Browsing by Author "Keiser O"

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Effect of baseline renal function on tenofovir-containing antiretroviral therapy outcomes in Zambia.
(2014-May) Mulenga L; Musonda P; Mwango A; Vinikoor MJ; Davies MA; Mweemba A; Calmy A; Stringer JS; Keiser O; Chi BH; Wandeler G; Centre for Infectious Disease Research in Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Although tenofovir disoproxil fumarate (TDF) use has increased as part of first-line antiretroviral therapy (ART) across sub-Saharan Africa, renal outcomes among patients receiving TDF remain poorly understood. We assessed changes in renal function and mortality in patients starting TDF- or non-TDF-containing ART in Lusaka, Zambia. METHODS: We included patients aged ≥16 years who started ART from 2007 onward, with documented baseline weight and serum creatinine. Renal dysfunction was categorized as mild (estimated glomerular filtration rate [eGFR], 60-89 mL/min), moderate (30-59 mL/min), or severe (<30 mL/min) according to the chronic kidney disease-epidemiology (CKD-EPI) formula. Differences in eGFR during ART were analyzed using linear mixed-effect models. The odds of developing moderate or severe eGFR decrease and mortality were assessed using logistic and competing risk regression, respectively. RESULTS: We included 62 230 adults, of which 38 716 (62.2%) initiated a TDF-based regimen. The proportion with moderate or severe renal dysfunction at baseline was lower in the TDF than in the non-TDF group (1.9% vs 4.0%). Among patients with no or mild renal dysfunction, those receiving TDF were more likely to develop moderate (adjusted odds ratio, 3.11; 95% confidence interval, 2.52-3.87) or severe (2.43; 1.80-3.28) eGFR decrease, although the incidence in such episodes was low. Among patients with moderate or severe renal dysfunction at baseline, renal function improved independently of ART regimen, and mortality rates were similar in both treatment groups. CONCLUSIONS: TDF use did not attenuate renal function recovery or increase the mortality rate in patients with renal dysfunction. Further studies are needed to determine the role of routine renal function monitoring before and during ART use in Africa.
Implementation and Operational Research: Risk Charts to Guide Targeted HIV-1 Viral Load Monitoring of ART: Development and Validation in Patients From Resource-Limited Settings.
(2015-Nov-01) Koller M; Fatti G; Chi BH; Keiser O; Hoffmann CJ; Wood R; Prozesky H; Stinson K; Giddy J; Mutevedzi P; Fox MP; Law M; Boulle A; Egger M; *Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland; †Kheth'Impilo, Cape Town, South Africa; ‡Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; §Aurum Institute for Health Research, Johannesburg, South Africa; ‖Gugulethu ART Programme and Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa; ¶Division of Infectious Diseases, Department of Medicine, University of Stellenbosch and Tygerberg Academic Hospital, Cape Town, South Africa; #Médecins Sans Frontières, Khayelitsha, Cape Town, South Africa; **Sinikithemba Clinic, McCord Hospital, Durban, South Africa; ††Africa Centre for Health and Population Studies, University of KwaZulu-Natal, Somkhele, South Africa; ‡‡Health Economics and Epidemiology Research Office, University of the Witwatersrand, Johannesburg, South Africa; §§Center for Global Health & Development and Department of Epidemiology, Boston University, Boston, MA; ‖‖Biostatistics and Databases Program, The Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia; and ¶¶Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, South Africa.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: HIV-1 RNA viral load (VL) testing is recommended to monitor antiretroviral therapy (ART) but not available in many resource-limited settings. We developed and validated CD4-based risk charts to guide targeted VL testing. METHODS: We modeled the probability of virologic failure up to 5 years of ART based on current and baseline CD4 counts, developed decision rules for targeted VL testing of 10%, 20%, or 40% of patients in 7 cohorts of patients starting ART in South Africa, and plotted cutoffs for VL testing on colour-coded risk charts. We assessed the accuracy of risk chart-guided VL testing to detect virologic failure in validation cohorts from South Africa, Zambia, and the Asia-Pacific. RESULTS: In total, 31,450 adult patients were included in the derivation and 25,294 patients in the validation cohorts. Positive predictive values increased with the percentage of patients tested: from 79% (10% tested) to 98% (40% tested) in the South African cohort, from 64% to 93% in the Zambian cohort, and from 73% to 96% in the Asia-Pacific cohort. Corresponding increases in sensitivity were from 35% to 68% in South Africa, from 55% to 82% in Zambia, and from 37% to 71% in Asia-Pacific. The area under the receiver operating curve increased from 0.75 to 0.91 in South Africa, from 0.76 to 0.91 in Zambia, and from 0.77 to 0.92 in Asia-Pacific. CONCLUSIONS: CD4-based risk charts with optimal cutoffs for targeted VL testing maybe useful to monitor ART in settings where VL capacity is limited.
Monitoring and switching of first-line antiretroviral therapy in adult treatment cohorts in sub-Saharan Africa: collaborative analysis.
(2015-Jul) Haas AD; Keiser O; Balestre E; Brown S; Bissagnene E; Chimbetete C; Dabis F; Davies MA; Hoffmann CJ; Oyaro P; Parkes-Ratanshi R; Reynolds SJ; Sikazwe I; Wools-Kaloustian K; Zannou DM; Wandeler G; Egger M; Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.; Newlands Clinic, Harare, Zimbabwe.; Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland; Department of Infectious Diseases, Bern University Hospital and University of Bern, Bern, Switzerland.; Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa.; Kenya Medical Research Institute - RCTP FACES Program, Kisumu, Kenya.; Johns Hopkins University, Baltimore, MD, USA; Aurum Institute, Johannesburg, South Africa.; Rakai Health Sciences Program, Entebbe, Uganda; Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA.; Indiana University School of Medicine, Indianapolis, IN, USA.; Faculté des Sciences de la Santé de l'Université d'Abomey-Calavi, and Centre de Traitement Ambulatoire du Centre National Hospitalier Universitaire Hubert Koutoukou Maga, Cotonou, Benin.; Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland; Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa. Electronic address: egger@ispm.unibe.ch.; Infectious Diseases Institute, Mulago Hospital Complex, Kampala, Uganda.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; Service de Maladies Infectieuses et Tropicales, Centre Hospitalier Universitaire de Treichville, Abidjan, Côte d'Ivoire.; Centre de Recherche INSERM U897, Epidemiologie-Biostatistique, Institut de Santé Publique, Epidémiologie et Développement, Université de Bordeaux, Bordeaux, France.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: HIV-1 viral load testing is recommended to monitor antiretroviral therapy (ART) but is not universally available. The aim of our study was to assess monitoring of first-line ART and switching to second-line ART in sub-Saharan Africa. METHODS: We did a collaborative analysis of cohort studies from 16 countries in east Africa, southern Africa, and west Africa that participate in the international epidemiological database to evaluate AIDS (IeDEA). We included adults infected with HIV-1 who started combination ART between January, 2004, and January, 2013. We defined switching of ART as a change from a non-nucleoside reverse-transcriptase inhibitor (NNRTI)-based regimen to one including a protease inhibitor, with adjustment of one or more nucleoside reverse-transcriptase inhibitors (NRTIs). Virological and immunological failures were defined according to WHO criteria. We calculated cumulative probabilities of switching and hazard ratios with 95% CIs comparing routine viral load monitoring, targeted viral load monitoring, CD4 monitoring, and clinical monitoring, adjusting for programme and individual characteristics. FINDINGS: Of 297,825 eligible patients, 10,352 (3%) switched to second-line ART during 782 ,412 person-years of follow-up. Compared with CD4 monitoring, hazard ratios for switching were 3·15 (95% CI 2·92-3·40) for routine viral load monitoring, 1·21 (1·13-1·30) for targeted viral load monitoring, and 0·49 (0·43-0·56) for clinical monitoring. Of 6450 patients with confirmed virological failure, 58·0% (95% CI 56·5-59·6) switched by 2 years, and of 15,892 patients with confirmed immunological failure, 19·3% (18·5-20·0) switched by 2 years. Of 10,352 patients who switched, evidence of treatment failure based on one CD4 count or viral load measurement ranged from 86 (32%) of 268 patients with clinical monitoring to 3754 (84%) of 4452 with targeted viral load monitoring. Median CD4 counts at switching were 215 cells per μL (IQR 117-335) with routine viral load monitoring, but were lower with other types of monitoring (range 114-133 cells per μL). INTERPRETATION: Overall, few patients switched to second-line ART and switching happened late in the absence of routine viral load monitoring. Switching was more common and happened earlier after initiation of ART with targeted or routine viral load testing. FUNDING: National Institute of Allergy and Infectious Diseases, Swiss National Science Foundation.
Prognosis of children with HIV-1 infection starting antiretroviral therapy in Southern Africa: a collaborative analysis of treatment programs.
(2014-Jun) Davies MA; May M; Bolton-Moore C; Chimbetete C; Eley B; Garone D; Giddy J; Moultrie H; Ndirangu J; Phiri S; Rabie H; Technau KG; Wood R; Boulle A; Egger M; Keiser O; From the *School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa; †School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom; ‡Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; §University of North Carolina, Chapel Hill, NC; ¶Newlands clinic, Harare, Zimbabwe; ‖Red Cross Children's Hospital and School of Child and Adolescent Health, University of Cape Town; **Médecins Sans Frontières (MSF) South Africa and Khayelitsha ART Programme, Cape Town; ††Sinikithemba Clinic, McCord Hospital, Durban; ‡‡Wits Reproductive Health and HIV Institute, University of the Witwatersrand, Johannesburg; §§Harriet Shezi Children's Clinic, Chris Hani Baragwanath Hospital, Soweto; ¶¶Africa Centre for Health and Population Studies, University of Kwazulu-Natal, Somkhele, South Africa; ‖‖Lighthouse Trust Clinic, Kamuzu Central Hospital, Lilongwe, Malawi and Liverpool School of Tropical Medicine, Liverpool, United Kingdom; ***Tygerberg Academic Hospital, University of Stellenbosch, Stellenbosch; †††Empilweni Services and Research Unit, Rahima Moosa Mother and Child Hospital, and University of the Witwatersrand, Johannesburg; ‡‡‡Gugulethu ART Programme and Desmond Tutu HIV Centre, University of Cape Town, Cape Town, South Africa; and §§§Institute of Social and Preventive Medicine (ISPM), University of Bern, Switzerland.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Prognostic models for children starting antiretroviral therapy (ART) in Africa are lacking. We developed models to estimate the probability of death during the first year receiving ART in Southern Africa. METHODS: We analyzed data from children ≤10 years of age who started ART in Malawi, South Africa, Zambia or Zimbabwe from 2004 to 2010. Children lost to follow up or transferred were excluded. The primary outcome was all-cause mortality in the first year of ART. We used Weibull survival models to construct 2 prognostic models: 1 with CD4%, age, World Health Organization clinical stage, weight-for-age z-score (WAZ) and anemia and the other without CD4%, because it is not routinely measured in many programs. We used multiple imputation to account for missing data. RESULTS: Among 12,655 children, 877 (6.9%) died in the first year of ART. We excluded 1780 children who were lost to follow up/transferred from main analyses; 10,875 children were therefore included. With the CD4% model probability of death at 1 year ranged from 1.8% [95% confidence interval (CI): 1.5-2.3] in children 5-10 years with CD4% ≥10%, World Health Organization stage I/II, WAZ ≥ -2 and without severe anemia to 46.3% (95% CI: 38.2-55.2) in children <1 year with CD4% < 5%, stage III/IV, WAZ< -3 and severe anemia. The corresponding range for the model without CD4% was 2.2% (95% CI: 1.8-2.7) to 33.4% (95% CI: 28.2-39.3). Agreement between predicted and observed mortality was good (C-statistics = 0.753 and 0.745 for models with and without CD4%, respectively). CONCLUSIONS: These models may be useful to counsel children/caregivers, for program planning and to assess program outcomes after allowing for differences in patient disease severity characteristics.
Temporal trends in the characteristics of children at antiretroviral therapy initiation in southern Africa: the IeDEA-SA Collaboration.
(2013) Davies MA; Phiri S; Wood R; Wellington M; Cox V; Bolton-Moore C; Timmerman V; Moultrie H; Ndirangu J; Rabie H; Technau K; Giddy J; Maxwell N; Boulle A; Keiser O; Egger M; Eley B; Newlands Clinic, Harare, Zimbabwe.; Africa Centre for Health and Population Studies, University of KwaZulu-Natal, Somkhele, South Africa.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia and University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.; Tygerberg Academic Hospital, University of Stellenbosch, Stellenbosch, South Africa.; Wits Reproductive Health and HIV Institute, Harriet Shezi Children's Clinic, Chris Hani Baragwanath Hospital, Faculty of Health Sciences, University of Witwatersrand, Soweto, Johannesburg, South Africa.; School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.; Red Cross Children's Hospital and School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa.; Empilweni Services and Research Unit, Rahima Moosa Mother and Child Hospital and University of Witwatersrand, Johannesburg, South Africa.; Knowledge Translation Unit, University of Cape Town Lung Institute, Cape Town, South Africa.; Médecins Sans Frontières South Africa and Khayelitsha ART Programme, Khayelitsha, Cape Town, South Africa.; Sinikithemba Clinic, McCord Hospital, Durban, South Africa.; Lighthouse Trust Clinic, Kamuzu Central Hospital, Lilongwe, Malawi.; Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.; Gugulethu Community Health Centre and Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Since 2005, increasing numbers of children have started antiretroviral therapy (ART) in sub-Saharan Africa and, in recent years, WHO and country treatment guidelines have recommended ART initiation for all infants and very young children, and at higher CD4 thresholds for older children. We examined temporal changes in patient and regimen characteristics at ART start using data from 12 cohorts in 4 countries participating in the IeDEA-SA collaboration. METHODOLOGY/PRINCIPAL FINDINGS: Data from 30,300 ART-naïve children aged <16 years at ART initiation who started therapy between 2005 and 2010 were analysed. We examined changes in median values for continuous variables using the Cuzick's test for trend over time. We also examined changes in the proportions of patients with particular disease severity characteristics (expressed as a binary variable e.g. WHO Stage III/IV vs I/II) using logistic regression. Between 2005 and 2010 the number of children starting ART each year increased and median age declined from 63 months (2006) to 56 months (2010). Both the proportion of children <1 year and ≥10 years of age increased from 12 to 19% and 18 to 22% respectively. Children had less severe disease at ART initiation in later years with significant declines in the percentage with severe immunosuppression (81 to 63%), WHO Stage III/IV disease (75 to 62%), severe anemia (12 to 7%) and weight-for-age z-score<-3 (31 to 28%). Similar results were seen when restricting to infants with significant declines in the proportion with severe immunodeficiency (98 to 82%) and Stage III/IV disease (81 to 63%). First-line regimen use followed country guidelines. CONCLUSIONS/SIGNIFICANCE: Between 2005 and 2010 increasing numbers of children have initiated ART with a decline in disease severity at start of therapy. However, even in 2010, a substantial number of infants and children started ART with advanced disease. These results highlight the importance of efforts to improve access to HIV diagnostic testing and ART in children.