***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: An open r and omized trial was conducted in 142 hospitalized and out- patients with acute purulent exacerbation of chronic bronchitis to compare the clinical efficacy and tolerability of azithromycin  ( n = 69 ) and amoxicillin/clavulanic acid ( n = 73 ) . Azithromycin ( 500 mg ) was administered as a single dose for three days and amoxicillin/clavulanic acid ( amoxicillin 875 mg-clavulanic acid 125 mg ) was given b.i.d . for 8 days ( 8.16 + /- 1.18 ) . Before therapy and 24 - 48 hours after the end of treatment , sputum culture ( by positioning five orthodontal swabs at the opening of salivary gl and ducts after a washing of the oral cavity with sterile saline solution to avoid oral contamination ) , chest X-rays , arterial blood gas analysis , trials of respiratory functions and routine blood tests were performed . In the azithromycin group ( 69 patients ) the efficacy rate was 67.6 % ( 46 patients : 34 cured and 12 improved ) ; in 22 patients ( 32.4 % ) the treatment failed ; 1 patient was not evaluated because of no follow-up . The overall efficacy rate in the amoxicillin/clavulanic acid group ( 73 patients ) was 97.3 % ( 71 patients : 60 cured and 11 improved ) ; in 1 patient ( 1.4 % ) the treatment failed and 1 patient was a drop-out for side effects . All pathogens isolated before treatment were susceptible to the antibiotics administered . At the end of treatment microbiological efficacy was 67.1 % in the azithromycin group and 98.6 % in the amoxicillin/clavulanic acid group . The tolerability was judged good in both treatment groups . Side effects were observed in 1 patient treated with amoxicillin/clavulanic acid ( diarrhea ) , which imposed interruption of treatment , and in 2 patients from the azithromycin group ( gastralgia and biochemical laboratory tests : renal function ) . ( ABSTRACT TRUNCATED AT 250 WORDS BACKGROUND There are few investigations into the aetiology of  lower respiratory tract infections ( LRTIs ) in general practice . AIM To describe the aetiology of  LRTI among adult patients in general practice in The Netherl and s. DESIGN OF STUDY Prospect i ve observational study . SETTING General practice s in the Leiden region , The Netherl and s. METHOD Adult patients with a defined LRTI were included . St and ard medical history and physical examination were performed .  Sputum , blood and throat swabs  were collected for diagnostic tests . Aetiological diagnosis , categorised as definite or possible , was based on the results of bacterial and viral cultures , serological techniques , and on polymerase chain reaction . Proportions of pathogens causing LRTI were assessed in relation to chest X-ray findings . RESULTS A bacterial cause was established in 43 ( 30 % ) , and a viral cause in 57 ( 39 % ) of the 145 patients with a LRTI . Influenza virus A was the most frequently diagnosed microorganism , followed by Haemophilus influenzae , and Mycoplasma pneumoniae . Streptococcus pneumoniae was found in 6 % of the patients . CONCLUSIONS Pathogens were found in two-thirds of the patients . In half of these patients there was a viral cause . Influenza virus A was the most frequently found pathogen . The treatment with antibiotics of at least one-third of the patients with LRTI was superfluous . This observation should result in changes in the prescription of antibiotics in LRTI A 3-day regimen of azithromycin ( 500 mg once daily ) and a 10-day regimen of co-amoxiclav ( 625 mg three times daily ) were compared in a double-blind study of 67 patients with acute infectious exacerbations of chronic bronchitis ( AIECBs , n = 54 ) , acute bronchitis ( n = 7 ) , or pneumonia ( n = 6 ) . In patients treated with azithromycin , satisfactory clinical responses ( cure or improvement ) were seen in 24/28 ( 86 % ) patients with AIECBs , 2/4 ( 50 % ) with acute bronchitis and 2/2 ( 100 % ) with pneumonia . Responses were satisfactory in 24/26 ( 92 % ) , 4/4 ( 100 % ) and 4/4 ( 100 % ) patients , respectively , receiving co-amoxiclav . Streptococcus pneumoniae and Haemophilus influenzae were the commonest pathogens isolated at baseline . At the end of treatment , baseline pathogens were eradicated in 9/10 microbiologically-assessable patients treated with azithromycin and in 10/10 treated with co-amoxiclav .  Adverse events related or possibly related to treatment occurred in five patients in each treatment group ; the majority of these events affected the gastrointestinal system . One patient in each treatment group discontinued therapy because of adverse events . The study , therefore , demonstrates that 500 mg azithromycin administered once daily for 3 days is as efficacious and well tolerated as co-amoxiclav given three times daily for 10 days in the domiciliary treatment of adults with acute lower respiratory tract infections The efficacy and safety of a three-day regimen of azithromycin ( 500 mg od ) and a ten-day regimen of co-amoxiclav ( 625 mg tid ) were compared in a single-blind study in 99 patients with acute lower respiratory tract infections . Of these , 70 ( 71 % ) suffered an infective exacerbation of their chronic obstructive pulmonary disease . Nine patients had pneumonia and 19 purulent bronchitis . Treatment success , defined as cure or improvement , occurred in 43 of 48 ( 90 % ) patients in the azithromycin group , compared with 45 of 51 ( 88 % ) patients in the co-amoxiclav group . The most common isolated pathogens were Haemophilus influenzae ( 25 cases ; MIC range of azithromycin ( A ) < or = 0.06 - 4 mg/L ; for co-amoxiclav ( CA ) 0.25 - 4 mg/L ; Streptococcus pneumoniae ( 10 cases ; A : < or = 0.06- > 128 ; CA : < or = 0.06 ) ; and Moraxella catarrhalis ( four cases ; A : < or = 0.06 ; CA : < or = 0.06 - 0.25 ) . Microbiological response rates were comparable in the two groups . In 5 % of patients , serological evidence for virus or atypical pathogens was found . Thirteen ( 26 % ) patients treated with co-amoxiclav had gastrointestinal complaints ( seven with diarrhoea ) , compared with five ( 10 % ) treated with azithromycin ( P = 0.09 ) . Additional complaints occurred in three patients treated with co-amoxiclav and in one patient treated with azithromycin . It was concluded that a three-day regimen of azithromycin was as effective , clinical ly and microbiologically , as a ten-day regimen of co-amoxiclav in the treatment of acute lower respiratory tract infections In an open , multicentre study , the clinical and bacteriological efficacy , safety and tolerance of azithromycin and roxithromycin were compared in a total of 204 adults with acute lower respiratory tract infections ( LRTIs ) [ acute bronchitis , acute infectious exacerbations of chronic bronchitis ( AIECBs ) , or pneumonia ] . Following treatment with 500 mg/day azithromycin administered orally once daily for 3 days , a satisfactory clinical response of cure or improvement was recorded in 91/99 ( 91.9 % ) evaluable patients at the post-therapy evaluation ( day 10 - 14 ) . Of the 94 evaluable patients treated with roxithromycin ( 150 mg given orally twice daily for 10 days ) , 82 ( 87.2 % ) were classified as cured or improved at post-therapy . The main pathogens isolated before treatment were Staphylococcus aureus , Streptococcus pneumoniae , Streptococcus species , Haemophilus influenzae and Moraxella catarrhalis . In the 46 azithromycin-treated patients evaluated both clinical ly and bacteriologically , 92.0 % of pathogens were eradicated ; H. influenzae persisted in one azithromycin-treated patient with acute bronchitis who was classed as clinical ly improved . In the roxithromycin group , 81.1 % of the pathogens were eradicated in 35 patients ; S. aureus persisted in one clinical ly cured patient with acute bronchitis , and H. influenzae persisted in one patient with AIECB and one with pneumonia , and Haemophilus species in one with AIECB , who were all classified as clinical ly improved . Azithromycin was well tolerated with a lower incidence of adverse events than that recorded in the roxithromycin treatment group . Treatment was not discontinued due to adverse events in any of the azithromycin-treated patients , whereas two roxithromycin-treated patients were withdrawn from treatment due to vomiting and /or dyspepsia Forty-eight patients with acute bronchitis and four with pneumonia were r and omly assigned to receive five doses ( 500 mg on day 1 , plus 250 mg/day on days 2–5 ) of azithromycin ;  54 patients with acute bronchitis and four with pneumonia were assigned 30 doses ( 625 mg every eight hours for ten days ) of amoxicillin/clavulanic acid ( CA ) . The two regimens were equally effective , with clinical improvement or cure in 92 % and 87 % of patients respectively , bacteriological cure in 89 % and 86 % , with 91 % and 89 % of pathogens eliminated . Minor side effects occurred in 6 % and 12 % of patients in the two groups , respectively . No major abnormalities in laboratory safety parameters were seen in either group BACKGROUND : The purpose of this study was to assess the causes of community-acquired pneumonia in adult patients admitted to hospital . METHODS : A prospect i ve study was performed on 346 consecutive adult patients ( 54 % men ) of mean ( SD ) 49.3 ( 19.5 ) years ( range 17 - 94 ) admitted to a university affiliated regional hospital in southern Israel with community-acquired pneumonia over a period of one year . Convalescent serum sample s were obtained from 308 patients ( 89 % ) . The aetiological diagnosis for community-acquired pneumonia was based on positive blood cultures and /or significant changes in antibody titres to Streptococcus pneumoniae , Haemophilus influenzae , Moraxella catarrhalis , respiratory viruses , Coxiella burnetii , Mycoplasma pneumoniae , Chlamydia pneumoniae , and Legionella sp. RESULTS : The aetiology of community-acquired pneumonia was identified in 279 patients ( 80.6 % ) . The distribution of causal agents was as follows : S pneumoniae , 148 patients ( 42.8 % ) ; M pneumoniae , 101 ( 29.2 % ) ; C pneumoniae , 62 ( 17.9 % ) ; Legionella sp , 56 ( 16.2 % ) ; respiratory viruses , 35 ( 10.1 % ) ; C burnetii , 20 ( 5.8 % ) ; H influenzae 19 ( 5.5 % ) ; and other causes , 21 patients ( 6.0 % ) . In patients above the age of 55 years C pneumoniae was the second most frequent aetiological agent ( 25.5 % ) . In 133 patients ( 38.4 % ) more than one causal agent was found . CONCLUSIONS : The causal agents for community-acquired pneumonia in Israel are different from those described in other parts of the world . In many of the patients more than one causal agent was found . In all these patients treatment should include a macrolide antibiotic , at least in the first stage of their illness The efficacy and safety of a 3-day regimen of azithromycin prescribed in the new tablet form and of a 10-day regimen of amoxycillin clavulanic acid ( co-amoxiclav , Augmentin ) were compared in patients with acute lower respiratory tract infections . Of the 144 enrolled patients , 123 had a Type 1 acute exacerbation of chronic bronchitis ( AECB ) , three patients had pneumonia , and 18 had purulent bronchitis . Treatment was successful , defined as cure or major improvement on day 14 , in 59/62 ( 95 % ) patients in the azithromycin treatment group compared with 54/61 ( 90 % ) patients in the co-amoxiclav . At 30 days , the incidence of success was 77 % ( 
    Output:
    
REVIEW ERS ' CONCLUSIONS There is unclear evidence that azithromycin is superior to amoxicillin or amoxicillin-clavulanic acid in treating acute LRTI .