Current Issue : April - June Volume : 2013 Issue Number : 2 Articles : 6 Articles
Background: Although cerebrospinal fluid (CSF) culture is the diagnostic reference standard for bacterial\r\nmeningitis, its sensitivity is limited, particularly when antibiotics were previously administered. CSF Gram staining\r\nand real-time PCR are theoretically less affected by antibiotics; however, it is difficult to evaluate these tests with an\r\nimperfect reference standard.\r\nMethods and findings: CSF from patients with suspected meningitis from Salvador, Brazil were tested with culture,\r\nGram stain, and real-time PCR using S. pneumoniae, N. meningitidis, and H. influenzae specific primers and probes.\r\nAn antibiotic detection disk bioassay was used to test for the presence of antibiotic activity in CSF. The diagnostic\r\naccuracy of tests were evaluated using multiple methods, including direct evaluation of Gram stain and real-time\r\nPCR against CSF culture, evaluation of real-time PCR against a composite reference standard, and latent class\r\nanalysis modeling to evaluate all three tests simultaneously.\r\nResults: Among 451 CSF specimens, 80 (17.7%) had culture isolation of one of the three pathogens (40 S. pneumoniae,\r\n36 N. meningitidis, and 4 H. influenzae), and 113 (25.1%) were real-time PCR positive (51 S. pneumoniae, 57 N.\r\nmeningitidis, and 5 H. influenzae). Compared to culture, real-time PCR sensitivity and specificity were 95.0% and 90.0%,\r\nrespectively. In a latent class analysis model, the sensitivity and specificity estimates were: culture, 81.3% and 99.7%;\r\nGram stain, 98.2% and 98.7%; and real-time PCR, 95.7% and 94.3%, respectively. Gram stain and real-time PCR sensitivity\r\ndid not change significantly when there was antibiotic activity in the CSF.\r\nConclusion: Real-time PCR and Gram stain were highly accurate in diagnosing meningitis caused by S. pneumoniae,\r\nN. meningitidis, and H. influenzae, though there were few cases of H. influenzae. Furthermore, real-time PCR and Gram\r\nstaining were less affected by antibiotic presence and might be useful when antibiotics were previously administered.\r\nGram staining, which is inexpensive and commonly available, should be encouraged in all clinical settings....
Background: Coxsackievirus A9 (CA9) was one of the most prevalent serotype of enteroviral infections in Taiwan in\r\n2011. After several patient series were reported in the 1960s and 1970s, few studies have focused on the clinical\r\nmanifestations of CA9 infections. Our study explores and deepens the current understanding of CA9.\r\nMethods: We analyzed the clinical presentations of 100 culture-proven CA9-infected patients in 2011 by reviewing\r\ntheir medical records and depicted the CA9 phylogenetic tree.\r\nResults: Of the 100 patients with culture-proven CA9 infections, the mean (SD) age was 4.6 (3.4) years and the\r\nmale to female ratio was 1.9. For clinical manifestations, 96 patients (96%) had fever and the mean (SD) duration of\r\nfever was 5.9 (3.4) days. Sixty one patients (61%) developed a skin rash, and the predominant pattern was a\r\ngeneralized non-itchy maculopapular rash without vesicular changes. While most patients showed injected throat,\r\noral ulcers were found in only 19 cases (19%), among whom, 6 were diagnosed as herpangina. Complicated cases\r\nincluded: aseptic meningitis (n=8), bronchopneumonia (n=6), acute cerebellitis (n=1), and polio-like syndrome\r\n(n=1). Phylogenetic analysis for current CA9 strains is closest to the CA9 isolate 27-YN-2008 from the border area of\r\nmainland China and Myanmar.\r\nConclusions: The most common feature of CA9 during the 2011 epidemic in Taiwan is generalized febrile\r\nexanthema rather than herpangina or hand, foot, and mouth disease. Given that prolonged fever and some\r\ncomplications are possible, caution should be advised in assessing patients as well as in predicting the clinical\r\ncourse....
Background: Hemophagocytic syndrome (HPS) is clinically defined as a combination of fever, liver dysfunction,\r\ncoagulation abnormalities, pancytopenia, progressive macrophage proliferation throughout the reticuloendothelial\r\nsystem, and cytokine over-production, and may be primary or secondary to infectious, auto-immune, and tumoral\r\ndiseases. The most consistent association is with viral infections but, as it is still debated whether any\r\nmicro-organisms are involved in its pathogenesis, we critically appraised the literature concerning HPS and its\r\nrelationship with infections.\r\nDiscussion: Infection-dependent HPS has been widely observed, but there are no data concerning its incidence in\r\nchildren. A better understanding of the pathophysiology of HPS may clarify the interactions between the immune\r\nsystem and the variously implicated potential infectious agents. Epstein-Barr virus (EBV) infection has been\r\nprominently associated with HPS, with clonal proliferation and the hyperactivation of EBV-infected T cells. However,\r\na number of other viral, bacterial, fungal, and parasitic infections have been reported in association with HPS. In the\r\ncase of low-risk HPS, corticosteroids and/or intravenous immunoglobulin or cyclosporine A may be sufficient to\r\ncontrol the biological process, but etoposide is recommended as a means of reversing infection-dependent\r\nlymphohistiocytic dysregulation in high-risk cases.\r\nSummary: HPS is a potential complication of various infections. A polymerase chain reaction search for infectious\r\nagents including EBV, cytomegalovirus and Leishmania is recommended in clinical settings characterised by\r\nnon-remitting fever, organomegaly, cytopenia and hyperferritinemia....
Background: Urinary tract infection (UTI) is one of the most common infectious diseases at the community level. In\r\norder to assess the adequacy of the empirical therapy, the prevalence and the resistance pattern of the main\r\nbacteria responsible for UTI in the community (in Aveiro, Portugal) was evaluated throughout a ten-year period.\r\nMethods: In this retrospective study, all urine samples from patients of the District of Aveiro, in ambulatory regime,\r\ncollected at the Clinical Analysis Laboratory Avelab during the period 2000ââ?¬â??2009 were analysed. Samples with more\r\nthan 105 CFU/mL bacteria were considered positive and, for these samples, the bacteria were identified and the\r\nprofile of antibiotic susceptibility was characterized.\r\nResults: From the 155597 samples analysed, 18797 (12.1%) were positive for bacterial infection. UTI was more\r\nfrequent in women (78.5%) and its incidence varied with age, affecting more the elderly patients (38.6%). Although\r\nE. coli was, as usual, the most common pathogen implicated in UTI, it were observed differences related to the\r\nother bacteria more implicated in UTI relatively to previous studies. The bacteria implicated in the UTI varied with\r\nthe sex of the patient, being P. aeruginosa a more important cause of infection in men than in women. The\r\nincidence of the main bacteria changed over the study period (P. aeruginosa, Klebsiella spp and Providencia spp\r\nincreased and Enterobacter spp decreased). Although E. coli was responsible for more than an half of UTI, its\r\nresistance to antibiotics was low when compared with other pathogens implicated in UTI, showing also the lowest\r\npercentage of multidrug resistant (MDR) isolates (17%). Bacteria isolated from females were less resistant than those\r\nisolated from males and this difference increased with the patient age.\r\nConclusions: The differences in sex and age must be taken into account at the moment of empirical prescription\r\nof antimicrobials. From the recommended antimicrobials by the European Association of Urology guidelines, the\r\nfirst line drugs (pivmecillinam and nitrofurantoin) and the alternative antibiotic amoxicillin-clavulanic acid (AMXCLA)\r\nare appropriate to treat community-acquired UTI, but the fluoroquinolones should not be suitable to treat\r\nmale infections and the trimethoprim-sulfamethoxazole (SXT) shall not be used in the treatment of UTI at this level....
Background: Vitamin D enhances host protective immune responses to Mycobacterium tuberculosis by suppressing\r\nInterferon-gamma (IFN-g) and reducing disease associated inflammation in the host. The objectives of this study\r\nwere to determine whether vitamin D supplementation to patients with tuberculosis (TB) could influence recovery.\r\nMethods: Two hundred and fifty nine patients with pulmonary TB were randomized to receive either 600,000 IU of\r\nIntramuscular vitamin D3 or placebo for 2 doses. Assessments were performed at 4, 8 and 12 weeks. Early secreted\r\nand T cell activated 6 kDa (ESAT6) and Mycobacterium tuberculosis sonicate (MTBs) antigen induced whole blood\r\nstimulated IFN-g responses were measured at 0 and 12 weeks. Statistical comparisons between outcome variables\r\nat 0 and 12 weeks were performed using Studentââ?¬â?¢s t-test and Chi2 tests.\r\nResults: After 12 weeks, the vitamin D supplemented arm demonstrated significantly greater mean weight gain\r\n(kg) + 3.75, (3.16 ââ?¬â?? 4.34) versus + 2.61 (95% CI 1.99 ââ?¬â?? 3.23) p 0.009 and lesser residual disease by chest radiograph;\r\nnumber of zones involved 1.35 v/s 1.82 p 0.004 (95% CI 0.15, 0.79) and 50% or greater reduction in cavity size 106\r\n(89.8%) v/s 111 (94.8%), p 0.035. Vitamin D supplementation led to significant increase in MTBs-induced IFN-g\r\nsecretion in patients with baseline ââ?¬Ë?Deficientââ?¬â?¢ 25-hydroxyvitamin D serum levels (p 0.021).\r\nConclusions: Supplementation with high doses of vitamin D accelerated clinical, radiographic improvement in all\r\nTB patients and increased host immune activation in patients with baseline ââ?¬Ë?Deficientââ?¬â?¢ serum vitamin D levels. These\r\nresults suggest a therapeutic role for vitamin D in the treatment of TB....
Background: Listeriosis is a foodborne infection with a low incidence but a high case fatality rate. Unlike common\r\nfoodborne diseases, the incubation period can be long. The first incubation periods were documented during a\r\nlarge listeriosis outbreak published in 1987 by Linnan and al. in the New England Journal of Medicine (range: 3 days\r\nto 70 days). Data on the incubation period of listeriosis are scarce. Our study aim was to estimate precisely the\r\nincubation period of listeriosis using available data since 1987.\r\nMethods: We estimated the incubation period of listeriosis using available published data and data from outbreak\r\ninvestigations carried out by the French National Institute for Public Health Surveillance. We selected cases with an\r\nincubation period calculated when a patient had a single exposure to a confirmed food source contaminated by\r\nListeria monocytogenes.\r\nResults: We identified 37 cases of invasive listeriosis (10 cases with central nervous system involvement (CNS cases),\r\n15 bacteraemia cases and 12 pregnancy-associated cases) and 9 outbreaks with gastroenteritis. The overall median\r\nincubation period of invasive listeriosis was 8 days (range: 1ââ?¬â??67 days) and differed significantly by clinical form of\r\nthe disease (p<0.0001). A longer incubation period was observed for pregnancy-associated cases (median: 27.5\r\ndays; range: 17ââ?¬â??67 days) than for CNS cases (median: 9 days; range: 1ââ?¬â??14 days) and for bacteraemia cases (median:\r\n2 days; range: 1ââ?¬â??12 days). For gastroenteritis cases, the median incubation period was 24 hours with variation from\r\n6 to 240 hours.\r\nConclusions: This information has implications for the investigation of food borne listeriosis outbreaks as the\r\nincubation period is used to determine the time period for which a food history is collected. We believe that, for\r\nlisteriosis outbreaks, adapting the exposure window for documenting patientsââ?¬â?¢ food histories in accordance with\r\nthe clinical form of infection will facilitate the identification of food products as the source of contamination. We\r\ntherefore propose to take an exposure window of 14 days before the diagnosis for CNS and bacteraemia cases, and\r\nof 6 weeks before the diagnosis, for pregnancy-associated cases....
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