Title: One Health Protocol for Vector-Borne Disease: an examination of Lyme disease Prevention
Authors: Mackenzie Hager, MAMS; Annalacia Glossen, MAMS
Lyme Disease Research Pamphlet
Introduction
Lyme disease (LD) caused by the bacterium, Borrelia spp., is spread from common mammalian reservoirs to the Ixodes tick, infecting an estimated 300,000 people and costing the US economy 3 billion dollars per year. With urbanization, forest fragmentation, and climate change, the human exposure rate of LD has increased over the past 50 years. Rural areas are at considerable risk for public health emergencies due to health disparities and lack of resources, thus prevention protocol is essential. This literature review is an examination of LD exposure risk denoted by geographical determinants and applying methods of preventative public health at the county level. There will also be suggestions for further research to better understand prevalent risk as well as applicable vector-borne disease control.
Methods
We used the online databases PubMed and google scholar, utilizing the key words LD, urban vs. rural LD exposure, and vector-borne diseases to find 15 relevant articles. Lastly, we were able to take these articles and suggest further research for any gaps in understanding.
Results
LD spread is due to improper design of residential developments. This is explained by flow centrality which determines how connected patches are with concern to the physical relationship between landscape elements and the degree to which landscapes facilitate movement of organisms between areas of habitat. The “dilution effect”, a reservoir targeted approach, increases species richness by control of competent reservoirs with lesser more competitive incompetent reservoirs to decrease the exposure risk of vector-borne disease. Even with significant effects this cannot be the only strategy due to assumptions made by this hypothesis. Vector focused strategies such as pesticides were not easily implemented nor were they environmentally sound so were excluded.
Conclusions
To create a protocol for prevention and control of LD at the county level we must consider the intersectionality of a triad approach of vector focused, reservoir targeted, and biocontrol via urbanization planning. By defining and categorizing each geographical area by classification systems, society will be able to more effectively separate potential vectors of infectious disease from the human population. By including the strategy of reservoir targeted methods, we can better complete a One Health approach of infectious disease prevention. With further knowledge of risk exposure, rural areas such as Yakima can have a readiness plan for LD as well as an approach to other infectious disease prevention.
Judge: Thank you for this presentation. What other strategies have you hypothesized for reducing LD risk exposure in rural areas?
Thank you for your comment. We hypothesized the most relevant strategies that we found with direct data to show a reduction of LD in rural areas. These were the reservoir targeted approach of the dilution effect and biocontrol via urbanization planning. While also simultaneously considering a One Health Approach of the environment, animals, and humans. There are other strategies, but we did not want to add these into our protocol for lack of supporting data as well as evidence of environmental, or animal damage.
The other methods hypothesized:
-Targeted acaricide delivery
-Kill pathogens in reservoir hosts via:
-Anti-pathogen
-anti-tick
-Alter reservoir competence via:
-CRISPR/Cas
-Pesticides
-Entomopathologic fungi/bacteria/viruses
-Alter vector competence via:
-tick gut microbiome
-CRISPR/Cas Engineering
-metabolic alterations
-Reduce deer population via:
-hunting
-contraception (vaccine/hormone)
-targeted acaricide delivery
*resources from Article 1 of work cited page*
Thanks for this presentation, I am one of your judges. If I were to design an outdoor space for the residents of Yakima to enjoy, what key elements would you recommend to help reduce the incidence of contracting LD at my nature preserve?
Thank you for your comment. If you were to design an outdoor space that is aimed to be a nature preserve, I would want to focus on a few things to prevent exposure to Lyme Disease. Assuming this preserve will be in the county of Yakima, I would first want to go to the city to collect geographical surveillance and geocoding data as well as climate over a year’s time. One convenience of developing protocol at the county-by-county level means we can easily map out areas of most risk.
The main aspects that impact the survival and development rates of the Ixodes tick:
-climate/humidity:
-desiccation risk
-temperature extremes are harmful to the tick
-animal host availability
-percent of population that are competent host (“dilution effect” application here)
-white-footed mouse has the highest level of reservoir competence (monitor this population)
-host movement
-environmental compatibility:
-forests preferred over grass/shrub habitats
-ground cover dominated by leaf or fir-needle litter increase population size
-patch-focused metrics, matrix connectivity, ecotones, and habitat use patterns (reforestation vs forest fragmentation)
-important to enzootic hazard
-“dilution effect” may be more effective at smaller patch sizes
-please review article 6 pg 1551-1552 for direct land use and enzootic hazard connection
Overall, I would follow our protocol mentioned, by determining risk according to the space you want to develop. As well as management of infection via the vector strategy of the dilution effect explained via our slides. We also must have education on preventing risky behavior and how to avoid possible exposure at a public health level.
Creating greenspaces such as a nature preserve is critical for human wellbeing but the potential negative effects such as increasing the risk of possible exposure needs to be considered. Thus, following the mapping and categorizing of risk we can determine the safest areas for these nature reserves. But consideration of other methods can be employed to decrease risk if an area is already developed or certain areas may benefit more greatly from greenspaces even if not in a geographically determined “safe” space.
Thank you for your presentation. I am one of the judges for your poster and originally from an area of the country where Lyme Disease is very common. How common is Lyme Disease in Eastern Washington?
Thank you for your comment. The highest prevalence of Lyme Disease in the country is going to be mainly on the east coast of the United States. But as we can see from these comparing images the increase from 2001 to 2019 into neighboring states is visible.
Lyme Disease Prevalence 2019 (please see images here: https://www.cdc.gov/lyme/stats/maps.html)
Lyme Disease Prevalence 2001 (please see images here: https://www.cdc.gov/lyme/stats/maps.html)
As mentioned with concern of climate change, urbanization, and forest fragmentation neighboring states are showing higher incidence with an expansion across the country. While, prevalence on the west coast of the united states remains low there has been increasing rates over the past decade. Thus, a public health protocol to prepare for and prevent this emergence is key. Please review this image here: https://www.cdc.gov/lyme/stats/graphs.html
Also considering Lyme disease with relation to race we see that there is a significant incidence in Native American peoples which should be of high concern for Yakima, to prevent the exposure to these disparaged individuals. Please review this image here: https://www.cdc.gov/lyme/datasurveillance/charts-figures-recent.html
The incidence for Lyme Disease in Washington state is 0.2 in 2019 and 25 probable cases.