Evaluation of strategies for the eradication of Pseudorabies virus (Aujeszky's disease) in commercial swine farms in Chiang-Mai and Lampoon Provinces, Thailand, using a simulation disease spread model

Several strategies for eradicating Pseudorabies virus (Aujeszky's disease) in Chiang-Mai and Lampoon Provinces, Thailand, were compared using a computer simulation model, the North American Animal Disease Spread Model (NAADSM). The duration of the outbreak, the number of affected herds and the number of destroyed herds were compared during these simulated outbreaks. Depopulation, zoning for restricted movement and improved detection and vaccination strategies were assessed. The most effective strategies to eradicate Pseudorabies as per the findings from this study are applying depopulation strategies with MOVEMENT RESTRICTIONS in 3-, 8- and 16-km ZONES surrounding infected herds and enhancing the eradication with vaccination campaign on 16-km radius surrounding infected herds.

Adapting existing models of highly contagious diseases to countries other than their country of origin

Many countries do not have the resources to develop epidemiological models of animal diseases. As a result, it is tempting to use models developed in other countries. However, an existing model may need to be adapted in order for it to be appropriately applied in a country, region, or situation other than that for which it was originally developed. The process of adapting a model has a number of benefits for both model builders and model users. For model builders, it provides insight into the applicability of their model and potentially the opportunity to obtain data for operational validation of components of their model. For users, it is a chance to think about the infection transmission process in detail, to review the data available for modelling, and to learn the principles of epidemiological modelling. Various issues must be addressed when considering adapting a model. Most critically, the assumptions and purpose behind the model must be thoroughly understood, so that new users can determine its suitability for their situation. The process of adapting a model might simply involve changing existing model parameter values (for example, to better represent livestock demographics in a country or region), or might require more substantial (and more labour-intensive) changes to the model code and conceptual model. Adapting a model is easier if the model has a user-friendly interface and easy-to-read user documentation. In addition, models built as frameworks within which disease processes and livestock demographics and contacts are flexible are good candidates for technology transfer projects, which lead to long-term collaborations.

Approaches for evaluating veterinary epidemiological models: verification, validation and limitations

The evaluation of models of the spread and control of animal diseases is crucial if these models are to be used to inform decisions about the control or management of such diseases. Two key steps in the evaluation of epidemiological models are model verification and model validation. Verification is the demonstration that a computer-driven model is operating correctly, and conforms to its intended design. Validation refers to the process of determining how well a model corresponds to the system that it is intended to represent. For a veterinary epidemiological model, validation would address such issues as how well the model represents the dynamics of the disease in question in the population to which this model is applied, and how well the model represents the application of different measures for disease control. Just as the development of epidemiological models is a subjective, continuous process, subject to change and refinement, so too is the evaluation of models. The purpose of model evaluation is not to demonstrate that a model is a 'true' or accurate' representation of a system, but to subject it to sufficient scrutiny so that it may be used with an appropriate degree of confidence to aid decision-making. To facilitate model verification and validation, epidemiological modellers should clearly state the purpose, assumptions and limitations of a model; provide a detailed description of the conceptual model; document those steps already taken to test the model; and thoroughly describe the data sources and the process used to produce model input parameters from those data.

Laparoscopic restorative proctocolectomy: a 10-year experience of an evolving technique

AIM

Restorative proctocolectomy is the definitive procedure for ulcerative colitis. The potential benefits of a minimal invasive approach make it appropriate to consider this approach provided that there are no adverse effects. The aim of the present study was to report our experience of laparoscopic assisted and 'total' laparoscopic restorative proctocolectomy (LRPC) and to highlight the difficulties encountered and the functional results obtained.

METHOD

Electronic data were prospectively collected from all patients who underwent laparoscopic restorative proctocolectomy (LRPC) from October 1999 to April 2010.

RESULTS

Seventy-two (40 male) patients [median body mass index 24 (19-48) kg/m(2) ] underwent LRPC over 10 years. Three had cancer. Forty-two had undergone a previous colectomy (laparoscopic in 38). There were 40 W- and 32 J-pouch reconstructions; seven were single-port procedures. The median operation time was 210 (75-330) min. There were five (7%) conversions, one of which resulted in immediate pouch failure. The median time to full diet was 36 (4-168) h, with a median hospital stay of 7 (2-64) days. There were seven (10%) readmissions. Complications were immediate (3%), early (22%) and long term (11%). The incidence of failure (excision or indefinite diversion) was 2.7%. The stoma has been closed in 67 patients. Median frequency of defaecation was 4/24 h, with normal continence in 90% and the ability to defer during the day in 98%. There was no new case of impotence or dyspareunia.

CONCLUSION

Laparoscopic restorative proctocolectomy is safe and gives good results when performed by an experienced laparoscopic surgeon.

FloSeal hemostatic matrix use for intraventricular hemorrhage during a neuroendoscopic procedure

INTRODUCTION

Neuroendoscopy is a rapidly growing field, but the risk of intraventricular hemorrhage is signficant. There are few novel ways of obtaining hemostasis for major hemorrhage described in the literature.

PATIENT

A 5-year-old boy with a history of intraventricular hemorrhage and multi-cystic hydrocephalus presented with worsening brainstem compression from dilation of a 4 (th) ventricle cyst.

RESULTS

During endoscopic surgery to fenestrate the cyst, arterial hemorrhage was emergently controlled with the hemostatic agent, FloSeal.

CONCLUSION

To the best of the authors' knowledge, this is the first report of a patient with intraoperative intraventricular hemorrhage controlled with FloSeal.