***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background There are conflicting reports of antiretroviral therapy ( ART ) effectiveness comparisons between primary healthcare ( PHC ) facilities and hospitals in low-income setting s. This comparison has not been evaluated on a broad scale in South Africa . Methodology /Principal Findings A retrospective cohort study was conducted including ART-naïve adults from 59 facilities in four provinces in South Africa , enrolled between 2004 and 2007 . Kaplan-Meier estimates , competing-risks Cox regression , generalised estimating equation population -averaged models and logistic regression were used to compare death , loss to follow-up ( LTFU ) and virological suppression ( VS ) between PHC , district and regional hospitals . 29 203 adults from 47 PHC facilities , nine district hospitals and three regional hospitals were included . Patients at PHC facilities had more advanced WHO stage disease when starting ART . Retention in care was 80.1 % ( 95 % CI : 79.3%–80.8 % ) , 71.5 % ( 95 % CI : 69.1%–73.8 % ) and 68.7 % ( 95 % CI : 67.0%–69.7 % ) at PHC , district and regional hospitals respectively , after 24 months of treatment ( P<0.0001 ) . In adjusted regression analyses , LTFU was independently increased at regional hospitals ( aHR 2.19 ; 95 % CI : 1.94−2.47 ) and mortality was independently elevated at district hospitals ( aHR 1.60 ; 95 % CI : 1.30−1.99 ) compared to PHC facilities after 12 months of ART . District and regional hospital patients had independently reduced probabilities of VS , aOR 0.76 ( 95 % CI : 0.59−0.97 ) and 0.64 ( 95 % CI : 0.56−0.75 ) respectively compared to PHC facilities over 24 months of treatment . Conclusions / Significance ART outcomes were superior at PHC facilities , despite PHC patients having more advanced clinical stage disease when starting ART , suggesting that ART can be adequately provided at this level and supporting the South African government 's call for rapid up-scaling of ART at the primary level of care . Further prospect i ve research is required to determine the degree to which outcome differences are attributable to either facility level characteristics or patient co-morbidity at hospital level BACKGROUND We investigated virological response and the emergence of resistance in the  Nevirapine or Abacavir ( NORA ) sub study of the Development of Antiretroviral Treatment in Africa ( DART ) trial . METHODS Six hundred symptomatic antiretroviral-naive human immunodeficiency virus (HIV)-infected adults ( CD4 cell count , < 200 cells/mm(3 ) ) from 2 Ug and an centers were r and omized to receive zidovudine-lamivudine plus abacavir or nevirapine .  Virology was performed retrospectively on stored plasma sample s at selected time points . In patients with HIV RNA levels > 1000 copies/mL , the residual activity of therapy was calculated as the reduction in HIV RNA level , compared with baseline . RESULTS Overall , HIV RNA levels were lower in the nevirapine group than in the abacavir group at 24 and 48 weeks ( P < .001 ) , although no differences were observed at weeks 4 and 12 . Virological responses were similar in the 2 treatment groups for baseline HIV RNA level < 100,000 copies/mL. The mean residual activity at week 48 was higher for abacavir in the presence of the typically observed resistance pattern of thymidine analogue mutations ( TAMs ) and M184V ( 1.47 log(10 ) copies/mL ) than for nevirapine with M184V and nonnucleoside reverse-transcriptase inhibitor mutations , whether accompanied by TAMs ( 0.96 log(10 ) copies/mL ) or not ( 1.18 log(10 ) copies/mL ) . CONCLUSIONS There was more extensive genotypic resistance in both treatment groups than is generally seen in re source -rich setting s. However , significant residual activity was observed among patients with virological failure , particularly those receiving zidovudine-lamivudine plus abacavir OBJECTIVE To assess the effectiveness of generic anti-retroviral drugs in terms of survival and virological and immunological responses , as well as their tolerability and the emergence of viral resistance . METHODS A total of 109 HIV-1-infected patients were enrolled in a prospect i ve cohort study in Yaoundé , Cameroon . Available generic drugs were a fixed-dose combination ( FDC ) of zidovudine ( ZDV ) and lamivudine ( 3TC ) , an FDC of 3TC , stavudine ( d4 T ) and nevirapine ( NVP ) , and individual formulations of ZDV , 3TC and NVP . RESULTS At baseline , the median CD4 cell count was 150/mm3 [ interquartile range ( IQR ) 61 - 223 ] and median viral load was 5.4 log10 copies/ml ( IQR 4.8 - 5.6 ) ; 78 % of patients received ZDV/3TC/NVP and 22 % received 3TC/d4T/NVP . Median follow-up was 16 months ( IQR 11 - 23 ) . The survival probability was high ( 0.92 at 12 months ) ; plasma viral load declined by a median of 3.3 log10 copies/ml and 86.9 % of the intention-to-treat population had viral load < 400 copies/ml at 12 months ; CD4 count had increased by a median of 106 cells/mm3 at 12 months ; drug resistance rarely emerged ( incidence rate 3.2 per 100 person-years ) ; and the treatments were reasonably well-tolerated ( incidence rate of severe adverse effects 7.8 per 100 person-years ) . CONCLUSION Together with previous pharmacological and clinical studies , this prospect i ve study suggests that these generic antiretroviral drugs can be used in developing countries Background : Numerous national antiretroviral ( ARV ) treatment initiatives offering protease inhibitor-sparing combination antiretroviral therapy ( cART ) have recently commenced in southern Africa , the first of which began in Botswana in January 2002 . Evaluation of the efficacy and tolerability of various protease inhibitor-sparing cART regimens requires intensive study in the region , as does investigation of the development of drug resistance and the optimal means of sustaining adherence . The “ Tshepo ” Study is the first large-scale , r and omized , clinical trial that addresses these important issues among HIV-1 subtype C-infected ARV treatment-naive adults in southern Africa . Methods : The Tshepo Study is a completed , open-labeled , r and omized study that enrolled 650 ARV-naive adults between December 2002 and 2004 . The study is a 3 × 2 × 2 factorial design comparing the efficacy and tolerability among factors : ( 1 ) 3 combinations of nucleoside reverse transcriptase inhibitors ( NRTIs ) : zidovudine ( ZDV ) + lamivudine ( 3TC ) , ZDV + didanosine ( ddI ) , and stavudine ( d4 T ) + 3TC ; ( 2 ) 2 different nonnucleoside reverse transcriptase inhibitors ( NNRTIs ) : nevirapine and efavirenz ; and ( 3 ) 2 different adherence strategies : the current national “ st and ard of care ” versus an “ intensified adherence strategy ” incorporating a “ community-based directly observed therapy . ” Study patients were stratified into 2 balanced CD4 + T-cell count groups : less than 201 versus 201 - 350 cells per cubic millimeter with viral load greater than 55,000 copies per milliliter . Following Data Safety Monitoring Board recommendations in April 2006 , ZDV/ddI-containing arms were discontinued due to inferiority in primary end point , namely , virologic failure with resistance . We report both overall data and pooled data from patients receiving ZDV/ddI- versus ZDV/3TC- and d4T/3TC-containing cART through April 1 , 2006 . Results : Four hundred fifty-one females ( 69.4 % ) and 199 males with a median age of 33.3 years were enrolled into the study . The median follow-up as of April 1 , 2006 , was 104 weeks , and loss to follow-up rate at 2 years was 4.1 % . The median baseline CD4 + T-cell count was 199 cells per cubic millimeter [ interquartile ratio ( IQR ) 136 - 252 ] , and the median plasma HIV-1 RNA level was 193,500 copies per milliliter ( IQR 69 - 250 , 472 - 500 ) . The proportion of participants with virologic failure and genotypic resistance mutations was 11 % in those receiving ZDV/ddI-based cART versus 2 % in those receiving either ZDV/3TC- or d4T/3TC-based cART ( P = 0.002 ) . The median CD4 + T-cell count increase at 1 year was 137 cells per cubic millimeter ( IQR 74 - 223 ) and 199 cells per cubic millimeter ( IQR 112 - 322 ) at 2 years with significantly lower gain in the ZDV/ddI arm . At 1 and 2 years , respectively , 92.0 % and 88.8 % of patients had an undetectable plasma HIV-1 RNA level ( ≤400 copies/mL ) . Kaplan-Meier survival estimates at 1 and 2 years were 96.6 % and 95.4 % . One hundred twenty patients ( 18.2 % ) had treatment-modifying toxicities , of which the most common were lipodystrophy , anemia , neutropenia , and Stevens-Johnson syndrome . There was a trend toward difference in time to treatment-modifying toxicity by pooled dual-NRTI combination and no difference in death rates . Conclusions : The preliminary study results show overall excellent efficacy and tolerability of NNRTI-based cART among HIV-1 subtype C-infected adults .  ZDV/ddI-containing cART , however , is inferior to the dual NRTIs d4T/3TC or ZDV/3TC when used with an NNRTI for first-line cART Background Little is known about immunovirological treatment outcomes and adherence in HIV/AIDS patients on antiretroviral therapy ( ART ) treated using a simplified management approach in rural areas of developing countries , or about the main factors influencing those outcomes in clinical practice . Methods Cross-sectional immunovirological , pharmacological , and adherence outcomes were evaluated in all patients alive and on fixed-dose ART combinations for 24 months , and in a r and om sample of those treated for 12 months . Risk factors for virological failure ( > 1,000 copies/ml ) and subtherapeutic antiretroviral ( ARV ) concentrations were investigated with multiple logistic regression . Results At 12 and 24 months of ART , 72 % ( n = 701 ) and 70 % ( n = 369 ) of patients , respectively , were alive and in care . About 8 % and 38 % of patients , respectively , were diagnosed with immunological failure ; and 75 % and 72 % of patients , respectively , had undetectable HIV RNA ( < 400 copies/ml ) . Risk factors for virological failure ( > 1,000 copies/ml ) were poor adherence , tuberculosis diagnosed after ART initiation , subtherapeutic NNRTI concentrations , general clinical symptoms , and lower weight than at baseline . About 14 % of patients had low ARV plasma concentrations . Digestive symptoms and poor adherence to ART were risk factors for low ARV plasma concentrations . Conclusion Efforts to improve both access to care and patient management to achieve better immunological and virological outcomes on ART are necessary to maximize the duration of first-line therapy Objectives : To determine short- and long-term efficacy of modified directly observed therapy ( m-DOT ) on antiretroviral adherence . Design : R and omized controlled trial . Setting and Analytic Approach : From September 2003 to November 2004 , 234 HIV-infected adults were assigned m-DOT ( 24 weeks of twice weekly health center visits for nurse-observed pill ingestion , adherence support , and medication collection ) or st and ard care . Follow-up continued until week 72 . Self-reported and pill-count adherence and , secondarily , viral suppression and body mass index measures are reported . Generalized estimating equations adjusted for intraclient clustering and covariates were used . Results : During weeks 1 - 24 , 9.1 % ( 9/99 ) of m-DOT participants reported missing doses compared with 19.1 % ( 20/105 ) of controls ( P = 0.04 ) and 96.5 % ( 517/571 ) of m-DOT  pill-count measures were ≥95 % compared with 86.1 % ( 4 
    Output:
    
The pooled estimates of viral suppression recorded after 12 months of ART in LMICs provide benchmarks that other ART programmes can use to set realistic goals and perform predictive modelling .