROUND: Lifetime costs of care and quality of life estimates for human immunodeficiency virus (HIV)-infected persons depend upon the disease stage at which these persons are diagnosed, enter care, and start antiretroviral therapy (ART). Using updated estimates, we analyzed the effect of late versus early diagnosis/entry on U.S. lifetime care costs, quality of life estimates, and HIV transmissions. METHODS: We used the Progression and Transmission of HIV/AIDS (PATH) model to estimate discounted (3%) lifetime treatment costs ($US 2011) and quality of life variables from time of infection for cohorts of 10,000 HIV-infected index patients in four categories of CD4 count (cells/microL) at diagnosis: (I) ≤ 200; (II) 201 - 350; (III) 351 - 500 and (IV) 501 - 900. We assumed index patient diagnoses were uniformly distributed across the CD4 count range in each category and that patients entered care at the time of diagnosis, remained in care, and were eligible to initiate ART at a CD4 count of 500 cells/microL. We also estimated lifetime transmissions of the index patients. RESULTS: Discounted average lifetime costs varied from $253,000 for category (I) index patients to $402,000 for category (IV) patients. Discounted quality-adjusted life years lost decreased from 7.95 to 4.45 across these categories, additional years of life expectancy increased from 30.8 to 38.1, and lifetime transmissions decreased from 1.40 to 0.72. CONCLUSIONS: Early diagnosis and treatment of HIV infection increases lifetime costs but improves length and quality of life and reduces by nearly 50% the number of new infections transmitted. |
Estimating the impact of state budget cuts and redirection of prevention resources on the HIV epidemic in 59 California local health departments
Lin F , Lasry A , Sansom SL , Wolitski RJ . PLoS One 2013 8 (3) e55713 BACKGROUND: In the wake of a national economic downturn, the state of California, in 2009-2010, implemented budget cuts that eliminated state funding of HIV prevention and testing. To mitigate the effect of these cuts remaining federal funds were redirected. This analysis estimates the impact of these budget cuts and reallocation of resources on HIV transmission and associated HIV treatment costs. METHODS AND FINDINGS: We estimated the effect of the budget cuts and reallocation for California county health departments (excluding Los Angeles and San Francisco) on the number of individuals living with or at-risk for HIV who received HIV prevention services. We used a Bernoulli model to estimate the number of new infections that would occur each year as a result of the changes, and assigned lifetime treatment costs to those new infections. We explored the effect of redirecting federal funds to more cost-effective programs, as well as the potential effect of allocating funds proportionately by transmission category. We estimated that cutting HIV prevention resulted in 55 new infections that were associated with $20 million in lifetime treatment costs. The redirection of federal funds to more cost-effective programs averted 15 HIV infections. If HIV prevention funding were allocated proportionately to transmission categories, we estimated that HIV infections could be reduced below the number that occurred annually before the state budget cuts. CONCLUSIONS: Reducing funding for HIV prevention may result in short-term savings at the expense of additional HIV infections and increased HIV treatment costs. Existing HIV prevention funds would likely have a greater impact on the epidemic if they were allocated to the more cost-effective programs and the populations most likely to acquire and transmit the infection. |
How much should we pay for a new HIV diagnosis? A mathematical model of HIV screening in US clinical settings
Farnham PG , Sansom SL , Hutchinson AB . Med Decis Making 2012 32 (3) 459-69 OBJECTIVE: To develop a model to assist clinical setting decision makers in determining how much they can spend on human immunodeficiency virus (HIV) screening and still be cost-effective. DESIGN: The authors developed a simple mathematical model relating the program cost per new HIV diagnosis to the cost per HIV infection averted and the cost per quality-adjusted life year (QALY) saved by screening. They estimated outcomes based on behavioral changes associated with awareness of HIV infection and applied the model to US sexually transmitted disease clinics. METHODS: The authors based the cost per new HIV diagnosis (2009 US dollars) on the costs of testing and the proportion of persons who tested positive. Infections averted were calculated from the reduction in annual transmission rates between persons aware and unaware of their infections. The authors defined program costs from the sexually transmitted disease clinic perspective and treatment costs and QALYs saved from the societal perspective. They undertook numerous sensitivity analyses to determine the robustness of the base case results. RESULTS: In the base case, the cost per new HIV diagnosis was $2528, the cost per infection averted was $40,516, and the cost per QALY saved was less than zero, or cost-saving. Given the model inputs, the cost per new diagnosis could increase to $22,909 to reach the cost-saving threshold and to $63,053 for the cost-effectiveness threshold. All sensitivity analyses showed that the cost-effectiveness results were consistent for extensive variation in the values of model inputs. CONCLUSIONS: HIV screening in a clinical setting is cost-effective for a wide range of testing costs, variations in positivity rates, reductions in HIV transmissions, and variation in the receipt of test results. |
Allocating HIV prevention funds in the United States: recommendations from an optimization model
Lasry A , Sansom SL , Hicks KA , Uzunangelov V . PLoS One 2012 7 (6) e37545 The Centers for Disease Control and Prevention (CDC) had an annual budget of approximately $327 million to fund health departments and community-based organizations for core HIV testing and prevention programs domestically between 2001 and 2006. Annual HIV incidence has been relatively stable since the year 2000 [1] and was estimated at 48,600 cases in 2006 and 48,100 in 2009 [2]. Using estimates on HIV incidence, prevalence, prevention program costs and benefits, and current spending, we created an HIV resource allocation model that can generate a mathematically optimal allocation of the Division of HIV/AIDS Prevention's extramural budget for HIV testing, and counseling and education programs. The model's data inputs and methods were reviewed by subject matter experts internal and external to the CDC via an extensive validation process. The model projects the HIV epidemic for the United States under different allocation strategies under a fixed budget. Our objective is to support national HIV prevention planning efforts and inform the decision-making process for HIV resource allocation. Model results can be summarized into three main recommendations. First, more funds should be allocated to testing and these should further target men who have sex with men and injecting drug users. Second, counseling and education interventions ought to provide a greater focus on HIV positive persons who are aware of their status. And lastly, interventions should target those at high risk for transmitting or acquiring HIV, rather than lower-risk members of the general population. The main conclusions of the HIV resource allocation model have played a role in the introduction of new programs and provide valuable guidance to target resources and improve the impact of HIV prevention efforts in the United States. |
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