Explore the vast range of titles available.

Defining the causal relationship between a microbe and encephalitis is complex. Over 100 different infectious agents may cause encephalitis, often as one of the rarer manifestations of infection. The gold-standard techniques to detect causative infectious agents in encephalitis in life depend on the study of brain biopsy material; however, in most cases this is not possible. We present the UK perspective on aetiological case definitions for acute encephalitis and extend them to include immune-mediated causes. Expert opinion was primarily used and was supplemented by literature-based methods. Wide usage of these definitions will facilitate comparison between studies and result in a better understanding of the causes of this devastating condition. They provide a framework for regular review and updating as the knowledge base increases both clinically and through improvements in diagnostic methods. The importance of new and emerging pathogens as causes of encephalitis can be assessed against the principles laid out here.

Reduced level of consciousness is a common clinical finding in acutely sick patients. In the majority of cases a cause for the encephalopathy is readily identifiable,whilst in a minority the aetiology is more difficult to ascertain. Frequently the onset of encephalopathy is associated with, or follows, infection. The mechanisms through which infection leads to encephalopathy are diverse. They range from direct microbial invasion of the brain or its supporting structures, to remote, infection-triggered mechanisms such as acute disseminated encephalomyelitis. Most common however, is the encephalopathy caused through a remote effect of systemic sepsis-septic encephalopathy. This article discusses the clinical presentation and underlying pathogeneses of the acute encephalopathies associated with infection, aiming to aid both their recognition and treatment.

A 27 year old woman developed a vesicular genital rash and cerebellar dysfunction with progressive neurological deterioration suggesting brain stem encephalitis. Respiratory support was required. Magnetic resonance imaging (MRI) of the brain on day 7 showed signal hyperintensity in the central medulla and ventral pons, typical of acute inflammation. The course was severe and relapse occurred. MRI on day 33 showed a haemorrhagic area in the medulla. Treatment with aciclovir/valaciclovir eventually led to gradual recovery. Herpes simplex virus 2 (HSV-2) DNA was detected in CSF on days 11 and 14. HSV-2 was also detected in vesicle fluid from the genital rash. Serum was initially negative for HSV-1 and HSV-2 antibodies, but convalescent samples showed seroconversion to HSV-2, indicating primary infection. Intrathecal synthesis of oligoclonal IgG bands specific for HSV was identified in the CSF. It is important to differentiate HSV-2 from HSV-1, and primary from initial or reactivated infection, so that prolonged aciclovir treatment followed by prophylaxis is instituted to prevent the high likelihood of symptomatic relapse in primary HSV-2 infection.

Background: Polymerase chain reaction (PCR) is used to detect viruses in the cerebrospinal fluid (CSF) of patients with neurological disease. However, data to assist its use or interpretation are limited. Objective: We investigated factors possibly influencing viral detection in CSF by PCR, which will also help clinicians interpret positive and negative results. Methods: CSF from patients with was tested for human herpesviruses types 1–6, JC virus, enteroviruses, and Toxoplasma gondii. The likelihood of central nervous system (CNS) infection was classified as likely, possible, or unlikely. PCR findings in these categories were compared using single variable and logistic regression analysis. Results: Of 787 samples tested, 97 (12%) were PCR positive for one or more viruses. Of episodes likely to be CNS viral infections, 30% were PCR positive compared to 5% categorised as unlikely. The most frequent positive findings were Epstein Barr virus (EBV), enteroviruses, and herpes simplex virus (HSV). Enteroviruses and HSV were found predominantly in the likely CNS viral infection group, whereas EBV was found mainly in the unlikely group. Positive PCR results were more likely when there were 3–14 days between symptom onset and lumbar puncture, and when CSF white cell count was abnormal, although a normal CSF did not exclude a viral infection. Conclusions: The diagnostic yield of PCR can be maximised by using sensitive assays to detect a range of pathogens in appropriately timed CSF samples. PCR results, in particular EBV, should be interpreted cautiously when symptoms cannot readily be attributed to the virus detected.

Background Cerebrospinal fluid (CSF) biomarkers Aβ1-42, t-tau and p-tau have a characteristic pattern in Alzheimer’s Disease (AD). Their roles in HIV-associated neurocognitive disorder (HAND) remains unclear. Methods Adults with chronic treated HIV disease were recruited (n = 43, aged 56.7 ± 7.9; 32% aged 60+; median HIV duration 20 years, >95% plasma and CSF HIV RNA <50 cp/mL, on cART for a median 24 months). All underwent standard neuropsychological testing (61% had HAND), APOE genotyping (30.9% carried APOE ε4 and 7.1% were ε4 homozygotes) and a lumbar puncture. Concentrations of Aβ1-42, t-tau and p-tau were assessed in the CSF using commercial ELISAs. Current neurocognitive status was defined using the continuous Global Deficit Score, which grades impairment in clinically relevant categories. History of HAND was recorded. Univariate correlations informed multivariate models, which were corrected for nadir CD4-T cell counts and HIV duration. Results Carriage of APOE ε4 predicted markedly lower levels of CSF Aβ1-42 in univariate (r = -.50; p = .001) and multivariate analyses (R 2 = .25; p < .0003). Greater levels of neurocognitive impairment were associated with higher CSF levels of p-tau in univariate analyses (r = .32; p = .03) and multivariate analyses (R 2 = .10; p = .03). AD risk prediction cut-offs incorporating all three CSF biomarkers suggested that 12.5% of participants had a high risk for AD. Having a CSF-AD like profile was more frequent in those with current ( p = .05) and past HIV-associated dementia ( p = .03). Conclusions Similarly to larger studies, APOE ε4 genotype was not directly associated with HAND, but moderated CSF levels of Aβ1-42 in a minority of participants. In the majority of participants, increased CSF p-tau levels were associated with current neurocognitive impairment. Combined CSF biomarker risk for AD in the current HIV+ sample is more than 10 times greater than in the Australian population of the same age. Larger prospective studies are warranted.

Slowly clearing infections in the pleural space are a source of substantial morbidity. This study showed that instillation of recombinant DNase and tissue plasminogen activator (t-PA) is more effective than placebo in clearing radiographic pleural effusions. Pleural infection affects more than 65,000 patients each year in the United States and the United Kingdom, 1 and the incidence is increasing in both countries — in both children 2 – 4 and adults. 5 , 6 The mortality rate from pleural infection is between 10% and 20%, 5 , 7 – 9 and drainage through a chest tube and administration of antibiotics fail in approximately one third of patients, who then require surgical drainage. 5 , 9 The median duration of the hospital stay for these patients is 12 to 15 days, 5 , 6 , 8 , 9 with 25% hospitalized for more than a month. Care of each patient costs . . .

BackgroundPleural infection is common, and has a >30% major morbidity and mortality—particularly when infection is caused by Gram-negative, Staphylococcus aureus or mixed aerobic pathogens. Standard pleural fluid culture is negative in ∼40% of cases. Culturing pleural fluid in blood culture bottles may increase microbial yield, and is cheap and easy to perform.ObjectivesTo determine whether inoculating pleural fluid into blood culture bottles increases the culture positivity of pleural infection over standard laboratory culture, and to assess the optimum volume of inoculum to introduce.Methods62 patients with pleural infection were enrolled. Pairs of aerobic and anaerobic blood culture bottles were inoculated at the bedside with 2, 5 or 10 ml of pleural fluid, and two pleural fluid specimens were sent for standard culture. Pleural fluid from nine control patients was cultured to test for ‘false-positive’ results.ResultsThe addition of blood culture bottle culture to standard culture increased the proportion of patients with identifiable pathogens by 20.8% (20/53 (37.7%) to 31/53 (58.5%) (difference 20.8%, 95% CI difference 8.9% to 20.8%, p<0.001)). The second standard culture did not similarly improve the culture positivity (19/49 (38.8%) to 22/49 (44.9%) (difference 6.1%, 95% CI difference −2.5% to 6.1%, p=0.08)). The culture inoculum volume did not influence bacterial isolation frequency. The control fluids were culture negative.ConclusionsBlood culture bottle culture of infected pleural fluid increases microbial yield when used in addition to standard culture. This technique should be part of routine care.

We previously reported preliminary findings that post induction imatinib mesylate (340 mg/m 2 /day), in combination with intensive chemotherapy, resulted in outcomes similar to blood and marrow transplant (BMT) for pediatric patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). We now report 5-year outcomes of imatinib plus intensive chemotherapy in 91 children (1–21 years) with and without allogeneic BMT ( N =91). We explore the impacts of additional chromosomal abnormalities and minimal residual disease (MRD) by flow cytometry on outcomes. The 5-year disease-free survival was similar for Cohort 5 patients, treated with chemotherapy plus imatinib (70%±12%, n =28), sibling donor BMT patients (65%±11%, n =21) and unrelated donor BMT patients (59±15%; P =0.60, n =13). Patients with additional cytogenetic abnormalities had worse outcomes ( P =0.05). End induction (pre-imatinib) MRD was not prognostic for Cohort 5 or allogeneic BMT patients, although limited by small numbers. The re-induction rate following relapse was similar to other higher-risk ALL groups. Longer-term follow-up confirms our initial observation of substantially good outcomes for children and adolescents with Ph+ ALL treated with imatinib plus intensive chemotherapy with no advantage for allogeneic BMT.

In this randomized trial involving 454 patients with pleural infections that required antibiotic therapy and chest-tube drainage, there was no benefit from the use of intrapleural streptokinase in terms of survival, the need for surgery, the length of the hospital stay, or the resolution of radiographic abnormalities. In this trial involving 454 patients with pleural infections, there was no benefit from the use of intrapleural streptokinase in terms of survival, the need for surgery, the length of the hospital stay, or the resolution of radiographic abnormalities. Pleural infection develops in about 65,000 patients each year in the United States and the United Kingdom. 1 Approximately 15 percent of patients die, 2 which is similar to the death rate among patients hospitalized with pneumonia, 3 , 4 and 15 to 40 percent require surgical drainage of the infected pleural space. 2 , 5 The median duration of inpatient care is 15 days, with 20 percent of patients remaining in the hospital for a month or longer. 2 Apart from antibiotic therapy, treatment in patients with pleural infection consists mainly of drainage of the infected pleural fluid, and the intrapleural administration of fibrinolytic drugs is . . .