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Sobkowich KE, Berke O, Bernardo TM, Pearl DL, Kozak P. Spatial analysis of Varroa destructor and the relationship with surrounding landscape types in Southern Ontario. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.1027297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Elevated colony losses have continued to be an issue for Canadian beekeepers for more than a decade. Numerous studies have identified unmanaged Apis mellifera colony infestation by the Varroa destructor mite as a main cause of the problem. V. destructor spread externally of the hive through a phoretic stage in their life cycle. Consequently, their movement outside the hive is influenced by honey bee flight behaviours, which can range to multiple kilometers from the originating hive in any direction. V. destructor are therefore of regional concern as neighboring colonies and yards share nearby forage which can serve as fomites. Additionally, mites can be transmitted through bee behaviours such as robbing and drifting, thus impacting surrounding colonies. Understanding the distribution of mites across a population is key for surveillance and equitable allocation of resources. Spatial patterns of V. destructor infestations in Southern Ontario, Canada, were investigated using a combination of cluster analysis, scan statistics, and geostatistical modelling, using 5 years of provincial apiary inspection data, from 2015 to 2019. A collection of disease clusters of V. destructor infestations was identified and found to be stable over multiple years with several other individual clusters occurring sporadically throughout Southern Ontario during the same study period. Universal kriging was applied to the V. destructor data in combination with regional colony density, and land use data as covariates, producing an isopleth map of the prevalence risk for V. destructor infestation. No substantial link between V. destructor infestation and environmental factors was found. This study highlights the need for more data and investigation to determine the cause of the identified clusters and areas of elevated risk. These results are hypothesis-generating but simultaneously provide information for government agencies, industry organizations, and beekeepers into the spatial distribution of V. destructor at a macro scale.
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Sararat C, Changruenngam S, Chumkaeo A, Wiratsudakul A, Pan-ngum W, Modchang C. The effects of geographical distributions of buildings and roads on the spatiotemporal spread of canine rabies: An individual-based modeling study. PLoS Negl Trop Dis 2022; 16:e0010397. [PMID: 35536861 PMCID: PMC9126089 DOI: 10.1371/journal.pntd.0010397] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/20/2022] [Accepted: 04/06/2022] [Indexed: 11/19/2022] Open
Abstract
Rabies is a fatal disease that has been a serious health concern, especially in developing countries. Although rabies is preventable by vaccination, the spread still occurs sporadically in many countries, including Thailand. Geographical structures, habitats, and behaviors of host populations are essential factors that may result in an enormous impact on the mechanism of propagation and persistence of the disease. To investigate the role of geographical structures on the transmission dynamics of canine rabies, we developed a stochastic individual-based model that integrates the exact configuration of buildings and roads. In our model, the spatial distribution of dogs was estimated based on the distribution of buildings, with roads considered to facilitate dog movement. Two contrasting areas with high- and low-risk of rabies transmission in Thailand, namely, Hatyai and Tepha districts, were chosen as study sites. Our modeling results indicated that the distinct geographical structures of buildings and roads in Hatyai and Tepha could contribute to the difference in the rabies transmission dynamics in these two areas. The high density of buildings and roads in Hatyai could facilitate more rabies transmission. We also investigated the impacts of rabies intervention, including reducing the dog population, restricting owned dog movement, and dog vaccination on the spread of canine rabies in these two areas. We found that reducing the dog population alone might not be sufficient for preventing rabies transmission in the high-risk area. Owned dog confinement could reduce more the likelihood of rabies transmission. Finally, a higher vaccination coverage may be required for controlling rabies transmission in the high-risk area compared to the low-risk area.
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Affiliation(s)
- Chayanin Sararat
- Biophysics Group, Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Suttikiat Changruenngam
- Biophysics Group, Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Arun Chumkaeo
- Songkhla Provincial Livestock Office, Muang, Songkhla, Thailand
| | - Anuwat Wiratsudakul
- Department of Clinical Sciences and Public Health, and the Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Wirichada Pan-ngum
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charin Modchang
- Biophysics Group, Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand
- Centre of Excellence in Mathematics, CHE, Ministry of Education, Bangkok, Thailand
- * E-mail:
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Changalucha J, Hampson K, Jaswant G, Lankester F, Yoder J. Human rabies: prospects for elimination. CAB REVIEWS : PERSPECTIVES IN AGRICULTURE, VETERINARY SCIENCE, NUTRITION AND NATURAL RESOURCES 2021; 16:039. [PMID: 34765015 PMCID: PMC8580373 DOI: 10.1079/pavsnnr202116039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Almost half of all countries in the world are effectively free of human deaths from dog-mediated rabies. But the disease still affects people in low- and middle-income countries, especially the rural poor, and children. Successful regional elimination of human rabies is attributable to advances in significant and sustained investment in dog vaccination, post-exposure vaccination and surveillance, illustrated by productive efforts to reduce human rabies in Latin America over the last 35 years. Nonetheless, countries still facing endemic rabies face significant barriers to elimination. Using the 2017 Global Strategic Plan to end human rabies deaths from dog-mediated rabies by 2030 as a reference point and an organizing framework, we assess progress toward global rabies elimination by examining the characteristics of successful regional control efforts and barriers to elimination. Although substantive barriers exist for countries where rabies remains endemic, advances in knowledge, technology, institutions, and economics provide a basis for optimism.
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Affiliation(s)
- Joel Changalucha
- Environmental Health and Ecological Science Department, Ifakara Health Institute, P.O. Box 78373, Dar es salaam, 14112, Tanzania
- Boyd Orr Centre for Population and ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12, 8QQ, UK
- College of Veterinary Medicine and Biomedical Science, Sokoine University of Agriculture, P.O. Box 3021, Morogoro, 23, Tanzania
| | - Katie Hampson
- Boyd Orr Centre for Population and ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12, 8QQ, UK
| | - Gurdeep Jaswant
- Boyd Orr Centre for Population and ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12, 8QQ, UK
- University of Nairobi Institute of Tropical and Infectious Diseases (UNITID), P.O. Box 30197, Nairobi, 00202, Kenya
- Tanzania Industrial Research Development Organisation (TIRDO), P.O. Box 23235, Dar es salaam, Tanzania
| | - Felix Lankester
- Global Animal Health Tanzania, Ngorongoro Conservation Area Authority Building, P.O. Box 1642, Arusha, Tanzania
- Paul G. Allen School for Global Animal Health, Washington state University, P.O. Box 647090, Pullman, Washington, WA 99164 United States of America
| | - Jonathan Yoder
- Paul G. Allen School for Global Animal Health, Washington state University, P.O. Box 647090, Pullman, Washington, WA 99164 United States of America
- School of Economic Sciences, Washington State University, P.O. Box 646210, Pullman, Washington, WA 99164-6210, United States of America
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