Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Dec 2016
ReviewThe Role of Streptococcus pneumoniae in Community-Acquired Pneumonia.
Streptococcus pneumoniae (the pneumococcus) remains one of the most common causes of bacterial community-acquired pneumonia (CAP), encompassing infections mild enough to be treated on an outpatient basis, as well as those requiring hospital care, or even intensive care unit admission. This microorganism is associated with a significant burden of disease, causing substantial morbidity and mortality worldwide, and generating considerable health-care costs. ⋯ Such risk factors include extremes of age, lifestyle factors, including smoking and alcohol abuse, and various underlying comorbid conditions, including congenital and acquired immunodeficiencies. This article will review various aspects of pneumococcal CAP, including the burden of pneumococcal disease, risk factors for pneumococcal infection, the occurrence of cardiovascular events in patients with pneumococcal CAP, the apparently pivotal role of pneumolysin, a major virulence factor of the pneumococcus, in the pathogenesis of severe infection and associated cardiac dysfunction, empiric antibiotic treatment for pneumococcal CAP, as well as adjunctive therapies, specifically those which target pneumolysin, and, finally, the mortality of such infections.
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Semin Respir Crit Care Med · Dec 2016
ReviewComplication of Community-Acquired Pneumonia (Including Cardiac Complications).
Community-acquired pneumonia (CAP) represents an important public health problem and carries significant morbidity, mortality, and costs. The incidence of CAP is highest among children and elderly patients, but the mortality is much higher in patients older than 65 years. Despite the advances in medicine, the administration of antimicrobials, and the overall better care, there are still patients with CAP dying due to systemic complications all over the world. ⋯ In this review, we present the characteristics of several CAP-related pulmonary and nonpulmonary organ dysfunction, such as those affecting the heart, kidneys, hematological, neurological, endocrine systems. Multiple severity of illness scores identified a series of systemic findings that indicate the organ dysfunctions and the associated related outcomes. However, further research is required to address the mechanisms, the management, and prevention of organ dysfunction in patients with CAP.
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Semin Respir Crit Care Med · Dec 2016
ReviewRole of Atypical Pathogens in the Etiology of Community-Acquired Pneumonia.
Atypical pneumonia has been described for over 100 years, but some of the pathogens attributed to it have been identified only in the past decades. The most common pathogens are Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila. The epidemiology and pathophysiology of these three pathogens have been studied since their discovery, and are reviewed herein to provide better insight when evaluating these patients, which hopefully translates into improved care. ⋯ Treatment is missed if an empiric regimen includes only monotherapy with a β-lactam antimicrobial; so, many country guidelines, including the Infectious Diseases Society of America/American Thoracic Society guidelines for community-acquired pneumonia, recommend using a regimen containing either a macrolide or a fluorinated quinolone. Once an atypical pathogen has been identified, evidence trends toward favoring a quinolone, but more data are needed to confirm. The concept of using combination therapy in severe patients is also explored.
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Semin Respir Crit Care Med · Dec 2016
ReviewAntibiotic Resistance in Community-Acquired Pneumonia Pathogens.
The overwhelming majority of cases of community-acquired pneumonia (CAP) can be treated with the standard antibiotic regimens of a macrolide and cephalosporin or a fluoroquinolone. Despite high rates, current levels of β-lactam resistance generally do not result in treatment failure for patients with CAP when appropriate agents and doses are used. Following the introduction of the pneumococcal conjugate vaccines, the incidence of invasive pneumococcal disease declined drastically, coinciding with a decrease in penicillin resistance. ⋯ The inability to routinely culture H. influenzae suggests that macrolide and β-lactam resistance, while present, is not a big issue. Unless risk factors for a hospital-associated strain are present, the most common Enterobacteriaceae to cause CAP, including Escherichia coli and Klebsiella, are generally susceptible to usual CAP antibiotics. Given the limited role of antibiotic resistance in CAP, a strong rationale is needed for use of antibiotics other than the standard β-lactam/macrolide or fluoroquinolone regimens.
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Community-acquired pneumonia (CAP) is associated with significant morbidity and mortality in Latin America and the Caribbean (LAC) region. Poverty, socioeconomic factors, and malnutrition influence the incidence and outcome of CAP in LAC. In LAC, Streptococcus pneumoniae is the most frequent microorganism responsible for CAP, (incidence: 24-78%); the incidence of atypical microorganisms is similar to other regions of the world. ⋯ More than 30 hantaviruses have been reported in the Western Hemisphere, with more frequent cases registered in the southern cone (Argentina, Chile, Uruguay, Paraguay, Bolivia, and Brazil). Respiratory viruses (particularly influenza) remain an important cause of morbidity and mortality, particularly in the elderly. Low rates of vaccination (against influenza as well as pneumococcus) may heighten the risk of these infections in low- and middle-income countries.