Clinical Microbiology and Infection, Volume 10, Supplement 3, 2004 87 Community-acquired infections: focus on unusual epidemics and update on S. pneumonia P430 Community-acquired pneumonia caused by ‘atypical’ Methods: Our institution covers a mainly rural area of approxi- pathogens: clinical discrimination with a predictive model and mately 160 000 adult population in the northwestern area of Spain. We retrospectively reviewed all invasive S. pneumoniae scoring system (blood, CSF) isolates recovered at our laboratory between 1998 M. Masia´, F. Gutie´rrez, J.C. Rodrı´guez, S. Padilla, G. Royo, and 2003, 3 years before and after the programme started, named J.M. Ramos, A. Ayelo, A. Martı´n-Hidalgo periods A and B respectively. Identification and susceptibility test- Elche, Alicante, E ing were performed following standard recommendations. Pneu- mococci were classified as susceptible, intermediate and resistant Objective: To develop a bedside predictive model and a scoring (S, I, R) according to 2001 definitions of NCCLS. Serotyping was system to identify patients with atypical community-acquired performed at a national reference laboratory. pneumonia (CAP), in order to select candidates for tailored antibi- Results: A total of 165 invasive pneumococci were recovered dur- otic therapy with macrolides. ing the whole period (period A, 1998–2000: 99 isolates; period B, Methods: Data from a prospective study of CAP conducted at a 2001–2003: 66). The rate of invasive disease dropped from an Spanish hospital during two consecutive periods, October 99–Sep- average of 20.6 cases per 100 000 persons in period A to an aver- tember 00, and October 00–September 01, were analysed. An age of 13.8 in period B (33% lower). A similar reduction was extensive non-invasive microbiological investigation was per- observed in those 65 years and older (49.2 per 100 000 vs. 37.8 per formed in all patients, including detection of Legionella pneumo- 100 000, 23.2% reduction). Penicillin susceptibility (S, I, R) in the phila and Streptococcus pneumoniae urinary antigen, and acute and two periods was: A: 73.4, 18.4, 8.2%, and B: 67.2, 31.2, 1.6% convalescent serologic testing. During the first 12-month study (P 0.05). Cefotaxime susceptibility was: A: 83.7, 13.3, 3%, and period, serum biochemical markers of bacterial infection [C-react- B: 85.9, 12.5, 1.6%. Erythromycin susceptibility was: A: 84.7, 1, ive protein, procalcitonin and lipopolysaccharide-binding protein 14.3%, and B: 68.7, 1.6, 29.7% (P 0.05). The most frequent sero- (LBP)] were also performed. Clinical, radiological and laboratory types were (per cent): period A: 4 (16.9), 3 (15.7), 8 (12), 14 (10.8); data of patients with atypical CAP were compared with data from and B: 3 (16.7), 14 (16.7), 19 (11.7), 6A (8.3). patients with non-atypical CAP by univariate and multivariable Conclusions: A significant reduction (33%) in the incidence of analysis. With the best-discriminating variables from the multivar- pneumococcal invasive disease was observed after the vaccination iable analysis, a scoring system model was devised. Each variable programme started. The slight increase in penicillin non-suscept- was assigned 1 point. ROC curves were used to describe sensitiv- ible strains (26.6% vs. 32.8%) was because of intermediate sus- ity and specificity of the model. Two separate models were run. ceptible ones, with a decrease in those highly resistant (8.2% vs. Results: A total of 493 patients were included. On multivariable 1.6%). Erythromycin resistance duplicated in the study period analysis, patients with atypical pneumonia were more likely to (14.3% vs. 29.7%). have air-conditioning exposure (OR 2.64), normal WBC count (OR 2.58), birds at home (OR 2.18), age under 65 years (OR 2.07), non- associated comorbid conditions (OR 2.04), absence of pleuritic chest pain (OR 1.95), and elevated GOT levels (OR 1.87). When the variables age was <65 years, normal WBC, birds at home, ele- vated transaminase levels, and a negative pneumococcal urinary antigen assay were included in the scoring system, a score of 4 P432 Effect of initial treatment on bacteraemic captured patients with atypical pneumonia with a sensitivity of Streptococcus pneumoniae pneumonia (BSPP) mortality 33% and a specificity of 95%. A second scoring system was con- structed with the 240 patients from the first 12-month study per- V. Pintado, R. Blazquez, E. Loza, J. Cobo, J. Fortun, E. Navas, iod. When the variables age <65 years, normal WBC count, birds C. Quereda, S. Moreno at home, LBP levels <14 mcg/mL and negative urinary antigen Madrid, E assay were included, a score of 4 captured patients with atypical pneumonia with a sensitivity of 49% and a specificity of 95%. Objectives: Community-acquired BSPP is associated with a high Conclusion: Selected patient factors and additional diagnostic test- mortality. Recent studies have suggested that monotherapy may ing can aid to discriminate atypical pneumonia with high specific- be sub-optimal for this infection. The aim of this study was to ity. This information could be useful to ensure effective and safe evaluate the effect of initial antimicrobial therapy on the outcome use of macrolides as empirical monotherapy in CAP. of BSPP. Methods: Retrospective study of adult cases (>18 years) of com- munity-acquired BSPP hospitalised at our institution from 1990 to 2003. Severity of pneumonia was assessed using PORT-score. The impact of penicillin susceptibility and initial empirical treatment (combined therapy vs. monotherapy) on the 30-day mortality were assessed by univariate and multivariate analyses. P431 Effects of a pneumococcal vaccination programme in Results: A total of 343 cases were evaluated. There were 220 adult invasive Streptococcus pneumoniae disease: a 3-year males (64%); the mean age was 56.9 years (range, 18–94). Most % experience patients had chronic predisposing conditions and 32 of them had HIV infection. Decreased susceptibility to penicillin F.J. Vasallo, A. Gonza´lez-Escalada, V. del Campo, S. Pe´rez, (MIC > 0.06 mg/L), cefotaxime (MIC > 0.5 mg/L), and erythro- J. Torres mycin (MIC > 1 mg/L) was observed in 34% (108/320), 10% Vigo, E (14/135), and 21% (61/292) of strains. Patients were empirically treated with a beta-lactam (50%), a beta-lactam plus macrolide Objectives: Streptococcus pneumoniae is a leading cause of serious (26%), or other regimens of monotherapy (10%) or combination infections. The prevention of pneumococcal disease has become therapy (14%). Overall mortality rate was 19%. Mortality was an important public health issue as a result of the rapid increase significantly associated (P < 0.001) with PORT groups: class in the prevalence of pneumococcal resistance to antibiotics. Our I ¼ 1/30 (3%), class II ¼ 5/59 (8%), class III ¼ 5/61 (8%), class aim was to evaluate the effect of a pneumococcal vaccination IV ¼ 25/123 (20%), class V ¼ 28/70 (40%). The mortality rate programme in elderly people (started in autumn, 1999) in was higher in patients with penicillin-resistant strains than in the incidence of invasive disease, and the changes observed in patients with susceptible strains (25% vs. 14%; P ¼ 0.03), but serotypes prevalence and antibiotic resistance during the study was similar in patients receiving monotherapy or combination period. therapy (16% vs. 22%; P ¼ 0.13). Multivariate analysis showed 88 Abstracts that the presence of septic shock and advanced age (>65 years) clinical and radiological parameters, for functional impairment, were the most important factors associated with mortality. and for life expectancy. From all patients valid sputum samples Conclusions: PORT score accurately identifies the mortality risk of were obtained at presentation. community-acquired BSPP. Decreased susceptibility to penicillin Results: A total of 193 patients with a history of COPD and an acute seems to be associated with a worse prognosis. Our study has not exacerbation were included. In 114 subjects, potentially pathogenic confirmed the beneficial impact of empirical combination therapy microbes were isolated, Pseudomonas aeruginosa in 12 cases (10.5%). for BSPP. In two patients, bronchiectasis was demonstrated by high-resolu- tion CT scan. Seven individuals infected with Pseudomonas aerugi- nosa died within 1–21 months after initial presentation. Between subjects who did or did not die, there were no significant differ- P433 Comparative, randomised, open, multicentre trial ences with respect to age, frequency of underlying diseases, smo- assessing the efficacy and safety of intravenous/oral king status, or treatment with systemic steroids. All individuals azithromycin compared with intravenous/oral clarithromycin for who succumbed had stage III disease (ATS classification: FEV1<35% predicted). On average, these had a worse lung function the treatment of community-acquired pneumonia due to (VC 49.1 Æ 9% vs. 78.8 Æ 18.9% predicted, FEV1 26 Æ 6.5% Legionella pneumophila vs.43.5 Æ 13.4% predicted, absolute FEV1 0.8 Æ 0.2L vs. 1.0 Æ 0.3L). Emphysema (5/0), a medical history with treatment in J. Roig, M. Sabria´, J. Alegre, M. Gurgui, J.C. Checa – Spanish an ITU (5/1), and with preceding mechanical ventilation (3/1) were Study Group for Legionella more frequent in subjects with a fatal outcome. Conclusion: Presence of Pseudomonas aeruginosa in individuals pre- Objective: To evaluate the efficacy and safety of intravenous (i.v.) senting with an acute exacerbation of COPD is associated with a /oral (p.o.) Azithromycin (AZM) compared with i.v./p.o. clarith- high fatality rate short-term outcome. Particularly severe underly- romycin (CLA) for the treatment of community-acquired pneu- ing airflow obstruction and a medical history of treatment in an monia (CAP) caused by Legionella pneumophila. ITS or mechanical ventilation is associated with an unfavourable Study design: Randomised, open-label, multicentre phase III clin- outcome.