Microbiology Of Community-acquired Pneumonia Research Articles

Epidemiology, pathophysiology, and microbiology of community-acquired pneumonia

Despite improvements in the clinical management of patients with community-acquired pneumonia (CAP) over the last decade, the incidence of the condition remains high, especially in Europe. Globally, pneumonia continues to be associated with high morbidity, mortality, and health costs. Moreover, its management poses many challenges. The microbial identification of pathogens remains difficult even though new molecular tests have been developed, mainly because of the difficulties interpreting the results. Also, the epidemiological changes due to serotype replacement after introducing the pneumococcal conjugate vaccine represent an emerging issue. Whereas the lungs were once thought to be sterile, it is now known that there is a respiratory microbiome with a dynamic microbiological ecosystem. However, this is a relatively unknown field. This review article provides an overview of our current understanding of the epidemiology, physiopathology, and microbial etiology of pneumonia.

Community-acquired pneumonia in the post 13-valent pneumococcal conjugate vaccine era.

This review covers the outpatient management of pediatric community-acquired pneumonia (CAP), discussing the changing microbiology of CAP since the introduction of the 13-valent pneumococcal conjugate vaccine in 2010, and providing an overview of national guideline recommendations for diagnostic evaluation and treatment. Rates of invasive pneumococcal disease and pneumococcal antibiotic resistance have plummeted since widespread 13-valent pneumococcal conjugate vaccine immunization. Viruses remain the most common cause of CAP in young children; children over age 5 years have increased rates of Mycoplasma pneumoniae. A recent national guideline offers recommendations for office-based diagnostic evaluation and treatment of pediatric CAP. This review offers a discussion of the above findings with practical recommendations for the office-based practitioner in the evaluation and treatment of an infant (>3 months) or child with suspected CAP.

Severity and outcomes of community acquired pneumonia in asthmatic patients

Limited information is available about clinical outcomes and microbiology of community-acquired pneumonia in asthma. We prospectively studied 4079 CAP patients over a 12-years period and found 139 (3.4%) asthmatic patients. Asthmatics showed younger age (57 ± 19 vs. 66 ± 19 years), less males (32% vs. 68%) and less active smokers (15% vs. 25%). Moreover, they had used more frequently inhaled corticosteroids (ICs, 53% vs. 17%, p < 0.001) and antibiotics (32% vs. 24%, p = 0.041). In comparison with non asthma-CAP, asthmatics showed at admission more pleuritic pain and dyspnoea but less severe pneumonia (PSI, CURB-65, PaO(2)/FIO(2) ratio; p < 0.05). No differences were observed in CAP microbiology, being Streptococcus pneumoniae the most frequent isolate. Clinical outcomes in asthmatic patients were similar to the general population (mortality, mechanical ventilation, etc.) but with a shorter median length of stay (6 [3; 9] vs. 7 [4; 10] days, p = 0.023). The chronic use of ICs did not influence clinical presentation and outcomes among asthmatic patients. Asthmatics were younger and showed similar clinical presentation. Consistently with PSI, asthmatics showed similar outcomes than the general population. The microbial aetiology of CAP in asthma did not differ from the general population and antibiotic therapy should follow current guidelines.

The Lebanese Society for Infectious Diseases and Clinical Microbiology ( LSIDCM ) Guidelines for Adult Community-Acquired Pneumonia ( CAP ) in Lebanon

Adult community-acquired pneumonia (CAP) is a common cause of morbidity and mortality which is managed by different disciplines in a heterogeneous fashion. Development of consensus guidelines to standardize these wide variations in care has become a prime objective. The Lebanese Society of Infectious Diseases and Clinical Microbiology (LSIDCM) convened to set Lebanese national guidelines for the management of CAP since it is a major and a prevalent disease affecting the Lebanese population. These guidelines, besides being helpful in direct clinical practice, play a major role in establishing stewardship programs in hospitals in an effort to contain antimicrobial resistance on the national level. These guidelines are intended for primary care practitioners and emergency medicine physicians. They constitute an appropriate starting point for specialists' consultation being based on the available local epidemiological and resistance data. This document includes the following: 1/ Rationale and scope of the guidelines; 2/ Microbiology of CAP based on Lebanese data; 3/ Clinical presentation and diagnostic workup of CAP; 4/ Management and prevention strategies based on the IDSA/ATS Consensus Guidelines, 2007, and the ESCMID Guidelines, 2011, and tailored to the microbiological data in Lebanon; 5/ Comparison to regional guidelines. The recommendations made in this document were graded based on the strength of the evidence as in the 2007 IDSA/ATS Consensus Guidelines. Hopefully, these guidelines will be an important step towards standardization of CAP care in Lebanon and set the agenda for further research in this area.

Etiology of community-acquired pneumonia in a population-based study: Link between etiology and patients characteristics, process-of-care, clinical evolution and outcomes

BackgroundThe etiologic profile of community-acquired pneumonia (CAP) for each age group could be similar among inpatients and outpatients. This fact brings up the link between etiology of CAP and its clinical evolution and outcome. Furthermore, the majority of pneumonia etiologic studies are based on hospitalized patients, whereas there have been no recent population-based studies encompassing both inpatients and outpatients.MethodsTo evaluate the etiology of CAP, and the relationship among the different pathogens of CAP to patients characteristics, process-of-care, clinical evolution and outcomes, a prospective population-based study was conducted in Spain from April 1, 2006, to June 30, 2007. Patients (age >18) with CAP were identified through the family physicians and the hospital area.ResultsA total of 700 patients with etiologic evaluation were included: 276 hospitalized and 424 ambulatory patients. We were able to define the aetiology of pneumonia in 55.7% (390/700). The most frequently isolated organism was S. pneumoniae (170/390, 43.6%), followed by C. burnetti (72/390, 18.5%), M. pneumoniae (62/390, 15.9%), virus as a group (56/390, 14.4%), Chlamydia species (39/390, 106%), and L. pneumophila (17/390, 4.4%). The atypical pathogens and the S. pneumoniae are present in pneumonias of a wide spectrum of severity and age. Patients infected by conventional bacteria were elderly, had a greater hospitalization rate, and higher mortality within 30 days.ConclusionsOur study provides information about the etiology of CAP in the general population. The microbiology of CAP remains stable: infections by conventional bacteria result in higher severity, and the S. pneumoniae remains the most important pathogen. However, atypical pathogens could also infect patients in a wide spectrum of severity and age.

Microbiology of Community-Acquired Pneumonia in the Gulf Corporation Council States

SummaryIn spite of advances in microbiological and serological investigations over the last two decades, etiological attribution remains difficult in community-acquired pneumonia (CAP). Even after exhaustive investigation, the etiology of CAP remains unknown in up to 50% of patients. Common pathogens include Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. In addition, several investigators document the importance of atypical pathogens including Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila in the etiology of CAP in the GCC region. Increasingly, other etiologies, particularly influenza viruses, varicella zoster virus and Mycobacterium tuberculosis, have been recognized as causative pathogens of CAP within the region. Rates of antimicrobial resistance of S. pneumoniae and other pathogens are rising in the Gulf Corporation Council (GCC) region and susceptibility profiles of antibiotics against intracellular pathogens such as Chlamydophila pneumoniae and Mycoplasma pneumoniae are not routinely performed. Injudicious prescribing and over-use of antibiotics drive much resistance. The GCC CAPWG calls for urgent governmental regulations to limit and monitor antibiotic prescription in the GCC region.

Pneumonia in older adults

PREVIEWThe microbiology of community-acquired pneumonia (CAP) in older adults, particularly in residents of long- term care facilities, differs from that in the general US population. Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are important, newly appreciated causes of pneumonia and triggers of comorbid disease exacerbations that often lead to hospitalization of high-risk elderly patients with underlying heart or lung disease. Here, Dr High examines the diagnostic and treatment strategies that are needed in older adults and outlines preventive methods that may greatly reduce the risk of illness in this population.

Community-acquired pneumonia in patients requiring hospitalization.

This study aimed to investigate the microbial aetiology of community-acquired pneumonia (CAP) in patients requiring hospitalization. A prospective study of consecutive non-immunocompromised patients aged 12 years and above admitted with CAP from August 1997 to May 1999 was undertaken. Of 127 patients hospitalized for CAP, an aetiological diagnosis was achieved in 53 cases (41.7%). Klebsiella pneumoniae was the most frequently isolated pathogen and caused 10.2% of all the cases, followed by Streptococcus pneumoniae (5.5%), Haemophilus influenzae (5.5%), Mycoplasma pneumoniae (3.9%) and Pseudomonas aeruginosa (3.9%). Gram-negative bacilli were significantly more frequently identified in patients aged 60 years or older and in patients with comorbid illnesses. Twelve of 13 patients who died from CAP had other comorbid illnesses compared to 63 of 114 patients who survived (P = 0.014). Three of eight bacteraemic patients died compared with 10 of 119 non-bacteraemic patients (P = 0.035). The microbiology of CAP in patients requiring hospitalization in Malaysia appears to be different from that in Western countries. Gram-negative bacilli were more frequently isolated in older patients and in those with comorbidity. Mortality from CAP is more likely in patients with comorbidity and in those who are bacteraemic.