Arboviral bottlenecks and challenges to maintaining diversity and fitness during mosquito transmission.

The term arbovirus denotes viruses that are transmitted by arthropods, such as ticks, mosquitoes, and other biting arthropods. The infection of these vectors produces a certain set of evolutionary pressures on the virus; involving migration from the midgut, where the blood meal containing the virus is processed, to the salivary glands, in order to transmit the virus to the next host. During this process the virus is subject to numerous bottlenecks, stochastic events that significantly reduce the number of viral particles that are able to infect the next stage. This article reviews the latest research on the bottlenecks that occur in arboviruses and the way in which these affect the evolution and fitness of these viruses. In particular we focus on the latest research on three important arboviruses, West Nile virus, Venezuelan equine encephalitis virus and Chikungunya viruses and compare the differing effects of the mosquito bottlenecks on these viruses as well as other evolutionary pressures that affect their evolution and transmission

Mobilising communities to address alcohol harm : an Alcohol Health Champion approach

In this article, Cathy Ure et al. look at engaging communities in order to reduce alcohol harms. By training Alcohol Health Champions, individuals can support vulnerable friends and family, and work within their communities to influence policy and promote change

A mixed methods analysis evaluating an alcohol health champion community intervention : how do newly trained champions perceive and understand their training and role?

Globally, alcohol harm is recognised as one of the greatest population risks and reducing alcohol harm is a key priority for the UK Government. The Communities in Charge of Alcohol (CICA) programme took an asset-based approach in training community members across nine areas to become alcohol health champions (AHCs); trained in how to have informal conversations about alcohol and get involved with alcohol licensing. This paper reports on the experiences of AHCs taking part in the training through the analysis of: questionnaires completed pre- and post-training (n=93) and semi-structured interviews with a purposive sample of five AHCs who had started their role. Questionnaires explored: characteristics of AHCs, perceived importance of community action around alcohol and health, and confidence in undertaking their role. Following training AHCs felt more confident to talk about alcohol harms, give brief advice and get involved in licensing decisions. Interviews explored: AHCs’ experiences of the training, barriers, and facilitators to the adoption of their role, and how they made sense of their role. Four overarching themes were identified through thematic analysis taking a framework approach: 1) perceptions of AHC training; 2) applying knowledge and skills in the AHC role; 3) barriers and facilitators to undertaking the AHC role; and 4) sustaining the AHC role. Findings highlight the challenges in establishing AHC roles can be overcome by combining the motivation of volunteers with environmental assets in a community setting: the most important personal asset being the confidence to have conversations with people about a sensitive topic, such as alcohol

An asset-based community development approach to reducing alcohol harm : exploring barriers and facilitators to community mobilisation at initial implementation stage

Globally there is a need to engage communities in actions to reduce alcohol harm. This paper reports on the initial implementation phase of an asset-based community development (ABCD) approach to reducing alcohol harm in ten pre-identified areas across Greater Manchester (UK). This qualitative study highlights the experiences of stakeholders responsible for, or engaged in, implementation. Findings show that it is challenging to recruit sufficient volunteers in a specific, small area/community, which may limit the ability to build health assets. Wider policy and organisational factors, which should be understood prior to implementing a place-based volunteer18 led health promotion programme, are also identified

An asset-based community development approach to reducing alcohol harm: Exploring barriers and facilitators to community mobilisation at initial implementation stage

Globally there is a need to engage communities in actions to reduce alcohol harm. This paper reports on the initial implementation phase of an asset-based community development (ABCD) approach to reducing alcohol harm in ten pre-identified areas across Greater Manchester (UK). This qualitative study highlights the experiences of stakeholders responsible for, or engaged in, implementation. Findings show that it is challenging to recruit sufficient volunteers in a specific, small area/community, which may limit the ability to build health assets. Wider policy and organisational factors that should be understood prior to implementing a place-based volunteer-led health promotion programme are also identified. Trial registration: https://www.isrctn.com/ISRCTN81942890

A mixed methods analysis evaluating an alcohol health champion community intervention: How do newly trained champions perceive and understand their training and role?

Globally, alcohol harm is recognised as one of the greatest population risks and reducing alcohol harm is a key priority for the UK Government. The Communities in Charge of Alcohol (CICA) programme took an asset-based approach in training community members across nine areas to become alcohol health champions (AHCs); trained in how to have informal conversations about alcohol and get involved with alcohol licensing. This paper reports on the experiences of AHCs taking part in the training through the analysis of: questionnaires completed pre- and post-training (n = 93) and semi-structured interviews with a purposive sample of five AHCs who had started their role. Questionnaires explored: characteristics of AHCs, perceived importance of community action around alcohol and health, and confidence in undertaking their role. Following training AHCs felt more confident to talk about alcohol harms, give brief advice and get involved in licensing decisions. Interviews explored: AHCs’ experiences of the training, barriers and facilitators to the adoption of their role, and how they made sense of their role. Four overarching themes were identified through thematic analysis taking a framework approach: (a) perceptions of AHC training; (b) applying knowledge and skills in the AHC role; (c) barriers and facilitators to undertaking the AHC role; and (d) sustaining the AHC role. Findings highlight the challenges in establishing AHC roles can be overcome by combining the motivation of volunteers with environmental assets in a community setting: the most important personal asset being the confidence to have conversations with people about a sensitive topic, such as alcohol

How can communities influence alcohol licensing at a local level? Licensing Officers’ perspectives of the barriers and facilitators to sustaining engagement in a volunteer-led alcohol harm reduction approach

Despite the World Health Organization’s assertion that communities need to become involved in reducing alcohol harm, evidence of community engagement in alcohol licensing decision-making in England remains limited. The evaluation of the Communities in Charge of Alcohol (CICA) programme offers policymakers, Licensing Authorities and public health practitioners, evidence regarding a specific volunteer-led, place-based approach designed to enable community engagement in licensing with the aim of reducing localised alcohol harm. The study explored factors affecting the sustainable involvement of volunteers in alcohol licensing decision-making from six Licensing Officers' perspectives, through semi-structured interviews. Routinely collected crime, disorder, and hospital admissions data were reviewed for further context as proxies for alcohol-related harm. Licensing Officers perceived sustainable engagement to be impacted by: (i) the extent of alignment with statutory requirements and local political support; (ii) the ability of Licensing Officers to operationalise CICA and support local assets, and; (iii) the opportunity for, and ability of, volunteers to raise licensing issues. The perspectives of Licensing Officers indicate complexities inherent in seeking to empower residents to engage in licensing decision-making at a community level. These relate to statutory and political factors, funding, social norms regarding engagement in licensing decision-making, and the need for networks between critical actors including Responsible Authorities and communities. The evidence indicates that after increasing community capacity to influence alcohol availability decision-making at local level, communities continue to struggle to influence statutory processes to affect alcohol availability where they live and work. More understanding of how to enable effective community engagement is required

How can communities influence alcohol licensing at a local level? Licensing officers’ perspectives of the barriers and facilitators to sustaining engagement in a volunteer-led alcohol harm reduction approach

Despite the World Health Organization's assertion that communities need to become involved in reducing alcohol harm, evidence of community engagement in alcohol licensing decision-making in England remains limited. The evaluation of the Communities in Charge of Alcohol (CICA) programme offers policymakers, Licensing authorities and public health practitioners, evidence regarding a specific volunteer-led, place-based approach, designed to enable community engagement in licensing with the aim of reducing localised alcohol harm. This study explored factors affecting the sustainable involvement of volunteers in alcohol licensing decision-making from six licensing officers' perspectives, through semi-structured interviews. Routinely collected crime, disorder, and hospital admissions data were reviewed for further context as proxy indicators for alcohol-related harm. Licensing officers perceived sustainable engagement to be impacted by: (i) the extent of alignment with statutory requirements and local political support; (ii) the ability of licensing officers to operationalise CICA and support local assets, and; (iii) the opportunity for, and ability of, volunteers to raise licensing issues. The perspectives of licensing officers indicate complexities inherent in seeking to empower residents to engage in licensing decision-making at a community level. These relate to statutory and political factors, funding, social norms regarding engagement in licensing decision-making, and the need for networks between critical actors including responsible authorities and communities. The evidence indicates that after increasing community capacity to influence alcohol availability decision-making at a local level, communities continue to struggle to influence statutory processes to affect alcohol availability where they live and work. More understanding of how to enable effective community engagement is required

West Nile Virus Experimental Evolution in vivo and the Trade-off Hypothesis

In nature, arthropod-borne viruses (arboviruses) perpetuate through alternating replication in vertebrate and invertebrate hosts. The trade-off hypothesis proposes that these viruses maintain adequate replicative fitness in two disparate hosts in exchange for superior fitness in one host. Releasing the virus from the constraints of a two-host cycle should thus facilitate adaptation to a single host. This theory has been addressed in a variety of systems, but remains poorly understood. We sought to determine the fitness implications of alternating host replication for West Nile virus (WNV) using an in vivo model system. Previously, WNV was serially or alternately passed 20 times in vivo in chicks or mosquitoes and resulting viruses were characterized genetically. In this study, these test viruses were competed in vivo in fitness assays against an unpassed marked reference virus. Fitness was assayed in chicks and in two important WNV vectors, Culex pipiens and Culex quinquefasciatus. Chick-specialized virus displayed clear fitness gains in chicks and in Cx. pipiens but not in Cx. quinquefasciatus. Cx. pipiens-specialized virus experienced reduced fitness in chicks and little change in either mosquito species. These data suggest that when fitness is measured in birds the trade-off hypothesis is supported; but in mosquitoes it is not. Overall, these results suggest that WNV evolution is driven by alternate cycles of genetic expansion in mosquitoes, where purifying selection is weak and genetic diversity generated, and restriction in birds, where purifying selection is strong

Experimental Passage of St. Louis Encephalitis Virus In Vivo in Mosquitoes and Chickens Reveals Evolutionarily Significant Virus Characteristics

St. Louis encephalitis virus (SLEV; Flaviviridae, flavivirus) was the major cause of epidemic flaviviral encephalitis in the U.S. prior to the introduction of West Nile virus (WNV) in 1999. However, outbreaks of SLEV have been significantly more limited then WNV in terms of levels of activity and geographic dispersal. One possible explanation for these variable levels of activity is that differences in the potential for each virus to adapt to its host cycle exist. The need for arboviruses to replicate in disparate hosts is thought to result in constraints on both evolution and host-specific adaptation. If cycling is the cause of genetic stability observed in nature and arboviruses lack host specialization, then sequential passage should result in both the accumulation of mutations and specialized viruses better suited for replication in that host. Previous studies suggest that WNV and SLEV differ in capacity for both genetic change and host specialization, and in the costs each accrues from specializing. In an attempt to clarify how selective pressures contribute to epidemiological patterns of WNV and SLEV, we evaluated mutant spectra size, consensus genetic change, and phenotypic changes for SLEV in vivo following 20 sequential passages via inoculation in either Culex pipiens mosquitoes or chickens. Results demonstrate that the capacity for genetic change is large for SLEV and that the size of the mutant spectrum is host-dependent using our passage methodology. Despite this, a general lack of consensus change resulted from passage in either host, a result that contrasts with the idea that constraints on evolution in nature result from host cycling alone. Results also suggest that a high level of adaptation to both hosts already exists, despite host cycling. A strain significantly more infectious in chickens did emerge from one lineage of chicken passage, yet other lineages and all mosquito passage strains did not display measurable host-specific fitness gains. In addition, increased infectivity in chickens did not decrease infectivity in mosquitoes, which further contrasts the concept of fitness trade-offs for arboviruses