Roberto Cosentini

Acute exacerbations of asthma in adults: role of Chlamydia pneumoniae infection

Respiratory infections precipitate wheezing in many asthmatic patients and may be involved in the aetiopathogenesis of asthma. Several studies have demonstrated that viral infections may provoke asthma. Bacterial infections seem to play a minor role. However, Chlamydia pneumoniae has been recently reported as a possible cause of asthma. The aim of the present study was to evaluate the role of C. pneumoniae infection in acute exacerbations of asthma in adults. Seventy four adult out-patients with a diagnosis of acute exacerbation of asthma were studied. Acute and convalescent (> or = 3 weeks) serological determination of antibodies to cytomegalovirus, respiratory syncytial virus, adenovirus, influenza A and B, parainfluenza 1 and 3, Mycoplasma pneumoniae and Legionella pneumophila were performed by means of immunofluorescence tests. C. pneumoniae specific antibodies were detected by two microimmunofluorescence tests using a specific antigen (TW-183) and a kit with three chlamydial antigens. Pharyngeal swab specimens were also obtained for C. pneumoniae identification. Samples for bacterial culture were obtained in patients with productive cough (15 out of 74 patients). Fifteen patients (20%) presented seroconversion to at least one of the studied pathogens. Seven were found to be infected by virus, six by C. pneumoniae alone, and one by M. pneumoniae. One more patient showed seroconversion to C. pneumoniae and cytomegalovirus.(ABSTRACT TRUNCATED AT 250 WORDS)

Stratifying Risk Factors for Multidrug-Resistant Pathogens in Hospitalized Patients Coming From the Community With Pneumonia

BACKGROUND  Not all risk factors for acquiring multidrug-resistant (MDR) organisms are equivalent in predicting pneumonia caused by resistant pathogens in the community. We evaluated risk factors for acquiring MDR bacteria in patients coming from the community who were hospitalized with pneumonia. Our evaluation was based on actual infection with a resistant pathogen and clinical outcome during hospitalization. METHODS  An observational, prospective study was conducted on consecutive patients coming from the community who were hospitalized with pneumonia. Data on admission and during hospitalization were collected. Logistic regression models were used to evaluate risk factors for acquiring MDR bacteria independently associated with the actual presence of a resistant pathogen and in-hospital mortality. RESULTS  Among the 935 patients enrolled in the study, 473 (51%) had at least 1 risk factor for acquiring MDR bacteria on admission. Of all risk factors, hospitalization in the preceding 90 days (odds ratio [OR], 4.87 95% confidence interval {CI}, 1.90-12.4]; P = .001) and residency in a nursing home (OR, 3.55 [95% CI, 1.12-11.24]; P = .031) were independent predictors for an actual infection with a resistant pathogen. A score able to predict pneumonia caused by a resistant pathogen was computed, including comorbidities and risk factors for MDR. Hospitalization in the preceding 90 days and residency in a nursing home were also independent predictors for in-hospital mortality. CONCLUSIONS  Risk factors for acquiring MDR bacteria should be weighted differently, and a probabilistic approach to identifying resistant pathogens among patients coming from the community with pneumonia should be embraced.

Chlamydia pneumoniae and chronic bronchitis: association with severity and bacterial clearance following treatment

Background: A study was undertaken to evaluate Chlamydia pneumoniae chronic infection, other respiratory infections, and functional impairment in patients with chronic bronchitis (stage 1) and to examine chronic C pneumoniae infection, rate of acute exacerbations of chronic bronchitis, and rate of C pneumoniae eradication following antibiotic treatment (stage 2). Methods: In the stage 1 study respiratory specimens from 42 patients with steady state chronic bronchitis were analysed for Gram staining, sputum culture, and C pneumoniae DNA detection by nested touchdown polymerase chain reaction (PCR). On the basis of the results of stage 1, a second population of 141 consecutive patients with steady state mild to moderate chronic bronchitis (FEV1 ≥50% predicted) was studied. On admission, at regular intervals, and at exacerbation all patients underwent serological testing for C pneumoniae (microimmunofluorescence) and a nested touchdown PCR to detect C pneumoniae DNA was performed on peripheral blood mononuclear cells (PBMCs). Patients were assessed over a 12 month period. Information regarding the previous 12 months was taken from medical records. Results: Chronic colonisation of the sputum with C pneumoniae was significantly associated with lower FEV1 and greater airway bacterial colonisation. On admission to the stage 2 study, 80 patients were PCR negative and 61 were PCR positive. Over the 2 years a mean (SD) of 1.43 (1.32) acute exacerbations occurred in PCR negative patients and 2.03 (1.21) in PCR positive patients (p<0.01). During the 12 month follow up period 34 PCR positive patients had acute exacerbations and were treated with azithromycin for 6 weeks. Serological evidence of acute C pneumoniae reinfection/reactivation was found in two of the 34 patients. The rate of C pneumoniae DNA clearance from blood following treatment was 29% at follow up. Conclusion: Chronic colonisation with C pneumoniae is associated with a higher rate of exacerbations of chronic bronchitis. Long term treatment is required to obtain clearance of the organism from the blood.

Chlamydia pneumoniae DNA Detection in Peripheral Blood Mononuclear Cells Is Predictive of Vascular Infection

Abdominal aortic aneurysm tissue and peripheral blood mononuclear cells (PBMC) of 41 consecutive subjects undergoing abdominal aortic aneurysm surgery were analyzed by polymerase chain reaction (PCR) for the presence of Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori DNA. Twenty patients (49%) were positive for C. pneumoniae DNA-16 (39%) in both PBMC and aneurysm tissue, 3 (7.3%) in PBMC only, and 1 (2.4%) in the artery specimen only. Previous exposure to C. pneumoniae was confirmed in 19 (95%) of the 20 PCR positive subjects by C. pneumoniae-specific serology, using the microimmunofluorescence test. None was positive for H. pylori or M. pneumoniae DNA, either in the PBMC or in the artery specimens. In conclusion, carriage of C. pneumoniae DNA is common both in PBMC and in abdominal aortic tissue from patients undergoing abdominal aneurysm surgery. Blood PCR may be a useful tool for identifying subjects carrying C. pneumoniae in the vascular wall.

Multidrug-resistant pathogens in hospitalised patients coming from the community with pneumonia: a European perspective

Background Probabilistic scores have been recently suggested to identify pneumonia caused by multidrug-resistant (MDR) bacteria. The aim of the study was to validate both Aliberti and Shorr scores in predicting MDR pneumonia, comparing them with healthcare associated pneumonia (HCAP) classification. Methods Two independent European cohorts of consecutive patients hospitalised with pneumonia were prospectively evaluated in Barcelona, Spain (BC) and Edinburgh, UK (EC). Data on admission and during hospitalisation were collected. The predictive value of the three scores was explored for correctly indicating the presence of MDR pneumonia via a receiver-operating characteristic (ROC) curve. Results A total of 1591 patients in the BC and 1883 patients in the EC were enrolled. The prevalence of patients with MDR pathogen among those with isolated bacteria was 7.6% in the BC and 3.3% in the EC. The most common MDR pathogen found in both cohorts was MRSA, followed by MDR P aeruginosa. A significantly higher prevalence of MDR bacteria was found among patients in the intensive care unit (ICU). The two probabilistic scores, and particularly the Aliberti one, showed an area under the ROC curve higher than the HCAP classification in predicting MDR pneumonia, especially in the ICU. Conclusions Risk scores able to identify MDR pneumonia could help in developing strategies for antimicrobial stewardship.

Severe asthma exacerbation: role of acute Chlamydophila pneumoniae and Mycoplasma pneumoniae infection

BackgroundChlamydophila pneumoniae and Mycoplasma pneumoniae are associated with acute exacerbation of bronchial asthma (AEBA). The aim of this study was to evaluate the correlation between these acute bacterial infections and the severity of AEBA.MethodsWe prospectively analysed consecutive patients admitted to the Emergency Department with acute asthma exacerbation. In every patient peak expiratory flow (PEF) measurement was performed on admission, and spirometry during follow-up. Serology for Chlamydophila and Mycoplasma pneumoniae was performed on admission and after 4–8 weeks.ResultsFifty-eight patients completed the study. Acute atypical infections (AAI) was observed in 22/58 cases; we found single acute C. pneumoniae in 19 cases, single acute M. pneumoniae in 2 cases, and double acute infection in one case. Functional impairment on admission was greater in patients with AAI than in patients without AAI (PEF 205 ± 104 L/min vs 276 ± 117 p = 0.02) and persisted until visit 2 (FEV1% 76.30 ± 24.54 vs FEV1% 92.91 ± 13.89, p = 0.002). Moreover, the proportion of patients who presented with severe AEBA was significantly greater in the group with AAI than in the group without AAI (15/22 vs 12/36, p = 0.01; OR 4.29, 95% CI 1.38–13.32).ConclusionOur data suggest an association between acute atypical infection and a more severe AEBA.

Helmet Continuous Positive Airway Pressure vs Oxygen Therapy To Improve Oxygenation in Community-Acquired Pneumonia A Randomized, Controlled Trial

OBJECTIVE Our objective was to evaluate the efficacy of noninvasive continuous positive airway pressure (CPAP) delivered by helmet in improving oxygenation in comparison with oxygen therapy in community-acquired pneumonia (CAP). METHODS This was a multicenter, randomized, controlled trial enrolling patients with CAP admitted to an ED with moderate hypoxemic acute respiratory failure (ARF) (Pa(O(2))/Fi(O(2)) ratio > or = 210 and < or = 285). Patients were randomized to helmet CPAP or standard oxygen therapy (control group). The primary end point was the time to reach a Pa(O(2))/Fi(O(2)) ratio > 315. After reaching this value, patients randomized to CPAP were switched to oxygen, and the proportion of subjects who could maintain a Pa(O(2))/Fi(O(2)) ratio > 315 at 1 h was recorded. RESULTS Forty-seven patients were recruited: 20 randomized to CPAP and 27 to controls. Patients randomized to CPAP reached the end point in a median of 1.5 h, whereas controls reached the end point in 48 h (P < .001). The proportion of patients who reached the primary end point was 95% (19/20) among the CPAP group and 30% (8/27) among controls (P < .001). One hour after reaching the primary end point, 2/14 patients in the CPAP group maintained a Pa(O(2))/Fi(O(2)) value > 315. CONCLUSIONS CPAP delivered by helmet rapidly improves oxygenation in patients with CAP suffering from a moderate hypoxemic ARF. This trial represents a proof-of-concept evaluation of the potential usefulness of CPAP in patients with CAP.

Severe community-acquired pneumonia: A possible role for Chlamydia pneumoniae

Between July 1992 and June 1993, 61 patients with severe community-acquired pneumonia were admitted to our semi-intensive care unit. For all patients chest X-ray, blood gas analysis while breathing room air, Gram stain and culture of bronchoaspirate, determination of acute and convalescent anti-body titers for Legionella pneumophila, Mycoplasma pneumoniae and Chlamydia pneumoniae, blood culture when body temperature was greater than 38 degrees C, and pharyngeal swab for C. pneumoniae detection by means of an indirect immunofluorescence test were obtained. Among the patients enrolled, 15 suffered from chronic obstructive pulmonary disease, 18 had serious chronic diseases, 9 were immunodeficient and 15 had cardiovascular diseases, and only 4 had no underlying disease. Etiologic diagnosis was reached in 30 cases (49%). As expected, due to the high rate of seriously ill patients, gram-negative pathogens were identified most commonly (15%), followed by Streptococcus pneumoniae (10%) and, surprisingly, by C. pneumoniae (10%). These data, showing the possible emergence of Pseudomonas aeruginosa and C. pneumoniae, warrant further studies in order to verify whether the epidemiological pattern of severe community-acquired pneumonia is actually changing.

Incidence of community-acquired pneumonia caused by Chlamydia pneumoniae in Italian patients.

The incidence ofChlamydia pneumoniae as a cause of community-acquired pneumonia was evaluated in a one-year prospective study in 108 patients with community-acquired pneumonia. The bacteriological diagnosis was based on culture of sputum or bronchial aspirate and examination of acute and convalescent phase sera forMycoplasma pneumoniae, Legionella pneumophila andChlamydia pneumoniae. A definitive microbiological diagnosis was obtained in 58 (54 %) patients.Chlamydia pneumoniae was the causative agent in 14 patients (13 %) on the basis of positive serological tests; in 10 of the 14 patientsChlamydia pneumoniae was also detected by means of an indirect immunofluorescence test using pharyngeal swab specimens. In conclusion,Chlamydia pneumoniae seems to be a common etiological agent of community-acquired pneumonia, as increasingly reported in the last six to seven years.

Predicting mortality in hospitalized patients with 2009 H1N1 influenza pneumonia.

BACKGROUND Community-acquired pneumonia (CAP) severity scores can identify patients at low risk for mortality who may be suitable for ambulatory care. Here, we follow the clinical course of hospitalized patients with CAP due to 2009 H1N1 influenza. OBJECTIVE To evaluate the role of CAP severity scores as predictors of mortality. METHODS This was a secondary data analysis of patients hospitalized with CAP due to 2009 H1N1 influenza confirmed by reverse transcriptase polymerase chain reaction enrolled in the CAPO (Community-Acquired Pneumonia Organization) international cohort study. CAP severity scores PSI (Pneumonia Severity Index), CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥ 65 years) and CRB-65 (confusion, respiratory rate, blood pressure, age ≥ 65 years) were calculated. Actual and predicted mortality rates were compared. A total of 37 predictor variables were evaluated to define those associated with mortality. RESULTS Data from 250 patients with CAP due to 2009 H1N1 influenza were analyzed. Patients with low predicted mortality rates (0-1.5%) had actual mortality rates ranging from 2.6% to 17.5%. Obesity and wheezing were the only novel variables associated with mortality. CONCLUSIONS The decision to hospitalize a patient with CAP due to 2009 H1N1 influenza should not be based on current CAP severity scores, as they underestimate mortality rates in a significant number of patients. Patients with obesity or wheezing should be considered at an increased risk for mortality.