Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
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Early diagnosis and treatment of invasive pulmonary aspergillosis (IPA) improves outcome. ⋯ A recently developed pan-Aspergillus PCR assay and GM testing of BAL fluid may facilitate the diagnosis of IPA after lung transplantation. A. fumigatus- and A. terreus-specific real-time PCR assays may be useful in rapidly identifying the most common cause of IPA and a species that is intrinsically resistant to amphotericin B, respectively.
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Serum procalcitonin (PCT) levels rapidly increase in patients with invasive bacterial disease. PCT levels increase faster than do C-reactive protein levels. ⋯ In patients with community-acquired bacterial pneumonia, sequential PCT levels are useful as a guide to shorter courses of antimicrobial therapy. With use of emerging multiplex real-time polymerase chain reaction platforms for the detection of viral and bacterial respiratory pathogens, it should be possible to critically assess whether an elevated serum PCT level is a valid biomarker of invasive bacterial infection.
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Review Case Reports
The diagnostic value of halo and reversed halo signs for invasive mold infections in compromised hosts.
The halo sign is a CT finding of ground-glass opacity surrounding a pulmonary nodule or mass. The reversed halo sign is a focal rounded area of ground-glass opacity surrounded by a crescent or complete ring of consolidation. In severely immunocompromised patients, these signs are highly suggestive of early infection by an angioinvasive fungus. ⋯ Many other infections and noninfectious conditions, such as neoplastic and inflammatory processes, may also manifest with pulmonary nodules associated with either sign. Although nonspecific, both signs can be useful for preemptive initiation of antifungal therapy in the appropriate clinical setting. This review aims to evaluate the diagnostic value of the halo sign and reversed halo sign in immunocompromised hosts and describes the wide spectrum of diseases associated with them.
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There is a global crisis of antibiotic resistance in part because of the collateral damage of antibiotic use. Reduction in antibiotic consumption is clearly important to minimize this problem. Limiting treatment duration may be the most clinically palatable means of reducing antibiotic consumption. ⋯ However, in most clinical scenarios, the recommended duration of therapy in published guidelines is based on expert opinion. Biological markers, such as procalcitonin, have been shown to reduce antimicrobial consumption with no adverse outcome in 11 randomized controlled trials. Although procalcitonin may not be the perfect biomarker, the concept of procalcitonin-guided antibiotic discontinuation after clinical stabilization, in conjunction with antimicrobial stewardship programs, appears to be ready for introduction into clinical practice.
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The Duffy-null trait and ethnic netropenia are both highly prevalent in Africa. The influence of pre-seroconversion levels of peripheral blood cell counts (PBCs) on the risk of acquiring human immunodeficiency virus (HIV)-1 infection among Africans is unknown. ⋯ Pre-seroconversion neutrophil and platelet counts influence risk of HIV infection. The trait of Duffy-null-associated low neutrophil counts influences HIV susceptibility. Because of the high prevalence of this trait among persons of African ancestry, it may contribute to the dynamics of the HIV epidemic in Africa.