Browsing by Author "Limbada M"

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An empirical approach to defining loss to follow-up among patients enrolled in antiretroviral treatment programs.
(2010-Apr-15) Chi BH; Cantrell RA; Mwango A; Westfall AO; Mutale W; Limbada M; Mulenga LB; Vermund SH; Stringer JS; Centre for Infectious Disease Research in Zambia, Box 34681, 1275 Lubuto Road, Lusaka, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
In many programs providing antiretroviral therapy (ART), clinicians report substantial patient attrition; however, there are no consensus criteria for defining patient loss to follow-up (LTFU). Data on a multisite human immunodeficiency virus (HIV) treatment cohort in Lusaka, Zambia, were used to determine an empirical "days-late" definition of LTFU among patients on ART. Cohort members were classified as either "in care" or LTFU as of December 31, 2007, according to a range of days-late intervals. The authors then looked forward in the database to determine which patients actually returned to care at any point over the following year. The interval that best minimized LTFU misclassification was described as "best-performing." Overall, 33,704 HIV-infected adults on ART were included. Nearly one-third (n = 10,196) were at least 1 day late for an appointment. The best-performing LTFU definition was 56 days after a missed visit, which had a sensitivity of 84.1% (95% confidence interval (CI): 83.2, 85.0), specificity of 97.5% (95% CI: 97.3, 97.7), and misclassification of 5.1% (95% CI: 4.8, 5.3). The 60-day threshold performed similarly well, with only a marginal difference (<0.1%) in misclassification. This analysis suggests that > or =60 days since the last appointment is a reasonable definition of LTFU. Standardization to empirically derived definitions of LTFU will permit more reliable comparisons within and across programs.
Antiretroviral Medication Adherence and Amplified HIV Transmission Risk Among Sexually Active HIV-Infected Individuals in Three Diverse International Settings.
(2016-Apr) Magidson JF; Li X; Mimiaga MJ; Moore AT; Srithanaviboonchai K; Friedman RK; Limbada M; Hughes JP; Cummings V; Gaydos CA; Elharrar V; Celentano D; Mayer KH; Safren SA; Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.; Department of Psychiatry, Harvard Medical School/Massachusetts General Hospital, One Bowdoin Square, 7th Floor, Boston, MA, 02114, USA.; FHI360, Durham, NC, USA.; University of Washington, Seattle, WA, USA.; Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.; Department of Psychiatry, Harvard Medical School/Massachusetts General Hospital, One Bowdoin Square, 7th Floor, Boston, MA, 02114, USA. jmagidson@mgh.harvard.edu.; National Institute of Allergy and Infectious Disease (NIAID), Bethesda, MD, USA.; Harvard Medical School/Beth Israel Deaconess Medical Center, Boston, MA, USA.; Instituto de Pesquisa Clinica Evandro Chagas, Rio de Janeiro, Brazil.; Fred Hutchinson Cancer Research Center, Seattle, WA, USA.; Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.; Department of Psychology, University of Miami, Coral Gables, FL, USA.; The Fenway Institute, Fenway Health, Boston, MA, USA.; Division of Infectious Diseases, Departments of Pathology and Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; Harvard School of Public Health, Boston, MA, USA.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Successful biomedical prevention/treatment-as-prevention (TasP) requires identifying individuals at greatest risk for transmitting HIV, including those with antiretroviral therapy (ART) nonadherence and/or 'amplified HIV transmission risk,' defined as condomless sex with HIV-uninfected/unknown-status partners when infectious (i.e., with detectable viremia or STI diagnosis according to Swiss criteria for infectiousness). This study recruited sexually-active, HIV-infected patients in Brazil, Thailand, and Zambia to examine correlates of ART nonadherence and 'amplified HIV transmission risk'. Lower alcohol use (OR = .71, p < .01) and higher health-related quality of life (OR = 1.10, p < .01) were associated with greater odds of ART adherence over and above region. Of those with viral load data available (in Brazil and Thailand only), 40 % met Swiss criteria for infectiousness, and 29 % had 'amplified HIV transmission risk.' MSM had almost three-fold (OR = 2.89, p < .001) increased odds of 'amplified HIV transmission risk' (vs. heterosexual men) over and above region. TasP efforts should consider psychosocial and contextual needs, particularly among MSM with detectable viremia.
CD4+ response and subsequent risk of death among patients on antiretroviral therapy in Lusaka, Zambia.
(2009-Sep-01) Chi BH; Giganti M; Mulenga PL; Limbada M; Reid SE; Mutale W; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: Where virologic monitoring is not routinely available, immunologic criteria are commonly used to determine treatment failure while on antiretroviral therapy (ART). However, few have studied CD4+ response and its relationship to subsequent clinical outcomes in a programmatic setting. METHODS: We analyzed cohort data from Zambia to investigate whether 6- and 12-month CD4+ response after ART initiation was associated with later mortality. We used Cox proportional hazards models that accounted for different strata of baseline CD4 counts and adjusted for age, sex, clinical stage, tuberculosis coinfection, baseline hemoglobin, initial ART regimen, and adherence behavior. RESULTS: We analyzed data from 2 cohorts, from 6 months onward (n = 24,366; median follow-up = 467 days, interquartile range 222-791) and from 12 months onward (n = 17,920; median follow-up = 423 days, interquartile range 191-689). In the post-6-month analysis, hazard for death was significantly higher when absolute CD4+ response was <100 cells per microliter [adjusted hazard ratio (AHR) = 2.25, 95% confidence interval (CI): 1.91 to 2.64], relative response was <10% above baseline (AHR = 2.60, 95% CI: 2.12 to 3.19), and absolute CD4+ count was <100 per microliter (AHR = 2.79, 95% CI: 2.26 to 3.45). In the post-12 month analysis, mortality was associated with rise in absolute CD4+ cell count <200 per microliter (AHR = 2.41, 95% CI: 1.83 to 3.17), relative rise in CD4+ cell count of <10% above baseline (AHR = 3.41, 95% CI: 2.51 to 4.64), and absolute CD4+ count at 12 months <100 per microliter (AHR = 4.11, 95% CI: 2.96 to 5.68). CONCLUSION: Commonly used definitions for immunologic treatment failure are associated with elevated mortality risk among patients on ART.
Frequency and predictors of estimated HIV transmissions and bacterial STI acquisition among HIV-positive patients in HIV care across three continents.
(2016) Safren SA; Hughes JP; Mimiaga MJ; Moore AT; Friedman RK; Srithanaviboonchai K; Limbada M; Williamson BD; Elharrar V; Cummings V; Magidson JF; Gaydos CA; Celentano DD; Mayer KH; Institute for Community Health Promotion, Brown University, Providence RI, USA.; Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.; Instituto Nacional de Infectologia Evandro Chagas, FIOCRUZ, Rio de Janeiro, Brazil.; Department of Medicine, Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, MD, USA.; Department of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USA.; FHI360, Durham, NC, USA.; Department of Psychology, University of Miami, Coral Gables, FL, USA; ssafren@miami.edu.; Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.; National Institute of Allergy and Infectious Disease (NIAID), Bethesda, MD, USA.; School of Public Health, University of Washington, Seattle, WA, USA.; Behavioral Medicine Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.; Department of Pathology, Division of Infectious Diseases, Johns Hopkins School of Medicine, Baltimore, MD, USA.; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.; Fred Hutchinson Cancer Research Center, Seattle, WA, USA.; The Fenway Institute, Fenway Health, Boston, MA, USA.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: Successful global treatment as prevention (TasP) requires identifying HIV-positive individuals at high risk for transmitting HIV, and having impact via potential infections averted. This study estimated the frequency and predictors of numbers of HIV transmissions and bacterial sexually transmitted infection (STI) acquisition among sexually active HIV-positive individuals in care from three representative global settings. METHODS: HIV-positive individuals ( RESULTS: An estimated 3.81 (standard error, (SE)=0.63) HIV transmissions occurred for every 100 participants over the 15 months, which decreased over time. The highest rate was 19.50 (SE=1.68) for every 100 MSM in Brazil. In a multivariable model, country×risk group interactions emerged: in Brazil, MSM had 2.85 (95% CI=1.45, 4.25, CONCLUSIONS: These data help to estimate the potential number of HIV infections transmitted and bacterial STIs acquired over time in patients established in care, a group typically considered at lower transmission risk, and found substantial numbers of estimated HIV transmissions. These findings provide an approach for evaluating the impact (in phase 2 studies) and potentially cost-effectiveness of global TasP efforts.
"I Wasn't in My Right Mind": Qualitative Findings on the Impact of Alcohol on Condom Use in Patients Living with HIV/AIDS in Brazil, Thailand, and Zambia (HPTN 063).
(2019-Feb) Rogers BG; Mendez NA; Mimiaga MJ; Sherman SG; Closson EF; Tangmunkongvorakul A; Friedman RK; Limbada M; Moore AT; Srithanaviboonchai K; Mayer KH; Safren SA; Department of Psychology, University of Miami, 5665 Ponce de Leon Blvd, Coral Gables, FL, 33146, USA.; Department of Psychology, University of Miami, 5665 Ponce de Leon Blvd, Coral Gables, FL, 33146, USA. brooke.rogers@miami.edu.; The Fenway Institute, Fenway Health, Boston, MA, 02215, USA.; Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA.; FHI 360, Durham, NC, 27701, USA.; London School of Hygiene & Tropical Medicine, London, UK.; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA.; Instituto de Pesquisa Clínica Evandro Chagas-Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.; School of Public Health, Brown University, Providence, RI, 02903, USA.; Department of Psychology, University of Miami, 5665 Ponce de Leon Blvd, Coral Gables, FL, 33146, USA. ssafren@miami.edu.; The Fenway Institute, Fenway Health, Boston, MA, 02215, USA. ssafren@miami.edu.; Chiang Mai University, Chiang Mai, Thailand.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
PURPOSE: There have been significant biomedical improvements in the treatment and prevention of HIV over the past few decades. However, new transmissions continue to occur. Alcohol use is a known barrier to medication adherence and consistent condom use and therefore may affect treatment as prevention (TasP) efforts. The purpose of this study was to further explore how alcohol is associated with condom use and sexual transmission behavior in three international cities. METHOD: HIV Prevention Trials Network 063 was an observational mixed-methods study of HIV-infected patients currently in care in Rio de Janeiro, Brazil; Chiang Mai, Thailand; and Lusaka, Zambia. Across these three global cities, 80 qualitative interviews were conducted from 2010 to 2012. From these interviews, quotes related to substance use, almost all of which were alcohol, were analyzed using thematic analysis to identify how the use was related to sexual transmission behaviors. RESULTS: Overall, the theme that alcohol impairs cognitive abilities emerged from the data and included the following subthemes: expectancies, impaired decision-making, loss of control, and less concern for others. Themes specific to international settings and risk subgroups were also identified. CONCLUSION: Our analysis identified how alcohol influences sexual transmission behavior in HIV patients in three international settings. These findings may provide direction for content development for future secondary prevention interventions to effectively implement TasP internationally.
Intimacy versus isolation: a qualitative study of sexual practices among sexually active HIV-infected patients in HIV care in Brazil, Thailand, and Zambia.
(2015) Closson EF; Mimiaga MJ; Sherman SG; Tangmunkongvorakul A; Friedman RK; Limbada M; Moore AT; Srithanaviboonchai K; Alves CA; Roberts S; Oldenburg CE; Elharrar V; Mayer KH; Safren SA; National Institute of Allergy and Infectious Disease, Bethesda, Maryland, United States of America.; The Fenway Institute, Fenway Health, Boston, Massachusetts, United States of America; Harvard School of Public Health, Boston, Massachusetts, United States of America; Harvard Medical School/Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America.; FHI360, Durham, North Carolina, United States of America.; Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand.; The Fenway Institute, Fenway Health, Boston, Massachusetts, United States of America; Harvard Medical School/Massachusetts General Hospital, Boston, Massachusetts, United States of America.; Instituto de Pesquisa Clinica Evandro Chagas, Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil.; Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, Thailand; Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.; Johns Hopkins School of Public Health, Baltimore, Maryland, United States of America.; The Fenway Institute, Fenway Health, Boston, Massachusetts, United States of America; Harvard Medical School/Massachusetts General Hospital, Boston, Massachusetts, United States of America; Harvard School of Public Health, Boston, Massachusetts, United States of America.; The Fenway Institute, Fenway Health, Boston, Massachusetts, United States of America.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; The Fenway Institute, Fenway Health, Boston, Massachusetts, United States of America; Harvard School of Public Health, Boston, Massachusetts, United States of America.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
The success of global treatment as prevention (TasP) efforts for individuals living with HIV/AIDS (PLWHA) is dependent on successful implementation, and therefore the appropriate contribution of social and behavioral science to these efforts. Understanding the psychosocial context of condomless sex among PLWHA could shed light on effective points of intervention. HPTN 063 was an observational mixed-methods study of sexually active, in-care PLWHA in Thailand, Zambia, and Brazil as a foundation for integrating secondary HIV prevention into HIV treatment. From 2010-2012, 80 qualitative interviews were conducted with PLWHA receiving HIV care and reported recent sexual risk. Thirty men who have sex with women (MSW) and 30 women who have sex with men (WSM) participated in equal numbers across the sites. Thailand and Brazil also enrolled 20 biologically-born men who have sex with men (MSM). Part of the interview focused on the impact of HIV on sexual practices and relationships. Interviews were recorded, transcribed, translated into English and examined using qualitative descriptive analysis. The mean age was 25 (SD = 3.2). There were numerous similarities in experiences and attitudes between MSM, MSW and WSM across the three settings. Participants had a high degree of HIV transmission risk awareness and practiced some protective sexual behaviors such as reduced sexual activity, increased use of condoms, and external ejaculation. Themes related to risk behavior can be categorized according to struggles for intimacy and fears of isolation, including: fear of infecting a sex partner, guilt about sex, sexual communication difficulty, HIV-stigma, and worry about sexual partnerships. Emphasizing sexual health, intimacy and protective practices as components of nonjudgmental sex-positive secondary HIV prevention interventions is recommended. For in-care PLWHA, this approach has the potential to support TasP. The overlap of themes across groups and countries indicates that similar intervention content may be effective for a range of settings.
Simple adherence assessments to predict virologic failure among HIV-infected adults with discordant immunologic and clinical responses to antiretroviral therapy.
(2008-Aug) Goldman JD; Cantrell RA; Mulenga LB; Tambatamba BC; Reid SE; Levy JW; Limbada M; Taylor A; Saag MS; Vermund SH; Stringer JS; Chi BH; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
We evaluated the association between two antiretroviral therapy (ART) adherence measurements--the medication possession ratio (MPR) and patient self-report--and detectable HIV viremia in the setting of rapid service scale-up in Lusaka, Zambia. Drug adherence and outcomes were assessed in a subset of patients suspected of treatment failure based on discordant clinical and immunologic responses to ART. A total of 913 patients were included in this analysis, with a median time of 744 days (Q1, Q3: 511, 919 days) from ART initiation to viral load (VL) measurement. On aggregate over the period of follow-up, 531 (58%) had optimal adherence (MPR > or =95%), 306 (34%) had suboptimal adherence (MPR 80-94%), and 76 (8%) had poor adherence (MPR <80%). Of the 913 patients, 238 (26%) had VL > or =400 copies/ml when tested. When compared to individuals with optimal adherence, there was increasing risk for virologic failure in those with suboptimal adherence [adjusted relative risk (ARR): 1.3; 95% confidence interval (CI): 1.0, 1.6] and those with poor adherence (ARR: 1.7; 95% CI: 1.3, 2.4) based on MPR. During the antiretroviral treatment course, 676 patients (74%) reported no missed doses. The proportion of patients with virologic failure did not differ significantly among those reporting any missed dose from those reporting perfect adherence (26% vs. 26%, p = 0.97). Among patients with suspected treatment failure, a lower MPR was associated with higher rates of detectable viremia. However, the suboptimal sensitivity and specificity of MPR limit its utility as a sole predictor of virologic failure.
Six-month hemoglobin concentration and its association with subsequent mortality among adults on antiretroviral therapy in Lusaka, Zambia.
(2012-Sep-01) Giganti MJ; Limbada M; Mwango A; Moyo C; Mulenga LB; Guffey MB; Mulenga PL; Bolton-Moore C; Stringer JS; Chi BH; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. giganticidrz@gmail.com; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Little is known about changes in hemoglobin concentration early in the course of antiretroviral therapy and its subsequent relation to survival. We analyzed data for 40,410 HIV-infected adults on antiretroviral therapy in Lusaka, Zambia. Our main exposure of interest was 6-month hemoglobin, but we stratified our analysis by baseline hemoglobin to allow for potential effect modification. Patients with a 6-month hemoglobin <8.5 g/dL, regardless of baseline, had the highest hazard for death after 6 months (hazard ratio: 4.5; 95% confidence interval: 3.3 to 6.3). Future work should look to identify causes of anemia in settings such as ours and evaluate strategies for more timely diagnosis and treatment.