Atypical bacterial infections of the central nervous system transmitted by ticks: An unknown threat.

Infections of the central nervous system caused by atypical bacteria are becoming more common. Borrelia burgdorferi and Rickettsia conorii are microorganisms transmitted by ticks; infection with these bacteria result in a wide spectrum of manifestations on imaging. In areas where these tick-borne microorganisms are endemic, including Spain, these infections must be included in the differential diagnosis of patients with a variety of systemic and neurologic symptoms. The clinical presentation of these infections is nonspecific, and CT is normally the initial imaging technique, although MRI is more sensitive to early changes. On MRI, these infections can manifest as small lesions in the deep supratentorial white matter that are hyperintense on T2-weighted/FLAIR sequences. It is fundamental to know the imaging characteristics of the different atypical bacterial infections and their differential diagnoses. Good history taking combined with complementary tests (blood tests and CSF analysis) and the neuroimaging findings can help reach the right diagnosis and enable appropriate treatment, thereby preventing possible neurological sequelae.

Accuracy of different diagnostic tests for early, delayed and late prosthetic joint infection.

BACKGROUND: A combination of laboratory, histopathological and microbiological tests for diagnosis of prosthetic joint infection (PJI) have been strongly recommended. This study aims to characterize the accuracy of individual or group tests, such as culture of sonicate fluid, synovial fluid and peri-implant tissue, C-reactive protein (CRP) and histopathology for detection of early, delayed and late PJI. METHODS: A prospective study of patients undergoing hip or knee arthroplasty from February 2009 to February 2014 was performed in a Spanish tertiary health care hospital. The diagnostic accuracy of the different methods was evaluated constructing receiver-operating-characteristic (ROC) curve areas. RESULTS: One hundred thirty consecutive patients were included: 18 (13.8%) early PJI, 35 (27%) delayed PJI and 77 (59.2%) late PJI. For individual parameters, the area under the ROC curve for peri-implant tissue culture was larger for early (0.917) than for delayed (0.829) and late PJI (0.778), p = 0.033. There was a significantly larger difference for ROC area in the synovial fluid culture for delayed (0.803) than for early (0.781) and late infections (0.679), p = 0.039. The comparison of the areas under the ROC curves for the two microbiological tests showed that sonicate fluid was significantly different from peri-implant tissue in delayed (0.951 vs 0.829, p = 0.005) and late PJI (0.901 vs 0.778, p = 0.000). The conjunction of preoperative parameters, synovial fluid culture and CRP, improved the accuracy for late PJI (p = 0.01). The conjunction of histopathology and sonicate fluid culture increased the area under ROC curve of sonication in early (0.917 vs 1.000); p = 0.06 and late cases (0.901 vs 0.999); p < 0.001. CONCLUSION: For early PJI, sonicate fluid and peri-implant tissue cultures achieve the same best sensitivity. For delayed and late PJI, sonicate fluid culture is the most sensitive individual diagnostic method. By combining histopathology and peri-implant tissue, all early, 97% of delayed and 94.8% of late cases are diagnosed. The conjunction of histopathology and sonicate fluid culture yields a sensitivity of 100% for all types of infection.

Strongyloides stercolaris y asma bronquial / Strongyloides stercolarisand bronchial asthma

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