This study analyzed Ross River virus (RRV) case data from 2002-2012 in the Peel region of Western Australia to determine disease risk associated with proximity to mosquito breeding habitats. Residents living within 1 km of breeding habitats had significantly higher RRV rates compared to background rates across the Peel region in all years studied. Cumulative data over the 10-year period showed residents within 1-2 km of habitats also had higher rates. The study demonstrates an increased RRV risk for residents near breeding habitats and highlights the need for planning authorities to consider mosquito-borne disease risks when assessing new development applications near such habitats.
Jardine et al RRV and GIS Muddy Lakes WA_AJTMH_May 2014Peter Neville
This study examined the dispersal of Aedes camptorhynchus mosquitoes from breeding habitat at Muddy Lakes in Western Australia and the associated risk of Ross River virus (RRV) in surrounding residential areas. Mark-release-recapture experiments found that Ae. camptorhynchus readily dispersed from Muddy Lakes up to 6.5 km away, with 91% recaptured within 3 km. A spatial analysis of 10 years of RRV case data found significantly higher rates of RRV within 2 km of Muddy Lakes, highlighting the disease risk posed to residents near mosquito breeding habitat. The findings suggest planning authorities should consider mosquito-borne disease risks when approving new residential developments near wetlands.
Pre-empting the emergence of zoonoses by understanding their socio-ecologyNaomi Marks
Keynote presentation by Dr Peter Daqszak, President, EcoHealth Alliance, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
This document provides a literature review on the influence of forest fragmentation on Lyme disease in the Upper Midwest. It outlines the zoonotic transmission cycle of Lyme disease and discusses how land use patterns, including urbanization, agriculture, and forest fragmentation can influence disease risk. Geographic information system (GIS) data on Lyme disease cases and land use/land cover are available and have been used to model disease risk, with studies finding forest fragmentation increases measures of Lyme disease occurrence.
Ecological Niche Modelling of Potential RVF Vector Mosquito Species and their...Nanyingi Mark
This document summarizes a study on ecological niche modeling and spatial risk analysis of Rift Valley Fever vectors in Kenya. The study aimed to evaluate the correlation between mosquito distribution and environmental factors associated with RVF outbreaks. Maximum entropy, boosted regression trees, and random forest models were used to develop risk maps predicting the potential spread of RVF vectors based on climatic and environmental variables. The models found that variables like rainfall, number of dry months, and moisture indices influenced the distributions of Culex and Aedes mosquitoes. The risk maps developed can help target RVF surveillance and control in high-risk areas. Limitations included lack of data from known outbreak hotspots and unreliable local climatic/ecological databases
Irrigation and the risk of Rift Valley fever transmission - a case study from...Naomi Marks
Presentation by Dr Bernard Bett of the International Livestock Research Institute, Nairobi, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
Spatial risk assessment of Rift Valley Fever potential outbreaks using a vect...Nanyingi Mark
Rift Valley fever (RVF) is a vector-borne, viral, zoonotic disease that threatens human and animal health. In Kenya the geographical distribution is determined by spread of competent transmission vectors. Existing RVF predictive risk maps are devoid of vectors interactions with eco-climatic parameters in emergence of disease. We envisage to develop a vector surveillance system (VSS) by mapping the distribution of potential RVF competent vectors in Kenya; To evaluate the correlation between mosquito distribution and environmental-climatic attributes favoring emergence of RVF and investigate by modeling the climatic, ecological and environmental drivers of RVF outbreaks and develop a risk map for spatial prediction of RVF outbreaks in Kenya. Using a cross-sectional design we classified Kenya into 30 spatial units/districts (15 case, 15 control for RVF) based on historical RVF outbreaks weighted probability indices for endemicity. Entomological and ecological surveillance using GPS mapping and monthly (May 2013- February 2014) trapping of mosquitoes is alternatively done in case and control areas. 2500 mosquitoes have been collected in 15 districts (50% geographical target for each for case and control). Species identified as (Culicines-86%, Anophelines-9.7%, Aedes- 2.6%) with over 65% distribution in RVF endemic areas. We demonstrate the applications of spatial epidemiology using GIS to illustrate RVF risk distribution and propose utilizing a Maximum Entropy (MaxEnt) approach to develop Ecological Niche Models (ENM) for prediction of competent RVF vector distributions in un-sampled areas. Targeting RVF hotspots can minimize the costs of large-scale vector surveillance hence enhancing vaccination and vector control strategies. A replicable VSS database and methods can be used for risk analysis of other vector-borne diseases.
Horizon scanning for emergence of new viruses in animal and public healthEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Ecohealth 2014 gianni lo iacono presentation on integrative modellingNaomi Marks
'A mechanistic model at the interface between epidemiology, ecology and environmental drivers', presented by Gianni Lo Iacono as part of a panel presentation on integrative modelling from the Dynamic Drivers of Disease Consortium at Ecohealth 2014
Jardine et al RRV and GIS Muddy Lakes WA_AJTMH_May 2014Peter Neville
This study examined the dispersal of Aedes camptorhynchus mosquitoes from breeding habitat at Muddy Lakes in Western Australia and the associated risk of Ross River virus (RRV) in surrounding residential areas. Mark-release-recapture experiments found that Ae. camptorhynchus readily dispersed from Muddy Lakes up to 6.5 km away, with 91% recaptured within 3 km. A spatial analysis of 10 years of RRV case data found significantly higher rates of RRV within 2 km of Muddy Lakes, highlighting the disease risk posed to residents near mosquito breeding habitat. The findings suggest planning authorities should consider mosquito-borne disease risks when approving new residential developments near wetlands.
Pre-empting the emergence of zoonoses by understanding their socio-ecologyNaomi Marks
Keynote presentation by Dr Peter Daqszak, President, EcoHealth Alliance, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
This document provides a literature review on the influence of forest fragmentation on Lyme disease in the Upper Midwest. It outlines the zoonotic transmission cycle of Lyme disease and discusses how land use patterns, including urbanization, agriculture, and forest fragmentation can influence disease risk. Geographic information system (GIS) data on Lyme disease cases and land use/land cover are available and have been used to model disease risk, with studies finding forest fragmentation increases measures of Lyme disease occurrence.
Ecological Niche Modelling of Potential RVF Vector Mosquito Species and their...Nanyingi Mark
This document summarizes a study on ecological niche modeling and spatial risk analysis of Rift Valley Fever vectors in Kenya. The study aimed to evaluate the correlation between mosquito distribution and environmental factors associated with RVF outbreaks. Maximum entropy, boosted regression trees, and random forest models were used to develop risk maps predicting the potential spread of RVF vectors based on climatic and environmental variables. The models found that variables like rainfall, number of dry months, and moisture indices influenced the distributions of Culex and Aedes mosquitoes. The risk maps developed can help target RVF surveillance and control in high-risk areas. Limitations included lack of data from known outbreak hotspots and unreliable local climatic/ecological databases
Irrigation and the risk of Rift Valley fever transmission - a case study from...Naomi Marks
Presentation by Dr Bernard Bett of the International Livestock Research Institute, Nairobi, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
Spatial risk assessment of Rift Valley Fever potential outbreaks using a vect...Nanyingi Mark
Rift Valley fever (RVF) is a vector-borne, viral, zoonotic disease that threatens human and animal health. In Kenya the geographical distribution is determined by spread of competent transmission vectors. Existing RVF predictive risk maps are devoid of vectors interactions with eco-climatic parameters in emergence of disease. We envisage to develop a vector surveillance system (VSS) by mapping the distribution of potential RVF competent vectors in Kenya; To evaluate the correlation between mosquito distribution and environmental-climatic attributes favoring emergence of RVF and investigate by modeling the climatic, ecological and environmental drivers of RVF outbreaks and develop a risk map for spatial prediction of RVF outbreaks in Kenya. Using a cross-sectional design we classified Kenya into 30 spatial units/districts (15 case, 15 control for RVF) based on historical RVF outbreaks weighted probability indices for endemicity. Entomological and ecological surveillance using GPS mapping and monthly (May 2013- February 2014) trapping of mosquitoes is alternatively done in case and control areas. 2500 mosquitoes have been collected in 15 districts (50% geographical target for each for case and control). Species identified as (Culicines-86%, Anophelines-9.7%, Aedes- 2.6%) with over 65% distribution in RVF endemic areas. We demonstrate the applications of spatial epidemiology using GIS to illustrate RVF risk distribution and propose utilizing a Maximum Entropy (MaxEnt) approach to develop Ecological Niche Models (ENM) for prediction of competent RVF vector distributions in un-sampled areas. Targeting RVF hotspots can minimize the costs of large-scale vector surveillance hence enhancing vaccination and vector control strategies. A replicable VSS database and methods can be used for risk analysis of other vector-borne diseases.
Horizon scanning for emergence of new viruses in animal and public healthEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Ecohealth 2014 gianni lo iacono presentation on integrative modellingNaomi Marks
'A mechanistic model at the interface between epidemiology, ecology and environmental drivers', presented by Gianni Lo Iacono as part of a panel presentation on integrative modelling from the Dynamic Drivers of Disease Consortium at Ecohealth 2014
Interepidemic Seroepidemiological Survey of Rift Valley Fever in Garissa, KenyaMark Nanyingi
Background: Rift Valley fever (RVF) is a vector-borne zoonotic disease that is caused by phlebovirus and transmitted primarily by aedes mosquitoes. RVF outbreaks have led to significant effects to human and animal health in the Horn of Africa and Arabian Peninsula. The economic impact of 1997-98, 2000 and 2006-2007 outbreaks due to massive livestock abortions, deaths, acute human illness and deaths was estimated at over $ 500 million. We hypothesize there is consistent virus circulation in RVF endemic areas of Northern Kenya and RVF epidemics have potential associations with environmental and climatic parameters. The objective of this study was to detect circulation of RVFV in goats, sheep and cattle in Garissa County, Kenya during the inter-epidemic period (IEP).
Methodology: We performed a cross-sectional surveillance of ruminants in RVF high risk areas of Garissa County, Kenya. Periodic blood sampling of sheep, goats and cattle was done in March 2012 and July 2013. Serological analysis for total antiRVF antibodies for 370 ruminants was investigated using a multispecies competitive Enzyme-Linked Immunosorbent Assay (ELISA) kit. Host risk factors for RVFV seropositivity were examined by both univariable analysis and mixed effects logistic regression model. Unadjusted odds ratios (OR) for seropositivity were estimated using log linear regression model.
Results: The overall seroprevalence for the 370 ruminants was 27.6%. Sheep (n= 87) and cattle (n= 12) had higher prevalence 32.2% (CI [20.6 -31]) and 33.3% (CI [6.7 -60]) respectively than goats (n = 271), 25.8% (CI [22.4 – 42]). Seropostivity in males was 31.8% (CI [22.2-31.8]) higher than 27% (CI [18.1-45.6]) in females. There was an increased likelihood of higher seropositivity in old (OR 18.24, CI [5.26 -116.4]), p < 0.0001) than young animals.
Conclusions: This study demonstrates the widespread serological evidence and potential RVFV circulation among domestic ruminants in Garissa district thus indicative of an endemic reservoir of infection. There is need for increased preparedness and response in RVF endemic areas by conducting animal-human syndromic sero-surveillance as part of one health early warning system.
Environmental change and vector borne diseaseNik Ronaidi
This document discusses how environmental change can impact vector-borne diseases. It identifies several factors of global change like climate change, urbanization, and land use that can influence disease transmission by affecting vectors, pathogens, or human exposure and sensitivity. Changes in temperature and precipitation from climate change can expand vector habitat and accelerate pathogen development. The document also examines how these global changes have impacted diseases like dengue and filariasis in Malaysia through influences on vector ecology and human activities. Effective adaptation requires assessing a population's vulnerability, exposure, and sensitivity to design vector control and other management options.
People, animals, plants, pests and pathogens: connections matterEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Early warning Systems for Vector Borne Climate Sensitive Diseases to Improve...Nanyingi Mark
The document discusses developing an early warning system for vector-borne diseases like malaria and Rift Valley fever in Kenya. It aims to 1) develop tools to detect likely disease outbreaks and 2) assess climate, hydrological, ecosystem and vector factors in high risk areas. The study will analyze disease prevalence, climate/environmental data, and vector surveillance to develop maps overlaying risk factors and disease patterns. This will inform development of predictive models, identify hotspots, and support early warnings to improve human health and resilience against climate-sensitive diseases.
Presented by Delia Grace, Bernard Bett, Karl Rich, Francis Wanyoike, Johanna Lindahl and Tom Randolph at a symposium on 'One Health for the Real World: Zoonoses, Ecosystems and Wellbeing', London, UK, 17–18 March 2016.
Bernard bett delia grace climate change impacts on animal health and vector ...Naomi Marks
'Climate change impacts on animal health and vector borne diseases. Presentation by Bernard Bett and Delia Grace of the International Livestock Research Institute to a USAID climate change technical officers meeting
Land use, biodiversity changes and the risk of zoonotic diseases: Findings fr...ILRI
Presented by B. Bett, M. Said, R. Sang, S. Bukachi, J. Lindahl, S. Wanyoike, E. Ontiri, I. Njeru, J. Karanja, F. Wanyoike, D. Mbotha and D. Grace at the 49th Kenya Veterinary Association annual scientific conference, Busia, Kenya, 22-25 April 2015.
Assessing the threats and strategic responses to exotic mosquito threats in t...DrCameronWebb
Exotic mosquitoes pose a threat to tropical and temperate Australia. These slides are from a presentation given at the Australian Entomological Society conference in Cairns, QLD, 27-30 September 2015 in the special symposium "Managing Current & Future Exotic Mosquito Threats"
Social dimensions of zoonoses in interdisciplinary researchNaomi Marks
This document summarizes Dr. Hayley MacGregor's research on the social dimensions of zoonoses (diseases that can be transmitted between animals and humans) in emerging livestock systems. It discusses two key areas: 1) how cultural and social practices influence zoonotic risk, and 2) the relationship between humans and animals. For area 1, it describes how factors like intensification of production, supply chains, processing practices, markets and consumer demand can drive zoonotic risk. For area 2, it discusses how human-animal relations blur traditional categories, and how the health of humans and animals is interdependent.
Anticipating infectious threats to Australia: Mosquito-borne DiseaseDrCameronWebb
What will drive increased risk of mosquito-borne disease in the future? Climate change, globalisation, or how we manage our local wetlands and wildlife?
This presentation, from Thursday 27 February 2014, was part of the “Anticipating infectious threats to Australia” coordinated by the Marie Bashir Institute for Infectious Disease and Biosecurity (University of Sydney).
http://sydney.edu.au/mbi/news/2014/anticipatinginfectiousthreats.php
Epidemiology of malaria in irrigated parts of Tana River County, KenyaILRI
1) The study examined malaria prevalence and risk factors in irrigated areas of Tana River County, Kenya. A survey found a 5% malaria prevalence.
2) Living farther than 5km from health facilities and larger household size were associated with higher risk of malaria.
3) A mathematical model was developed that accurately predicted malaria prevalence based on local data on rainfall, irrigation patterns, and mosquito lifecycles.
This study surveyed honey bee colonies in urban, rural, and agricultural areas to examine potential exposure to neonicotinoid pesticides. Beebread (stored pollen) and wax samples were tested for residues of imidacloprid and other neonicotinoids. Samples from agricultural areas were more likely to contain detectable residues of thiamethoxam and clothianidin than rural or urban samples. The maximum residue found was 3.9 ppb of imidacloprid. A risk assessment found the residues posed a low potential for negative effects on bee behavior or health based on a no observable adverse effect concentration. The study aimed to understand pesticide exposure risks to bees foraging near agricultural and urban landscapes.
Climate change impacts on animal health and vector borne diseasesILRI
Presentation by Bernard Bett and Delia Grace at a United States Agency for International Development (USAID) climate change technical officers' meeting, Nairobi, Kenya, 1 April 2014.
Future mosquito-borne disease threats in AustraliaDrCameronWebb
These are the slides accompanying my presentation at the 2015 Australian Society for Microbiology conference at QT, Canberra, 12-15 July 2015. This invited presentation provides are overview of the critical driving factors in mosquito-borne disease threats facing Australia in the future. These include both endemic pathogens and exotic vectors and pathogens. How will the public health risk in Australia shift with a changing climate and ever increasing movement or people and their possessions? Full details of the program are available here: http://asm2015.asnevents.com.au/programs/scientific-program/
Serological evidence of MERS-CoV antibodies in dromedary camels (Camelus drom...ILRI
Presented by Eric M. Fèvre, Sharon L. Deem, Margaret Kinnaird, Springer Browne, Dishon Muloi, Gert-Jan Godeke, Marion Koopmans and C.B.E.M. Reusken at the 4th Medical and Veterinary Virus Research Symposium in Kenya (MVVR), Nairobi, Kenya, 15-16 October 2015.
Study of the Seroprevalence of Anti-Leptospirosis Antibodies in Subjects in T...IIJSRJournal
Leptospirosis is a tropical and subtropical zoonotic disease culminating as a serious public health problem worldwide, apparently existing as co-infections with various other unrelated diseases, such as malaria. It is caused by spiral bacteria and the main vectors of which are rodents. These bacteria have various survival mechanisms in the environment allowing them to carry out their infectious cycle within their host organisms. The pathophysiological mechanisms pertaining to leptospirosis is still not understood in full and mis or underdiagnosed.
A cross-sectional descriptive study was carried out in three different localities in Niamey where respondents were screened for to demonstrate transmission to humans. Indirect ELISA method as a laboratory diagnostic or screening toll is used by utilizing leptospiral-specific IgG from serum samples of the respondents.
Results from the study showed that 11 people are found to be positive for leptospirosis (with a seroprevalence of 2.75%) with a strong tendency in the slaughterhouse workers which presents a fairly high risk compared to the other localities of the study. Indeed, the different areas/localities of this pilot study do not present the same level of risk because they are not subject to the same risk associated factors. In this vein, we have 87.6% of population exposed to the presence of rats, 48% are in contact with animals, 38.6% live in homes near water and 12.9% go swimming.
This study made it possible, on the one hand, to highlight the transmission of leptospirosis from animals to humans and, on the other hand, to draw attention to the involvement of the various identified risk factors.
Estimating Extinction Rates: Habitat loss, species-area curves, and the “exti...Flinders University
This document discusses methods for estimating extinction rates and examines the limitations of using species-area relationships (SAR) to estimate extinction rates from habitat loss. Specifically, SAR methods may overestimate extinction rates because they assume species are randomly distributed when in reality species distributions are often non-random. The document explores how non-random spatial distributions violate the mirror-image relationship between forward and backward modeling using SAR and endemics-area curves. Data from forest plots are analyzed showing SAR may not accurately capture extinction risks from habitat loss for non-randomly distributed species.
The Real World: One Health - zoonoses, ecosystems and wellbeingNaomi Marks
Opening keynote presentation by Professor Jeremy Farrar, Director, Wellcome Trust, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
A statistical analysis of cockroach and rodent’s infestationAlexander Decker
This study analyzed the rates of cockroach and rodent infestation across three communities in Nigeria and the control methods used by households. The study found that cockroach infestation (68%) was significantly higher than rodent infestation (32%). Common evidence of infestation included rat runs (40%) and sightings of live cockroaches (30%). Local pesticides like Sniper were perceived as more effective and cheaper controls compared to commercial brands. Statistical analysis confirmed a significant difference between cockroach and rodent infestation rates across the communities.
One health Perspective and Vector Borne DiseasesNanyingi Mark
Vector borne diseases like malaria and Rift Valley fever pose significant risks to human and animal health in Africa. One Health approaches that consider the environmental, animal, and human factors are needed to develop early warning systems. The document discusses developing tools to detect climate sensitive disease outbreaks and assessing environmental and vector characteristics. It also presents models of Rift Valley fever transmission dynamics and the importance of vertical transmission between outbreaks. Spatial distribution models of Rift Valley fever vectors in Kenya were developed using climatic and ecological variables. The results can help target surveillance and control in high-risk areas.
Ecological factors associated with abundance and distribution of mosquito vec...ILRI
Poster by Max Korir, Joel Lutomiah and Bernard Bett presented the 8th All Africa Conference on Animal Agriculture, Gaborone, Botswana, 26–29 September 2023.
Interepidemic Seroepidemiological Survey of Rift Valley Fever in Garissa, KenyaMark Nanyingi
Background: Rift Valley fever (RVF) is a vector-borne zoonotic disease that is caused by phlebovirus and transmitted primarily by aedes mosquitoes. RVF outbreaks have led to significant effects to human and animal health in the Horn of Africa and Arabian Peninsula. The economic impact of 1997-98, 2000 and 2006-2007 outbreaks due to massive livestock abortions, deaths, acute human illness and deaths was estimated at over $ 500 million. We hypothesize there is consistent virus circulation in RVF endemic areas of Northern Kenya and RVF epidemics have potential associations with environmental and climatic parameters. The objective of this study was to detect circulation of RVFV in goats, sheep and cattle in Garissa County, Kenya during the inter-epidemic period (IEP).
Methodology: We performed a cross-sectional surveillance of ruminants in RVF high risk areas of Garissa County, Kenya. Periodic blood sampling of sheep, goats and cattle was done in March 2012 and July 2013. Serological analysis for total antiRVF antibodies for 370 ruminants was investigated using a multispecies competitive Enzyme-Linked Immunosorbent Assay (ELISA) kit. Host risk factors for RVFV seropositivity were examined by both univariable analysis and mixed effects logistic regression model. Unadjusted odds ratios (OR) for seropositivity were estimated using log linear regression model.
Results: The overall seroprevalence for the 370 ruminants was 27.6%. Sheep (n= 87) and cattle (n= 12) had higher prevalence 32.2% (CI [20.6 -31]) and 33.3% (CI [6.7 -60]) respectively than goats (n = 271), 25.8% (CI [22.4 – 42]). Seropostivity in males was 31.8% (CI [22.2-31.8]) higher than 27% (CI [18.1-45.6]) in females. There was an increased likelihood of higher seropositivity in old (OR 18.24, CI [5.26 -116.4]), p < 0.0001) than young animals.
Conclusions: This study demonstrates the widespread serological evidence and potential RVFV circulation among domestic ruminants in Garissa district thus indicative of an endemic reservoir of infection. There is need for increased preparedness and response in RVF endemic areas by conducting animal-human syndromic sero-surveillance as part of one health early warning system.
Environmental change and vector borne diseaseNik Ronaidi
This document discusses how environmental change can impact vector-borne diseases. It identifies several factors of global change like climate change, urbanization, and land use that can influence disease transmission by affecting vectors, pathogens, or human exposure and sensitivity. Changes in temperature and precipitation from climate change can expand vector habitat and accelerate pathogen development. The document also examines how these global changes have impacted diseases like dengue and filariasis in Malaysia through influences on vector ecology and human activities. Effective adaptation requires assessing a population's vulnerability, exposure, and sensitivity to design vector control and other management options.
People, animals, plants, pests and pathogens: connections matterEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Early warning Systems for Vector Borne Climate Sensitive Diseases to Improve...Nanyingi Mark
The document discusses developing an early warning system for vector-borne diseases like malaria and Rift Valley fever in Kenya. It aims to 1) develop tools to detect likely disease outbreaks and 2) assess climate, hydrological, ecosystem and vector factors in high risk areas. The study will analyze disease prevalence, climate/environmental data, and vector surveillance to develop maps overlaying risk factors and disease patterns. This will inform development of predictive models, identify hotspots, and support early warnings to improve human health and resilience against climate-sensitive diseases.
Presented by Delia Grace, Bernard Bett, Karl Rich, Francis Wanyoike, Johanna Lindahl and Tom Randolph at a symposium on 'One Health for the Real World: Zoonoses, Ecosystems and Wellbeing', London, UK, 17–18 March 2016.
Bernard bett delia grace climate change impacts on animal health and vector ...Naomi Marks
'Climate change impacts on animal health and vector borne diseases. Presentation by Bernard Bett and Delia Grace of the International Livestock Research Institute to a USAID climate change technical officers meeting
Land use, biodiversity changes and the risk of zoonotic diseases: Findings fr...ILRI
Presented by B. Bett, M. Said, R. Sang, S. Bukachi, J. Lindahl, S. Wanyoike, E. Ontiri, I. Njeru, J. Karanja, F. Wanyoike, D. Mbotha and D. Grace at the 49th Kenya Veterinary Association annual scientific conference, Busia, Kenya, 22-25 April 2015.
Assessing the threats and strategic responses to exotic mosquito threats in t...DrCameronWebb
Exotic mosquitoes pose a threat to tropical and temperate Australia. These slides are from a presentation given at the Australian Entomological Society conference in Cairns, QLD, 27-30 September 2015 in the special symposium "Managing Current & Future Exotic Mosquito Threats"
Social dimensions of zoonoses in interdisciplinary researchNaomi Marks
This document summarizes Dr. Hayley MacGregor's research on the social dimensions of zoonoses (diseases that can be transmitted between animals and humans) in emerging livestock systems. It discusses two key areas: 1) how cultural and social practices influence zoonotic risk, and 2) the relationship between humans and animals. For area 1, it describes how factors like intensification of production, supply chains, processing practices, markets and consumer demand can drive zoonotic risk. For area 2, it discusses how human-animal relations blur traditional categories, and how the health of humans and animals is interdependent.
Anticipating infectious threats to Australia: Mosquito-borne DiseaseDrCameronWebb
What will drive increased risk of mosquito-borne disease in the future? Climate change, globalisation, or how we manage our local wetlands and wildlife?
This presentation, from Thursday 27 February 2014, was part of the “Anticipating infectious threats to Australia” coordinated by the Marie Bashir Institute for Infectious Disease and Biosecurity (University of Sydney).
http://sydney.edu.au/mbi/news/2014/anticipatinginfectiousthreats.php
Epidemiology of malaria in irrigated parts of Tana River County, KenyaILRI
1) The study examined malaria prevalence and risk factors in irrigated areas of Tana River County, Kenya. A survey found a 5% malaria prevalence.
2) Living farther than 5km from health facilities and larger household size were associated with higher risk of malaria.
3) A mathematical model was developed that accurately predicted malaria prevalence based on local data on rainfall, irrigation patterns, and mosquito lifecycles.
This study surveyed honey bee colonies in urban, rural, and agricultural areas to examine potential exposure to neonicotinoid pesticides. Beebread (stored pollen) and wax samples were tested for residues of imidacloprid and other neonicotinoids. Samples from agricultural areas were more likely to contain detectable residues of thiamethoxam and clothianidin than rural or urban samples. The maximum residue found was 3.9 ppb of imidacloprid. A risk assessment found the residues posed a low potential for negative effects on bee behavior or health based on a no observable adverse effect concentration. The study aimed to understand pesticide exposure risks to bees foraging near agricultural and urban landscapes.
Climate change impacts on animal health and vector borne diseasesILRI
Presentation by Bernard Bett and Delia Grace at a United States Agency for International Development (USAID) climate change technical officers' meeting, Nairobi, Kenya, 1 April 2014.
Future mosquito-borne disease threats in AustraliaDrCameronWebb
These are the slides accompanying my presentation at the 2015 Australian Society for Microbiology conference at QT, Canberra, 12-15 July 2015. This invited presentation provides are overview of the critical driving factors in mosquito-borne disease threats facing Australia in the future. These include both endemic pathogens and exotic vectors and pathogens. How will the public health risk in Australia shift with a changing climate and ever increasing movement or people and their possessions? Full details of the program are available here: http://asm2015.asnevents.com.au/programs/scientific-program/
Serological evidence of MERS-CoV antibodies in dromedary camels (Camelus drom...ILRI
Presented by Eric M. Fèvre, Sharon L. Deem, Margaret Kinnaird, Springer Browne, Dishon Muloi, Gert-Jan Godeke, Marion Koopmans and C.B.E.M. Reusken at the 4th Medical and Veterinary Virus Research Symposium in Kenya (MVVR), Nairobi, Kenya, 15-16 October 2015.
Study of the Seroprevalence of Anti-Leptospirosis Antibodies in Subjects in T...IIJSRJournal
Leptospirosis is a tropical and subtropical zoonotic disease culminating as a serious public health problem worldwide, apparently existing as co-infections with various other unrelated diseases, such as malaria. It is caused by spiral bacteria and the main vectors of which are rodents. These bacteria have various survival mechanisms in the environment allowing them to carry out their infectious cycle within their host organisms. The pathophysiological mechanisms pertaining to leptospirosis is still not understood in full and mis or underdiagnosed.
A cross-sectional descriptive study was carried out in three different localities in Niamey where respondents were screened for to demonstrate transmission to humans. Indirect ELISA method as a laboratory diagnostic or screening toll is used by utilizing leptospiral-specific IgG from serum samples of the respondents.
Results from the study showed that 11 people are found to be positive for leptospirosis (with a seroprevalence of 2.75%) with a strong tendency in the slaughterhouse workers which presents a fairly high risk compared to the other localities of the study. Indeed, the different areas/localities of this pilot study do not present the same level of risk because they are not subject to the same risk associated factors. In this vein, we have 87.6% of population exposed to the presence of rats, 48% are in contact with animals, 38.6% live in homes near water and 12.9% go swimming.
This study made it possible, on the one hand, to highlight the transmission of leptospirosis from animals to humans and, on the other hand, to draw attention to the involvement of the various identified risk factors.
Estimating Extinction Rates: Habitat loss, species-area curves, and the “exti...Flinders University
This document discusses methods for estimating extinction rates and examines the limitations of using species-area relationships (SAR) to estimate extinction rates from habitat loss. Specifically, SAR methods may overestimate extinction rates because they assume species are randomly distributed when in reality species distributions are often non-random. The document explores how non-random spatial distributions violate the mirror-image relationship between forward and backward modeling using SAR and endemics-area curves. Data from forest plots are analyzed showing SAR may not accurately capture extinction risks from habitat loss for non-randomly distributed species.
The Real World: One Health - zoonoses, ecosystems and wellbeingNaomi Marks
Opening keynote presentation by Professor Jeremy Farrar, Director, Wellcome Trust, at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, London 17-18 March 2016
A statistical analysis of cockroach and rodent’s infestationAlexander Decker
This study analyzed the rates of cockroach and rodent infestation across three communities in Nigeria and the control methods used by households. The study found that cockroach infestation (68%) was significantly higher than rodent infestation (32%). Common evidence of infestation included rat runs (40%) and sightings of live cockroaches (30%). Local pesticides like Sniper were perceived as more effective and cheaper controls compared to commercial brands. Statistical analysis confirmed a significant difference between cockroach and rodent infestation rates across the communities.
One health Perspective and Vector Borne DiseasesNanyingi Mark
Vector borne diseases like malaria and Rift Valley fever pose significant risks to human and animal health in Africa. One Health approaches that consider the environmental, animal, and human factors are needed to develop early warning systems. The document discusses developing tools to detect climate sensitive disease outbreaks and assessing environmental and vector characteristics. It also presents models of Rift Valley fever transmission dynamics and the importance of vertical transmission between outbreaks. Spatial distribution models of Rift Valley fever vectors in Kenya were developed using climatic and ecological variables. The results can help target surveillance and control in high-risk areas.
Ecological factors associated with abundance and distribution of mosquito vec...ILRI
Poster by Max Korir, Joel Lutomiah and Bernard Bett presented the 8th All Africa Conference on Animal Agriculture, Gaborone, Botswana, 26–29 September 2023.
Perspectives of predictive epidemiology and early warning systems for Rift Va...ILRI
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Identifying Malaria Hazard Areas Using GIS and Multi Criteria: The Case Study...Premier Publishers
Malaria is one of the most severe public health problems worldwide with 300 to 500 million cases and about one million deaths reported to date, 90% of which were reported from Sub Saharan African countries like Ethiopia. The main objective of the study was identification of malaria hazard areas by using the Arc GIS in East Gojjam zone. Weighted overlay technique of multi-criteria analysis was used to develop the malaria-hazard map. Temperature, rainfall, altitude, slope, distance from rivers, and soil types were considered as variables to prepare malaria hazard map. The malaria hazard map was classified into four suitability index such as very high suitable, high suitable, moderately suitable, and low suitable. The result shows that around 22% areas is highly suitable for malaria hazard, 27% is high suitable, 26% is moderately suitable and 25 % is low suitable for malaria hazard areas. It is suggested that effective identification and mapping of malaria hazard areas may contribute for the prevention system cost effective, least time taking, easily manageable in controlling the disease.
This document summarizes the development of a new geospatial database and analysis project in Australia called the Australian Venomous Injury Project (AVIP). The project aims to build the first national geospatial dataset on venomous injuries in Australia. It involves collecting and integrating mortality, morbidity, clinical, and environmental data. The goal is to better understand the burden of venomous injuries on Australian populations and identify factors that influence outcomes. This will help guide future research, prevention strategies, public health policy, and education. The initial phase involved obtaining ethics approvals and developing a geodatabase to analyze national coroner records on mortality. Hospital admission data will also be integrated to enhance geographic analysis. The project has the potential to inform public health
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This study analyzed the correlation between tuberculosis (TB) and human immunodeficiency virus (HIV) infections at the census tract level in Harris County, Texas from 2009-2010. The authors found that census tracts with higher percentages of poverty, Black residents, and foreign-born residents had above average rates of both HIV and TB. Logistic regression also showed these factors were associated with higher odds of co-infection of HIV/TB. The authors conclude targeted testing and education programs should focus on areas with these high-risk demographic characteristics.
A statistical analysis of cockroach and rodent’s infestationAlexander Decker
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Background: Rift Valley fever (RVF) is a vector-borne zoonotic disease that is caused by phlebovirus and transmitted primarily by aedes mosquitoes. RVF outbreaks have led to significant effects to human and animal health in the Horn of Africa and Arabian Peninsula. The economic impact of 1997-98, 2000 and 2006-2007 outbreaks due to massive livestock abortions, deaths, acute human illness and deaths was estimated at over $ 500 million. We hypothesize there is consistent virus circulation in RVF endemic areas of Northern Kenya and RVF epidemics have potential associations with environmental and climatic parameters. The objective of this study was to detect circulation of RVFV in goats, sheep and cattle in Garissa County, Kenya during the inter-epidemic period (IEP).
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Results: The overall seroprevalence for the 370 ruminants was 27.6%. Sheep (n= 87) and cattle (n= 12) had higher prevalence 32.2% (CI [20.6 -31]) and 33.3% (CI [6.7 -60]) respectively than goats (n = 271), 25.8% (CI [22.4 – 42]). Seropostivity in males was 31.8% (CI [22.2-31.8]) higher than 27% (CI [18.1-45.6]) in females. There was an increased likelihood of higher seropositivity in old (OR 18.24, CI [5.26 -116.4]), p < 0.0001) than young animals.
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Dr. Amy Kinsley - Movement Matters: Using Swine Shipment Patterns to Identify...John Blue
Movement Matters: Using Swine Shipment Patterns to Identify Farms For Targeted Disease Surveillance and Control - Dr. Amy Kinsley, from the 2018 Allen D. Leman Swine Conference, September 15-18, 2018, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2018-leman-swine-conference-material
This study examined the impact of human disturbance on waterfowl diversity at two sites within the Wilderness Lakes System in South Africa. Abundance, diversity, and species richness were significantly higher at Rondevlei lake, which prohibits water activities, than at Touw River, which allows limited recreation. A total of 35 waterbird species were observed, but only 11 were found at both sites. Red-knobbed coot was the most abundant species overall. Human disturbance events were more common and potentially disturbing to waterfowl at Touw River than Rondevlei. The results provide evidence that human disturbances negatively impact the waterfowl community at Touw River relative to the protected Rondevlei lake.
This document discusses challenges and opportunities for discovering and documenting biodiversity in the current information age. It argues that current taxonomic processes are too slow and that new approaches are needed to integrate distributed data sources and leverage community contributions. Specifically, it proposes:
1) Publishing new biodiversity data prior to formal documentation to accelerate discovery.
2) Developing automated workflows and online workspaces to integrate phylogenetic, distribution, and trait data.
3) Enabling community participation through open data sharing and collaborative annotation platforms.
This document discusses challenges and opportunities for discovering and documenting biodiversity in the current information age. It argues that current taxonomic processes are too slow and that new approaches are needed to integrate distributed data sources and leverage community sourcing. Specifically, it advocates for:
1) Publishing new biodiversity data prior to formal documentation to accelerate discovery.
2) Developing automated workflows and online workspaces to integrate phylogenetic, distribution, and trait data.
3) Enabling community participation in annotating and improving global biodiversity models and maps.
4) Changing incentives to value data sharing over individual "kudos" and prioritize the collective good of the scientific community.
Similar to Jardine at al RRV in Peel region_proximity to wetlands_VBZD Feb 2015_Vol 15 p 141-146 (20)
Jardine at al RRV in Peel region_proximity to wetlands_VBZD Feb 2015_Vol 15 p 141-146
1. Proximity to Mosquito Breeding Habitat and Ross River
Virus Risk in the Peel Region of Western Australia
Andrew Jardine,1
Peter J. Neville,1
and Michael D.A. Lindsay2
Abstract
It is intuitive that vector-borne disease exposure risk is related to proximity to sources of vector breeding, but
this aspect rarely receives empirical testing. The population of Western Australia (WA) is increasing rapidly,
with many new residential developments proposed in close proximity to mosquito breeding habitat. However,
potential mosquito-borne disease risks for future residents are given little consideration by planning authorities.
The Peel region is one of the fastest growing regions in WA and regularly experiences a large number of cases
of the mosquito-borne Ross River virus (RRV) disease with epidemics occuring in the region every few years.
A spatial analysis of RRV disease data in the Peel region was undertaken to determine the risk associated with
proximity to a mosquito breeding habitat. Geographic Information Systems (GIS) software was used to create
buffers between 1 and 6 km from the breeding habitat. The number of cases per 1000 dwellings in each buffer
was calculated between 2002/03 to 2011/12 for years with > 100 cases across all buffers (n = 5) in addition to
the cumulative rate over the entire period in each buffer. Residents living within 1 km of a mosquito breeding
habitat had a significantly higher rate of RRV disease compared to the background rate across the Peel region in
all individual years investigated. The cumulative data over the 10-year study period showed that residents in the
1- and 2-km buffers had a significantly higher rate, whereas those living between 3 and 6 km away did not. This
study demonstrates an increased mosquito-borne disease risk associated with living in close proximity to a
mosquito breeding habitat in a rapidly expanding region of WA and highlights the importance of considering
mosquito-borne disease risks when planning authorities assess new residential development applications.
Known mosquito breeding wetlands should be incorporated into land use planning scheme maps to ensure that
they are accurately delineated and the implications are considered when planning decisions are made.
Key Words: Mosquitoes—Geographic Information Systems (GIS)—Epidemiology—Arbovirus.
Introduction
Burgeoning population growth and associated urban
expansion present significant challenges to local gov-
ernment and planning authorities globally. One often ne-
glected outcome of such urban expansion is heightened
disease risk as human populations encroach closer to natural
mosquito breeding habitats. For example, an increased risk of
malaria in Africa (Staedke et al. 2003, Midega et al. 2012) and
Asia (Haque et al. 2009) has been demonstrated with decreasing
distance to mosquito breeding habitats; living in a residence
located within 100 meters from one or more tree hole breeding
sites was demonstrated to be associated with almost four times
greater risk of La Crosse encephalitis infection in eastern Ten-
nessee (Erwin et al. 2002); and areas in southeast Queensland
with a greater proportion of wetlands and native vegetation and
levels of adult mosquito activity have been associated with
higher rates of Ross River virus (RRV; Togaviridae: Alpha-
virus) (Muhar et al. 2000, Ryan et al. 2006, Hu et al. 2010).
These studies exemplify the risks associated with living in
proximity to sources of vector populations. In areas experienc-
ing significant population and urban expansion, there is a critical
need for research evaluating such links and for associated evi-
dence and guidance to be provided to planning authorities.
Western Australia (WA) was the fastest growing state in
Australia between 2003 and 2013, with a population increase
of 29% compared to 17% nationally over this period (Aus-
tralian Bureau of Statistics 2014). Much of this population
1
Mosquito-Borne Disease Control, Environmental Health Hazards Unit, Environmental Health Directorate, Department of Health
Western Australia, Western Australia, Australia.
2
Environmental Health Hazards Unit, Environmental Health Directorate, Department of Health Western Australia, Western Australia,
Australia.
VECTOR-BORNE AND ZOONOTIC DISEASES
Volume 15, Number 2, 2015
ª Mary Ann Liebert, Inc.
DOI: 10.1089/vbz.2014.1693
141
2. growth occurred in the outer suburbs of Perth, most notably in
the Peel region (defined here as the Local Government Areas
of Rockingham, Mandurah, Murray, and Waroona; Fig. 1),
and it increased by 53% between 2003 and 2013 (Australian
Bureau of Statistics 2014). Population forecasts by the
Western Australian Planning Commission indicate that this
rapid growth rate is expected to continue in the region over
coming decades (Western Australian Planning Commission
2012), placing further pressure to develop surrounding land
into new residential areas that are often proposed close to
water due to intrinsic aesthetic values. Residents who live in
close proximity to breeding sites may be subjected to intense
nuisance problems and, more importantly, increased risk of
infection with a mosquito-borne virus.
A substantial number of cases of RRV (Togaviridae: Al-
phavirus) disease, a nonfatal but potentially debilitating
polyarthritic disease (Russell 2002), are reported annually
from the Peel region, and large outbreaks are experienced
every few years despite significant mosquito control efforts
(Lindsay et al. 1996). Extensive areas of salt marsh mosquito
breeding habitat are located in the lower reaches of the Ser-
pentine River, the Peel Inlet, and the Harvey Estuary (Fig. 1)
(Wright 1988), many of which are protected under the
Ramsar Convention listed Peel-Yalgorup system (Depart-
ment of the Environment 2011). Mosquito surveillance in the
Peel region over the last 20 years has shown that Aedes (Ae.)
camptorhynchus is the predominant species between April
and December, whereas Ae. vigilax is the major species
present from January to March each year (Lindsay et al.
1996). Both species are important vectors of RRV in coastal
regions of WA (Lindsay et al. 1996, Russell 2002). Fur-
thermore, substantial areas of native bushland remain in close
proximity to many mosquito breeding sites in the Peel region
that support western grey kangaroo populations (Macropus
fuliginosus), an important vertebrate host of RRV in southern
WA (Russell 2002, Potter et al. 2014).
Significant residential development has occurred and
continues to expand in close proximity to mosquito breeding
habitats in the Peel region due to the aesthetic values of living
near water. Unfortunately, the potential for residents who
move into these areas to be exposed to mosquito-borne dis-
eases and intense nuisance problems is given little consid-
eration by planning authorities because limited evidence
presently exists to quantify this risk. In WA, RRV incidence
was found to decrease with distance from a tidal estuary with
extensive mosquito breeding habitats in rural and semirural
areas (Vally et al. 2012). However, no relationship was found
in urban areas with higher population density (Vally et al.
2012). We also recently demonstrated a significant increase
in RRV risk within 2 km of a known highly productive
breeding habitat located 200 km south of the current study
region that resulted from dispersal of Ae. camptorhynchus
into surrounding residential areas (Jardine et al. 2014).
The aim of the current study is to build on these previous
findings and quantify the risk associated with proximity to
mosquito breeding habitats in the Peel region, a key focus of
RRV activity and population growth. The larger spatial scale
and more detailed temporal analysis in this study add to the
evidence basis to inform planning decisions and target
mosquito control activities.
FIG. 1. Location of the study site within the Peel Region with 1- to 6-km buffer zones indicated by the solid black lines
surrounding known mosquito breeding wetlands of the Peel and Harvey Estuaries.
142 JARDINE ET AL.
3. Materials and Methods
RRV is a notifiable disease in Australia, meaning that all cases
of RRV diagnosed by a doctor or detected in laboratory tests in
WA are required to be notified to the Department of Health under
the Health Act (1911). WA also undertakes an ‘‘enhanced sur-
veillance’’ program through which RRV cases are followed up
via patient interviews to determine the most likely location and
timing of exposure. Residential address is assumed to be the
location of exposure if the case cannot be contacted.
The dataset created for spatial analyses consisted of all cases
for which the most likely place of exposure could be precisely
geocoded to a specific cadastral lot (a legally defined property
boundary). In addition, if place of exposure data or residential
data are not given as an exact location but can be pinpointed
with reasonable confidence (e.g., a street corner within 250
meters), then these cases are also geocoded. All other cases
were excluded from the dataset for spatial analyses.
Mosquito breeding habitats identified from field surveys in
the Peel Inlet, Harvey Estuary, and the lower reaches of the
Serpentine River (Wright 1988) were mapped, and six 1-km
buffers were created around them using Quantum Geo-
graphic Information System (GIS) 1.7.4 (Quantum GIS De-
velopment Team 2012) (Fig. 1). The intersection of the
buffers with the RRV case data was used to determine the
number of cases within each buffer.
A property street address cadastral lot data layer main-
tained by Landgate was overlaid by the Peel Regional Plan-
ning Scheme data layer maintained by the Western
Australian Planning Commission. Addresses in areas zoned
as urban or rural were retained and all other lots were ex-
cluded. Any other addresses not defined as a house were also
excluded. Finally, the remaining property street address lots
were intersected with the buffers to determine the number of
dwellings within each buffer.
The case and cadastral data were then summed for each
buffer, the rate of RRV notifications per 1000 dwellings was
determined, and 95% confidence intervals (CIs) were calculated.
Poisson regression was then undertaken to determine if a sta-
tistically significant trend in the rate of RRV notifications with
buffer distance was present. The number of cases was assigned
as the dependent variable, the buffer distance as the independent
variable, and the number of dwellings as the exposure variable.
Finally, to determine the expected background rate for the
Peel region, the number of RRV cases and dwellings for the
whole region was calculated using the same methods described
above. The rate for each buffer was determined to be signifi-
cantly elevated if the 95% CI did not span the background rate.
Rates were calculated for cases recorded between July 1,
2002, and June 30, 2012, to establish the cumulative risk for
each buffer over the 10-year period. The same analysis was also
undertaken for individual financial years in which more than
100 cases were notified across all buffers, which included 2005/
06, 2007/08, 2008/09, 2010/11, and 2011/12 mosquito seasons,
to determine if the pattern repeated in all outbreak years.
Ethics approval was not required because our study eval-
uated data collected during the routine public health response
to RRV as a notifiable disease.
Results
The background rate of RRV per 1000 dwellings across the
Peel region from July, 2002, to June, 2012, was 0.93 cases per
year, and average annual rates for each buffer are shown in
Table 1. A clear decreasing trend with increasing buffer
distance was evident (Fig. 2), and Poisson regression indi-
cated this trend to be significant ( p < 0.001). The number of
RRV cases per 1000 dwellings was significantly higher than
the rate across the Peel region for buffer distances up to 2 km
during the 10-year period.
Figure 3 shows the number of RRV cases per 1000
dwelling for each buffer distance for the years in which more
than 100 cases were notified across all buffers, which in-
cluded 2005/06, 2007/08, 2008/09, 2010/11, and 2011/12
mosquito seasons. It was consistently demonstrated across all
years investigated that residents living within 1 km of a
mosquito breeding habitat had a significantly higher rate of
RRV disease compared to the background rate across the Peel
region. Poisson regression also indicated that a statistically
significant reduction ( p < 0.05) in RRV rate with increasing
buffer distance was evident in all years except 2011/12.
Discussion
This study sought to quantify disease risk associated with
proximity to sources of vector breeding and a significantly
increased risk of contracting RRV associated with living in
close proximity to a mosquito breeding salt marsh habitat in
the Peel region of WA was demonstrated. Between July,
2002, and June, 2012, the rate of RRV cases per 1000
dwellings within 1 km of a breeding habitat was double the
rate compared to the Peel region as a whole, and 26% higher
between 1 and 2 km from a mosquito breeding habitat. A
significant decreasing trend with increasing buffer distance
was evident over the 10-year period and in most individual
years with high case numbers ( > 100).
Only one year, 2011/12, was divergent from this trend. In
this year, a cluster of cases occurred in the 5- to 6-km buffer,
which was thought to be associated with a separate breeding
site, not related to those in the Peel Inlet or Harvey Estuary
that were mapped as part of this study. Given that this year
was otherwise comparable with the other high case number
years (i.e., case numbers in the 1-km buffer were still sig-
nificantly higher than the background rate and the other
buffers were not different from the background rate), we
consider this an atypical event for this region. Overall, the
data show that those living within 2 km of a mosquito
breeding habitat were at increased risk of RRV disease,
Table 1. Number of Dwellings, Ross River
Virus Cases, and Rate per 1000 Dwellings
by Buffer Distance from Mosquito Breeding
Habitat, Peel Region, July, 2002, to June, 2012
July, 2002, to June, 2012
Buffer
distance Dwellings Cases
Average annual
cases/1000 dwellings
< 1 km 20,128 381 1.89
1–2 km 17,724 209 1.18
2–3 km 8,555 94 1.10
3–4 km 4,605 38 0.83
4–5 km 6,874 45 0.65
5–6 km 4,178 25 0.60
Background 0.93
PROXIMITY TO MOSQUITO BREEDING HABITATS AND RRV RISK 143
4. which is further evidence to support the results of previous
spatial analyses of RRV case data in close proximity to Ae.
camptorhynchus breeding habitats in other locations in
southwestern WA (Vally et al. 2012, Jardine el al. 2014).
With increasing pressure to release land for residential
development in the Peel region, these findings provide evi-
dence to planning authorities for consideration when asses-
sing applications for new residential developments in close
proximity of recognized permanent or semipermanent natural
mosquito breeding sites, such as wetlands, salt marshes, or
estuarine environments. It is recommended that planning
authorities incorporate known mosquito breeding wetlands
into land use planning scheme maps to ensure that they are
accurately delineated and the implications are considered
when planning decisions are made. Notifications should be
placed on the land titles within 2 km of known mosquito
breeding habitats to advise prospective buyers of the in-
creased health risk. Built form design measures such as insect
screening on doors and windows and screened outdoor en-
closures, public education packages, and public signage
should also be included as part of the conditions of approval.
Physical changes to topography should prevent runoff from
creating surface retention and constructed water bodies
should be located, designed, and maintained so they do not
create or contribute to additional mosquito breeding. It may
also be appropriate for developers of land in close proximity
to breeding habitats to contribute to the cost of mosquito
control by the local authority.
FIG. 2. Number of Ross River virus (RRV) cases per 1000 dwellings versus buffer distance from a mosquito breeding
habitat, Peel region, July, 2002, to June, 2012.
FIG. 3. Number of Ross River virus cases per 1000 dwellings versus buffer distance during years in which more than 100
cases were notified across all buffers.
144 JARDINE ET AL.
5. It is also recommended that environmental managers of
natural wetlands that support mosquito breeding should be
made aware that mosquito management actions that may
impact on the wetlands could be required if developments in
close proximity are approved to proceed. Where possible,
public open space with limited vegetation should be located
between a mosquito breeding habitat and residential areas to
create an area that is refractory to mosquito dispersal, thereby
reducing the number of mosquitoes impacting residents. Fi-
nally, similar to the proposal for bushfire management plans
to be required for planning development in high fire danger
areas in WA (Department of Planning 2014), a mosquito
management plan should be developed in high-risk mosqui-
to-borne disease areas or for developments in close proximity
to mosquito breeding sites to ensure that viable measures
have been considered and can be applied to reduce the risk of
exposure to disease carrying mosquitoes.
Although we are confident in the robustness of the find-
ings of this study, there are also limitations that should be
acknowledged. Limitations include the accuracy of expo-
sure location for the RRV data and the need to use dwelling
counts to approximate the population at risk. Follow-up data
was not available for about half the cases, therefore resi-
dential address was assumed to be the location of exposure.
An analysis of RRV case data since 2002 showed that
where enhanced surveillance information was available,
location of exposure was at the place for residence for
66.2% of cases (unpublished data). Therefore, whereas the
exposure location of some of the RRV cases included in this
study will not be accurate, the overall proportion will be
relatively small. Furthermore, there is no reason to suspect
the proportion of cases with inaccurate exposure informa-
tion would have varied across the buffers and therefore
the potential for differential bias to be introduced is low.
Finally, PSA data were only available for 2012; therefore,
rates over 10 years are likely to be an underestimate be-
cause fewer dwellings would have been present in previous
years. Nevertheless, again there is no evidence that these
limitations in the dwelling counts were different between
the buffers and is therefore unlikely to significantly bias the
outcomes of the study.
Conclusions
This study highlights the importance for planning au-
thorities to consider mosquito-borne disease risk when
considering residential development applications. This is
particularly important in WA where rapid population
growth has resulted in acute pressure to develop land for
residential purposes, with many new developments pro-
posed in close proximity to mosquito breeding habitats due
to the aesthetic value of living near water. However, as
discussed previously, similar results have also been dem-
onstrated for other diseases, so the potential health impact
from mosquitoes on future residents should be considered
wherever new developments are proposed across Australia
and globally.
Acknowledgment
This study was funded by the Western Australia Depart-
ment of Health.
Author Disclosure Statement
No competing financial interests exist.
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Address correspondence to:
Andrew Jardine
Mosquito-Borne Disease Control
Environmental Health Hazards Unit
Environmental Health Directorate
Department of Health Western Australia
Western Australia
Australia
E-mail: Andrew.Jardine@health.wa.gov.au
146 JARDINE ET AL.