Investigating the effect of high spring incidence of pandemic influenza A(H1N1) on early autumn incidence.

A pandemic H1N1 infection wave in the USA occurred during spring 2009. Some hypothesized that for regions affected by the spring wave, an autumn outbreak would be less likely or delayed compared to unaffected regions because of herd immunity. We investigated this hypothesis using the Outpatient Influenza-like Illness (ILI) Network, a collaboration among the Centers for Disease Control and Prevention, health departments, and care providers. We evaluated the likelihood of high early autumn incidence given high spring incidence in core-based statistical areas (CBSAs). Using a surrogate incidence measure based on influenza-related illness ratios, we calculated the odds of high early autumn incidence given high spring incidence. CBSAs with high spring ILI ratios proved more likely than unaffected CBSAs to have high early autumn ratios, suggesting that elevated spring illness did not protect against early autumn increases. These novel methods are applicable to planning and studies involving other infectious diseases.

Vena cava filter fracture with migration to the pulmonary artery.

Inferior vena cava filter (IVCF) placement has been recommended by clinicians for patients with venous thromboembolism who are at high risk for pulmonary embolism. There are a number of complications with IVCF insertion, removal, and migration that have been reported in the literature. Although those resulting from structural failure are rare, they can also be among the most critical. We describe a 48-year-old woman with a history of hypercoagulability whose IVCF fractured during retrieval, resulting in partial embolization to the right middle lobe pulmonary artery.

Immune mechanisms in the pathogenesis of bronchiolitis obliterans syndrome after lung transplantation.

Lung transplantation is recognized as the only viable treatment option in a variety of end-stage pulmonary diseases. However, the long-term survival after lung transplantation is limited by the development of obliterative bronchiolitis, and its clinical correlate bronchiolitis obliterans syndrome (BOS), which is considered to represent chronic lung allograft rejection. Histopathologically, BOS is an inflammatory process that leads to fibrous scarring of the terminal and respiratory bronchioles and subsequent total occlusion of the airways. The specific etiology and pathogenesis of BOS are not well understood. The current premise is that BOS represents a common lesion in which different inflammatory insults such as ischemia-reperfusion, rejection, and infection can lead to a similar histological and clinical outcome. However, the low incidence of BOS in non-transplanted individuals and the observation that early development of BOS is predicted by the frequency and severity of acute rejection episodes indicate that alloimmune-dependent mechanisms play a crucial role in the pathogenesis of BOS. The evidence presented in this review indicates that BOS is the result of humoral and cellular immune responses developed against major histocompatibility complex molecules expressed by airway epithelial cells of the lung allograft. This process is aggravated by alloimmune-independent mechanisms such as ischemia-reperfusion and infection. Currently, treatment of BOS is frequently unsuccessful. Therefore, a better understanding of the immunopathogenesis of BOS is of paramount importance toward improving long-term patient and graft survival after lung transplantation.

Role of data aggregation in biosurveillance detection strategies with applications from ESSENCE.

INTRODUCTION: Syndromic surveillance systems are used to monitor daily electronic data streams for anomalous counts of features of varying specificity. The monitored quantities might be counts of clinical diagnoses, sales of over-the-counter influenza remedies, school absenteeism among a given age group, and so forth. Basic data-aggregation decisions for these systems include determining which records to count and how to group them in space and time. OBJECTIVES: This paper discusses the application of spatial and temporal data-aggregation strategies for multiple data streams to alerting algorithms appropriate to the surveillance region and public health threat of interest. Such a strategy was applied and evaluated for a complex, authentic, multisource, multiregion environment, including >2 years of data records from a system-evaluation exercise for the Defense Advanced Research Project Agency (DARPA). METHODS: Multivariate and multiple univariate statistical process control methods were adapted and applied to the DARPA data collection. Comparative parametric analyses based on temporal aggregation were used to optimize the performance of these algorithms for timely detection of a set of outbreaks identified in the data by a team of epidemiologists. RESULTS: The sensitivity and timeliness of the most promising detection methods were tested at empirically calculated thresholds corresponding to multiple practical false-alert rates. Even at the strictest false-alert rate, all but one of the outbreaks were detected by the best method, and the best methods achieved a 1-day median time before alert over the set of test outbreaks. CONCLUSIONS: These results indicate that a biosurveillance system can provide a substantial alerting-timeliness advantage over traditional public health monitoring for certain outbreaks. Comparative analyses of individual algorithm results indicate further achievable improvement in sensitivity and specificity.

Cut it out: Managing hepatic abscesses in patients with chronic granulomatous disease.

BACKGROUND: Hepatic abscesses develop in patients with chronic granulomatous disease (CGD) because the liver is a site of constant bacterial challenge. The authors investigated the roles of drainage and hepatic resection in the management of liver abscesses in CGD patients. METHODS: Medical records of CGD patients with hepatic abscesses from 1990 to 2001 were reviewed. RESULTS: There were 6 patients. Mean age of initial abscess was 7.2 years (range, 3 weeks to 18.9 years). All abscesses involved the right lobe of the liver (2 single, 4 multiple). All patients received appropriate antibiotics. Four patients were treated with one to 6 drainage procedures over one to 4 admissions before ultimately undergoing resection. The other 2 patients underwent primary resection without preliminary drainage. Of the 6 resections, 4 were nonanatomic, and 2 were anatomic. There was one major postoperative complication (bleeding) requiring reoperation. There were no recurrences after resection (mean follow-up 4.3 yr). Mean total days in hospital for the treatment of liver abscess was 49 in the preliminary drainage group and 8.5 in the primary resection group. Three patients required admission into the intensive care unit, one after a drainage procedure and 2 after resection. CONCLUSIONS: For CGD patients with hepatic abscesses, drainage procedures are associated with recurrence and prolonged hospitalization. Primary hepatic resection removing all involved tissue is safe and definitive for the management of this problem.