Harriet Whiley | Flinders University of South Australia (original) (raw)

Papers by Harriet Whiley

Research paper thumbnail of The 1999 National Environmental Health Strategy and Closing the Gap: lessons learnt, and hope for the future

Australian and New Zealand Journal of Public Health

Research paper thumbnail of The Application of Passive Sampling Devices in Wastewater Surveillance

Water

Wastewater-based epidemiology (WBE) is a surveillance approach used to examine chemical and biolo... more Wastewater-based epidemiology (WBE) is a surveillance approach used to examine chemical and biological targets within a population. Historically, the most common approaches to wastewater sampling include grab sampling and composite sampling, which can be performed manually or using an automated sampler. However, there are inherent flaws with these sampling methods. They can miss analytes due to fluctuation events in wastewater and can have high cost and labour implications. Alternately, passive sampling is a technique that involves a sampling medium that can stay in an aqueous matrix for extended periods of time to provide a greater temporal coverage. This literature review examines the current passive sampling devices used in wastewater surveillance and the general contaminants they are targeting. The polar organic chemical integrated sampler, Chemcatcher®, diffusive gradients in thin films sampler and semipermeable membrane devices were among the most frequently deployed samplers ...

Research paper thumbnail of Efficacy of the PlasmaShield®, a Non-Thermal, Plasma-Based Air Purification Device, in Removing Airborne Microorganisms

Electrochem

Airborne microorganisms play a significant role in the transmission of infectious diseases. As su... more Airborne microorganisms play a significant role in the transmission of infectious diseases. As such, improving indoor microbial air quality can enhance infection control in numerous settings. This study examined the efficacy of the PlasmaShield® air purification device to remove airborne microorganisms under laboratory conditions. Pure cultures of model microorganisms at varying concentrations were aerosolized using a 1-jet Collison nebulizer through stainless-steel removable piping prior to reaching the PlasmaShield® device. The surviving microorganisms were captured using the Staplex® MBS-6 Six Stage Microbial Air Sampler and enumerated via culture on agar plates. The positive-hole-corrected colony/plaque-forming units were compared with the negative control (microorganisms aerosolized through an empty PlasmaShield® casing). The PlasmaShield® statistically significantly (p < 0.05) reduced airborne Escherichia coli, Staphylococcus epidermidis, Bacteriophage MS2 and Cladosporium ...

Research paper thumbnail of The Presence of Opportunistic Premise Plumbing Pathogens in Residential Buildings: A Literature Review

Water, 2022

Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbin... more Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbing environment and that present an emerging infectious disease problem. They share characteristics, such as disinfectant resistance, thermal tolerance, and biofilm formation. The colonisation of domestic water systems presents an elevated health risk for immune-compromised individuals who receive healthcare at home. The literature that has identified the previously described OPPPs (Aeromonas spp., Acinetobacter spp., Helicobacter spp., Legionella spp., Methylobacterium spp., Mycobacteria spp., Pseudomonas spp., and Stenotrophomonas spp.) in residential drinking water systems were systematically reviewed. By applying the Preferred reporting items for systematic reviews and meta-analyses guidelines, 214 studies were identified from the Scopus and Web of Science databases, which included 30 clinical case investigations. Tap components and showerheads were the most frequently identified sourc...

Research paper thumbnail of Overview of Current Practices in the Methamphetamine Testing and Decontamination Industry: An Australian Case Study

International Journal of Environmental Research and Public Health, 2021

To better protect public health from third-hand exposure to methamphetamine, it is important to u... more To better protect public health from third-hand exposure to methamphetamine, it is important to understand the techniques and current practices used within the methamphetamine testing and decontamination industry in Australia. A survey was conducted focusing on business owners that advertised testing and/or remediation services online. They were also invited to participate in a follow-up phone interview upon completion. The survey demonstrated that testing and decontamination methods were highly varied, which was expected for an industry with no regulation. Most companies offered methamphetamine testing and remediation which could be a conflict of interest. Participants also shared personal experiences, including the conduct of other industry members, demonstrating both poor practice and/or the competitive nature of the business. Participating business owners were following Australian guidelines to the best of their ability, and many are advocates for regulation to be implemented wi...

Research paper thumbnail of A Successful Technique for the Surface Decontamination of Salmonella enterica Serovar Typhimurium Externally Contaminated Whole Shell Eggs Using Common Commercial Kitchen Equipment

Foodborne Pathogens and Disease, 2020

Eggs are a highly nutritious food source used in a wide range of food products. In Australia, egg... more Eggs are a highly nutritious food source used in a wide range of food products. In Australia, eggs are a frequent source of foodborne salmonellosis outbreaks, associated with eggshell contamination with Salmonella enterica serovar Typhimurium (ST). Despite their potentially hazardous nature, raw eggs are often used and consumed in mayonnaise, mousse, ice cream and eggnog. The aim of this study was to develop a shell egg decontamination method that removed ST contamination from the outside of an egg without impacting its usability. The decontamination method was developed by the adaptation of a temperature-controlled water bath (commonly present in kitchens and associated with the sous-vide technique) for the surface decontamination of eggs. The outside of whole eggs was artificially inoculated with two ST strains. The eggs were decontaminated by placing in a sous-vide cooker with the water heated to 57°C. The remaining viable ST present on the whole shell egg, crushed shells, internal egg contents and sous-vide water were enumerated over time by culturing onto XLD agar. The quality of the uncontaminated heat-treated eggs was determined by measuring the Haugh unit, yolk index, albumen pH, thermocoagulation, and stability of foam. A blind control study was conducted to assess the acceptability and usability of the treated eggs by chefs and food handlers for the preparation of mayonnaise. Complete decontamination of ST was achieved by treating eggs for 9 min in the sous-vide cooker (57°C). No statistically significant difference was observed in the quality of treated eggs compared with nontreated eggs using the quality measurements and acceptability score from chefs. This method provides a simple approach that can be adopted by chefs and food handlers to obtain safe eggs before the preparation of raw egg products.

Research paper thumbnail of Defining Food Safety Inspection

International Journal of Environmental Research and Public Health, 2022

Food safety inspections are a key health protection measure applied by governments to prevent fo... more Food safety inspections are a key health protection measure applied by governments to prevent foodborne illness, yet they remain the subject of sustained criticism. These criticisms include inconsistency and inadequacy of methods applied to inspection, and ineffectiveness in preventing foodborne illness. Investigating the validity of these criticisms represent important areas for further research. However, a defined construct around the meanings society attributes to food safety inspection must first be established. Through critical examination of available literature, this review identified meanings attributed to food safety inspection and explicates some of the key elements that compose food safety inspection as a social construct. A total of 18 meanings were found to be attributed to food safety inspection. Variation in meanings were found between consumers, food business associates and food safety inspectors. For some, inspection meant a source of assurance, for others a threat...

Research paper thumbnail of Investigation into the Cause of Iron-Related Clogging of Groundwater Bores Used for Viticulture in the Limestone Coast, South Australia

Water, 2021

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem f... more Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limesto...

Research paper thumbnail of The New Environmental Health in Australia: Failure to Launch?

International Journal of Environmental Research and Public Health, 2021

Background: The New Environmental Health is an approach to environmental health adopted in 1999. ... more Background: The New Environmental Health is an approach to environmental health adopted in 1999. The new approach was in response to emerging health risks from the pressures that development placed on the environment, climate change, and increasing vulnerabilities of local communities. The new approach heralded a change in perception and roles within environmental health. Twenty years on, it seems these changes have not been embraced by local government. Methods: To determine whether this was the case, we assessed the use of the term “environmental health” in local government annual reports, and where environmental health functions sit within the organisational structure of councils. Results: We found that the New Environmental Health has not been adopted by councils and environmental health relates solely to the delivery of statutory services and legislative compliance. Conclusions: One result of this is local environmental health practitioners, who constitute the major health prot...

Research paper thumbnail of Factors Influencing Legionella Contamination of Domestic Household Showers

Pathogens, 2019

Legionnaires’ disease is a potentially fatal pneumonia like infection caused by inhalation or asp... more Legionnaires’ disease is a potentially fatal pneumonia like infection caused by inhalation or aspiration of water particles contaminated with pathogenic Legionella spp. Household showers have been identified as a potential source of sporadic, community-acquired Legionnaires’ disease. This study used qPCR to enumerate Legionella spp. and Legionella pneumophila in water samples collected from domestic showers across metropolitan Adelaide, South Australia. A survey was used to identify risk factors associated with contamination and to examine awareness of Legionella control in the home. The hot water temperature was also measured. A total of 74.6% (50/68) and 64.2% (43/68) showers were positive for Legionella spp. and L. pneumophila, respectively. Statistically significant associations were found between Legionella spp. concentration and maximum hot water temperature (p = 0.000), frequency of shower use (p = 0.000) and age of house (p = 0.037). Lower Legionella spp. concentrations were...

Research paper thumbnail of A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control

Pathogens, 2021

Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of publ... more Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergarte...

Research paper thumbnail of Legionella pneumophila and Protozoan Hosts: Implications for the Control of Hospital and Potable Water Systems

Pathogens, 2020

Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is th... more Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is the causative agent of Legionnaires’ disease (LD) and Pontiac fever and is ubiquitous in manufactured water systems, where protozoan hosts and complex microbial communities provide protection from disinfection procedures. This review collates the literature describing interactions between L. pneumophila and protozoan hosts in hospital and municipal potable water distribution systems. The effectiveness of currently available water disinfection protocols to control L. pneumophila and its protozoan hosts is explored. The studies identified in this systematic literature review demonstrated the failure of common disinfection procedures to achieve long term elimination of L. pneumophila and protozoan hosts from potable water. It has been demonstrated that protozoan hosts facilitate the intracellular replication and packaging of viable L. pneumophila in infectious vesicles; whereas, cyst-forming ...

Research paper thumbnail of Zoonotic and Public Health Implications of Campylobacter Species and Squamates (Lizards, Snakes and Amphisbaenians)

Pathogens, 2020

Campylobacter spp. is one of the most widespread infectious diseases of veterinary and public hea... more Campylobacter spp. is one of the most widespread infectious diseases of veterinary and public health significance. Globally, the incidence of campylobacteriosis has increased over the last decade in both developing and developed countries. Squamates (lizards, snakes and amphisbaenians) are a potential reservoir and source of transmission of campylobacteriosis to humans. This systematic review examined studies from the last 20 years that have reported squamate-associated human campylobacteriosis. It was found that C. fetus subsp. testudinum and C. fetus subsp. fetus were the most common species responsible for human campylobacteriosis from a squamate host. The common squamate hosts identified included bearded dragons (Pogona vitticeps), green iguana (Iguana iguana), western beaked gecko (Rhynchoedura ornate) and blotched blue-tongued skink (Tiliqua nigrolutea). People with underlying chronic illnesses, the immunocompromised and the elderly were identified as the most vulnerable popul...

Research paper thumbnail of Water as a Source of Antimicrobial Resistance and Healthcare-Associated Infections

Pathogens, 2020

Healthcare-associated infections (HAIs) are one of the most common patient complications, affecti... more Healthcare-associated infections (HAIs) are one of the most common patient complications, affecting 7% of patients in developed countries each year. The rise of antimicrobial resistant (AMR) bacteria has been identified as one of the biggest global health challenges, resulting in an estimated 23,000 deaths in the US annually. Environmental reservoirs for AMR bacteria such as bed rails, light switches and doorknobs have been identified in the past and addressed with infection prevention guidelines. However, water and water-related devices are often overlooked as potential sources of HAI outbreaks. This systematic review examines the role of water and water-related devices in the transmission of AMR bacteria responsible for HAIs, discussing common waterborne devices, pathogens, and surveillance strategies. AMR strains of previously described waterborne pathogens including Pseudomonas aeruginosa, Mycobacterium spp., and Legionella spp. were commonly isolated. However, methicillin-resis...

Research paper thumbnail of Opportunistic Mapping of Strongyloides stercoralis and Hookworm in Dogs in Remote Australian Communities

Pathogens, 2020

Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Aust... more Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, S. stercoralis and some species of hookworms infect canids and therefore present both environmental and zoonotic sources of transmission to humans. Currently, there is limited information available on the prevalence of hookworms and S. stercoralis infections in dogs living in communities across the Northern Territory in Australia. In this study, 274 dog faecal samples and 11 faecal samples of unknown origin were collected from the environment and directly from animals across 27 remote communities in Northern and Central Australia. Samples were examined using real-time polymerase chain reaction (PCR) analysis for the presence of S. stercoralis and four hookworm species: Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma braziliense and Uncinaria stenocephala. The prevalence of S. stercoralis in dogs was found to be 21.9% (60/274)....

Research paper thumbnail of The Combined Effect of pH and Temperature on the Survival of Salmonella enterica Serovar Typhimurium and Implications for the Preparation of Raw Egg Mayonnaise

Pathogens, 2019

Raw egg products are often associated with salmonellosis. The Australian guidelines recommend raw... more Raw egg products are often associated with salmonellosis. The Australian guidelines recommend raw egg mayonnaise to be prepared and stored under 5 °C and adjusted to a pH less than 4.6 or 4.2. Despite these guidelines, a significant amount of salmonellosis outbreaks are recorded annually in Australia. The aim of this study was to investigate the effect of pH and temperature on the survival of Salmonella Typhimurium (ST) in peptone water (PW) and mayonnaise. The pH of PW and mayonnaise was adjusted to 4.2, 4.4 and 4.6 using acetic acid and vinegar, respectively. The PW and mayonnaise were inoculated with ST and incubated at 37 °C, 23 °C, and 4 °C. The survival of Salmonella was determined using the drop plate method. Survival was significantly (p < 0.05) improved at 4 °C. In both mayonnaise and PW, following 24 h, there was no ST growth at pH 4.2. Resuscitation of ST was rapidly observed at 4 °C while complete inactivation was observed at 37 °C at pH 4.2, 4.4, and 4.6 in both PW a...

Research paper thumbnail of Public Health Risks Associated with Heavy Metal and Microbial Contamination of Drinking Water in Australia

International Journal of Environmental Research and Public Health, 2019

Recently in Australia concerns have been raised regarding the contamination of municipal drinking... more Recently in Australia concerns have been raised regarding the contamination of municipal drinking water supplies with lead. This is of particular concern to children due to the impact of lead exposure on cognitive development and as such these findings have received much media attention. The response from legislators has been swift, and The Victorian School Building Authority has announced that all new schools and school upgrade works will only use lead-free tapware and piping systems. However, while the immediate replacement of lead-containing brass fittings may seem a logical and obvious response, it does not consider the potential implications on microbial contamination. This is particularly concerning given the increasing public health threat posed by opportunistic premise plumbing pathogens (OPPPs). This commentary explores this public health risk of lead exposure from plumbing materials compared to the potential public health risks from OPPPs. Non-tuberculous mycobacterium was...

Research paper thumbnail of Antifungal properties of essential oils for improvement of indoor air quality: a review

Reviews on Environmental Health, 2018

Concerns regarding indoor air quality, particularly the presence of fungi and moulds, are increas... more Concerns regarding indoor air quality, particularly the presence of fungi and moulds, are increasing. The potential for essential oils to reduce, control or remove fungi, is gaining interest as they are seen as a “natural” alternative to synthetic chemical fungicides. This review examines published research on essential oils as a method of fungal control in indoor environments. It was difficult to compare the relative performances of essential oils due to differences in research methods and reporting languages. In addition, there are limited studies that scale up laboratory results and assess the efficacy of essential oils within building environments. However, generally, there appears to be some evidence to support the essential oils clove oil, tea tree oil, oregano, thyme and lemon as potential antifungal agents. Essential oils from heartwood, marjoram, cinnamon, lemon basil, caraway, bay tree, fir, peppermint, pine, cedar leaf and manuka were identified in at least one study as h...

Research paper thumbnail of A Review of Strongyloides spp. Environmental Sources Worldwide

Pathogens, 2019

Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are c... more Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are capable of causing disease. These nematodes affect an estimated 3–300 million humans worldwide. Identifying the environmental reservoirs of Strongyloides spp. is essential for the development of appropriate control strategies. This systematic literature review examined all published studies that identified Strongyloides stercoralis, Strongyloides fuelleborni, Strongyloides fuelleborni kellyi, and Strongyloides spp. from an environmental source. Most studies detected the nematode from dog and primate fecal samples. Other environmental sources identified were ruminants, cats, rodents, insects, water, soil, as well as fruit and vegetables. Most studies used microscopy-based identification techniques; however, several employed molecular-based techniques, which have become increasingly popular for the detection of Strongyloides spp. A limitation identified was a lack of studies that comprehens...

Research paper thumbnail of Strongyloidiasis in Ethiopia: systematic review on risk factors, diagnosis, prevalence and clinical outcomes

Infectious Diseases of Poverty, 2019

Background: Strongyloidiasis is a gastrointestinal infection caused by the parasitic nematode Str... more Background: Strongyloidiasis is a gastrointestinal infection caused by the parasitic nematode Strongyloides stercoralis. It is estimated to infect up to 370 million people globally and is predominately found in tropical and subtropical areas of socioeconomic disadvantage. Main body: This systematic literature review identified studies published in the last ten years on the risk factors, diagnosis, prevalence and/or clinical outcomes of strongyloidiasis in Ethiopia. The prevalence of S. stercoralis ranged from 0.2 to 11.1% in adults, 0.3% to 20.7% in children, 1.5% to 17.3% in HIV positive adults and 5% in HIV positive children. The identified studies primarily used microscopy based techniques that potentially underestimated the prevalence four fold compared with serology and PCR. Strongyloidiasis in children presents a particularly significant issue in Ethiopia as children often presented with anemia, which is associated with impaired mental and cognitive development. The most significant risk factor for strongyloidiasis was HIV status and although other risk factors were identified for helminth infections, none were statistically significant for S. stercoralis specifically. Several studies detected S. stercoralis in dogs and non-biting cyclorrhaphan flies. However, future research is needed to explore the role of these reservoirs in disease transmission. Conclusions: This review demonstrated that strongyloidiasis is an overlooked and neglected disease in Ethiopia. There is a need for a systematic approach using a combination of molecular and serology based diagnostic methods to ascertain the true incidence and burden of strongyloidiasis in Ethiopia. Further research is also needed to break the cycle of transmission by identifying environmental reservoirs, risk factors and exploring the potential for zoonotic transfer.

Research paper thumbnail of The 1999 National Environmental Health Strategy and Closing the Gap: lessons learnt, and hope for the future

Australian and New Zealand Journal of Public Health

Research paper thumbnail of The Application of Passive Sampling Devices in Wastewater Surveillance

Water

Wastewater-based epidemiology (WBE) is a surveillance approach used to examine chemical and biolo... more Wastewater-based epidemiology (WBE) is a surveillance approach used to examine chemical and biological targets within a population. Historically, the most common approaches to wastewater sampling include grab sampling and composite sampling, which can be performed manually or using an automated sampler. However, there are inherent flaws with these sampling methods. They can miss analytes due to fluctuation events in wastewater and can have high cost and labour implications. Alternately, passive sampling is a technique that involves a sampling medium that can stay in an aqueous matrix for extended periods of time to provide a greater temporal coverage. This literature review examines the current passive sampling devices used in wastewater surveillance and the general contaminants they are targeting. The polar organic chemical integrated sampler, Chemcatcher®, diffusive gradients in thin films sampler and semipermeable membrane devices were among the most frequently deployed samplers ...

Research paper thumbnail of Efficacy of the PlasmaShield®, a Non-Thermal, Plasma-Based Air Purification Device, in Removing Airborne Microorganisms

Electrochem

Airborne microorganisms play a significant role in the transmission of infectious diseases. As su... more Airborne microorganisms play a significant role in the transmission of infectious diseases. As such, improving indoor microbial air quality can enhance infection control in numerous settings. This study examined the efficacy of the PlasmaShield® air purification device to remove airborne microorganisms under laboratory conditions. Pure cultures of model microorganisms at varying concentrations were aerosolized using a 1-jet Collison nebulizer through stainless-steel removable piping prior to reaching the PlasmaShield® device. The surviving microorganisms were captured using the Staplex® MBS-6 Six Stage Microbial Air Sampler and enumerated via culture on agar plates. The positive-hole-corrected colony/plaque-forming units were compared with the negative control (microorganisms aerosolized through an empty PlasmaShield® casing). The PlasmaShield® statistically significantly (p < 0.05) reduced airborne Escherichia coli, Staphylococcus epidermidis, Bacteriophage MS2 and Cladosporium ...

Research paper thumbnail of The Presence of Opportunistic Premise Plumbing Pathogens in Residential Buildings: A Literature Review

Water, 2022

Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbin... more Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbing environment and that present an emerging infectious disease problem. They share characteristics, such as disinfectant resistance, thermal tolerance, and biofilm formation. The colonisation of domestic water systems presents an elevated health risk for immune-compromised individuals who receive healthcare at home. The literature that has identified the previously described OPPPs (Aeromonas spp., Acinetobacter spp., Helicobacter spp., Legionella spp., Methylobacterium spp., Mycobacteria spp., Pseudomonas spp., and Stenotrophomonas spp.) in residential drinking water systems were systematically reviewed. By applying the Preferred reporting items for systematic reviews and meta-analyses guidelines, 214 studies were identified from the Scopus and Web of Science databases, which included 30 clinical case investigations. Tap components and showerheads were the most frequently identified sourc...

Research paper thumbnail of Overview of Current Practices in the Methamphetamine Testing and Decontamination Industry: An Australian Case Study

International Journal of Environmental Research and Public Health, 2021

To better protect public health from third-hand exposure to methamphetamine, it is important to u... more To better protect public health from third-hand exposure to methamphetamine, it is important to understand the techniques and current practices used within the methamphetamine testing and decontamination industry in Australia. A survey was conducted focusing on business owners that advertised testing and/or remediation services online. They were also invited to participate in a follow-up phone interview upon completion. The survey demonstrated that testing and decontamination methods were highly varied, which was expected for an industry with no regulation. Most companies offered methamphetamine testing and remediation which could be a conflict of interest. Participants also shared personal experiences, including the conduct of other industry members, demonstrating both poor practice and/or the competitive nature of the business. Participating business owners were following Australian guidelines to the best of their ability, and many are advocates for regulation to be implemented wi...

Research paper thumbnail of A Successful Technique for the Surface Decontamination of Salmonella enterica Serovar Typhimurium Externally Contaminated Whole Shell Eggs Using Common Commercial Kitchen Equipment

Foodborne Pathogens and Disease, 2020

Eggs are a highly nutritious food source used in a wide range of food products. In Australia, egg... more Eggs are a highly nutritious food source used in a wide range of food products. In Australia, eggs are a frequent source of foodborne salmonellosis outbreaks, associated with eggshell contamination with Salmonella enterica serovar Typhimurium (ST). Despite their potentially hazardous nature, raw eggs are often used and consumed in mayonnaise, mousse, ice cream and eggnog. The aim of this study was to develop a shell egg decontamination method that removed ST contamination from the outside of an egg without impacting its usability. The decontamination method was developed by the adaptation of a temperature-controlled water bath (commonly present in kitchens and associated with the sous-vide technique) for the surface decontamination of eggs. The outside of whole eggs was artificially inoculated with two ST strains. The eggs were decontaminated by placing in a sous-vide cooker with the water heated to 57°C. The remaining viable ST present on the whole shell egg, crushed shells, internal egg contents and sous-vide water were enumerated over time by culturing onto XLD agar. The quality of the uncontaminated heat-treated eggs was determined by measuring the Haugh unit, yolk index, albumen pH, thermocoagulation, and stability of foam. A blind control study was conducted to assess the acceptability and usability of the treated eggs by chefs and food handlers for the preparation of mayonnaise. Complete decontamination of ST was achieved by treating eggs for 9 min in the sous-vide cooker (57°C). No statistically significant difference was observed in the quality of treated eggs compared with nontreated eggs using the quality measurements and acceptability score from chefs. This method provides a simple approach that can be adopted by chefs and food handlers to obtain safe eggs before the preparation of raw egg products.

Research paper thumbnail of Defining Food Safety Inspection

International Journal of Environmental Research and Public Health, 2022

Food safety inspections are a key health protection measure applied by governments to prevent fo... more Food safety inspections are a key health protection measure applied by governments to prevent foodborne illness, yet they remain the subject of sustained criticism. These criticisms include inconsistency and inadequacy of methods applied to inspection, and ineffectiveness in preventing foodborne illness. Investigating the validity of these criticisms represent important areas for further research. However, a defined construct around the meanings society attributes to food safety inspection must first be established. Through critical examination of available literature, this review identified meanings attributed to food safety inspection and explicates some of the key elements that compose food safety inspection as a social construct. A total of 18 meanings were found to be attributed to food safety inspection. Variation in meanings were found between consumers, food business associates and food safety inspectors. For some, inspection meant a source of assurance, for others a threat...

Research paper thumbnail of Investigation into the Cause of Iron-Related Clogging of Groundwater Bores Used for Viticulture in the Limestone Coast, South Australia

Water, 2021

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem f... more Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limesto...

Research paper thumbnail of The New Environmental Health in Australia: Failure to Launch?

International Journal of Environmental Research and Public Health, 2021

Background: The New Environmental Health is an approach to environmental health adopted in 1999. ... more Background: The New Environmental Health is an approach to environmental health adopted in 1999. The new approach was in response to emerging health risks from the pressures that development placed on the environment, climate change, and increasing vulnerabilities of local communities. The new approach heralded a change in perception and roles within environmental health. Twenty years on, it seems these changes have not been embraced by local government. Methods: To determine whether this was the case, we assessed the use of the term “environmental health” in local government annual reports, and where environmental health functions sit within the organisational structure of councils. Results: We found that the New Environmental Health has not been adopted by councils and environmental health relates solely to the delivery of statutory services and legislative compliance. Conclusions: One result of this is local environmental health practitioners, who constitute the major health prot...

Research paper thumbnail of Factors Influencing Legionella Contamination of Domestic Household Showers

Pathogens, 2019

Legionnaires’ disease is a potentially fatal pneumonia like infection caused by inhalation or asp... more Legionnaires’ disease is a potentially fatal pneumonia like infection caused by inhalation or aspiration of water particles contaminated with pathogenic Legionella spp. Household showers have been identified as a potential source of sporadic, community-acquired Legionnaires’ disease. This study used qPCR to enumerate Legionella spp. and Legionella pneumophila in water samples collected from domestic showers across metropolitan Adelaide, South Australia. A survey was used to identify risk factors associated with contamination and to examine awareness of Legionella control in the home. The hot water temperature was also measured. A total of 74.6% (50/68) and 64.2% (43/68) showers were positive for Legionella spp. and L. pneumophila, respectively. Statistically significant associations were found between Legionella spp. concentration and maximum hot water temperature (p = 0.000), frequency of shower use (p = 0.000) and age of house (p = 0.037). Lower Legionella spp. concentrations were...

Research paper thumbnail of A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control

Pathogens, 2021

Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of publ... more Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergarte...

Research paper thumbnail of Legionella pneumophila and Protozoan Hosts: Implications for the Control of Hospital and Potable Water Systems

Pathogens, 2020

Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is th... more Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is the causative agent of Legionnaires’ disease (LD) and Pontiac fever and is ubiquitous in manufactured water systems, where protozoan hosts and complex microbial communities provide protection from disinfection procedures. This review collates the literature describing interactions between L. pneumophila and protozoan hosts in hospital and municipal potable water distribution systems. The effectiveness of currently available water disinfection protocols to control L. pneumophila and its protozoan hosts is explored. The studies identified in this systematic literature review demonstrated the failure of common disinfection procedures to achieve long term elimination of L. pneumophila and protozoan hosts from potable water. It has been demonstrated that protozoan hosts facilitate the intracellular replication and packaging of viable L. pneumophila in infectious vesicles; whereas, cyst-forming ...

Research paper thumbnail of Zoonotic and Public Health Implications of Campylobacter Species and Squamates (Lizards, Snakes and Amphisbaenians)

Pathogens, 2020

Campylobacter spp. is one of the most widespread infectious diseases of veterinary and public hea... more Campylobacter spp. is one of the most widespread infectious diseases of veterinary and public health significance. Globally, the incidence of campylobacteriosis has increased over the last decade in both developing and developed countries. Squamates (lizards, snakes and amphisbaenians) are a potential reservoir and source of transmission of campylobacteriosis to humans. This systematic review examined studies from the last 20 years that have reported squamate-associated human campylobacteriosis. It was found that C. fetus subsp. testudinum and C. fetus subsp. fetus were the most common species responsible for human campylobacteriosis from a squamate host. The common squamate hosts identified included bearded dragons (Pogona vitticeps), green iguana (Iguana iguana), western beaked gecko (Rhynchoedura ornate) and blotched blue-tongued skink (Tiliqua nigrolutea). People with underlying chronic illnesses, the immunocompromised and the elderly were identified as the most vulnerable popul...

Research paper thumbnail of Water as a Source of Antimicrobial Resistance and Healthcare-Associated Infections

Pathogens, 2020

Healthcare-associated infections (HAIs) are one of the most common patient complications, affecti... more Healthcare-associated infections (HAIs) are one of the most common patient complications, affecting 7% of patients in developed countries each year. The rise of antimicrobial resistant (AMR) bacteria has been identified as one of the biggest global health challenges, resulting in an estimated 23,000 deaths in the US annually. Environmental reservoirs for AMR bacteria such as bed rails, light switches and doorknobs have been identified in the past and addressed with infection prevention guidelines. However, water and water-related devices are often overlooked as potential sources of HAI outbreaks. This systematic review examines the role of water and water-related devices in the transmission of AMR bacteria responsible for HAIs, discussing common waterborne devices, pathogens, and surveillance strategies. AMR strains of previously described waterborne pathogens including Pseudomonas aeruginosa, Mycobacterium spp., and Legionella spp. were commonly isolated. However, methicillin-resis...

Research paper thumbnail of Opportunistic Mapping of Strongyloides stercoralis and Hookworm in Dogs in Remote Australian Communities

Pathogens, 2020

Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Aust... more Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, S. stercoralis and some species of hookworms infect canids and therefore present both environmental and zoonotic sources of transmission to humans. Currently, there is limited information available on the prevalence of hookworms and S. stercoralis infections in dogs living in communities across the Northern Territory in Australia. In this study, 274 dog faecal samples and 11 faecal samples of unknown origin were collected from the environment and directly from animals across 27 remote communities in Northern and Central Australia. Samples were examined using real-time polymerase chain reaction (PCR) analysis for the presence of S. stercoralis and four hookworm species: Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma braziliense and Uncinaria stenocephala. The prevalence of S. stercoralis in dogs was found to be 21.9% (60/274)....

Research paper thumbnail of The Combined Effect of pH and Temperature on the Survival of Salmonella enterica Serovar Typhimurium and Implications for the Preparation of Raw Egg Mayonnaise

Pathogens, 2019

Raw egg products are often associated with salmonellosis. The Australian guidelines recommend raw... more Raw egg products are often associated with salmonellosis. The Australian guidelines recommend raw egg mayonnaise to be prepared and stored under 5 °C and adjusted to a pH less than 4.6 or 4.2. Despite these guidelines, a significant amount of salmonellosis outbreaks are recorded annually in Australia. The aim of this study was to investigate the effect of pH and temperature on the survival of Salmonella Typhimurium (ST) in peptone water (PW) and mayonnaise. The pH of PW and mayonnaise was adjusted to 4.2, 4.4 and 4.6 using acetic acid and vinegar, respectively. The PW and mayonnaise were inoculated with ST and incubated at 37 °C, 23 °C, and 4 °C. The survival of Salmonella was determined using the drop plate method. Survival was significantly (p < 0.05) improved at 4 °C. In both mayonnaise and PW, following 24 h, there was no ST growth at pH 4.2. Resuscitation of ST was rapidly observed at 4 °C while complete inactivation was observed at 37 °C at pH 4.2, 4.4, and 4.6 in both PW a...

Research paper thumbnail of Public Health Risks Associated with Heavy Metal and Microbial Contamination of Drinking Water in Australia

International Journal of Environmental Research and Public Health, 2019

Recently in Australia concerns have been raised regarding the contamination of municipal drinking... more Recently in Australia concerns have been raised regarding the contamination of municipal drinking water supplies with lead. This is of particular concern to children due to the impact of lead exposure on cognitive development and as such these findings have received much media attention. The response from legislators has been swift, and The Victorian School Building Authority has announced that all new schools and school upgrade works will only use lead-free tapware and piping systems. However, while the immediate replacement of lead-containing brass fittings may seem a logical and obvious response, it does not consider the potential implications on microbial contamination. This is particularly concerning given the increasing public health threat posed by opportunistic premise plumbing pathogens (OPPPs). This commentary explores this public health risk of lead exposure from plumbing materials compared to the potential public health risks from OPPPs. Non-tuberculous mycobacterium was...

Research paper thumbnail of Antifungal properties of essential oils for improvement of indoor air quality: a review

Reviews on Environmental Health, 2018

Concerns regarding indoor air quality, particularly the presence of fungi and moulds, are increas... more Concerns regarding indoor air quality, particularly the presence of fungi and moulds, are increasing. The potential for essential oils to reduce, control or remove fungi, is gaining interest as they are seen as a “natural” alternative to synthetic chemical fungicides. This review examines published research on essential oils as a method of fungal control in indoor environments. It was difficult to compare the relative performances of essential oils due to differences in research methods and reporting languages. In addition, there are limited studies that scale up laboratory results and assess the efficacy of essential oils within building environments. However, generally, there appears to be some evidence to support the essential oils clove oil, tea tree oil, oregano, thyme and lemon as potential antifungal agents. Essential oils from heartwood, marjoram, cinnamon, lemon basil, caraway, bay tree, fir, peppermint, pine, cedar leaf and manuka were identified in at least one study as h...

Research paper thumbnail of A Review of Strongyloides spp. Environmental Sources Worldwide

Pathogens, 2019

Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are c... more Strongyloides spp. are parasitic nematodes that are transmitted through the environment and are capable of causing disease. These nematodes affect an estimated 3–300 million humans worldwide. Identifying the environmental reservoirs of Strongyloides spp. is essential for the development of appropriate control strategies. This systematic literature review examined all published studies that identified Strongyloides stercoralis, Strongyloides fuelleborni, Strongyloides fuelleborni kellyi, and Strongyloides spp. from an environmental source. Most studies detected the nematode from dog and primate fecal samples. Other environmental sources identified were ruminants, cats, rodents, insects, water, soil, as well as fruit and vegetables. Most studies used microscopy-based identification techniques; however, several employed molecular-based techniques, which have become increasingly popular for the detection of Strongyloides spp. A limitation identified was a lack of studies that comprehens...

Research paper thumbnail of Strongyloidiasis in Ethiopia: systematic review on risk factors, diagnosis, prevalence and clinical outcomes

Infectious Diseases of Poverty, 2019

Background: Strongyloidiasis is a gastrointestinal infection caused by the parasitic nematode Str... more Background: Strongyloidiasis is a gastrointestinal infection caused by the parasitic nematode Strongyloides stercoralis. It is estimated to infect up to 370 million people globally and is predominately found in tropical and subtropical areas of socioeconomic disadvantage. Main body: This systematic literature review identified studies published in the last ten years on the risk factors, diagnosis, prevalence and/or clinical outcomes of strongyloidiasis in Ethiopia. The prevalence of S. stercoralis ranged from 0.2 to 11.1% in adults, 0.3% to 20.7% in children, 1.5% to 17.3% in HIV positive adults and 5% in HIV positive children. The identified studies primarily used microscopy based techniques that potentially underestimated the prevalence four fold compared with serology and PCR. Strongyloidiasis in children presents a particularly significant issue in Ethiopia as children often presented with anemia, which is associated with impaired mental and cognitive development. The most significant risk factor for strongyloidiasis was HIV status and although other risk factors were identified for helminth infections, none were statistically significant for S. stercoralis specifically. Several studies detected S. stercoralis in dogs and non-biting cyclorrhaphan flies. However, future research is needed to explore the role of these reservoirs in disease transmission. Conclusions: This review demonstrated that strongyloidiasis is an overlooked and neglected disease in Ethiopia. There is a need for a systematic approach using a combination of molecular and serology based diagnostic methods to ascertain the true incidence and burden of strongyloidiasis in Ethiopia. Further research is also needed to break the cycle of transmission by identifying environmental reservoirs, risk factors and exploring the potential for zoonotic transfer.