scholarly journals Mice Against Ticks: an experimental community-guided effort to prevent tick-borne disease by altering the shared environment

2019 ◽  
Vol 374 (1772) ◽  
pp. 20180105 ◽  
Author(s):  
Joanna Buchthal ◽  
Sam Weiss Evans ◽  
Jeantine Lunshof ◽  
Sam R. Telford ◽  
Kevin M. Esvelt

Mice Against Ticks is a community-guided ecological engineering project that aims to prevent tick-borne disease by using CRISPR-based genome editing to heritably immunize the white-footed mice ( Peromyscus leucopus ) responsible for infecting many ticks in eastern North America. Introducing antibody-encoding resistance alleles into the local mouse population is anticipated to disrupt the disease transmission cycle for decades. Technology development is shaped by engagement with community members and visitors to the islands of Nantucket and Martha's Vineyard, including decisions at project inception about which types of disease resistance to pursue. This engagement process has prompted the researchers to use only white-footed mouse DNA if possible, meaning the current project will not involve gene drive. Instead, engineered mice would be released in the spring when the natural population is low, a plan unlikely to increase total numbers above the normal maximum in autumn. Community members are continually asked to share their suggestions and concerns, a process that has already identified potential ecological consequences unanticipated by the research team that will likely affect implementation. As an early example of CRISPR-based ecological engineering, Mice Against Ticks aims to start small and simple by working with island communities whose mouse populations can be lastingly immunized without gene drive. This article is part of a discussion meeting issue ‘The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems’.

2017 ◽  
Author(s):  
John Min ◽  
Charleston Noble ◽  
Devora Najjar ◽  
Kevin M. Esvelt

AbstractAn ideal gene drive system to alter wild populations would 1) exclusively affect organisms within the political boundaries of consenting communities, and 2) be capable of restoring any engineered population to its original genetic state. Here we describe ‘daisy quorum’ drive systems that meet these criteria by combining daisy drive with underdominance. A daisy quorum drive system is predicted to spread through a population until all of its daisy elements have been lost, at which point its fitness becomes frequency-dependent: mostly altered populations become fixed for the desired change, while engineered genes at low frequency are swiftly eliminated by natural selection. The result is an engineered population surrounded by wild-type organisms with limited mixing at the boundary. Releasing large numbers of wild-type organisms or a few bearing a population suppression element can reduce the engineered population below the quorum, triggering elimination of all engineered sequences. In principle, the technology can restore any drive-amenable population carrying engineered genes to wild-type genetics. Daisy quorum systems may enable efficient, community-supported, and genetically reversible ecological engineering.SummaryLocal communities should be able to control their own environments without forcing those choices on others. Ideally, each community could reversibly alter local wild organisms in ways that cannot spread beyond their own boundaries, and any engineered population could be restored to its original genetic state. We've invented a 'daisy quorum' drive system that appears to meet these criteria.“Daisy” refers to a daisy drive, which typically uses a daisy-chain of linked genes to spread a change through a local population while losing links every generation until it stops spreading. “Quorum” reflects the system's ability to “vote” on whether a local population should be altered or not: once all daisy elements are lost, it favors replication by the altered version or the original depending on which is more abundant in the local area. Put together, they result in a change that first spreads through a local population, then either becomes locally prevalent is eliminating, inhibiting mixing at the boundary. All organisms in the target population are altered, but changes are unable to spread much beyond that area due to being greatly outnumbered by wild-type organisms and consequently less able to replicate.We haven't yet performed any experiments involving daisy quorum systems. Rather, we’re describing what we intend to do, including the safeguards we will use and our assessment of risks, in the hope that others will evaluate our plans and tell us if there's anything wrong that we missed. We hope that all researchers working on gene drive systems - and other technologies that could impact the shared environment - will similarly pre-register their plans. Sharing plans can reduce needless duplication, accelerate progress, and make the proposed work safer for everyone.


2021 ◽  
Author(s):  
Xuechun Feng ◽  
Víctor López Del Amo ◽  
Enzo Mameli ◽  
Megan Lee ◽  
Alena L. Bishop ◽  
...  

ABSTRACTCulex mosquitoes are a global vector for multiple human and animal diseases, including West Nile virus, lymphatic filariasis, and avian malaria, posing a constant threat to public health, livestock, companion animals, and endangered birds. While rising insecticide resistance has threatened the control of Culex mosquitoes, advances in CRISPR genome-editing tools have fostered the development of alternative genetic strategies such as gene drive systems to fight disease vectors. However, though gene-drive technology has quickly progressed in other mosquitoes, advances have been lacking in Culex. Here, we developed a Culex-specific Cas9/gRNA expression toolkit and used site-directed homology-based transgenesis to generate and validate a Culex quinquefasciatus Cas9-expressing line. We showed that gRNA scaffold variants improve transgenesis efficiency in both Culex and Drosophila and boost gene-drive performance in the fruit fly. These findings support future technology development to control Culex mosquitoes and provide valuable insight for improving these tools in other species.


2021 ◽  
Vol 15 (4) ◽  
pp. e0009307
Author(s):  
Amy C. Morrison ◽  
Julia Schwarz ◽  
Jennie L. Mckenney ◽  
Jhonny Cordova ◽  
Jennifer E. Rios ◽  
...  

Rapid diagnostic tests (RDTs) have the potential to identify infectious diseases quickly, minimize disease transmission, and could complement and improve surveillance and control of infectious and vector-borne diseases during outbreaks. The U.S. Defense Threat Reduction Agency’s Joint Science and Technology Office (DTRA-JSTO) program set out to develop novel point-of-need RDTs for infectious diseases and deploy them for home use with no training. The aim of this formative study was to address two questions: 1) could community members in Iquitos, Peru and Phnom Penh, Cambodia competently use RDTs of different levels of complexity at home with visually based instructions provided, and 2) if an RDT were provided at no cost, would it be used at home if family members displayed febrile symptoms? Test kits with written and video (Peru only) instructions were provided to community members (Peru [n = 202]; Cambodia [n = 50]) or community health workers (Cambodia [n = 45]), and trained observers evaluated the competency level for each of the several steps required to successfully operate one of two multiplex RDTs on themselves or other consenting participant (i.e., family member). In Iquitos, >80% of residents were able to perform 11/12 steps and 7/15 steps for the two- and five-pathogen test, respectively. Competency in Phnom Penh never reached 80% for any of the 12 or 15 steps for either test; the percentage of participants able to perform a step ranged from 26–76% and 23–72%, for the two- and five-pathogen tests, respectively. Commercially available NS1 dengue rapid tests were distributed, at no cost, to households with confirmed exposure to dengue or Zika virus; of 14 febrile cases reported, six used the provided RDT. Our findings support the need for further implementation research on the appropriate level of instructions or training needed for diverse devices in different settings, as well as how to best integrate RDTs into existing local public health and disease surveillance programs at a large scale.


2021 ◽  
Vol 8 (3) ◽  
pp. 76-79
Author(s):  
Peter I May ◽  
Matthew Lagomarsino ◽  
Patrick Kangas

In urban harbors there is a reliance on the “gray infrastructure” of armored bulkheads along shorelines. While this form of shoreline technology provides stability and eliminates erosion, it limits shoreline biodiversity and lacks aesthetic value. In this paper, a living shoreline concept, termed the Green Bulkhead, is described and demonstrated. This is a kind of artificial vertical wetland with plants grown in a porous plastic fabric that is draped over the surface of an existing bulkhead. The system is irrigated with water that is pumped from the harbor. Several alternate designs have been tested for different medium types, planting patterns and water pumping regimes. It is proposed that the green bulkhead system can provide limited treatment wetland services in an urban setting where cost-effective water quality management options are minimal. Testing found that high percentages of sediment were retained within the matrix of the different media. The system has aesthetic benefits by “greening” the harbor environment with wetland plants and, because of its vertical orientation, it can be managed adaptively for sea level rise. This work is a report of an on-going ecological engineering project with demonstrations along the Baltimore, Maryland Inner Harbor and the Anacostia Waterfront in Washington, DC.


2018 ◽  
Vol 10 (12) ◽  
pp. 4789 ◽  
Author(s):  
Stephanie James ◽  
Karen Tountas

After years of success in reducing the global malaria burden, the World Health Organization (WHO) recently reported that progress has stalled. Over 90% of malaria deaths world-wide occurred in the WHO African Region. New tools are needed to regain momentum and further decrease the burden of malaria. Gene drive, an emerging technology that can enhance the inheritance of beneficial genes, offers potentially transformative solutions for overcoming these challenges. Gene drives may decrease disease transmission by interfering with the growth of the malaria parasite in the mosquito vector or reducing mosquito reproductive capacity. Like other emerging technologies, development of gene drive products faces technical and non-technical challenges and uncertainties. In 2018, to begin addressing such challenges, a multidisciplinary group of international experts published comprehensive recommendations for responsible testing and implementation of gene drive-modified mosquitoes to combat malaria in Sub-Saharan Africa. Considering requirements for containment, efficacy and safety testing, monitoring, stakeholder engagement and authorization, as well as policy and regulatory issues, the group concluded that gene drive products for malaria can be tested safely and ethically, but that this will require substantial coordination, planning, and capacity development. The group emphasized the importance of co-development and co-ownership of products by in-country scientists.


Oecologia ◽  
2019 ◽  
Vol 190 (1) ◽  
pp. 115-126 ◽  
Author(s):  
Atle Mysterud ◽  
Vetle Malmer Stigum ◽  
Harald Linløkken ◽  
Anders Herland ◽  
Hildegunn Viljugrein

BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e051184
Author(s):  
Samantha Streuli ◽  
Najla Ibrahim ◽  
Alia Mohamed ◽  
Manupriya Sharma ◽  
Markie Esmailian ◽  
...  

ObjectivesTo combat misinformation, engender trust and increase health literacy, we developed a culturally and linguistically appropriate virtual reality (VR) vaccination education platform using community-engaged approaches within a Somali refugee community.DesignCommunity-based participatory research (CBPR) methods including focus group discussions, interviews, and surveys were conducted with Somali community members and expert advisors to design the educational content. Co-design approaches with community input were employed in a phased approach to develop the VR storyline.Participants60 adult Somali refugees and seven expert advisors who specialise in healthcare, autism research, technology development and community engagement.SettingSomali refugees participated at the offices of a community-based organisation, Somali Family Service, in San Diego, California and online. Expert advisors responded to surveys virtually.ResultsWe find that a CBPR approach can be effectively used for the co-design of a VR educational programme. Additionally, cultural and linguistic sensitivities can be incorporated within a VR educational programme and are essential factors for effective community engagement. Finally, effective VR utilisation requires flexibility so that it can be used among community members with varying levels of health and technology literacy.ConclusionWe describe using community co-design to create a culturally and linguistically sensitive VR experience promoting vaccination within a refugee community. Our approach to VR development incorporated community members at each step of the process. Our methodology is potentially applicable to other populations where cultural sensitivities and language are common health education barriers.


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