The Acquisition and Retention of Lumpy Skin Disease Virus by Blood-Feeding Insects Is Influenced by the Source of Virus, the Insect Body Part, and the Time since Feeding.

Lumpy skin disease virus (LSDV) is a poxvirus that causes severe systemic disease in cattle and is spread by mechanical arthropod-borne transmission. This study quantified the acquisition and retention of LSDV by four species of Diptera (Stomoxys calcitrans, Aedes aegypti, Culex quinquefasciatus, and Culicoides nubeculosus) from cutaneous lesions, normal skin, and blood from a clinically affected animal. The acquisition and retention of LSDV by Ae. aegypti from an artificial membrane feeding system was also examined. Mathematical models of the data were generated to identify the parameters which influence insect acquisition and retention of LSDV. For all four insect species, the probability of acquiring LSDV was substantially greater when feeding on a lesion compared with feeding on normal skin or blood from a clinically affected animal. After feeding on a skin lesion LSDV was retained on the proboscis for a similar length of time (around 9 days) for all four species and for a shorter time in the rest of the body, ranging from 2.2 to 6.4 days. Acquisition and retention of LSDV by Ae. aegypti after feeding on an artificial membrane feeding system that contained a high titer of LSDV was comparable to feeding on a skin lesion on a clinically affected animal, supporting the use of this laboratory model as a replacement for some animal studies. This work reveals that the cutaneous lesions of LSD provide the high-titer source required for acquisition of the virus by insects, thereby enabling the mechanical vector-borne transmission. IMPORTANCE Lumpy skin disease virus (LSDV) is a high consequence pathogen of cattle that is rapidly expanding its geographical boundaries into new regions such as Europe and Asia. This expansion is promoted by the mechanical transmission of the virus via hematogenous arthropods. This study quantifies the acquisition and retention of LSDV by four species of blood-feeding insects and reveals that the cutaneous lesions of LSD provide the high titer virus source necessary for virus acquisition by the insects. An artificial membrane feeding system containing a high titer of LSDV was shown to be comparable to a skin lesion on a clinically affected animal when used as a virus source. This promotes the use of these laboratory-based systems as replacements for some animal studies. Overall, this work advances our understanding of the mechanical vector-borne transmission of LSDV and provides evidence to support the design of more effective disease control programmes.

An animated model of reticulorumen motility.

Understanding reticulorumen motility is important to the assessment of ruminant health and optimal production, and in the recognition, diagnosis, and treatment of disease. Accordingly, the teaching of reticulorumen motility is a staple of all veterinary curricula. This teaching has historically been based on written descriptions, line drawings, or pressure tracings obtained during contraction sequences. We developed an animated model of reticulorumen motility and hypothesized that veterinary students would prefer use of the model over traditional instructional methods. First-year veterinary students were randomly allocated to one of two online learning exercises: with the animated model (Group A) or with text and line drawings (Group B) depicting reticulorumen motility. Learning was assessed with a multiple-choice quiz and feedback on the learning alternatives was obtained by survey. Seventy-four students participated in the study, including 38/42 in Group A and 36/36 in Group B. Sixty-four out of 72 students (89%) responded that they would prefer use of the animated model if only one of the two learning methods was available. A majority of students agreed or strongly agreed that the animated model was easy to understand and improved their knowledge and appreciation of the importance of reticulorumen motility, and would recommend the model to other veterinary students. Interestingly, students in Group B achieved higher scores on examination than students in Group A. This could be speculatively attributed to the inclusion of an itemized list of contraction sequences in the text provided to Group B and failure of Group A students to read the text associated with the animations.

Handwashing practice and policy variability when caring for central venous catheters in paediatric intensive care.

It has been estimated that there may be as many as 150,000 healthcare associated infections (HCAI) in Australia each year, contributing to 7,000 deaths, many of which could be prevented through the implementation of appropriate infection control practices. Contact with contaminated hands is a primary source of HCAI. Intensive care staff have been identified as one of the least adherent groups of health care professionals with handwashing; they are less likely to practise hand antisepsis before invasive procedures than staff working in other patient care specialties. The study examined the self-reported clean and aseptic handwashing practices of nurses working in paediatric intensive care units (PICUs) across Australia and New Zealand, the patterns in variation between nurses' reported handwashing practices and the local policies, and patterns in the duration of procedural handwashing for specific procedures. A survey was undertaken in 2001 in which participating tertiary paediatric hospitals provided copies of their infection control policies pertaining to central venous catheter (CVC) management; five nurses on each unit were asked to provide information in relation to their handwashing practices. Seven hospitals agreed to participate and 30 nurses completed the survey. The study found an enormous level of variation among and between nurses' reported practices and local policies. This variation extended across all aspects of handwashing practices - duration and extent of handwash, type of solution and drying method used. The rigour of handwashing varied according to the procedure undertaken, with some evidence that nurses made their own risk assessments based on the proximity of the procedure to the patient. In conclusion, this study's findings substantiate the need for standardisation of practice in line with the current Centers for Disease Control and Prevention Guidelines, including the introduction of alcohol handrub.

Central venous access and handwashing: variability in policies and practices.

This study examined variability in handwashing policy between hospitals, variability in handwashing practices in nurses and how practice differed from policy in tertiary paediatric hospitals in Australia and New Zealand. Eight of the possible nine major paediatric hospitals provided a copy of their handwashing and/or central venous access device (CVAD) policies, and 67 nurses completed a survey on their handwashing practices associated with CVAD management. A high degree of variability was found in relation to all the questions posed in the study. There was little consistency between policies and little agreement between policies and clinical practice, with many nurses washing for longer than required by policy. Rigour of handwashing also varied according to the procedure undertaken and the type of CVAD with activities undertaken farther from the insertion site of the device more likely to be performed using a clean rather than an aseptic handwashing technique. As both patients and nursing staff move within and between hospitals, a uniform and evidence-based approach to handwashing is highly desirable.