***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: Objective To study the feasibility , effectiveness , adherence , toxicity and viral resistance in an African government HAART initiative . Methods A prospect i ve observational cohort study started in Dakar in August 1998 . Initial treatment consisted of two nucleoside reverse transcriptase inhibitors and one protease inhibitor . The patients attended monthly medical examinations . Plasma HIV-1 RNA and CD4 cell counts were determined at baseline and every 6 months . Intention-to-treat analyses were performed . Results Fifty-eight treatment-naive patients , mostly infected by HIV-1 strain CRF02-AG , were enrolled . Most were at an advanced stage of HIV disease ( 86.2 % had AIDS )  . Adherence was good in 87.9 % of patients and treatment was effective in most of them . Thus , HIV-1 RNA was undetectable in 79.6 , 71.2 , 51.4 and 59.3 % of patients at months 1 , 6 , 12 and 18 , respectively and the median viral load reduction was ∼2.5 log10 copies/ml . The CD4 cell count rose by a median of 82 , 147 and 180 × 106 cells/l at months 6 , 12 and 18 , respectively . At the same time points , the cumulative probability of remaining alive or free of new AIDS-defining events was 94.8 , 85.0 and 82.3 % . Most adverse effects ( 80.8 % ) were mild or moderate and only two cases of drug resistance occurred . Conclusion This study shows that HAART is feasible and well tolerated in African patients . Clinical and biological results were comparable to those seen in western cohorts , despite differences in the HIV-1 subtype distribution and an advanced disease stage when the treatment was initiated . Contrary to other recent studies in Africa , viral resistance rarely emerged BACKGROUND Generic fixed-dose combinations have been prequalified by WHO to treat HIV-infected patients in re source -limited countries . Despite their widespread use they are , however , not yet recommended by some of the major donor agencies owing to scarcity of clinical data on effectiveness , safety , and quality . We aim ed to assess these issues for one of the most frequently prescribed treatments in Africa , a generic fixed-dose combination of nevirapine , stavudine , and lamivudine . METHODS 60 patients were followed in an open-label , 24-week multicentre trial in Cameroon . All patients received one tablet of the fixed-dose combination drug twice daily . The primary outcome measure was the proportion of patients with viral load less than 400 copies per mL at the end of the study period , in an intention-to-treat analysis . FINDINGS At baseline , 92 % of patients ( n=55 ) had AIDS ; median CD4 count was 118 cells per microL ( IQR 78 - 167 ) and median plasma HIV-1 RNA was 104?736 copies per mL ( 40804 - 243787 ) . The proportion of patients with undetectable viral load ( < 400 copies per mL ) after 24 weeks of treatment was 80 % ( 95 % CI 68 - 89 ) . Median ( IQR ) change in viral load was -3.1 log10 copies per mL ( -2.5 to -3.6 ) and in CD4 count 83 cells per microL ( 40 - 178 ) . The probability of remaining alive or free of new AIDS-defining events was 0.85 ( 95 % CI 0.73 - 0.92 ) . Frequency of disease progression was 32.0 ( 95 % CI 16.6 - 61.5 ) , severe adverse effects 17.8 ( 7.4 - 42.7 ) , and genotypic resistance mutations 7.1 ( 1.8 - 28.4 ) per 100 person-years . Mean reported adherence rate was 99 % . Median drug concentrations in tablets were 96 % of expected values for nevirapine , 89 % for stavudine , and 99 % for lamivudine . INTERPRETATION Our findings lend support to use and funding of a generic fixed-dose combination of nevirapine , stavudine , and lamivudine as first-line antiretroviral treatment in developing countries BACKGROUND Despite rapid expansion of antiretroviral therapy ( ART ) in sub-Saharan Africa there are few longitudinal data describing programme performance during rapid scale-up . METHODS We compared mortality , viral suppression and programme retention in 3 consecutive years of a public sector community-based ART clinic in a South African township . Data were collected prospect ively from establishment of services in October 2002 to the censoring date in September 2005 . Viral load and CD4 counts were monitored at 4-monthly intervals . Community-based counsellors provided adherence and programme support . RESULTS During the study period 1139 ART-naïve patients received ART ( 161 , 280 and 698 in the 1st , 2nd and 3rd years respectively ) . The median CD4 cell counts were 84 cells/microl ( interquartile range ( IQR ) 42 - 139 ) , 89 cells/microl ( IQR 490 - 149 ) , and 110 cells/microl ( IQR 55 - 172 ) , and the proportions of patients with World Health Organization ( WHO ) clinical stages 3 and 4 were 90 % , 79 % and 76 % in each sequential year respectively . The number of counsellors increased from 6 to 28 and the median number of clients allocated to each counsellor increased from 13 to 33 . The overall loss to follow-up was .9 % . At the date of censoring , the Kaplan-Meier estimates of the proportion of patients still on the programme were 82 % , 86 % and 91 % , and the proportion who were virally suppressed ( < 400 copies/ml ) were 100 % , 92 % and 98 % for the 2002 , 2003 and 2004 cohorts respectively . CONCLUSIONS While further operational research is required into optimal models of care in different population s across sub-Saharan Africa , these results demonstrate that a single community-based public sector ART clinic can extend care to over 1000 patients in an urban setting without compromising programme performance CONTEXT Rifampicin-based antitubercular therapy reduces the plasma concentrations of nevirapine and efavirenz . The virological consequences of these interactions are not well described . OBJECTIVE To assess the effectiveness and tolerability of concomitant efavirenz- or nevirapine-based combination antiretroviral therapy and rifampicin-based antitubercular therapy . DESIGN , SETTING , AND PARTICIPANTS Cohort analysis of prospect ively collected routine clinical data in a community-based South African antiretroviral treatment program . Antiretroviral treatment-naive adults enrolled between May 2001 and June 2006 were included in the analysis , and were followed up until the end of 2006 . INTERVENTIONS Patients starting antiretroviral therapy with or without  concurrent antitubercular therapy  received either efavirenz or nevirapine at st and ard doses . Patients developing tuberculosis while taking antiretroviral therapy that included nevirapine  were either changed to efavirenz or continued taking nevirapine . MAIN OUTCOME MEASURES Viral load of 400 copies/mL or more after 6 , 12 , and 18 months of antiretroviral therapy ; time to the first viral load of 400 copies/mL or more ; time to confirmed virological failure ( 2 consecutive values > or = 5000 copies/mL ) ; time to death ; and time to treatment-limiting toxicity were assessed . RESULTS The analysis included 2035 individuals who started antiretroviral therapy with efavirenz ( 1074 with concurrent tuberculosis ) and 1935 with nevirapine ( 209 with concurrent tuberculosis ) . There were no differences in time to death or substitution of either antiretroviral drug for toxicity with and without concurrent tuberculosis . Patients starting nevirapine with concurrent tuberculosis were at a higher risk of elevated viral load most notably at 6 months ( 16.3 % ; 95 % confidence interval [ CI ] , 10.6%-23.5 % ) than those without tuberculosis ( 8.3 % ; 95 % CI , 6.7%-10.0 % ; adjusted odds ratio [ OR ] , 2.1 ; 95 % CI , 1.2 - 3.4 ; and in the combined estimate , adjusted OR , 1.7 ; 95 % CI , 1.2 - 2.6 ) . In the time-to-event analysis of confirmed virological failure ( 2 consecutive values of > or = 5000 copies/mL ) , patients starting nevirapine with concurrent tuberculosis developed virological failure sooner ( adjusted hazard ratio [ HR ] 2.2 ; 95 % CI , 1.3 - 3.7 ) . There were no differences between patients starting efavirenz with and without concurrent tuberculosis ( adjusted OR , 1.1 ; 95 % CI , 0.8 - 1.5 [ combined estimate ] and adjusted HR , 1.1 ; 95 % CI , 0.6 - 2.0 , respectively ) . There was no difference in time to virological rebound in patients free of tuberculosis and those developing tuberculosis during follow-up while taking nevirapine ( adjusted HR , 1.0 ; 95 % CI , 0.5 - 2.0 ) or efavirenz ( adjusted HR , 0.8 ; 95 % CI , 0.4 - 1.7 ) . CONCLUSION In this cohort study , virological outcomes were inferior when nevirapine-based antiretroviral therapy was commenced while taking antitubercular treatment ( vs without concurrent tuberculosis ) but comparable when starting efavirenz-based antiretroviral therapy ( vs without concurrent tuberculosis ) or when tuberculosis developed while taking established nevirapine- or efavirenz-based therapies 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 ) 
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However , drug-resistance patterns were largely similar to those in subtype B. Resistance profiles were associated with the antiretroviral drugs commonly used : the lamivudine-associated M184V mutation was most common , followed by K103N which is associated with non-nucleoside reverse transcriptase inhibitors .
Thymidine-analogue mutations and the K65R mutation were less common .
First-line antiretroviral therapy regimens used in sub-Saharan Africa are effective .
Profiles of drug resistance suggest that a second-line treatment regimen based on protease inhibitors , with a backbone of nucleoside reverse transcriptase inhibitors , is a reasonable option for patients with HIV in sub-Saharan Africa who experience first-line treatment failure