Abstract
Background Vector-borne pathogens impact public health and economies worldwide. It has long been recognized that research on arthropod vectors such as mosquitoes, ticks, sandflies and midges which transmit parasites and arboviruses to humans and economically important animals is crucial for development of new control measures that target transmission by the vector. While insecticides are an important part of this arsenal, appearance of resistance mechanisms is an increasing issue. Novel tools for genetic manipulation of vectors, use of Wolbachia endosymbiotic bacteria and other biological control mechanisms to prevent pathogen transmission have led to promising new intervention strategies. This has increased interest in vector biology and genetics as well as vector-pathogen interactions. Vector research is therefore at a crucial juncture, and strategic decisions on future research directions and research infrastructures will benefit from community input.
Methodology/Principal Findings A survey initiated by the European Horizon2020 INFRAVEC-2 consortium set out to canvass priorities in the vector biology research community and to determine key issues that should be addressed for researchers to efficiently study vectors, vector-pathogen interactions, as well as access the structures and services that allow such work to be carried out.
Conclusions/Significance We summarize the key findings of the survey which in particular reflect priorities in European countries, and which will be of use to stakeholders that include researchers, government, and research organizations.
Author Summary Research on arthropod vectors that transmit so-called arboviruses or parasites, such as mosquitoes, ticks, sandflies and midges is important for the development of control measures that target transmission of these pathogens. Important developments in this research area, for example vector genome sequencing, genome manipulation and use of transmission-blocking endosymbionts such as Wolbachia have increased interest in vector biology. As such, strategic decisions on research directions as well as research infrastructures will benefit from community input. A survey initiated by the European Horizon2020 INFRAVEC-2 consortium set out to investigate priorities in the vector biology research community as well as key issues that impact on research, and access to the structures and services that allow such studies to be carried out. Here we summarize the key findings of this survey, which in particular reflect priorities in European countries. The survey data will be of use to decision makers such as governments and research organizations, but also researchers and others in the field.
Introduction
Vector-borne diseases such as those transmitted by mosquitoes have a major impact on human and animal health. Among the many examples, malaria (caused by Plasmodium parasites) and dengue (caused by four serotypes of dengue virus, Flaviviridae) stand out as major diseases that affect populations worldwide, but new threats such chikungunya virus (Togaviridae) and more recently Zika virus (Flaviviridae) have emerged [1-4]. Both known and emerging pathogens put huge pressure on communities and public health systems. Vaccine development against key threats to human health such as dengue virus and Plasmodium parasites may offer tools against transmission and disease, and progress is encouraging [5-8]. However, issues such as pathogen strain variation and vaccine or drug production/distribution costs will remain as challenges [9], and even with vaccines vector control will be a crucial part of a multivalent arsenal. Although drugs against malaria parasites are on the market, availability, administration and resistance are problematic [10-12]. Drugs targeting dengue virus are in the development stages [13-16]. In the case of chikungunya virus vaccine candidates and drugs are now in development [17]. Only veterinary vaccines are currently in use for the animal pathogen Rift Valley fever virus (Bunyaviridae) and efforts to produce human vaccines are urgently needed [18, 19].
Many ongoing efforts to control vector-borne diseases rely on control measures that target mosquitoes including control of larval breeding sites, use of insecticides, use of bed nets (often used in combination with insecticides) (see for example, [20-25]). These efforts have been successful when implemented consistently, although issues such as insecticide resistance, changes in vector behavior, and difficulties with breeding site control (see for example [26-35]) require that research in vector biology and control is continuously developed and strengthened. Technological developments over the last decade are transforming modern vector research. These include: vector genome sequences, high-throughput genomics, transcriptomics, and population genetics with results in public databases [36], improved methods for genetic manipulation of arthropods (that have led to field trials) [37-43], studies on the influence of the mosquito midgut microbiome on pathogen transmission [44-46], studies on the impact of the insect-specific viruses on arbovirus transmission [47, 48], and the use of Wolbachia endosymbiotic bacteria that prevent pathogen transmission [37, 49-52]. Nonetheless the opportunity to access and make best use of ongoing research can be difficult, given the specialized knowledge, costs and infrastructures required.
The European Union (EU) has identified access to specialized Research Infrastructures (RIs) as a key to producing high quality science. RIs are defined as “Tools for science….RIs offer unique research services to users from different countries, attract young people to science, and help to shape scientific communities…‥ RIs may be ‘single-sited’ (a single resource at a single location), ‘distributed’ (a network of distributed resources), or ‘virtual’ (the service is provided electronically)” [53]. Such RIs can be research facilities, resources and related services. Within the Framework Programmes (FP) of the EU, Research Infrastructure projects support the improvement of key high-level facilities for research, and allow access to the facilities by researchers in Europe and eligible member states. A wide range of research disciplines have been targeted by RI projects, including physics, information science, earth science and medicine. One such Research Infrastructure project under EU FP7 was Infravec, which focused on developing and providing research resources for insect vector biology from 2009-2014. Infravec, which was constituted as an EC Starting Community under FP7, obtained the opportunity to renew the project as an Advanced Community (AC) called INFRAVEC-2 under the Horizon 2020 framework. Research Infrastructure projects are not research networks, but rather are tasked to identify the key unique and rare research infrastructures necessary for a research community, and organize them so that researchers at institutes lacking the Research Infrastructures can access the facilities in order to expand the scope of their research. Thus, Research Infrastructures are exceptional facilities that permit experiments that could not routinely be done without this structure. Use of Research Infrastructure facilities by external researchers is provided as so-called “Transnational Access” (TNA), with access costs reimbursed by the Research Infrastructure project, thus provided at no cost to the end-user.
Conditions have changed since the inception of the FP7 Infravec project, including the emergence and transmission of arboviruses in Europe and elsewhere, as well as widening the project scope to include vector-borne diseases of economically important animals and the most recently developed innovative technologies. Collecting information about the current and perceived future infrastructure needs of the vector biology research community and other stakeholders is an important step to ensure that the services offered via Transnational Access reflect actual needs of the advanced community. Here we present the findings of a survey of scientists and associated stakeholders in the field of vector biology or fields that are linked to vector biology such as pathogen studies, which will help to define priorities and requirements within INFRAVEC-2 but should also be of interest to governments, research organizations and researchers in the field. Participation numbers suggest that in particular European research priorities are reflected in the results, but the data can inform stakeholders worldwide.
Materials and Methods
Survey structure
A questionnaire (S1 Table) was sent to organizational email lists (European Society for Vector Ecology; the journal Pathogens and Global Health; National Center of Expertise in Vectors (CNEV, France); CIRM-Italian Malaria Network; FP7 Infravec mail list; International Meeting on Arboviruses and their Vectors mail list; BioInsectes; EU/DEVCO MEDILABSECURE network), as well as to other lists owned by the authors. The questionnaire was sent as a URL link to the online form along with an explanatory note to scientists in the vector biology field and associated stakeholders. The questionnaire request was spontaneously retransmitted by an unknown number of recipients to organizational and other lists.
Briefly, the cover note explained the aims of the INFRAVEC-2 community, followed by a series of questions. The key areas covered by the survey are as follows: 1) vectors and vector-borne pathogens studied by survey participants, 2) research area (with several responses allowed), 3) infrastructures available at the respondents home institution including those for vector and animal research, 4) ease of access to vector research facilities outside the survey participants’ home institution, 5) infrastructures that participants would use, offered by the facilities at no cost to user, 6) identification of research priorities over the next 5-10 years, and 7) additional feedback. The survey was carried out from October to November 2015. Respondents were given the opportunity to provide their name and institution, although this was not required for completion of the questionnaire. However, all respondents (n=211) identified themselves, indicating that repeat voting or vote stuffing is not a concern for interpretation of the results. All results shown here are anonymized, and no survey participant details published.
Results and Discussion
In total 211 responses were obtained (see S2 Table). Approximately 88% of respondents were from countries across Europe, with France, and then the UK providing the highest numbers of responses. This suggests that the results reflect a good overview of current priorities in European vector biology and vector research areas. Below we summarize and analyze the data obtained in the survey.
Research areas: arthropods and pathogens relevant to survey participants
Our goal was to obtain an overview of the research areas and work of survey participants, which are thus likely to guide their future research needs (S1 Table, Survey Questionnaire). First, respondents indicated vectors relevant to their research as major or minor area of interest (Table 1). Aedes species mosquitoes were the top field, followed by Anopheles and Culex species. The strong interest in aedine species may reflect the emergence of arboviruses such as chikungunya transmitted by Ae. aegypti and Ae. albopictus as well as the expansion of the latter species in Europe (and other areas) and acting as arbovirus vector [54-60]. Despite their importance in the European context as major vectors of pathogens, comparatively little research is carried out on ticks and Culicoides midges. This suggests that the European vector biology community presently lacks sufficient opportunities and resources for research on these vectors. Among the category “Other”, comments by participants indicated phlebotomines/sand flies as a key area, with tsetse flies, fleas, triatomines and tabanids/horse flies also mentioned.
We also quantified the major and minor interests of survey participants (Table 2). There was a notably strong indication of research interests in arboviruses, mainly affecting humans but also livestock pathogens as well. These research interests and activities are likely due to the emergence and importance of arboviruses such as chikungunya, Zika, Schmallenberg and bluetongue [2, 55, 61-63]. Given the historically important role of malaria research also in Europe, the overall importance in the vector field is not surprising. Of note was the impact of tick-borne pathogens in the category “Other” and this is worth mentioning especially with the impact of Lyme disease across Europe and North America [64] and surge in interest in Crimean-Congo hemorrhagic fever virus [65, 66].
To describe their activities in more detail, we collected further data on the research areas of interest to the survey participants (Table 3). In general vector biology describes the research of over half of the participants, however this is a very broad term. Vector ecology, behavior and control were also commonly reported. Of note, genetic modification and vector immunity remain relatively small fields despite important advances in these areas. Interest may increase with better tools and access to new resources such as strains and facilities. The survey data showed that studies of pathogens either directly or within the context of host-pathogen or vector-pathogen interactions are a key area of research. This needs to be emphasized as it integrates disciplines such as virology, parasitology, cell biology, microbiology and genetics into the vector field. Similarly, surveillance, diagnostics and epidemiology were important areas and this (alongside vector control, behavior and ecology) was an indication of the applied character of many activities in the field of vector-borne diseases.
Assessment of currently available facilities
Knowledge of availability and/or ease of access to research infrastructures is a key factor in future planning of research activities. Survey participants were therefore asked to indicate their current organization’s current capabilities. As shown in Table 4, survey participants indicated a certain level of capacity to provide vectors but also material across the community. Moreover facilities for biosafety level (BSL) 2 and 3 experiments with vectors, animals and pathogens are available in several places. The concept of Research Infrastructure can be extended to reagent provision and has been successfully established by FP7 Infravec and the European Virus Archive (http://www.european-virus-archive.com). This indicates an existing infrastructure base that can be developed and made available for research on vectors and pathogens on a wider basis (for example those who do not have immediate access to BSL 3 level insectaries but would require experiments to be carried out in such facilities) through communities such as INFRAVEC-2.
Assessment of infrastructure and service requirements
When survey participants were asked to indicate how many had requested access to insectaries at BSL2 or 3 in other institutions, in total 62 positive responses were received. However out of these, 18 responses indicated that access could not be granted in a timely manner. This suggests that inability to consistently access secure insectary facilities comprises a systematic weakness that impedes research on vector-pathogen interactions and may also explain the weaker interest in vector immunity studies, for example. The relevant secure insectary facilities exist in Europe (Table 4), and thus a mutualized network of insectaries at BSL2 and 3 could resolve access limitations and promote elevated levels of vector research under BSL2 and 3 conditions.
Access needs, or provision of infected vectors or extracts from infected vectors were assessed and participants were asked to indicate which pathogens or facilities/services would be of interest in the context of INRFAVEC-2 where these are free of cost (or the requirement for collaboration) for the end user (Table 5). Although the questions below were originally aimed at potential European users all answers were taken into account. Survey data show that in particular services and structures for arbovirus research would likely generate strong demand. Again this may be due to the surge in research in this field described above. Similarly, BSL2 and 3 studies on infected vectors and insecticides as well as behavior scored highly. Regarding technologies novel for the field, functional siRNA screens and imaging of vectors did not score particularly high but this demand may increase in the future, particularly if facilities were available for access.
Vector genetics and genomics (see www.vectorbase.org, [36]) but also studies of vector microbiomes (given their influence on mosquito infection with arboviruses and parasites [44-46, 67]) are expanding fields. These research areas have strongly benefited from high-throughput sequencing techniques and bioinformatics. Survey participants were enthusiastic about developing insect vector-oriented infrastructures, services and expertise in high throughput genomics and bioinformatics, especially transcriptional profiling and genome and population analysis (Table 6).
The era of genomics has brought about much needed information on vector genomes (see for example [68-70]). Genetic manipulation of genomes in basic biological studies of gene/sequence structure and function, and applications based on genome manipulation (see for example [71-73]) are useful tools to maximize the value of this information, and for example CRISPR/Cas9-mediated genome manipulation is an important technical advance also for the vector field [74, 75]. We therefore asked survey participants about their interest in applying genome editing technologies within their work. As shown in Table 7, there was particularly strong interest in genetic manipulation of aedine mosquitoes. Culicoides midges seemed at present a less popular subject, probably at least in part because the community is small as mentioned above, as well as that the technologies have not yet been applied to this system or general issues with establishing colonies of important midge vector species. Among the category “Other”, ticks stood out.
Studies on vectors (infected, uninfected or genetically modified) often include components that analyze behavior and ecology. A further section of this survey therefore focused on a number of specific potential requirements in this area. As indicated in Table 8, the interest to work in field sites in endemic countries if access could be provided, as well as standardized behavioral assays and bioassays for vectors generated strong positive responses. This suggested a need for these in the vector research community. Positive responses for large cage studies (controlled indoors or semi-controlled outdoors) were also strong considering that such applications are very specialized, and the facilities are rare. However, this illustrates the potential contribution of a Research Infrastructure project, because community mutualization of rare infrastructures can allow access to state of the art facilities for researchers with occasional needs. In the future, the possibility to access such facilities may become stronger as more genetically modified vectors will be assessed in pre-release assays. Few positive responses for electrophysiology experiments were obtained, suggesting that there is no major need for additional facilities beyond what is already in place.
Survey participants were also asked about their requirements for more specific vector-related data and research resources such as reference genomes, specific cell lines and mosquito strains (Table 9). Results indicated that in particular, a bank of standard vector colonies would be of interest to the community. Easily accessible quality-controlled vector colonies available from a European repository could be an important influence promoting comparability and reproducibility of experimental infection and other results across laboratories. Similarly vector systematics and collections generated high interest. However, the practices of systematics may be at a juncture, because the technological capacity will soon be available to whole-genome sequence large numbers of unidentified individuals of a putative vector clade, and cluster them bioinformatically to determine phylogenetic relatedness. These results will need to be compared to existing collections, including voucher specimens. Perhaps surprisingly, new reference and cloned vector cell lines did not score highly but these may be of interest to smaller research areas such as virologists who carry out particular types of studies. Cell lines may be of less interest in malaria vector research where the biology is not consistent with simple cell models of Plasmodium-mosquito interaction. Despite high interest in Wolbachia to block pathogen transmission [51], generation of novel trans-infected vector strains was also not a priority. Finally, a small number of responses under “Other needs” mentioned the importance of training.
Our survey specifically addressed training needs, community networking and communication. As shown in Table 10, all suggestions - training in vector BSL2 and 3 methods, training in bioinformatics and genomics and scientific communication by conferencing - were positively received by the survey participants. Clearly these are areas of need that should be developed as a real requirement within the vector research field.
Survey participants were also asked to give their opinions in a text field on research priorities for vector biology over the next 5-10 years. Answers varied but some key areas were identified: 1) Vector interactions with hosts and pathogens, including vector competence and transmission; 2) Insecticide resistance and novel insecticides; 3) Ecology and behavior, including of infected vectors, introduction of vectors etc.; 4) Vector control, novel control measures and surveillance; 5) Vaccines, including anti-vector vaccines; 6) Modelling; 7) Vector genomics/genetics and bioinformatics. Although no survey can be complete, the data presented here yields a valuable picture of the needs and requirements in disease vector biology, especially of European scientists. We thus expect this study to be relevant to stakeholders such as governments, research councils and organizations but also researchers as priorities for future activities such as those planned by INFRAVEC-2 are determined.
S1 Table. The INFRAVEC-2 Survey Questionnaire, as sent out to participants. A brief description of the INRFAVEC-2 community is given, and the aims of the questionnaire explained.
HORIZON 2020 INFRAVEC-2 Questionnaire
Introduction
A consortium of European institutions based in the former FP7/INFRAVEC project is responding to the new H2020 call “Integrating Activities for Advanced Communities” of the European Research Infrastructures (RI) Programme under the item “Research Infrastructures for the control of vector-borne diseases”. The primary purpose of an “integrated infrastructure” is to provide the EU scientific community with access to its network of RI facilities and services, without charge to the end user, at the state-of-the art premises of participating institutions. Access to the specialized RI enables European researchers and SME to carry out experiments beyond their current capacities.
Building upon the major achievements of FP7/INFRAVEC in forging a European Starting Community of insect vector RI, we worked with EC representatives to generate the current H2020 call for an Advanced Community (AC). With strong commitment obtained from collaborating institutions hosting top-level specialized EU facilities for vector-borne disease (including Institut Pasteur FR, Imperial College UK, Centre de Recerca en Sanitat Animal (IRTA-CReSA) ES, Wageningen University NL, University of Glasgow UK, Institut de Recherche pour le Développement (IRD)-Montpellier FR, Polo d’Innovazione di Genomica, Genetica e Biologia (Polo GGB) IT, Pirbright Institute UK, Max-Planck-Institut für Infektionsbiologie DE, Radboud University Medical Center NL, and EMBL European Bioinformatics Institute DE), the group, chaired by K. Vernick (Institut Pasteur), has been invited to organize the AC.
The RI consortium will provide enabling infrastructures and support for research on disease vectors and their pathogens. We have listed possible RI and services within the following questionnaire, and we would like to solicit as wide as possible feedback from potential users in order to understand the major needs of the vector biology community. Your particular requirements and feedback will have strong impact on how the project will be structured, as this “integrated infrastructure” needs to be tightly tailored to, and inspired by real community needs. Please, take a minute to fill in a short questionnaire (~15 min) that will help us mobilize necessary resources for the future of our community.
Please feel free to forward this email to relevant colleagues. The primary target audience is EU insect vector researchers and SME, but we welcome replies from outside the EU as well. All individual replies and identity information will be kept confidential. Questions can be addressed to email: infravec-survey{at}pasteur.fr
Please complete this form as soon as you can. The survey will close November 25th 2015.
Thank you for your collaboration.
Q1. Please provide your name and contact details.
Title
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First name
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Last name
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Position
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Email (optional)
Providing an email address is optional, but will permit us to keep you informed about the consortium; contact information will not be shared with other parties.
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Q2. Please identify the arthropod vectors and/or vector borne pathogens that you research
Select all that apply
If other other area
Please specify below
Select all that apply
If other other area
Please specify below
Q3. Please select the most relevant areas that describe your research interests from the list below
Select all that apply
If other
Please specify below
Q4. Does your organization have infrastructure facilities described by the list below?
Select all that apply
Q5. Have you ever tried to access BSL-2 or 3 vector research facilities based at organizations other than your own?
a. If yes, did the facility have sufficient capacity to accommodate your request in a timely manner?
Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
a. VECTOR INFECTION AND VECTOR-PATHOGEN INTERACTIONS. Access to BSL-2 or 3 secure insectary facilities for infection of vectors, or provision of infected vectors or extracts custom-generated by such a facility. Vectors infected by the following pathogens, and for the following research purposes (select all that apply).
If other needs–please specify below
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Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
b. VECTOR GENOMICS AND BIOINFORMATICS. High-throughput genomic services. If desired, with upstream bioinformatic design advice and downstream bioinformatic analysis (select all that apply)
If other needs–please specify below
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Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
c. VECTOR GENOME EDITING. Provision of custom genetic modification of your requested target gene or sequence using CRISPR or other technology in vectors (select all that apply). Could also include phenotyping the mutation effect by pathogen challenge under (a) above.
If other needs–please specify below
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Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
d. VECTOR ECOLOGY AND BEHAVIOR. Provision of access to facilities or custom-performed assays (select all that apply). Could also include pathogen infection of vectors under (a) above.
If other needs–please specify below
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Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
e. VECTOR BIOLOGY RESOURCES. Provision of vector research resources by request (select all that apply).
If other needs–please specify below
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Q6. Which infrastructure services offered to European users would you be likely to use, with user access costs paid by a Horizon 2020 Research Infrastructure consortium (i.e., at no charge to the end-user). Items provided as user access or custom service, which does not require scientific collaboration with the providing facility.
f. TRAINING AND NETWORKING ACTIVITIES. Promotion of expertise using standardized, comparable practices, scientific exchange.
If other needs–please specify below
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Q7. In your opinion, what are the top research priorities (up to 5) in vector biology and/or vector borne disease that need to be addressed in the next 5-10 yrs in the European research context?
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Thank you for participating!
Please use the space provided below to send us any additional feedback on this survey.
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Acknowledgments
We acknowledge the assistance of Sarah J. Plowman of the UK BBSRC for advice in survey design, and survey participants.