Summary of Pandemic Influenza Preparedness Models

Pandemic planning models of influenza coordinate response efforts across all levels of government. They aim to minimize death and serious illness, and to mitigate the economic and social impact of a pandemic. The H1N1 outbreak in 2009 brought to light a number of incongruences between international, federal, provincial, regional and local pandemic influenza planning. Specifically, it highlighted a lack of clear common communication protocols between all levels of decision makers; demonstrating the need for coordinated pandemic planning that addresses the health, social and economic impacts of an influenza pandemic. Extensive research has been done on pandemic preparedness, and has been used to create many response strategies. However, no studies were found that addressed the necessary elements of a preparedness plan. The purpose of this review was to summarize the main components of a comprehensive, community wide pandemic influenza preparedness plan to inform flu preparation by the Erie-St. Clair Local Health Integration Network (LHIN). Our search strategy was to identify pandemic plans from all over the world that were based on similar population demographics as Erie-St. Clair. Eleven pandemic preparedness plans were identified. The plans were then broken down into their key components, interpreted and synthesized. We found that there were two main sections in a pandemic influenza plan: the foundation, and preparedness activities. The foundation consists of objectives, principles, ethics and outlined roles and responsibilities. Preparedness activities include using pandemic phases, key domains and a risk assessment. The identification of these elements shall serve to inform the Erie-St. Clair LHIN’s pandemic influenza preparations, leading to an efficient, comprehensive plan

Follow-up of Staphylococcus aureus nasal carriage after 8 years: redefining the persistent carrier state

Studies of Staphylococcus aureus nasal carriage have distinguished three carriage patterns: persistent, intermittent, and noncarriage. The criteria used to identify these carriage patterns have been inconsistent. In 1988 the S. aureus nasal carrier index, i.e., the proportion of nasal swab specimen cultures yielding S. aureus, was determined for 91 staff members of various departments of a large university hospital by obtaining weekly nasal swab specimens for culture over a 12-week period. Thirty-three (36%) persons had carrier indices of 0.80 or higher, 15 (17%) had indices between 0.1 and 0.7, and 43 (47%) had indices of zero. In 1995, 17 individuals with carrier indices of 0.80 or higher in 1988 were available for reexamination. For 12 (71%) of these individuals, S. aureus was again isolated from a single nasal swab, i.e., from each individual with a 1988 carrier index of 1.0 but from only half of those with indices below 1.0. Genotyping (by randomly amplified polymorphic DNA analysis and pulsed-field gel electrophoresis) of all S. aureus strains showed that strains isolated from only three individuals, all with 1988 carrier indices of 1.0, in 1988 and 1995 showed genetic similarity. In conclusion, persistent S. aureus nasal carriage is a unique characteristic of a fraction of the population, and the attribute "persistent" should be confined to those individuals for whom serial nasal swab specimen cultures consistently yield S. aureus

Comparative genome analysis of a large Dutch Legionella pneumophila strain collection identifies five markers highly correlated with clinical strains

<p>Abstract</p> <p>Background</p> <p>Discrimination between clinical and environmental strains within many bacterial species is currently underexplored. Genomic analyses have clearly shown the enormous variability in genome composition between different strains of a bacterial species. In this study we have used <it>Legionella pneumophila</it>, the causative agent of Legionnaire's disease, to search for genomic markers related to pathogenicity. During a large surveillance study in The Netherlands well-characterized patient-derived strains and environmental strains were collected. We have used a mixed-genome microarray to perform comparative-genome analysis of 257 strains from this collection.</p> <p>Results</p> <p>Microarray analysis indicated that 480 DNA markers (out of in total 3360 markers) showed clear variation in presence between individual strains and these were therefore selected for further analysis. Unsupervised statistical analysis of these markers showed the enormous genomic variation within the species but did not show any correlation with a pathogenic phenotype. We therefore used supervised statistical analysis to identify discriminating markers. Genetic programming was used both to identify predictive markers and to define their interrelationships. A model consisting of five markers was developed that together correctly predicted 100% of the clinical strains and 69% of the environmental strains.</p> <p>Conclusions</p> <p>A novel approach for identifying predictive markers enabling discrimination between clinical and environmental isolates of <it>L. pneumophila </it>is presented. Out of over 3000 possible markers, five were selected that together enabled correct prediction of all the clinical strains included in this study. This novel approach for identifying predictive markers can be applied to all bacterial species, allowing for better discrimination between strains well equipped to cause human disease and relatively harmless strains.</p

How often is a work-up for Legionella pursued in patients with pneumonia? A retrospective study

<p>Abstract</p> <p>Background</p> <p>It is unclear how often patients with pneumonia are assessed for <it>Legionella </it>in endemic areas. Additionally, the sensitivity of the IDSA/ATS criteria for recommended <it>Legionella </it>testing is undefined.</p> <p>Methods</p> <p>We performed a single-center, retrospective study of patients diagnosed with <it>Legionella </it>pneumonia at our hospital to determine: 1) how often <it>Legionella </it>diagnostic testing is obtained on patients with pneumonia at the time of hospitalization or when pneumonia developed during hospitalization; and 2) how often patient's with <it>Legionella </it>pneumonia met at least one of the five criteria in the IDSA/ATS guidelines recommending a work-up for <it>Legionella</it>. Patients with <it>Legionella </it>pneumonia were identified using an infection control software program. Medical records of these patients were then reviewed.</p> <p>Results</p> <p>Thirty-five percent of patients with a discharge diagnosis of pneumonia had <it>Legionella </it>urine antigen testing and/or a <it>Legionella </it>culture performed. Forty-four percent of patients who had a bronchoscopic specimen sent for microbiologic testing had a <it>Legionella </it>culture performed on the bronchoscopic specimen and/or <it>Legionella </it>urine antigen testing. Of 37 adult patients with <it>Legionella </it>pneumonia, 22 (59%) met the IDSA-ATS criteria recommending <it>Legionella </it>testing.</p> <p>Conclusion</p> <p>Following current recommendations for <it>Legionella </it>testing missed 41% of <it>Legionella </it>cases in adults in our single-center study. A work-up for <it>Legionella </it>(i.e., urine antigen test and/or culture) was performed in less than half of patients who have a bronchoscopic specimen sent for microbiologic testing.</p