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Objectives: To analyse the usefulness and performance of several biomarkers [C-reactive protein (CRP), mid-regional pro-adrenomedullin (MR-proADM), procalcitonin (PCT)] and lactate in predicting short- and medium-term mortality compared with the prognostic severity scales (PSS) usually employed for community-acquired pneumonia (CAP) and in assessing the aetiological suspicion of infection by Streptococcus pneumoniae and bacteraemia., Methods: Observational, prospective and analytical study was conducted on patients who were diagnosed with CAP in our emergency department (ED). The data collected included socio-demographic and comorbidity variables, Charlson index, priority level according to the Spanish Triage System (STS), stage in the Pneumonia Severity Index (PSI) and in the CURB-65 (confusion, urea, respiratory rate, blood pressure and age ≥65years), criteria of severe CAP, microbiological studies, and biomarkers determinations. The patients were followed-up for 180days to calculate the prognostic power and the diagnostic performance for bacteraemia and aetiology., Results: A total of 127patients were finally enrolled in the study. The 30-day mortality was 10.3% (13), and 22.6% (28) at 180 days. Blood cultures were positive in 29 patients (23%) and S.pneumoniae was identified as the responsible pathogen in 28 cases (22.2%). The area under the ROC curve (AUC-ROC) for lactate and MR-proADM to predict 30-day mortality was 0.898 (95%CI: 0.824-0.973; P<.0001) and 0.892 (95%CI: 0.811-0.974; P<.0001), respectively, and for MR-proADM at 180 days it was 0.921 (95%CI: 0.874-0.968; P<.0001). The AUC-ROC for PCT to predict bacteraemia was 0.952 (95%CI: 0.898-1.000; P<.0001) and, considering a cut-off value ≥0.95ng/ml, the negative predictive value (NPV) and the likelihood ratio (LR+) were 97.8% and 9.03, respectively. Using a PCT cut-off value >0.85ng/ml, the NPV and the LR+ were 96.6% and 5.89%, respectively, to predict a S.pneumoniae infection., Conclusions: MR-proADM and lactate showed a similar or even better performance for 30-day intra-hospital mortality than PSI, CURB-65, STS and CAP severity criteria in patients diagnosed with CAP (P>.05). Furthermore, the MR-proADM capacity to predict 180-day mortality was higher than PSS and the rest of biomarkers (P>.05), and its AUC-ROC increased if it was used in combination with PSI, CURB65 and STS. The determination of PCT has a remarkable diagnostic performance to rule out bacteraemia and to orientate the aetiology towards a S.pneumoniae infection., (Copyright © 2012 Elsevier España, S.L. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

The hospital acquired pneumonia (HAP) is one of the most common infections acquired among hospitalised patients. Within the HAP, the ventilator-associated pneumonia (VAP) is the most common nosocomial infection complication among patients with acute respiratory failure. The VAP and HAP are associated with increased mortality and increased hospital costs. The rise in HAP due to antibiotic-resistant bacteria also causes an increase in the incidence of inappropriate empirical antibiotic therapy, with an associated increased risk of hospital mortality. It is very important to know the most common organisms responsible for these infections in each hospital and each Intensive Care Unit, as well as their antimicrobial susceptibility patterns, in order to reduce the incidence of inappropriate antibiotic therapy and improve the prognosis of patients. Additionally, clinical strategies aimed at the prevention of HAP and VAP should be employed in hospital settings caring for patients at risk for these infections., (Copyright © 2013 Elsevier España, S.L. All rights reserved.)

Microbiological diagnosis of bacterial lower respiratory tract infections has relevant limitations and related controversy, depending on the clinical setting and diagnostic methods used, and its value is contingent on an accurate clinical diagnosis and previous antimicrobial therapy. The limitations reside in a low diagnostic yield of the causative agent and the difficulty of determining the clinical significance of the agents recovered. This report examines the current microbiological diagnostic yield of the main clinical entities and etiological agents, indications for invasive or non-invasive specimen collection procedures, and proper specimen processing and culture in the appropriate media. Criteria regarding specimen suitability and indications for quantitative cultures are established. Criteria for evaluating the results are provided, and the current fast diagnostic techniques are described.

Objective: The aim of this study was to describe an outbreak of Q fever pneumonia in the North of Spain., Material and Methods: We report 60 cases of Coxiella burnetii pneumonia in a rural area with 16,000 inhabitants during January and February 2003. The diagnosis was serologically confirmed by indirect immunofluorescence., Results: Mean age of the patients was 46 years and the male/female ratio was 2.5. Overall, 52% of the patients lived in urbanized areas and contact with animals was declared in only 7% of patients. Sixty percent of patients were hospitalized. The most frequent clinical presentation was an acute febrile process (100%) and headache (80%); respiratory symptoms were infrequent. The most common liver function alteration was elevated transaminase levels (35%). Radiologic evidence of a single lobar or segmental alveolar opacity was found in 87% of patients, and most commonly affected the lower lobes. Chest radiographs returned to normal in 70% of patients within the two first months. Empirical treatment consisted of beta-lactams and macrolides in 38%, macrolides alone in 8%, and quinolones in 23%; 27% were treated with beta-lactams alone. No deaths occurred., Conclusions: Coxiella burnetii infection is very prevalent in the north of Spain and should be suspected and investigated when outbreaks of a pneumonic illness occur.

Acinetobacter baumannii is a significant cause of nosocomial pneumonia, especially late ventilator-associated pneumonia. In Spain, A. baumannii is the third leading pathogen after Pseudomonas aeruginosa and Staphylococcus aureus. Risk factors for pneumonia due to A. baumannii are head injury, neurosurgery, acute respiratory distress syndrome, aspiration, and previous antibiotic therapy. Definitive diagnosis requires respiratory samples and invasive techniques with quantitative cultures to differentiate true infections from simple colonizations. The crude mortality of patients with ventilator-associated A. baumannii pneumonia is high, although the attributable mortality is controversial. Adequate empirical antimicrobial therapy of A. baumannii pneumonia is a protective factor, even though the therapeutic options are often limited. The treatment of choice is imipenem and sulbactam may be considered an acceptable alternative. Nowadays, colistin is the treatment of choice in A. baumannii pneumonia caused by panresistant strains. The associations of imipenem and rifampin or imipenem and sulbactam may be acceptable alternatives to colistin in infections caused by these strains. Surveillance measures are essential to eradicate this multidrug-resistant pathogen in outbreaks and reduce the number of episodes in endemic situations. Although these measures are important throughout the hospital, intensive care units are especially high-risk areas.

The etiologic diagnosis of ventilator-associated pneumonia (VAP) should be considered as a microbiological emergency due to its impact on morbidity and mortality. Sampling of the lower respiratory tract (LRT) must be performed before starting or modifying antimicrobial therapy. Surveillance cultures in patients without criteria of VAP are not recommended. There is no evidence of any superiority of bronchoscopic over non-bronchoscopic sampling procedures, but quantitative bacterial cultures are essential to allow colonization to be differentiated from true infection of the LRT. Under these conditions, negative cultures practically rule out bacterial infection or, at least, identify patients who will not benefit from antibiotic therapy or who will require a very short course of treatment. Given that identification and antimicrobial susceptibility testing of microorganisms usually takes up to 3 or 4 days, rapid procedures that provide the clinician with useful information are essential. Rapid information, even if partial or less than perfect, is clearly better for the patient than a perfect but delayed report. Gram stain of LRT secretions is an immediate procedure that can guide management and it has a reasonable correlation with culture results. At present, new antibiogram procedures, performed on direct clinical samples, allow presumptive identification and information on susceptibility to commonly used antibiotics in less than 24 hours after sampling. The impact of using this procedure in clinical practice is currently under research.

Ventilator-associated pneumonia (VAP) is the most frequent infection in the intensive care unit. The importance of this entity lies not only in its high incidence but also in the significant mortality it produces. Therefore, a new episode of VAP should be clinically suspected when new or persistent radiological opacity, purulent respiratory secretions and other signs of sepsis (fever and leukocytosis) are present. In these patients, at the very least, tracheal aspirate samples with quantitative culture and direct staining should be immediately obtained, followed by prompt initiation of empirical broad-spectrum antibiotic therapy. The choice of initial antibiotic therapy should be patient-based, taking into account the risk factors associated especially with VAP caused by Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus, because of the high associated mortality. To evaluate resolution of VAP, we analyze various clinical variables (based mainly on resolution of fever and hypoxemia) and microbiologic information. Once the microorganism responsible for VAP has been isolated, antibiotic therapy can be adapted, based on de-escalation, to reduce the emergence of resistant bacteria. Recent studies suggest that shorter antibiotic regimens reduce the emergence of antibiotic-resistant pathogens, cost and adverse events.

Background: Injury and infection are characterized by the activation of the acute phase proteins response. C-reactive protein (CRP), an acute phase protein, has been mentioned as an useful indicator of infection and sepsis in critically ill patients., Objective: To study the evolution of serum CRP in patients with severe blunt trauma and to ascertain its ability as a biological marker of infection during the first seven days after injury., Methods: We prospectively studied 54 patients with blunt trauma (injury severity score>=16) age>14 years and length of the Intensive Care Unit (ICU) estay>= 7 days, over a 4-month period. Culture-proven infections were collected and serum CRP was determinated every day, during the first week after ICU admission., Results: Twenty-eight patients (51.8%) developed an infection during the first week, and the median day of diagnosis of infection was day 6. Pneumonia was the most common infection (50%) and Gram-negative bacilli (63.3%) were the most common microorganisms recovered. Serum CRP levels were significantly higher in the infected patients group after day 4, showing a median value higher than 170 mg/l. Based on the receiver operating characteristic (ROC) curve analysis, a cutoff value of 109.5 mg/l for CRP gives a sensitivity of 78.6% and a specifity of 73.1% in predicting the presence of infection., Conclusions: The course of serum CRP levels is different in the group of patients with severe blunt trauma and infection, compared with the non-infected group during the first week after injury and it could be an useful supplementary marker for infection after postinjury day 4. A value of 110 mg/l or higher for CRP should suggest an underlying infectious complication.

People infected with human immunodeficiency virus (HIV) are at increased risk for bacterial infections due to HIV-associated immunologic defects. Bacterial infections were found to be, both a predictor of progression to AIDS and a substantial cause of mortality in pre-AIDS stages. Most bacterial infections are caused by Streptococcus pneumoniae, Haemophilus influenzae, Salmonella spp. and Pseudomonas aeruginosa. Rhodococcus equi, Nocardia spp., Campylobacter spp. and Bartonella spp. are less common. Data derived from two AIDS Clinical Trials Group studies showed that the most common bacterial infections were sinusitis (8.5 per 100 episodes per person years [py]), bacterial pneumonia (5.0 per 100 py), bronchitis (4.1 per 100 py) and soft tissue infections (3.5 per 100 py). In this review clinical characteristics and treatment recommendations according to data available in the literature for these infections are summarized.

Pneumocystis carinii pneumonia (PCP) is one of the leading complications among HIV-infected patients. Recent advances in PCP prophylaxis, diagnosis and treatment have caused a decrease in PCP-related morbidity and mortality. Despite these advances, PCP continues to be frequent in patients not known to be HIV-infected and in those patients with poor adherence to prophylactic regimens or severe immunosuppression. In typical cases diagnosis may be suspected by the patient's clinical presentation. Clinicians are frequently faced with the differential diagnosis between PCP, bacterial pneumonia, pulmonary tuberculosis, and other specific respiratory disorders HIV-associated. Definitive diagnosis of PCP requires demonstration of Pneumocystis carinii (PC) in respiratory secretions or lung tissue. Conventional techniques, immunofluorescence using monoclonal antibodies and molecular techniques are highly specific, but sensitivity varies depending on the PC load present in the sample. Best diagnostic yield is obtained analyzing samples obtained by bronchoalveolar lavage. PC diagnosis using highly sensitive PCR in sputum-induced samples might allow noninvasive diagnosis in most HIV-infected patients suffering from PCP but PCR techniques remain to be standardized. Like in PCP prophylaxis, trimethoprim-sulphametoxazole (TS) is the drug of choice for PCP treatment. In severe case, TS is given intravenously. If patient is intolerant to TS, i.v. pentamidine or i.v. trimetrexate with folinic acid can be used. TS has a dose-dependent toxicity. In cases of hypersensitivity to TS, drug-desensitization should be tried. In severe documented PCP adjunctive corticosteroid therapy is effective and safe. In mild to moderate PCP, TS can be given orally. Best alternatives to TS in this situation are dapsone-pyrimethamine or clindamycin-primaquine (CP). Other effective options are oral atovaquone, aerosolize pentamidine and i.v. pentamidine.