Browsing by Author "Maganga, Lucas"

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    Clinical similarities and differences between two large HIV cohorts in the United States and Africa
    (Plos one, 2022) Monroe, Anne K.; Polyak, Christina S.; Castel, Amanda D.; Esber, Allahna L.; Maganga, Lucas; Kibuuka, Hannah; Kiweewa, Francis; Ake, Julie A.
    Washington, DC, and sub-Saharan Africa are both affected by generalized HIV epidemics. However, care for persons living with HIV (PLWH) and clinical outcomes may differ in these geographically and culturally diverse areas. We compared patient and clinical site characteristics among adult persons living with HIV (PLWH) enrolled in two longitudinal HIV cohort studies—the African Cohort Study (AFRICOS) and the DC Cohort. Methods The DC Cohort is a clinic-based city-wide longitudinal cohort comprised of PLWH attending 15 HIV clinics in Washington, DC. Patients’ socio-demographic characteristics, clinical evaluations, and laboratory data are retrospectively collected from electronic medical records and limited manual chart abstraction. AFRICOS is a prospective observational cohort of PLWH and uninfected volunteers attending 12 select HIV care and treatment facilities in Nigeria, Kenya, Uganda and Tanzania. AFRICOS study participants are a subset of clinic patients who complete protocol-specific visits every 6 months with history and physical examination, questionnaire administration, and blood/sputum collection for ascertainment of HIV outcomes and comorbidities, and neurocognitive and functional assessments. Among participants aged 18 years, we generated descriptive statistics for demographic and clinical characteristics at enrollment and follow up and compared them using bivariable analyses. Results The study sample included 2,774 AFRICOS and 8,420 DC Cohort participants who enrolled from January 2013 (AFRICOS)/January 2011 (DC Cohort) through March 2018. AFRICOS participants were significantly more likely to be women (58.8% vs 27.1%) and younger (83.3% vs 61.1% aged < 50 years old) and significantly less likely to be MSM (only 0.1% of AFRICOS population reported MSM risk factor) than DC Cohort. Similar rates of current viral suppression (about 75% of both samples), hypertension, hepatitis B coinfection and alcohol use were observed. However, AFRICOS participants had significantly higher rates of CD4<200 and tuberculosis and significantly lower rates of obesity, DM, hepatitis C coinfection and syphilis. Conclusions With similar viral suppression outcomes, but many differences between our cohorts noted, the combined sample provides unique opportunities to assess and compare HIV care and treatment outcomes in the U.S. and sub-Saharan Africa. Comparing these two cohorts may inform care and treatment practices and may pave the way for future pathophysiologic analyses.
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    Contraceptive Use in Women Enrolled into Preventive HIV Vaccine Trials: Experience from a Phase I/II Trial in East Africa
    (PLoS ONE, 2009) Kibuuka, Hannah; Guwatudde, David; Kimutai, Robert; Maganga, Lucas; Maboko, Leonard; Watyema, Cecilia; Sawe, Fredrick; Shaffer, Douglas; Matsiko, Dickson; Millard, Monica; Michael, Nelson; Wabwire-Mangen, Fred; Robb, Merlin
    HIV vaccine trials generally require that pregnant women are excluded from participation, and contraceptive methods must be used to prevent pregnancy during the trial. However, access to quality services and misconceptions associated with contraceptive methods may impact on their effective use in developing countries. We describe the pattern of contraceptive use in a multi-site phase I/IIa HIV Vaccine trial in East Africa (Uganda, Kenya and Tanzania) and factors that may have influenced their use during the trial. Methods: Pregnancy prevention counseling was provided to female participants during informed consent process and at each study visit. Participants’ methods of contraception used were documented. Methods of contraceptives were provided on site. Pregnancy testing was done at designated visits during the trial. Obstacles to contraceptive use were identified and addressed at each visit. Results: Overall, 103 (31.8%) of a total of 324 enrolled volunteers were females. Female participants were generally young with a mean age of 29(67.2), married (49.5%) and had less than high school education (62.1%). Hormonal contraceptives were the most common method of contraception (58.3%) followed by condom use (22.3%). The distribution of methods of contraception among the three sites was similar except for more condom use and less abstinence in Uganda. The majority of women (85.4%) reported to contraceptive use prior to screening. The reasons for not using contraception included access to quality services, insufficient knowledge of certain methods, and misconceptions. Conclusion: Although hormonal contraceptives were frequently used by females participating in the vaccine trial, misconceptions and their incorrect use might have led to inconsistent use resulting in undesired pregnancies. The study underscores the need for an integrated approach to pregnancy prevention counseling during HIV vaccine trials.
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    Factors influencing estimates of HIV-1 infection timing using BEAST
    (PLOS Computational Biology, 2021) Dearlove, Bethany; Tovanabutra, Sodsai; Owen, Christopher L.; Kibuuka, Hannah; Maganga, Lucas; Michael, Nelson L.; Robb, Merlin L.; Rolland, Morgane
    While large datasets of HIV-1 sequences are increasingly being generated, many studies rely on a single gene or fragment of the genome and few comparative studies across genes have been done. We performed genome-based and gene-specific Bayesian phylogenetic analyses to investigate how certain factors impact estimates of the infection dates in an acute HIV-1 infection cohort, RV217. In this cohort, HIV-1 diagnosis corresponded to the first RNA positive test and occurred a median of four days after the last negative test, allowing us to compare timing estimates using BEAST to a narrow window of infection. We analyzed HIV-1 sequences sampled one week, one month and six months after HIV-1 diagnosis in 39 individuals. We found that shared diversity and temporal signal was limited in acute infection, and insufficient to allow timing inferences in the shortest HIV-1 genes, thus dated phylogenies were primarily analyzed for env, gag, pol and near full-length genomes. There was no one best-fitting model across participants and genes, though relaxed molecular clocks (73% of best-fitting models) and the Bayesian skyline (49%) tended to be favored. For infections with single founders, the infection date was estimated to be around one week pre-diagnosis for env (IQR: 3–9 days) and gag (IQR: 5–9 days), whilst the genome placed it at a median of 10 days (IQR: 4–19). Multiply-founded infections proved problematic to date. Our ability to compare timing inferences to precise estimates of HIV-1 infection (within a week) highlights that molecular dating methods can be applied to withinhost datasets from early infection. Nonetheless, our results also suggest caution when using uniform clock and population models or short genes with limited information content.
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    Molecular dating and viral load growth rates suggested that the eclipse phase lasted about a week in HIV-1 infected adults in East Africa and Thailand
    (PLoS Pathog, 2020) Rolland, Morgane; Tovanabutra, Sodsai; Dearlove, Bethany; Li, Yifan; Kibuuka, Hannah; Maganga, Lucas; Michael, Nelson L.; Robb, Merlin L.
    Most HIV-1 infected individuals do not know their infection dates. Precise infection timing is crucial information for studies that document transmission networks or drug levels at infection. To improve infection timing, we used the prospective RV217 cohort where the window when plasma viremia becomes detectable is narrow: the last negative visit occurred a median of four days before the first detectable HIV-1 viremia with an RNA test, referred below as diagnosis. We sequenced 1,280 HIV-1 genomes from 39 participants at a median of 4, 32 and 170 days post-diagnosis. HIV-1 infections were dated by using sequencebased methods and a viral load regression method. Bayesian coalescent and viral load regression estimated that infections occurred a median of 6 days prior to diagnosis (IQR: 9–3 and 11–4 days prior, respectively). Poisson-Fitter, which analyzes the distribution of hamming distances among sequences, estimated a median of 7 days prior to diagnosis (IQR: 15–4 days) based on sequences sampled 4 days post-diagnosis, but it did not yield plausible results using sequences sampled at 32 days. Fourteen participants reported a high-risk exposure event at a median of 8 days prior to diagnosis (IQR: 12 to 6 days prior). These different methods concurred that HIV-1 infection occurred about a week before detectable viremia, corresponding to 20 days (IQR: 34–15 days) before peak viral load.
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    Perceived satisfaction with HIV care and its association with adherence to antiretroviral therapy and viral suppression in the African Cohort Study
    (AIDS research and therapy, 2021) Somi, Nancy; Dear, Nicole; Reed, Domonique; Parikh, Ajay; Lwilla, Anange; Bahemana, Emmanuel; Khamadi, Samoel; Iroezindu, Michael; Kibuuka, Hannah; Maswai, Jonah; Crowell, Trevor A.; Owuoth, John; Maganga, Lucas; Polyak, Christina; Ake, Julie; Esber, Allahna
    Increased availability of HIV care over the past decade has dramatically reduced morbidity and mortality among people living with HIV (PLWH) in sub-Saharan Africa. However, perceived and experienced barriers to care, including dissatisfaction with services, may impact adherence and viral suppression. We examined the associations between satisfaction with HIV care and antiretroviral therapy (ART) adherence and viral load suppression. Methods: The African Cohort Study (AFRICOS) is a prospective observational study conducted at PEPFAR-supported clinics in four African countries. At enrollment and twice-yearly study visits, participants received a clinical assessment and a socio-behavioral questionnaire was administered. Participants were classified as dissatisfied with care if they reported dissatisfaction with any of the following: waiting time, health care worker skills, health care worker attitudes, quality of clinic building, or overall quality of care received. Robust Poisson regression was used to estimate prevalence ratios and 95% confidence intervals (CIs) for associations between satisfaction with care and ART adherence and between satisfaction with care and viral suppression (viral load < 1000 copies/mL). Results: As of 1 March 2020, 2928 PLWH were enrolled and 2311 had a year of follow-up visits. At the first annual follow-up visit, 2309 participants responded to questions regarding satisfaction with quality of care, and 2069 (89.6%) reported satisfaction with care. Dissatisfaction with waiting time was reported by 177 (7.6%), building quality by 59 (2.6%), overall quality of care by 18 (0.8%), health care worker attitudes by 16 (0.7%), and health care worker skills by 15 (0.7%). After adjusting for age and site, there was no significant difference in viral suppression between those who were satisfied with care and those who were dissatisfied (aPR: 1.03, 95% CI 0.97–1.09). Satisfaction with HIV care was moderately associated with ART adherence among AFRICOS participants (aPR: 1.09; 95% CI 1.00–1.16). Conclusions: While patient satisfaction in AFRICOS was high and the association between perceived quality of care and adherence to ART was marginal, we did identify potential target areas for HIV care improvement, including reducing clinic waiting times.
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    Temporal Dynamics of CD8+ T Cell Effector Responses during Primary HIV Infection
    (PLOS Pathogens, 2016) Demers, Korey R.; Makedonas, George; Buggert, Marcus; Eller, Michael A.; Ratcliffe, Sarah J.; Goonetilleke, Nilu; Li, Chris K.; Anne Eller, Leigh; Rono, Kathleen; Maganga, Lucas; Nitayaphan, Sorachai; Kibuuka, Hannah; Routy, Jean-Pierre; Slifka, Mark K.; Haynes, Barton F.; McMichael, Andrew J.; Bernard, Nicole F.; Robb, Merlin L.; Betts, Michael R.
    The loss of HIV-specific CD8+ T cell cytolytic function is a primary factor underlying progressive HIV infection, but whether HIV-specific CD8+ T cells initially possess cytolytic effector capacity, and when and why this may be lost during infection, is unclear. Here, we assessed CD8+ T cell functional evolution from primary to chronic HIV infection. We observed a profound expansion of perforin+ CD8+ T cells immediately following HIV infection that quickly waned after acute viremia resolution. Selective expression of the effector-associated transcription factors T-bet and eomesodermin in cytokine-producing HIV-specific CD8+ T cells differentiated HIV-specific from bulk memory CD8+ T cell effector expansion. As infection progressed expression of perforin was maintained in HIV-specific CD8+ T cells with high levels of T-bet, but not necessarily in the population of T-betLo HIV-specific CD8+ T cells that expand as infection progresses. Together, these data demonstrate that while HIV-specific CD8+ T cells in acute HIV infection initially possess cytolytic potential, progressive transcriptional dysregulation leads to the reduced CD8+ T cell perforin expression characteristic of chronic HIV infection.