***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 
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    Input: A controlled clinical trial of three short-course chemotherapy regimens was undertaken in patients with newly diagnosed bacteriologically positive pulmonary tuberculosis . The patients were r and omly allocated to receive one of three regimens : rifampicin , streptomycin , isoniazid and pyrazinamide daily for 2 months , followed by streptomycin , isoniazid and pyrazinamide twice weekly for 3 months ( R/5 ) or for 5 months ( R/7 ) , or the same regimen as R/7 but without rifampicin ( Z/7 ) . A bacteriological relapse requiring retreatment occurred by 5 years in 7.1 % of 126 R/5 , 4.0 % of 124 R/7 and 6.7 % of 253 Z/7 patients with organisms initially sensitive to streptomycin and isoniazid ; none of these differences is statistically significant . Of the 31 relapses , 16 occurred within 2 years of the completion of chemotherapy and the remaining 15 between 2 and 5 years . Among 65 patients with initial drug resistance to streptomycin or isoniazid or both , there were six bacteriological relapses requiring retreatment In a study in Hong Kong 1,386 Chinese patients with sputum smear-positive pulmonary tuberculosis were allocated at r and om to four 6-month regimens of chemotherapy , all given three times weekly from the start and all containing isoniazid ( H ) and rifampin ( R ) throughout . Three contained streptomycin ( S ) for the first 4 months and pyrazinamide ( Z ) for 2 months ( Z2 ) , 4 months ( Z4 ) , or 6 months ( Z6 ) ; the fourth contained pyrazinamide for 6 months but no streptomycin ( Z6noS ) . Every dose of all four regimens was given under the direct supervision of clinic staff on a predominantly outpatient basis . During the later part of the intake patients were allocated at r and om to be given their HRZ either as a combined formulation ( Rifater ) , each tablet containing 125 mg isoniazid , 100 mg rifampin , and 375 mg pyrazinamide , or as the three drugs separately . Among 892 assessable patients with drug-susceptible strains of tubercle bacilli pretreatment , bacteriologic failure during chemotherapy occurred in 4 , all Z6noS ( 2 % of 224 ; p less than 0.005 for the comparison with the S-containing regimens ) . During 30 months of follow-up after the end of chemotherapy , bacteriologic relapse occurred in 2 ( 3 % ) of 71 Z2 , 2 ( 3 % ) of 72 Z4 , 4 ( 6 % ) of 66 Z6 , and 6 ( 9 % ) of 64 Z6noS patients allocated to Rifater , and in 4 ( 3 % ) of 149 Z2 , 8 ( 6 % ) of 133 Z4 , 2 ( 1 % ) of 142 Z6 , and 6 ( 4 % ) of 135 Z6noS patients allocated to separate drugs . In the relapse rates there were no significant differences between the Rifater and separate drug regimens , the different duration s of pyrazinamide , or the regimens with and without streptomycin . ( ABSTRACT TRUNCATED AT 250 WORDS In an area where default from out-patient treatment for tuberculosis is very frequent and leads to 16 % known failures on the 2SHT/16HT regimen , a 1-year follow-up study was carried out on 201 new sputum smear-positive patients who were hospitalised for the first 2 months of treatment . The first 103 patients were treated with 2SHT/10HT and the remaining 98 with 2SHRZ/10HT . In the first group 15 ( 17 % ) out of 89 traced patients were sputum-positive on a single smear after 1 year , compared with 1 ( 1 % ) out of 78 in the second group ( P less than 0.001 ) In a study in Singapore 310 patients with sputum smear-positive pulmonary tuberculosis were allocated at r and om to daily chemotherapy with streptomycin , isoniazid , rifampin , and pyrazinamide ( 1 ) for 2 months ( 2SHRZ ) , ( 2 ) for 1 month ( 1SHRZ ) , or ( 3 ) for 2 months without streptomycin ( 2HRZ ) . This was followed for all patients by three times weekly isoniazid and rifampin to a total duration of 6 months . During the initial period of daily chemotherapy the patients were also allocated at r and om to be given their HRZ either as a combined formulation ( Rifater ) , each tablet containing 50 mg isoniazid , 120 mg rifampin , and 300 mg pyrazinamide , or as three separate drugs . During the Rifater versus separate drugs comparison the most common spontaneous complaints were of nausea and vomiting , reported by 8 % of 155 patients receiving Rifater and 7 % of 155 separate drugs . Other adverse effects were also reported in similar proportions in the two series . Among 271 patients with drug-susceptible strains of tubercle bacilli pretreatment there were no bacteriologic failures during chemotherapy . During 18 months of subsequent follow-up bacteriologic relapse occurred in 3 ( 7 % ) of 46 2SHRZ , 2 ( 5 % ) of 42 1SHRZ , and 3 ( 8 % ) of 40 2HRZ patients allocated to Rifater and in 0 of 47 2SHRZ , 1 ( 2 % ) of 46 1SHRZ , and 1 ( 2 % ) of 44 2HRZ patients allocated to separate drugs . There was no evidence of therapeutic benefit from continuing SHRZ administration beyond 1 month or from adding streptomycin to HRZ . The relapse rates were slightly higher in the Rifater series ( p = 0.04 ) . Further follow-up and results from other studies are therefore needed fully to assess the combined preparation This study examined whether adding levofloxacin to a st and ard four-drug regimen improved the 8-week culture response and compared effectiveness of 9 versus 6 months of intermittent therapy for human immunodeficiency virus-related pansusceptible pulmonary tuberculosis . Patients were r and omized to receive either four or five drugs , the fifth being levofloxacin . Patients who completed induction therapy were r and omized to complete 9 versus 6 months of intermittent therapy with isoniazid and rifampin . In the r and omized induction phase , 97.3 % of patients in the four-drug group and 95.8 % in the five-drug group had sputum culture conversion at 8 weeks ( P = 1.00 ) . In the continuation phase , one patient ( 2 % ) assigned to 9 months and two patients ( 3.9 % ) assigned to 6 months of therapy had treatment failure/relapse ( P = 1.00 ) . In conclusion , this study showed that levofloxacin added no benefit to a highly effective , largely intermittent , four-drug induction regimen . Both 9 and 6 months of intermittent therapy were associated with low treatment failure/relapse rates A rigimen of rifampicin plus isoniazid , supplemented in the first two months by ethambutol or streptomycin , was given for six , nine , twelve , or eighteen months in a controlled study of 696 patients with culture-positive pulmonary tuberculosis . The results obtained in the thirty-three months since the start of treatment when all the patients in the six-month and nine-month groups had completed at least two years and those in the twelve-month group had completed twenty-one months of post-chemotherapy follow-up revealed no relapses among patients receiving nine months chemotherapy and a 1 % relapse-rate in the twelve-month group . The same regimen given for only six months result ed in a relapse-rate of 5 % during the subsequent twenty-seven months . There were adverse effects with streptomycin but not with ethambutol . It is concluded that treatment with rifampicin plus isoniazid for nine months , supplemented by ethambutol in a dose of 25 mg/kg for the first two months , is now acceptable as st and ard chemotherapy for pulmonary tuberculosis in Britain Five 6-month antituberculosis regimens , allocated at r and om to patients with acid-fast bacilli in their sputum on microscopy , were studied . Four , given three times a week from the start , contained isoniazid and rifampicin together with ( 1 ) streptomycin , pyrazinamide , and ethambutol , ( 2 ) streptomycin and pyrazinamide , ( 3 ) streptomycin and ethambutol , or ( 4 ) pyrazinamide and ethambutol . The fifth was daily isoniazid , rifampicin , pyrazinamide , and ethambutol .  All 833 patients with drug-sensitive strains of bacilli before treatment had a  favourable bacteriological response during chemotherapy , and the bacteriological relapse rates during 12 months after stopping chemotherapy were 2 % or less for all regimens except thrice-weekly isoniazid , rifampicin , streptomycin , and ethambutol ( the only regimen without pyrazinamide ) , which had a relapse rate of 8 % . The results were equally good for the 138 patients with bacilli resistant to isoniazid , streptomycin , or both drugs initially . The incidence of potentially serious toxicity was low . The daily regimen is relevant to programmes in which patients self-administer their drugs , and the 3 pyrazinamide-containing intermittent regimens are relevant to fully supervised outpatient programmes A controlled study of three short-course regimens was undertaken in South Indian patients with newly diagnosed , sputum-positive pulmonary tuberculosis . The patients were allocated at r and om to one of three regimens : a ) Rifampicin , streptomycin , isoniazid and pyrazinamide daily for 3 months ( R3 ) ; b ) the same regimen as above but followed by streptomycin , isoniazid and pyrazinamide twice-weekly for a further period of 2 months ( R5 ) ; c ) the same as R5 but without rifampicin ( Z5 ) . A bacteriological relapse requiring treatment occurred by 5 years in 16.8 % of 113 R3 , 5.2 % of 97 R5 , and 20.0 % of 115 Z5 patients with organisms sensitive to streptomycin and isoniazid initially . The differences in the relapse rates between the R3 and R5 regimens and the R5 and Z5 regimens were statistically significant ( p less than 0.01 for both ) . Considering patients with organisms initially resistant to streptomycin or isoniazid or both , 7 of 52 patients ( 4 R3 , 2 R5 , 1 Z5 ) had a bacteriological relapse requiring retreatment OBJECTIVES To determine rates of drug resistance to Mycobacterium tuberculosis and associated risk factors , including HIV infection . DESIGN Prospect i ve cohort study of patients with pulmonary tuberculosis . SETTING The study population comprised 28,522 men working on four goldmines in Westonaria , Gauteng . Health care is provided at a 240-bed mine hospital , Gold Fields West Hospital , and its primary health care facilities . SUBJECTS All 425 patients with culture-positive pulmonary tuberculosis identified in 1995 . OUTCOME MEASURES Tuberculosis drug resistance on enrollment and after 6 months ' treatment . RESULTS There were 292 cases of new tuberculosis , 77 of recurrent disease and 56 prevalent cases in treatment failure . Two hundred and seven patients ( 48.7 % ) were HIV infected .  Primary resistance to one or more drugs ( 9 % ) was similar to the 11 % found in a previous study done on goldminers in 1989 . Primary multidrug resistance ( 0.3 % ) was also similar ( 0.8 % ) . Acquired multidrug resistance was 18.1 % : 6.5 % for recurrent disease and 33.9 % in treatment failure cases . Neither HIV infection nor the degree of immunosuppression as assessed by CD4 + lymphocyte counts was associated with drug resistance at the start or end of treatment . New patterns of drug resistance were present in 9 of 52 patients in treatment failure at 6 months , 1 of whom was HIV-infected . CONCLUSION Primary and acquired drug resistance rates are stable in this population and are not affected by the high prevalence of HIV infection We report on the first trial in the Republic of Irel and to look at chemotherapy for TB . This management trial , carried out in single unit , which treats a third of all TB cases in the Republic of Irel and compared to effectiveness of a three drug/nine month regimen ( Rifampicin ( R ) , Isoniazed ( R ) , supplemented with Ethambutol ( E ) for the first two months = RHE9 ) with a four drug six months regimen ( R , H supplemented with E and Pyrazinamide ( Z ) for the first two months = RHEZ6 ) . Two hundred and eighty eight patients ( 288 ) were entered into the study . A total of 143 , ( 76 were in the RHE9 group and 67 in the RHEZ6 group ) completed the trial as planned . At the end of the third month 
    Output:
    
In a systematic review of r and omized controlled trials on tuberculosis treatment , Dick Menzies and colleagues find shorter courses of rifampin to be associated with poorer treatment outcomes