Research Committee Selected Articles for the Week of June_22_2015
★ ***-Article is considered for Award Nomination***
Lee J., Jung E. A spatial-temporal transmission model and early intervention policies of 2009 A/H1N1 influenza in South Korea
Liu M., Zhang Z., Zhang D. A dynamic allocation model for medical resources in the control of influenza diffusion ★
Willem L., Stijven S., Tijskens E., Beutels P., Hens N., Broeckhove J. Optimizing agent-based transmission models for infectious diseases
Badenhorst M., Page P., Ganswindt A., Laver P., Guthrie A., Schulman M. Detection of equine herpesvirus-4 and physiological stress patterns in young Thoroughbreds consigned to a South African auction sale
Wells C., Yamin D., Ndeffo-Mbah M.L., Wenzel N., Gaffney S.G., Townsend J.P., Meyers L.A., Fallah M. Harnessing Case Isolation and Ring Vaccination to Control Ebola
Sang S., Gu S., Bi P., Yang W., Yang Z., Xu L., Yang J., Liu X., Jiang T., Wu H., Chu C., Liu Q. Predicting Unprecedented Dengue Outbreak Using Imported Cases and Climatic Factors in Guangzhou, 2014 ★
Ahmed S.S., Oviedo-Orta E., Mekaru S.R., Freifeld C.C., Tougas G., Brownstein J.S. Surveillance for Neisseria meningitidis disease activity and transmission using information technology ★
Kesorn K., Ongruk P., Chompoosri J., Phumee A., Thavara U., Tawatsin A., Siriyasatien P. Morbidity rate prediction of dengue hemorrhagic fever (DHF) using the support vector machine and the Aedes aegypti infection rate in similar climates and geographical areas ★
Ibanez-Justicia A., Cianci D. Modelling the spatial distribution of the nuisance mosquito species Anopheles plumbeus (Diptera: Culicidae) in the Netherlands Mathematical models for parasites and vectors
Rodriguez-Prieto V., Vicente-Rubiano M., Sanchez-Matamoros A., Rubio-Guerri C., Melero M., Martinez- Systematic review of surveillance systems and methods for early detection of exotic, new and re-emerging diseases in animal populations ★
Hickmann K.S., Fairchild G., Priedhorsky R., Generous N., Hyman J.M., Deshpande A., Del Valle S.Y. Forecasting the 2013–2014 Influenza Season Using Wikipedia ★
Paul M.M., Greene C.M., Newton-Dame R., Thorpe L.E., Perlman S.E., McVeigh K.H., Gourevitch M.N. The state of population health surveillance using electronic health records: A narrative review
Brookes V.J., Hernandez-Jover M., Black P.F., Ward M.P. Preparedness for emerging infectious diseases: Pathways from anticipation to action
Tinguely J., Lindemann J. Emerging infections and old friends: remaining prepared in South Dakota
Green H.K., Zhao H., Boddington N.L., Andrews N., Durnall H., Elliot A.J., Smith G., Gorton R., Dona Detection of varying influenza circulation within England in 2012/13: Informing antiviral prescription and public health response
Nakao J.H., Pringle J., Jones R.W., Nix B.E., Borders J., Heseltine G., Gomez T.M., McCluskey B., Ro 'One Health' investigation: Outbreak of human Salmonella Braenderup infections traced to a mail-order hatchery-United States, 2012-2013
Weng W., Ni S. Evaluation of containment and mitigation strategies for an influenza A pandemic in China
Rachah A., Torres D.F.M. Mathematical modelling, simulation, and optimal control of the 2014 ebola outbreak in West Africa ★
Von Dobschuetz S., De Nardi M., Harris K.A., Munoz O., Breed A.C., Wieland B., Dauphin G., Lubroth J Influenza surveillance in animals: What is our capacity to detect emerging influenza viruses with zoonotic potential?
Yom-Tov E., Johansson-Cox I., Lampos V., Hayward A.C. Estimating the secondary attack rate and serial interval of influenza-like illnesses using social media ★
Morato D.G., Barreto F.R., Braga J.U., Natividade M.S., da Costa M.C.N., Morato V., Da Teixeira M.G. The spatiotemporal trajectory of a dengue epidemic in a medium-sized city
Watson C.H., Edmunds W.J. A review of typhoid fever transmission dynamic models and economic evaluations of vaccination ★
Huang Q.S., Turner N., Baker M.G., Williamson D.A., Wong C., Webby R., Widdowson M.-A., Aley D., Ban Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance
Hassanian-Moghaddam H., Nikfarjam A., Mirafzal A., Saberinia A., Nasehi A.A., Masoumi Asl H., Memary Methanol mass poisoning in Iran: Role of case finding in outbreak management
Zhao B., Qin S., Teng Z., Chen J., Yu X., Gao Y., Shen J., Cui X., Zeng M., Zhang X. Epidemiological study of influenza B in Shanghai during the 2009-2014 seasons: Implications for influenza vaccination strategy
Dugas A.F., Valsamakis A., Atreya M.R., Thind K., Alarcon Manchego P., Faisal A., Gaydos C.A., Rothm Clinical diagnosis of influenza in the ED ★
Acosta A.M., DeBolt C., Tasslimi A., Lewis M., Stewart L.K., Misegades L.K., Messonnier N.E., Clark Tdap vaccine effectiveness in adolescents during the 2012 Washington State pertussis epidemic
Wolff G., Bell M., Escobar J., Ruiz S. Estimates of pertussis vaccine effectiveness in United States air force pediatric dependents
Roberts-Witteveen A., Reinten T., Christensen A., Sintchenko V., Seale P., Lowbridge C. Multidrug-resistant tuberculosis in New South Wales, Australia, 1999-2010: A case series report
A spatial-temporal transmission model and early intervention policies of 2009 A/H1N1 influenza in South Korea
We developed a spatial-temporal model of the 2009 A/H1N1 influenza pandemic in the Seoul metropolitan area (SMA), which is located in the north-west of South Korea and is the second-most complex metropolitan area worldwide. This multi-patch influenza model consists of a SEIAR influenza transmission model and flow model between two districts. This model is based on the daily confirmed cases of A/H1N1 influenza collected by the Korea Center for Disease Control and Prevention from April 27 to September 15, 200 9 and the daily commuting data from 33 districts of SMA reported in the 2010 Population and Housing Census (PHC). We analyzed the spread patterns of 2009 influenza in the SMA by the reproductive numbers and geographic information systems. During the early period of novel influenza pandemics, when pharmaceutical interventions are lacking, non-pharmaceutical public health interventions will be the most critical strategies for impeding the spread of influenza and delaying an epidemic. Using the spatial-tempora l model developed herein, we also investigated the impact of non-pharmaceutical public health interventions, isolation and/or commuting restrictions, on the incidence reduction in various scenarios. Our model provides scientific evidence for predicting the spread of disease and preparedness for a future pandemic. © 2015 Elsevier Ltd.'
A dynamic allocation model for medical resources in the control of influenza diffusion
In this paper, we develop a unique time-varying forecasting model for dynamic demand of medical resources based on a susceptible-exposed-infected-recovered (SEIR) influenza diffusion model. In this forecasting mechanism, medical resources allocated in the early period will take effect in subduing the spread of influenza and thus impact the demand in the later period. We adopt a discrete time-space network to describe the medical resources allocation process following a hypothetical influenza outbreak in a r egion. The entire medical resources allocation process is constructed as a multi-stage integer programming problem. At each stage, we solve a cost minimization sub-problem subject to the time-varying demand. The corresponding optimal allocation result is t hen used as an input to the control process of influenza spread, which in turn determines the demand for the next stage. In addition, we present a comparison between the proposed model and an empirical model. Our results could help decision makers prepare for a pandemic, including how to allocate limited resources dynamically. © 2015 Systems Engineering Society of China and Springer-Verlag Berlin Heidelberg'
Optimizing agent-based transmission models for infectious diseases
Background: Infectious disease modeling and computational power have evolved such that large-scale agent-based models (ABMs) have become feasible. However, the increasing hardware complexity requires adapted software designs to achieve the full potential o f current high-performance workstations. Results: We have found large performance differences with a discrete-time ABM for close-contact disease transmission due to data locality. Sorting the population according to the social contact clusters reduced simu lation time by a factor of two. Data locality and model performance can also be improved by storing person attributes separately instead of using person objects. Next, decreasing the number of operations by sorting people by health status before processing disease transmission has also a large impact on model performance. Depending of the clinical attack rate, target population and computer hardware, the introduction of the sort phase decreased the run time from 26 % up to more than 70 %. We have investigat ed the application of parallel programming techniques and found that the speedup is significant but it drops quickly with the number of cores. We observed that the effect of scheduling and workload chunk size is model specific and can make a large differen ce. Conclusions: Investment in performance optimization of ABM simulator code can lead to significant run time reductions. The key steps are straightforward: the data structure for the population and sorting people on health status before effecting disease propagation. We believe these conclusions to be valid for a wide range of infectious disease ABMs. We recommend that future studies evaluate the impact of data management, algorithmic procedures and parallelization on model performance. © 2015 Willem et a l.; licensee BioMed Central.'
Detection of equine herpesvirus-4 and physiological stress patterns in young Thoroughbreds consigned to a South African auction sale
Background: The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together with physiological stress related to their transport and confinement at a sales complex, may be associated with shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds consigned from eight farms, originating from three provinces representative of the South African Thoroughbred breeding demographic to a sales complex. Nasal swabs for quantitative real-time polymerase chain reaction (qPCR) assay to detect EHV-1 and -4 nucleic acid and blood samples for enzyme-linked immunosorbent assay for EHV-1 a nd -4 antibodies were collected from all horses on arrival and departure. Additional nasal swabs for qPCR were obtained serially from those displaying pyrexia and, or nasal discharge. Daily faecal samples were used for determination of faecal glucocorticoi d metabolite (FGM) concentrations as a measurement of physiological stress and these values were modelled to determine the factors best explaining FGM variability. Results: EHV-4 nucleic acid was detected in 14.4 % and EHV-1 from none of the animals in the study population. Most (93.3 %) and very few (1.1 %) of this population showed antibodies indicating prior exposure to EHV-4 and EHV-1 respectively. Pyrexia and nasal discharge were poor predictors for detecting EHV-4 nucleic acid. The horses' FGM concent rations increased following arrival before decreasing for most of the remaining study period including the auction process. Model averaging showed that variation in FGM concentrations was best explained by days post-arrival and transport duration. Conclusi ons: In this study population, sales consignment was associated with limited detection of EHV-4 nucleic acid in nasal secretions, with most showing prior exposure to EHV-4 and very few to EHV-1. The physiolog'
Harnessing Case Isolation and Ring Vaccination to Control Ebola
As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy can didate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine . To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest tha t if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benef it of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts. © 2015 Wells et al.'
Predicting Unprecedented Dengue Outbreak Using Imported Cases and Climatic Factors in Guangzhou, 2014
Dengue is endemic in more than 100 countries, mainly in tropical and subtropical regions, and the incidence has increased 30-fold in the past 50 years. The situation of dengue in China has become more and more severe, with an unprecedented dengue outbreak hitting south China in 2014. Building a dengue early warning system is therefore urgent and necessary for timely and effective response. In the study we developed a time series Poisson multivariate regression model using imported dengue cases, local minimu m temperature and accumulative precipitation to predict the dengue occurrence in four districts of Guangzhou, China. The time series data were decomposed into seasonal, trend and remainder components using a seasonal-trend decomposition procedure based on loess (STL). The time lag of climatic factors included in the model was chosen based on Spearman correlation analysis. Autocorrelation, seasonality and long-term trend were controlled in the model. A best model was selected and validated using Generalized Cross Validation (GCV) score and residual test. The data from March 2006 to December 2012 were used to develop the model while the data from January 2013 to September 2014 were employed to validate the model. Time series Poisson model showed that imported cases in the previous month, minimum temperature in the previous month and accumulative precipitation with three month lags could project the dengue outbreaks occurred in 2013 and 2014 after controlling the autocorrelation, seasonality and long-term trend. Together with the sole transmission vector Aedes albopictus, imported cases, monthly minimum temperature and monthly accumulative precipitation may be used to develop a low-cost effective early warning system. © 2015 Sang et al.'
Surveillance for Neisseria meningitidis disease activity and transmission using information technology
Background: While formal reporting, surveillance, and response structures remain essential to protecting public health, a new generation of freely accessible, online, and real-time informatics tools for disease tracking are expanding the ability to raise e arlier public awareness of emerging disease threats. The rationale for this study is to test the hypothesis that the HealthMap informatics tools can complement epidemiological data captured by traditional surveillance monitoring systems for meningitis due to Neisseria meningitides (N. meningitides) by highlighting severe transmissible disease activity and outbreaks in the United States. Methods: Annual analyses of N. meningitides disease alerts captured by HealthMap were compared to epidemiological data cap tured by the Centers for Disease Control's Active Bacterial Core surveillance (ABCs) for N. meningitides. Morbidity and mortality case reports were measured annually from 2010 to 2013 (HealthMap) and 2005 to 2012 (ABCs). Findings: HealthMap N. meningitides monitoring captured 80-90% of alerts as diagnosed N. meningitides, 5-20% of alerts as suspected cases, and 5-10% of alerts as related news articles. HealthMap disease alert activity for emerging disease threats related to N. meningitides were in agreement with patterns identified historically using traditional surveillance systems. HealthMap's strength lies in its ability to provide a cumulative "snapshot" of weak signals that allows for rapid dissemination of knowledge and earlier public awareness of pote ntial outbreak status while formal testing and confirmation for specific serotypes is ongoing by public health authorities. Conclusions: The underreporting of disease cases in internet-based data streaming makes inadequate any comparison to epidemiological trends illustrated by the more comprehensive ABCs network published by the Centers for Disease Control. However, the expected delays in compiling confirmatory reports by traditional surveillance systems (at'
Morbidity rate prediction of dengue hemorrhagic fever (DHF) using the support vector machine and the Aedes aegypti infection rate in similar climates and geographical areas
Background: In the past few decades, several researchers have proposed highly accurate prediction models that have typically relied on climate parameters. However, climate factors can be unreliable and can lower the effectiveness of prediction when they ar e applied in locations where climate factors do not differ significantly. The purpose of this study was to improve a dengue surveillance system in areas with similar climate by exploiting the infection rate in the Aedes aegypti mosquito and using the suppo rt vector machine (SVM) technique for forecasting the dengue morbidity rate. Methods and Findings: Areas with high incidence of dengue outbreaks in central Thailand were studied. The proposed framework consisted of the following three major parts: 1) data integration, 2) model construction, and 3) model evaluation. We discovered that the Ae. aegypti female and larvae mosquito infection rates were significantly positively associated with the morbidity rate. Thus, the increasing infection rate of female mosqu itoes and larvae led to a higher number of dengue cases, and the prediction performance increased when those predictors were integrated into a predictive model. In this research, we applied the SVM with the radial basis function (RBF) kernel to forecast th e high morbidity rate and take precautions to prevent the development of pervasive dengue epidemics. The experimental results showed that the introduced parameters significantly increased the prediction accuracy to 88.37% when used on the test set data, an d these parameters led to the highest performance compared to state-of-the-art forecasting models. Conclusions: The infection rates of the Ae. aegypti female mosquitoes and larvae improved the morbidity rate forecasting efficiency better than the climate p arameters used in classical frameworks. We demonstrated that the SVM-R-based model has high generalization performance and obtained the highest prediction performance compared to classical models as measured'
Modelling the spatial distribution of the nuisance mosquito species Anopheles plumbeus (Diptera: Culicidae) in the Netherlands Mathematical models for parasites and vectors
Background: Landscape modifications, urbanization or changes of use of rural-agricultural areas can create more favourable conditions for certain mosquito species and therefore indirectly cause nuisance problems for humans. This could potentially result in mosquito-borne disease outbreaks when the nuisance is caused by mosquito species that can transmit pathogens. Anopheles plumbeus is a nuisance mosquito species and a potential malaria vector. It is one of the most frequently observed species in the Nether lands. Information on the distribution of this species is essential for risk assessments. The purpose of the study was to investigate the potential spatial distribution of An. plumbeus in the Netherlands. Methods: Random forest models were used to link the occurrence and the abundance of An. plumbeus with environmental features and to produce distribution maps in the Netherlands. Mosquito data were collected using a cross-sectional study design in the Netherlands, from April to October 2010-2013. The enviro nmental data were obtained from satellite imagery and weather stations. Statistical measures (accuracy for the occurrence model and mean squared error for the abundance model) were used to evaluate the models performance. The models were externally validat ed. Results: The maps show that forested areas (centre of the Netherlands) and the east of the country were predicted as suitable for An. plumbeus. In particular high suitability and high abundance was predicted in the south-eastern provinces Limburg and N orth Brabant. Elevation, precipitation, day and night temperature and vegetation indices were important predictors for calculating the probability of occurrence for An. plumbeus. The probability of occurrence, vegetation indices and precipitation were impo rtant for predicting its abundance. The AUC value was 0.73 and the error in the validation was 0.29; the mean squared error value was 0.12. Conclusions: The areas identified by the model as suitable and with'
Systematic review of surveillance systems and methods for early detection of exotic, new and re-emerging diseases in animal populations
In this globalized world, the spread of new, exotic and re-emerging diseases has become one of the most important threats to animal production and public health. This systematic review analyses conventional and novel early detection methods applied to surv eillance. In all, 125 scientific documents were considered for this study. Exotic (n = 49) and re-emerging (n = 27) diseases constituted the most frequently represented health threats. In addition, the majority of studies were related to zoonoses (n = 66). The approaches found in the review could be divided in surveillance modalities, both active (n = 23) and passive (n = 5); and tools and methodologies that support surveillance activities (n = 57). Combinations of surveillance modalities and tools (n = 40) were also found. Risk-based approaches were very common (n = 60), especially in the papers describing tools and methodologies (n = 50). The main applications, benefits and limitations of each approach were extracted from the papers. This information will be very useful for informing the development of tools to facilitate the design of cost-effective surveillance strategies. Thus, the current literature review provides key information about the advantages, disadvantages, limitations and potential applicatio n of methodologies for the early detection of new, exotic and re-emerging diseases. © 2014 Cambridge University Press.'
Forecasting the 2013–2014 Influenza Season Using Wikipedia
Infectious diseases are one of the leading causes of morbidity and mortality around the world; thus, forecasting their impact is crucial for planning an effective response strategy. According to the Centers for Disease Control and Prevention (CDC), seasona l influenza affects 5% to 20% of the U.S. population and causes major economic impacts resulting from hospitalization and absenteeism. Understanding influenza dynamics and forecasting its impact is fundamental for developing prevention and mitigation strat egies. We combine modern data assimilation methods with Wikipedia access logs and CDC influenza-like illness (ILI) reports to create a weekly forecast for seasonal influenza. The methods are applied to the 2013-2014 influenza season but are sufficiently ge neral to forecast any disease outbreak, given incidence or case count data. We adjust the initialization and parametrization of a disease model and show that this allows us to determine systematic model bias. In addition, we provide a way to determine wher e the model diverges from observation and evaluate forecast accuracy. Wikipedia article access logs are shown to be highly correlated with historical ILI records and allow for accurate prediction of ILI data several weeks before it becomes available. The r esults show that prior to the peak of the flu season, our forecasting method produced 50% and 95% credible intervals for the 2013-2014 ILI observations that contained the actual observations for most weeks in the forecast. However, since our model does not account for re-infection or multiple strains of influenza, the tail of the epidemic is not predicted well after the peak of flu season has passed.'
The state of population health surveillance using electronic health records: A narrative review
Electronic health records (EHRs) are transforming the practice of clinical medicine, but the extent to which they are being harnessed to advance public health goals remains uncertain. Data extracted from integrated EHR networks offer the potential for almo st real-time determination of the health status of populations in care, for targeting interventions to vulnerable populations, and for monitoring the impact of such initiatives over time. This is especially true in ambulatory care settings, which are uniqu ely suited for monitoring population health indicators including risk factors and disease management indicators associated with chronic diseases. As efforts gather steam to integrate health data across delivery systems, large networks of electronic patient information are increasingly emerging. Few of the national population health surveillance systems that rely on EHR data have progressed beyond laying groundwork to launch and maintain EHR-based surveillance, but a limited number of more focused or local e fforts have demonstrated innovation in population health surveillance. Common challenges include incompleteness of population coverage, lack of interoperability across data systems, and variable data quality. This review defines progress, opportunities, an d challenges in using EHR data for population health surveillance. © Copyright 2015, Mary Ann Liebert, Inc.'
Preparedness for emerging infectious diseases: Pathways from anticipation to action
Emerging and re-emerging infectious disease (EID) events can have devastating human, animal and environmental health impacts. The emergence of EIDs has been associated with interconnected economic, social and environmental changes. Understanding these chan ges is crucial for EID preparedness and subsequent prevention and control of EID events. The aim of this review is to describe tools currently available for identification, prioritization and investigation of EIDs impacting human and animal health, and how these might be integrated into a systematic approach for directing EID preparedness. Environmental scanning, foresight programmes, horizon scanning and surveillance are used to collect and assess information for rapidly responding to EIDs and to anticipat e drivers of emergence for mitigating future EID impacts. Prioritization of EIDs-using transparent and repeatable methods-based on disease impacts and the importance of those impacts to decision-makers can then be used for more efficient resource allocatio n for prevention and control. Risk assessment and simulation modelling methods assess the likelihood of EIDs occurring, define impact and identify mitigation strategies. Each of these tools has a role to play individually; however, we propose integration o f these tools into a framework that enhances the development of tactical and strategic plans for emerging risk preparedness. © 2014 Cambridge University Press.'
Emerging infections and old friends: remaining prepared in South Dakota
Recent reports of serious infection outbreaks internationally remind us of the importance of accurate information and continual vigilance. The Ebola outbreak in West Africa has captured headlines as the most severe outbreak in the history of this disease. West Nile disease, measles, pertussis and tuberculosis infect South Dakota patients on a yearly basis. A significant rise in syphilis cases has prompted recommendations for increased prenatal screening. The more unusual viral diseases, Ebola, Middle East r espiratory syndrome (MERS) and Chikungunha virus, receive media attention but present minimal risk to the state, while the annual influenza epidemic continues to plague us all. We review these infections, both old and emerging, and describe national and lo cal preparedness practices.'
Detection of varying influenza circulation within England in 2012/13: Informing antiviral prescription and public health response
Background Subnational variation of 2009 pandemic influenza activity in England has been reported; however, little work has been published on this topic for seasonal influenza. If variation is present, this knowledge may assist with both identifying the on set of influenza epidemics, informing community antiviral prescription and local health planning. Methods An end-of-season analysis of influenza surveillance systems (acute respiratory outbreaks, primary care consultations, virological testing, influenza-c onfirmed secondary care admissions and excess all-cause mortality) was undertaken at national and subnational levels for 2012/13 when influenza B and A(H3N2) dominated. Results National community antiviral prescription was recommended in Week 51 following national threshold exceedance. However, this was preceded up to 2 weeks by subnational influenza activity in 2/9 regions in England. Regional variation in circulation of influenza subtypes was observed and severe influenza surveillance data sources were ab le to monitor the subnational impact. Conclusions Evidence of virological activity in two or more regions above a threshold indicated the onset of the 2012/13 season. Subnational thresholds should be determined and evaluated in order to improve timeliness of the national antiviral alert. During the season, outputs should be reported at levels that can inform local public health responses and variation considered when retrospectively evaluating the impact of interventions. © 2014 The Author 2014. Published b y Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.'
'One Health' investigation: Outbreak of human Salmonella Braenderup infections traced to a mail-order hatchery-United States, 2012-2013
Human salmonellosis linked to contact with live poultry is an increasing public health concern. In 2012, eight unrelated outbreaks of human salmonellosis linked to live poultry contact resulted in 517 illnesses. In July 2012, PulseNet, a national molecular surveillance network, reported a multistate cluster of a rare strain of Salmonella Braenderup infections which we investigated. We defined a case as infection with the outbreak strain, determined by pulsed-field gel electrophoresis, with illness onset fro m 25 July 2012-27 February 2013. Ill persons and mail-order hatchery (MOH) owners were interviewed using standardized questionnaires. Traceback and environmental investigations were conducted. We identified 48 cases in 24 states. Twenty-six (81%) of 32 ill persons reported live poultry contact in the week before illness; case-patients named 12 different MOHs from eight states. The investigation identified hatchery D as the ultimate poultry source. Sampling at hatchery D yielded the outbreak strain. Hatchery D improved sanitation procedures and pest control; subsequent sampling failed to yield Salmonella. This outbreak highlights the interconnectedness of humans, animals, and the environment and the importance of industry knowledge and involvement in solving complex outbreaks. Preventing these infections requires a 'One Health' approach that leverages expertise in human, animal, and environmental health. © 2015 Cambridge University Press.'
Evaluation of containment and mitigation strategies for an influenza A pandemic in China
The world is still in heightened awareness of the potential threat of another influenza pandemic, although it has been 5 years since the 2009 influenza A (H1N1) pandemic. Evaluation of the adopted intervention strategies for handling the 2009 H1N1 pandemic is helpful for dealing with future outbreaks. In this paper we developed a hybrid model combining meta-population and agent-based models to evaluate the containment and mitigation strategies (e.g., contact tracing and quarantine of contacts at assembly si tes in the early phase, more medical institutions to detect cases and treat serious patients in the developing phase, and rapid vaccines delivered to students first) for an H1N1 pandemic that were adopted in China. We find that the presented model can retr ospectively fit relatively well to the spreading progress through comparison of the simulation results with actual infections data, and it can be used for practical application in evaluating the containment and mitigation strategies for an influenza pandem ic if model validation and parameter estimation can be conducted by using actual data. The results will contribute to understanding the spread of viruses and the control of infectious diseases, and to helping government officials create policies on handlin g an influenza pandemic, especially beneficial to a large and diverse country such as the People's Republic of China. © 2015 The Author(s).'
Mathematical modelling, simulation, and optimal control of the 2014 ebola outbreak in West Africa
The Ebola virus is currently one of the most virulent pathogens for humans. The latest major outbreak occurred in Guinea, Sierra Leone, and Liberia in 2014. With the aim of understanding the spread of infection in the affected countries, it is crucial to m odelize the virus and simulate it. In this paper, we begin by studying a simple mathematical model that describes the 2014 Ebola outbreak in Liberia. Then, we use numerical simulations and available data provided by the World Health Organization to validat e the obtained mathematical model. Moreover, we develop a new mathematical model including vaccination of individuals. We discuss different cases of vaccination in order to predict the effect of vaccination on the infected individuals over time. Finally, w e apply optimal control to study the impact of vaccination on the spread of the Ebola virus. The optimal control problem is solved numerically by using a direct multiple shooting method. © 2015 Amira Rachah and Delfim F. M. Torres.'
Influenza surveillance in animals: What is our capacity to detect emerging influenza viruses with zoonotic potential?
A survey of national animal influenza surveillance programmes was conducted to assess the current capacity to detect influenza viruses with zoonotic potential in animals (i.e. those influenza viruses that can be naturally transmitted between animals and hu mans) at regional and global levels. Information on 587 animal influenza surveillance system components was collected for 99 countries from Chief Veterinary Officers (CVOs) (n = 94) and published literature. Less than 1% (n = 4) of these components were sp ecifically aimed at detecting influenza viruses with pandemic potential in animals (i.e. those influenza viruses that are capable of causing epidemic spread in human populations over large geographical regions or worldwide), which would have zoonotic poten tial as a prerequisite. Those countries that sought to detect influenza viruses with pandemic potential searched for such viruses exclusively in domestic pigs. This work shows the global need for increasing surveillance that targets potentially zoonotic in fluenza viruses in relevant animal species. © 2014 Food and Agriculture Organization of the United Nations.'
Estimating the secondary attack rate and serial interval of influenza-like illnesses using social media
Objectives: Knowledge of the secondary attack rate (SAR) and serial interval (SI) of influenza is important for assessing the severity of seasonal epidemics of the virus. To date, such estimates have required extensive surveys of target populations. Here, we propose a method for estimating the intrafamily SAR and SI from postings on the Twitter social network. This estimate is derived from a large number of people reporting ILI symptoms in them and\or their immediate family members. Design: We analyze data from the 2012-2013 and the 2013-2014 influenza seasons in England and find that increases in the estimated SAR precede increases in ILI rates reported by physicians. Results: We hypothesize that observed variations in the peak value of SAR are related to t he appearance of specific strains of the virus and demonstrate this by comparing the changes in SAR values over time in relation to known virology. In addition, we estimate SI (the average time between cases) as 2·41 days for 2012 and 2·48 days for 2013. C onclusions: The proposed method can assist health authorities by providing near-real-time estimation of SAR and SI, and especially in alerting to sudden increases thereof. © 2015 The Authors.'
The spatiotemporal trajectory of a dengue epidemic in a medium-sized city
Understanding the transmission dynamics of infectious diseases is important to allow for improvements of control measures. To investigate the spatiotemporal pattern of an epidemic dengue occurred at a medium-sized city in the Northeast Region of Brazil in 2009, we conducted an ecological study of the notified dengue cases georeferenced according to epidemiological week (EW) and home address. Kernel density estimation and space-time interaction were analysed using the Knox method. The evolution of the epidem ic was analysed using an animated projection technique. The dengue incidence was 6.918.7/100,000 inhabitants; the peak of the epidemic occurred from 8 February-1 March, EWs 6-9 (828.7/100,000 inhabitants). There were cases throughout the city and was ident ified space-time interaction. Three epicenters were responsible for spreading the disease in an expansion and relocation diffusion pattern. If the health services could detect in real time the epicenters and apply nimbly control measures, may possibly redu ce the magnitude of dengue epidemics. © 2015 Fundacao Oswaldo Cruz. All rights reserved.'
A review of typhoid fever transmission dynamic models and economic evaluations of vaccination
Despite a recommendation by the World Health Organization (WHO) that typhoid vaccines be considered for the control of endemic disease and outbreaks, programmatic use remains limited. Transmission models and economic evaluation may be informative in decisi on making about vaccine programme introductions and their role alongside other control measures. A literature search found few typhoid transmission models or economic evaluations relative to analyses of other infectious diseases of similar or lower health burden.Modelling suggests vaccines alone are unlikely to eliminate endemic disease in the short to medium term without measures to reduce transmission from asymptomatic carriage. The single identified data-fitted transmission model of typhoid vaccination s uggests vaccines can reduce disease burden substantially when introduced programmatically but that indirect protection depends on the relative contribution of carriage to transmission in a given setting. This is an important source of epidemiological uncer tainty, alongside the extent and nature of natural immunity.Economic evaluations suggest that typhoid vaccination can be cost-saving to health services if incidence is extremely high and cost-effective in other high-incidence situations, when compared to W HO norms. Targeting vaccination to the highest incidence age-groups is likely to improve cost-effectiveness substantially. Economic perspective and vaccine costs substantially affect estimates, with disease incidence, case-fatality rates, and vaccine effic acy over time also important determinants of cost-effectiveness and sources of uncertainty. Static economic models may under-estimate benefits of typhoid vaccination by omitting indirect protection.Typhoid fever transmission models currently require per-se tting epidemiological parameterisation to inform their use in economic evaluation, which may limit their generalisability. We found no economic evaluation based on transmission dynamic modelling, and no econo'
Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance
The 2009 influenza A(H1N1)pdm09 pandemic highlighted the need for improved scientific knowledge to support better pandemic preparedness and seasonal influenza control. The Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (S HIVERS) project, a 5-year (2012-2016) multiagency and multidisciplinary collaboration, aimed to measure disease burden, epidemiology, aetiology, risk factors, immunology, effectiveness of vaccination and other prevention strategies for influenza and other respiratory infectious diseases of public health importance. Two active, prospective, population-based surveillance systems were established for monitoring influenza and other respiratory pathogens among those hospitalized patients with acute respiratory i llness and those enrolled patients seeking consultations at sentinel general practices. In 2015, a sero-epidemiological study will use a sample of patients from the same practices. These data will provide a full picture of the disease burden and risk facto rs from asymptomatic infections to severe hospitalized disease and deaths and related economic burden. The results during the first 2 years (2012-2013) provided scientific evidence to (a) support a change to NZ's vaccination policy for young children due t o high influenza hospitalizations in these children; (b) contribute to the revision of the World Health Organization's case definition for severe acute respiratory illness for global influenza surveillance; and (c) contribute in part to vaccine strain sele ction using vaccine effectiveness assessment in the prevention of influenza-related consultations and hospitalizations. In summary, SHIVERS provides valuable international platforms for supporting seasonal influenza control and pandemic preparedness, and r esponding to other emerging/endemic respiratory-related infections. © 2015 The Authors.'
Methanol mass poisoning in Iran: Role of case finding in outbreak management
Background There are no guidelines addressing the public health aspects of methanol poisoning during larger outbreaks. The current study was done to discuss the role of active case finding and a national guideline that organizes all available resources acc ording to a triage strategy in the successful management of a methanol mass poisoning in Rafsanjan, Iran, in May 2013. Methods A retrospective cross-sectional study was performed reviewing the outbreak Emergency Operation Center files. The objectives were to describe the characteristics, management and outcome of a methanol outbreak using Active Case Finding to trace the victims. Results A total of 694 patients presented to emergency departments in Rafsanjan after public announcement of the outbreak between 29th May and 3rd June 2013. The announcement was mainly performed via short message service (SMS) and local radio broadcasting. A total of 361 cases were observed and managed in Rafsanjan and 333 were transferred to other cities. Seventy-five and 100 pati ents underwent hemodialysis (HD), retrospectively. The main indication for HD was refractory metabolic acidosis. Eight patients expired due to the intoxication. Except for the deceased cases, no serum methanol level was available. Conclusion In developing countries, where diagnostic resources are limited, use of active case finding and developing national guidelines can help in the management of large outbreaks of methanol poisonings. © 2014 The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: email@example.com.'
Epidemiological study of influenza B in Shanghai during the 2009-2014 seasons: Implications for influenza vaccination strategy
A new quadrivalent influenza vaccine has been available for influenza B, which can pose a significant global health burden. Shanghai has the highest GDP and largest metropolitan population in China. To understand the impact of influenza B in Shanghai in te rms of age-related incidence and relative prevalence compared with other subtypes, we conducted this retrospective epidemiological study of influenza B in the 2009-2014 seasons. A total of 71 354 outpatients with influenza-like illness were included, and b oth lineages of influenza B and subtypes of influenza A were identified using real-time RT-PCR. The antigenic characteristics of influenza B isolates were analysed by sequencing and reciprocal haemagglutinin inhibition assay. On average, 33.45% of influenz a strains were influenza B, and 40.20% of strains isolated from children were influenza B. The incidence of influenza B was highest (12.52 per 100 people with influenza-like illness) in children ages 6-17 years and usually peaked in this age group at the e arly stage of an influenza B epidemic. Overall, both matched and mismatched influenza B strains co-circulated in Shanghai annually, and 44.57% of the circulating influenza B belonged to the opposite lineage of the vaccine strains. We concluded that influen za B has caused a substantial impact in Shanghai and that school-aged children play a key role in the transmission of influenza B. Hence, it may be beneficial to prioritize influenza vaccination for school-aged children to mitigate the outbreaks of influen za B. © 2015 The Authors.'
Clinical diagnosis of influenza in the ED
Background Timely and accurate diagnosis of influenza remains a challenge but is critical for patients who may benefit from antiviral therapy. This study determined the test characteristics of provider diagnosis of influenza, final ED electronic medical re cord (EMR) diagnosis of influenza, and influenza-like illness (ILI) in patients recommended to receive antiviral treatment according to Centers for Disease Control and Prevention (CDC) guidelines. In addition, we evaluated the compliance with CDC antiviral guidelines. Methods A prospective cohort of adults presenting to a tertiary care ED with an acute respiratory illness who met CDC criteria for recommended antiviral treatment were enrolled and tested for influenza. A clinical diagnosis of influenza was as sessed by asking the clinician: "Do you think this patient has influenza?" Influenza-like illness was defined according to current CDC criteria. Results In this cohort of 270 subjects, 42 (16%; 95% confidence interval [CI], 11%-20%) had influenza. Clinicia n diagnosis had a sensitivity of 36% (95% CI, 22%-52%) and specificity of 78% (95% CI, 72%-83%); EMR final ED diagnosis had a sensitivity of 26% (95% CI, 14%-42%) and specificity of 97% (95% CI, 94%-99%); ILI had a sensitivity of 31% (95% CI, 18%-47%) and specificity of 88% (95% CI, 83%-92%). Only 15 influenza-positive patients (36%) received antiviral treatment. Conclusion Clinician diagnosis, final ED EMR diagnosis, and ILI have low sensitivity for diagnosing influenza, and there is overall poor complianc e with CDC antiviral treatment recommendations. Improved methods of influenza diagnosis are needed to help guide management in the clinical setting. © 2015 Elsevier Inc.'
Tdap vaccine effectiveness in adolescents during the 2012 Washington State pertussis epidemic
BACKGROUND: Acellular pertussis vaccines replaced whole-cell vaccines for the 5-dose childhood vaccination series in 1997. A sixth dose of pertussis-containing vaccine, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis, adsorbed (Tdap), wa s recommended in 2005 for adolescents and adults. Studies examining Tdap vaccine effectiveness (VE) among adolescents who have received all acellular vaccines are limited. METHODS: To assess Tdap VE and duration of protection, we conducted a matched case-c ontrol study during the 2012 pertussis epidemic in Washington among adolescents born during 1993-2000. All pertussis cases reported from January 1 through June 30, 2012, in 7 counties were included; 3 controls were matched by primary provider clinic and bi rth year to each case. Vaccination histories were obtained through medical records, the state immunization registry, and parent interviews. Participants were classified by type of pertussis vaccine received on the basis of birth year: a mix of whole-cell a nd acellular vaccines (1993-1997) or all acellular vaccines (1998-2000). We used conditional logistic regression to calculate odds ratios comparing Tdap receipt between cases and controls. RESULTS: Among adolescents who received all acellular vaccines (450 cases, 1246 controls), overall Tdap VE was 63.9% (95% confidence interval [CI]: 50% to 74%). VE within 1 year of vaccination was 73% (95% CI: 60% to 82%). At 2 to 4 years postvaccination, VE declined to 34% (95% CI: -0.03% to 58%). CONCLUSIONS: Tdap prote ction wanes within 2 to 4 years. Lack of long-term protection after vaccination is likely contributing to increases in pertussis among adolescents. Copyright © 2015 by the American Academy of Pediatrics.'
Estimates of pertussis vaccine effectiveness in United States air force pediatric dependents
Background: Pertussis vaccination compliance is critical for reduction in the prevalence of disease; however, the current acellular pertussis vaccine may not provide sufficient protection from infection. This study examined acellular pertussis vaccine effe ctiveness (VE) for Air Force dependents less than 12 years of age. Methods: We conducted a case-control study among Air Force pediatric dependents from 2011 to 2013, comparing cases with positive pertussis test results to controls who received the same lab tests with a negative result. Our study population was categorized by age group and vaccination status based on the Centers for Disease Control and Prevention recommended pertussis vaccination schedule. VE was calculated with respect to vaccination status and pertussis lab results. Results: We compared 27 pertussis laboratory positive cases with 974 pertussis laboratory negative controls, 2 months to <12 years old. Comparing completely vaccinated to non-vaccinated patients, the overall VE was 78.3% (95% co nfidence interval (CI): 48.6, 90.8; p<. 0.001). VE was highest among those 15 months to <6 years old: 97.6% (95% CI: 78.5, 99.7; p<. 0.001). Children 6 to <12 years old had the lowest VE: 48.5% (95% CI: -74.0, 84.7; p= 0.28). Comparing partially vaccinated patients to nonvaccinated patients yielded 64.2% (95% CI: -7.2, 88.1; p= 0.06) overall VE. Conclusions: Acellular pertussis vaccination was effective at preventing laboratory confirmed pertussis among our Air Force pediatric dependent population, with hig hest protection among completely vaccinated, young children. Older children received the lowest amount of protection. Partial vaccination had near significant protection. Our overall calculated pertussis VE corroborates other pertussis VE studies looking a t similar age groups. © 2015 Elsevier Ltd.'
Multidrug-resistant tuberculosis in New South Wales, Australia, 1999-2010: A case series report
SETTING : The emergence of multidrug-resistant tuberculosis (MDR-TB) threatens the ongoing control of tuberculosis (TB). The Australian state of New South Wales (NSW) has low TB and MDR-TB incidence. OBJ ECT IVE : To examine the epidemiology and the clinic al and public health management of MDR-TB in NSW. DESIGN : A retrospective case-series analysis of MDRTB diagnosed in NSW between 1999 and 2010 was undertaken. A standardised questionnaire was used to collect information from the public health surveillance system, medical records and the State Mycobacterium Reference Laboratory about clinical features, drug susceptibility, treatment regimens, hospitalisation, risk factors for tuberculous infection, contact tracing and patient outcomes. RESULTS : Fifty-five cases of culture-confirmed MDRTB, including two cases of extensively drug-resistant TB, were diagnosed. All cases were reviewed by an expert management panel. Fifty cases (91%) were foreign-born, and 50 cases (91%) had fully supervised treatment. Of the 55 cases, 46 (84%) successfully completed treatment, 3 (5%) died of TB and 3 (5%) required surgery. No MDR-TB cases were reported among contacts. CONCLUSION: Using a multidisciplinary, expert guided, case-management approach, the NSW TB Control Program achie ved excellent MDR-TB outcomes. The impact of global increases in MDR-TB requires sustained commitment to TB in all settings. © 2015 The Union.
Zotero article collection 1(no login needed)
Zotero article collection 2(with supplementary info) (*login required)