Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Aug 2020
ReviewMiddle East Respiratory Syndrome Coronavirus and Severe Acute Respiratory Syndrome Coronavirus.
Emerging infectious diseases continue to be of a significant importance worldwide with the potential to cause major outbreaks and global pandemics. In 2002, the world had witnessed the appearance of the severe acute respiratory syndrome coronavirus in China which disappeared abruptly within 6 months. ⋯ These two coronaviruses shared multiple similarities in the epidemiology, clinical presentations, and posed challenges in its prevention and management. Seven years since its discovery, MERS-CoV continues to be a lethal zoonotic pathogen capable of causing severe pneumonia with high case fatality rates and the ability to cause large health care-associated outbreaks.
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Semin Respir Crit Care Med · Aug 2020
ReviewEmerging Resistance of Gram Negative Pathogens in Community-Acquired Pneumonia.
In recent decades, there has been a growing interest about the role of gram negative bacteria in community-acquired pneumonia (CAP), especially Pseudomonas aeruginosa, Enterobacteriaceae, and Acinetobacter baumannii. The prevalence of these pathogens differs largely according to the local ecology and the geographical location. Identifying gram negative bacteria, and in particular resistant gram negative bacteria, is of paramount importance in patients with CAP because these pathogens are associated with higher clinical severity and unfavorable outcomes. ⋯ New diagnostic techniques, such as molecular testing, are promising methods for early detection of these gram negative pathogens. The increasing mechanisms of resistance to antibiotics of these pathogens have limited our therapeutic approach. This narrative review focuses on the epidemiology, risk factors, diagnosis, and therapeutic options for the most relevant gram negative bacteria that cause CAP.
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Semin Respir Crit Care Med · Aug 2020
ReviewEndemic Fungi Presenting as Community-Acquired Pneumonia: A Review.
In endemic areas, dimorphic fungal infections due to Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides posadasii/immitis account for up to 30% of cases of community-acquired pneumonia. Because respiratory manifestations are often indistinguishable from common bacterial causes of pneumonia, the diagnosis of pulmonary histoplasmosis, blastomycosis, and coccidioidomycosis is often delayed and associated with antibiotics overuse. In addition to being highly endemic to certain regions of North America, dimorphic fungi have global significance due to established areas of endemicity in all six inhabited continents, an increasingly interconnected world of travelers and transported goods, and a changing epidemiology as a result of global heating and anthropomorphic land utilization. In this review, we discuss the epidemiology, pathogenesis, clinical presentation, diagnostic modalities, and treatment strategies for histoplasmosis, blastomycosis, and coccidioidomycosis.
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Members of the Nocardia genus are ubiquitous in the environment. These aerobic, gram-positive organisms can lead to life-threatening infection, typically in immunocompromised hosts such as solid organ transplant recipients or those receiving immunosuppressive medications for other reasons. This current review discusses the microbiology of nocardiosis, risk factors for infection, clinical manifestations, methods for diagnosis, and treatment. ⋯ Species identification is important in determining treatment, as is in vitro susceptibility testing. Sulfonamide therapy is usually indicated, although a variety of other antimicrobials may be useful, depending on the species and susceptibility testing. Prolonged therapy is usually indicated, for 6 to 12 months, and in some cases surgical debridement may be required to resolve infection.
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Q fever is a zoonotic infectious disease caused by the Coxiella burnetii bacterium. It is an obligate intracellular pathogen with a high infection capacity that proliferates exclusively in an acidified medium, forming a lysosome-like vacuole. It presents a peculiar phenomenon called "antigenic phase variation," produced by a modification in the complexity of the membrane lipopolysaccharides. ⋯ Treatment of the acute form in both children and adults consists of administering doxycycline, while persistent focalized infection should be treated with at least two antibiotics, such as doxycycline and hydroxychloroquine. Several measures should be undertaken to minimize exposure among people working with animals or handling birth products. Different vaccines have been developed to prevent infection, though few data are available.