Evaluation of Ph Neutral Electrochemically Activated Solution (ECAS): as a Sanitiser for Livestock Husbandry and Food Safety Applications

The agriculture production, animal farming, and food processing industries heavily depend on biocides to either reduce microbial load or inactivate microorganisms. These chemical biocides are associated with issues such as bacterial co-resistance to antibiotics, production of toxic residues, and reduced consumer acceptability. Electrolysed oxidising (EO) water, also termed electrochemically activated solution (ECAS) is an eco-friendly broad-spectrum biocidal agent. Among acidic, slightly acidic, and neutral pH forms of ECAS, the neutral type is preferred for its non-corrosiveness while still ensuring antimicrobial activity. In veterinary husbandry and shelled egg decontamination, ECAS is currently used in the form of a solution or spray wash. Therefore, in this thesis, the disinfection efficacy of an ECAS aerosol fogging regimen to decontaminate a pig farm environment and shell eggs was evaluated. Additionally, the effectiveness and impact of ECAS as a wash was assessed and compared to commonly used chemical agents for the sanitisation of ready-to-eat spinach leaves, including evaluation of organoleptic properties, shelf life, and nutritional attributes. In turn, this offered the possibility of exploring the effects of ECAS on spinach leaf microbiota composition, in comparison to peroxyacetic acid, a widely used, environmentally friendly sanitiser. The pig farm fogging experiment was conducted using optimised parameters for farm air sample collection and qPCR techniques that discern between live and dead bacteria. ECAS was fogged at 0.75 mg of free available chlorine (FAC) per cubic meter of air for 3 min every 30 mins, for 5 hours. A time-dependent total bacteria reduction was observed, with the population reduced by 78%, 97%, 99.4%, 99.8%, and 99.998% every hour until the fifth hour. For the shelled egg sanitisation and cuticle integrity experiment, ECAS at 150 mg/L FAC spray washing for 45 s and a fogging for 2 min achieved a complete inactivation of total bacteria and Salmonella Enteritidis; a similar reduction was also observed for sodium hypochlorite spray washes (45 s). Most importantly, however, ECAS spray and aerosol fog washing did not significantly affect the cuticle of the eggshell. In the spinach leaf sanitisation experiment, the effectiveness of ECAS (50 & 85 mg/L of FAC) and peroxyacetic acid (PAA) based sanitiser (50 mg/L of PAA) in reducing the total microbial load and the purposely inoculated non-pathogenic bacteria, and their effect on sensory attributes in comparison to that of tap water washing was assessed. All types of sanitising washes significantly reduced (p < 0.05) total bacteria and coliforms, keeping sensory characteristics above the acceptance level even after ten days of storage at 4ºC. The inactivation of purposely inoculated bacteria varied with the bacterial species and the type of sanitiser. Overall, ECAS (85 mg/L of FAC) showed greater efficacy in reducing Escherichia coli, and Listeria innocua than PAA. Furthermore, the PAA inactivation trends for these species suggested the induction of a viable but not-culturable state. All three types of sanitising wash significantly reduced S. Enteritidis, and the reduction for all three sampling days was higher for PAA. Microbiome profile using 16s rRNA amplicon sequencing showed that all treatment types did not affect the composition and structure of the autochthonous bacterial community, but storage time significantly reduced (p < 0.05) the heterogeneity of the identifiable bacterial species. Compared to other eco-friendly biocidal agents, ECAS could find increasing application in horticulture production, livestock farming and food safety due to its high antimicrobial efficacy and low production costs, as well as due to increasingly restrictive regulations on the use of chemical disinfectants and the change in consumer perception. In addition, the use of ECAS would reduce the use of chemical disinfectants and sanitisers, which may co-select for bacterial antimicrobial resistance and cause occupational safety and environmental issues through the generation of toxic residues.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 202

Community-based study on knowledge, attitudes and perception of rabies in Gelephu, south-central Bhutan.

postprintCommunity knowledge, attitudes and practices are important both for prevention of human deaths due to rabies and for control of the disease in animals. This study was a cross-sectional survey investigating the level of community knowledge as well as attitudes and perceptions about rabies in Gelephu, south central Bhutan, a region endemic for rabies. A total of 615 household respondents were interviewed, of which 224 (36%) were males and 391 (64%) were females. The majority of the respondents had high level of knowledge, and attitude and perception of rabies, and has a positive attitude towards the prevention and control of rabies. Multivariable logistic regression model showed that better knowledge about rabies was predicted by gender, educational level and dog ownership status of the respondents, whilst health-seeking behaviours of animal bite injuries were predicted by dog ownership status, presence of children in the household and occupation of the respondents. The majority of the respondents believed that stray dogs are a problem in the community and felt that it was important to control the dog population in Gelephu. These findings also indicate that there exists a knowledge gap about rabies in the community that could be improved by creating an awareness education programme. Keywords: Knowledge, Attitude, Perception, Rabies, Cross-sectional survey, Bhuta

Community-based study on knowledge, attitudes and perception of rabies in Gelephu, south-central Bhutan.

Community knowledge, attitudes and practices are important both for prevention of human deaths due to rabies and for control of the disease in animals. This study was a cross-sectional survey investigating the level of community knowledge as well as attitudes and perceptions about rabies in Gelephu, south central Bhutan, a region endemic for rabies. A total of 615 household respondents were interviewed, of which 224 (36%) were males and 391 (64%) were females. The majority of the respondents had high level of knowledge, and attitude and perception of rabies, and has a positive attitude towards the prevention and control of rabies. Multivariable logistic regression model showed that better knowledge about rabies was predicted by gender, educational level and dog ownership status of the respondents, whilst health-seeking behaviours of animal bite injuries were predicted by dog ownership status, presence of children in the household and occupation of the respondents. The majority of the respondents believed that stray dogs are a problem in the community and felt that it was important to control the dog population in Gelephu. These findings also indicate that there exists a knowledge gap about rabies in the community that could be improved by creating an awareness education programme. Keywords: Knowledge, Attitude, Perception, Rabies, Cross-sectional survey, Bhuta

Rates and indications of caesarean section deliveries in Bhutan 2015-2019: a national review

BACKGROUND: Bhutan has made much efforts to provide timely access to health services during pregnancy and increase institutional deliveries. However, as specialist obstetric services became available in seven hospitals in the country, there has been a steady increase in the rates of caesarean deliveries. This article describes the national rates and indications of caesarean section deliveries in Bhutan. METHODS: This is a review of hospital records and a qualitative analysis of peer-reviewed articles on caesarean deliveries in Bhutan. Data on the volume of all deliveries that happened in the country from 2015 to 2019 were retrieved from the Annual Health Bulletins published by the Ministry of Health. The volume of deliveries and caesarean deliveries were extracted from the Annual Report of the National Referral Hospital 2015-2019 and the data were collected from hospital records of six other obstetric centres. A national rate of caesarean section was calculated as a proportion out of the total institutional deliveries at all hospitals combined. At the hospital level, the proportion of caesarean deliveries are presented as a proportion out of total institutional deliveries conducted in that hospital. RESULTS: For the period 2015-2019, the average national rate of caesarean section was 20.1% with a statistically significant increase from 18.1 to 21.5%. The average rate at the six obstetric centres was 29.9% with Phuentsholing Hospital (37.2%), Eastern Regional Referral Hospital (34.2%) and Samtse General Hospital (32.0%) reporting rates higher than that of the National Referral Hospital (28.1%). Except for the Eastern Regional Referral and Trashigang Hospitals, the other three centres showed significant increase in the proportion of caesarean deliveries during the study period. The proportion of emergency caesarean section at National Referral Hospital, Central Regional Referral Hospital and the Phuentsholing General Hospital was 58.8%. The National Referral Hospital (71.6%) and Phuentsholing General Hospital reported higher proportions of emergency caesarean sections (64.4%) while the Central Regional Referral Hospital reported higher proportions of elective sections (59.5%). The common indications were 'past caesarean section' (27.5%), foetal distress and non-reassuring cardiotocograph (14.3%), failed progress of labour (13.2%), cephalo-pelvic disproportion or shoulder dystocia (12.0%), and malpresentation including breech (8.8%). CONCLUSION: Bhutan's caesarean section rates are high and on the rise despite a shortage of obstetricians. This trend may be counterproductive to Bhutan's efforts towards 2030 Sustainable Development Goal agendas and calls for a review of obstetric standards and practices to reduce primary caesarean sections

Community-based survey during rabies outbreaks in Rangjung town, Trashigang, eastern Bhutan, 2016

Abstract Background Rabies is a highly fatal disease transmitted through the bite of a rabid animal. Human deaths can be prevented by prompt administering of rabies vaccine and rabies immunoglobulin following the exposure. An assessment of community knowledge, awareness and practices on rabies is important during outbreak to understand their preparedness and target educational messages and response activities by the rapid response team. Methods A rabies outbreak has occurred in Rangjung town, eastern Bhutan on 4 October 2016. A rapid response team was activated to investigate outbreak and to establish a control program. A community-based questionnaire survey was conducted from 20 to 21 October 2016 to assess the community knowledge of rabies to guide outbreak preparedness and also target educational messages and response activities by the RRT. Results A total of 67 respondents were interviewed, of which 61% were female and 39% male. All the respondents have heard of rabies (100%), have knowledge on source of rabies (dog) and its mode of transmission in animals and humans. Most (61%) respondents were aware and also indicated that they would wash the animal bite wound with soap and water and seek medical care on the same day of exposure (100%). Majority (94%) of the respondents have indicated that they would report to the government agencies if they see any suspected rabid dogs in the community and suggested various control measures for dog population management and rabies in Rangjung including neutering procedure and mass dog vaccination. Although only few (10%) of the respondents households owned dogs and cats, but 50% of them have indicated that their dogs were allowed to roam outside the home premises posing risk of contracting rabies through rabid dog bites. Conclusions Although this study indicates a high level of knowledge and awareness on rabies among the community, there exists some knowledge gaps about rabies and therefore, an awareness education should be focused on the source of rabies and rabies virus transmission route to reduce public concern on nonexposure events thereby reducing the cost on unnecessary postexposure treatment

Application of Event Cameras and Neuromorphic Computing to VSLAM: A Survey

Simultaneous Localization and Mapping (SLAM) is a crucial function for most autonomous systems, allowing them to both navigate through and create maps of unfamiliar surroundings. Traditional Visual SLAM, also commonly known as VSLAM, relies on frame-based cameras and structured processing pipelines, which face challenges in dynamic or low-light environments. However, recent advancements in event camera technology and neuromorphic processing offer promising opportunities to overcome these limitations. Event cameras inspired by biological vision systems capture the scenes asynchronously, consuming minimal power but with higher temporal resolution. Neuromorphic processors, which are designed to mimic the parallel processing capabilities of the human brain, offer efficient computation for real-time data processing of event-based data streams. This paper provides a comprehensive overview of recent research efforts in integrating event cameras and neuromorphic processors into VSLAM systems. It discusses the principles behind event cameras and neuromorphic processors, highlighting their advantages over traditional sensing and processing methods. Furthermore, an in-depth survey was conducted on state-of-the-art approaches in event-based SLAM, including feature extraction, motion estimation, and map reconstruction techniques. Additionally, the integration of event cameras with neuromorphic processors, focusing on their synergistic benefits in terms of energy efficiency, robustness, and real-time performance, was explored. The paper also discusses the challenges and open research questions in this emerging field, such as sensor calibration, data fusion, and algorithmic development. Finally, the potential applications and future directions for event-based SLAM systems are outlined, ranging from robotics and autonomous vehicles to augmented reality