N Govella, Ifakara Health Institute, Integrating intervention targetable behaviours of malaria vectors to optimize interventions selection and impact

Lead Research Organisation: University of Glasgow
Department Name: College of Medical, Veterinary &Life Sci

Abstract

Malaria continues to impose a huge burden upon human health despite widespread use of insecticide-treated nets (ITNs), improved diagnosis, and treatment. The global problem this study aims to address is the lack of understanding of the mosquito and human behaviours that limit the impact of existing malaria vector control interventions like ITNs, but which also create opportunities for new ones to achieve further gains. For example, human exposure persisting outdoors could be targeted with insecticide vapour emanators and vector mosquitoes that survive by feeding on livestock could be targeted with veterinary approaches. Like most other African countries, Tanzania has achieved great success in reducing malaria with widespread use of ITNs. However, many new cases and deaths still occur, with a wide range of regional variation, from 0 up to 27 people infected per 100 tested for malaria. It is highly likely that much of this geographic variability in malaria transmission arises from the exceptional variability of climatic conditions in Tanzania and knock-on effects on relevant behaviours of mosquitoes and humans.

I therefore propose to identify, quantify and address the underlying behavioural causes of persisting malaria transmission in climatically distinct geographic strata, so that they can be optimally tackled with supplementary vector control measures. This problem has already been prioritized as an important question by the Government of Tanzania, acting through the National Malaria Control Programme (NMCP) with the aim of adjusting intervention choices according to the local context to maximize impact. Specifically, I will integrate intervention-targetable behaviours of mosquitoes (e.g. feeding early and outdoors when most people are still outside or feeding on non-human host) and humans (e.g. use or not use of ITNs, time spent outdoor in the evening) into existing nationally-representative longitudinal, community-based surveillance system that monitors vector densities and infection rates in 32 districts of Tanzania, to assess how these behaviours are shaped across wide distinct environmental conditions and provide insight on how interventions could be tailored to local conditions for maximum impact.

This study will provide insights into which additional strategies are likely to be most effective on the basis of local vector ecology. This could be a game changer in the development of locally-tailored, highly effective mosquito control packages in Africa, which accelerate progress toward malaria elimination. It will also form the basis for improved policy and practice with respect to effective targeting of supplementary vector control measures.

Technical Summary

Malaria burden in Tanzania has been reduced by more than 50% over the past 15 years. Vector control with insecticide-treated nets (ITNs) and, indoor residual spraying, account for most of these reductions. Despite these gains and sustained community-wide use of ITNs, new malaria cases continue to occur across the country, but with regional variation in prevalence ranges from 0 up to 24%. Underlying drivers for geographic heterogeneity in transmission remain unclear, and will limit Tanzania's efforts to eliminate malaria by 2030. Tanzania is climatically heterogeneous countries, and such climatic variations most likely affect the mosquito and human behaviours that allow malaria vectors to survive by attacking people outdoors or by feeding on animals. New technologies like insecticide vapour emanators and veterinary endectocides could be used to respectively target these behaviours. However, lack of information about where each of these measures may be optimal limits potential for effective geographic targeting of these complementary vector control tools.
I propose to integrate surveys of intervention-targetable behaviours of mosquitoes and humans into the existing nationally-representative vector surveillance platform in Tanzania and use this to identify what human and mosquito behaviours drive persisting malaria transmission. Specifically, I will quantify intervention-targetable behaviours of malaria vectors and characterize both environmental and anthropological determinants of how those behaviours vary across 32 locations in diverse ecological settings in mainland Tanzania. These data will be used to model and predict which supplementary vector control tools are likely to be most effective in different ecological zones, and provide NMCP with a framework for rational selection of interventions to optimize vector control impact.

Planned Impact

a) Community Impact
Based on the scope of this research which is about figuring out effective approaches to accelerate malaria elimination efforts, the people of Tanzania, who are most affected by the disease (Tanzania ranked the 5th highest number of deaths due to malaria globally) would be the immediate beneficiaries. Knowledge generated would contribute to further reduction and/or elimination of malaria and consequently reduce burden on health care infrastructure and catastrophic household expenditure in Tanzania, thus contributing to addressing global development goals (SDG 1, SDG 2, SDG 3 and SDG10). This will be achieved through partnership with government, local communities and development partners in which critical evidence for national policy may be generated and disseminated.

b) Strengthening African Institution capacity building
The proposed study would generate significant added value for the IHI's institutional priorities and capacity needs including developing senior leadership in malaria vector research which can be internationally competitive, and mentor more early career African scientists. The programme would also offer opportunities to work closely with local communities, policy-makers and policy-implementers and development partners through meetings. This will increase the visibility of the IHI and its capacity to influence both national and international health policy.

c) This programme will strengthen the ability of the ARL to independently lead large research programmes, consolidating and improve both research competence and research management. This long term funding would also allow the ARL to strengthen his newly established research group and train and supervise other African Masters and Ph.D students to create the next generation of scientists and opinion leaders in public and global health matters. Existing collaboration between the PI based in UK and other partners will be strengthened, thus promoting knowledge, skills and technological exchange over a longer period.
 
Description Ifakara Health Institute, Tanzania 
Organisation Ifakara Health Institute
Country Tanzania, United Republic of 
Sector Charity/Non Profit 
PI Contribution We collaborate with the Ifakara Health Institute on research related to the ecology, surveillance and control of mosquito vectors of malaria. My team contributes through collaboration on the developing of new mosquito trapping technologies, leading research into malaria vector ecology and their response to control measures, and strengthening research capacity through the provision of postgraduate training and mentorship to PhD students and Fellows from the Institute
Collaborator Contribution Our partners at IHI contribute to this research by co-leadership and development of research on vector ecology and surveillance, hosting and leadership of our field-based collaborations in rural Tanzania, and provision of capacity strengthening by providing training to postgraduate students and postdoctoral researchers from the University of Glasgow
Impact 1) Publications - Through this collaboration, I have published numerous co-authored publications with postgraduate students and scientists from the Ifakara Health Institute https://doi.org/10.1186/s12936-021-03677-3 2021: Doi: 10.1186/s12936-021-03677-3 Doi: 10.1186/s13071-021-04989-8 2020: Doi: 10.1038/s41598-020-71187-4. 2019: Doi:10.1186/s12936-019-2719-9 Doi: 10.1186/s12936-019-2726-x Doi: 10.12688/wellcomeopenres.15201.3 Doi: 10.1186/s12936-019-2822-y Doi: 10.1088/1748-9326/ab26c7 Doi: 10.1186/s12936-019-2982-9 2018: Doi: 10.1038/s41598-018-31805-8 Doi: 10.1186/s13071-018-3249-y 2017: Doi: 10.12688/wellcomeopenres.12928.1 2016 Doi: 10.1186/s12936-016-1513-1 Doi: 10.1371/journal.pgen.1006303 Doi: 10.1371/journal.pmed.1002002 Doi: 10.1186/s13071-016-1394-8 2015 Doi: 10.1186/s12936-014-0536-8 Doi: 10.1186/s13071-015-1066-0 Doi: 10.1186/s12936-015-1025-4 Doi: 10.1186/s12936-014-0523-0 2014 Doi: 10.1371/journal.pntd.0003310 Doi: 10.1098/rspb.2012.2823 2013 Doi: 10.1371/journal.pntd.0002510 2013 Doi: 10.1186/1475-2875-11-425 2012 Doi: 10.3389/fphys.2012.00199 2011 Doi: 10.1111/j.1420-9101.2011.02442.x Doi: 10.1186/1475-2875-11-106 Doi: 10.1186/1475-2875-11-118 Doi: 10.1098/rspb.2011.0153 Doi: 10.1186/1475-2875-10-289 2010 Doi: 10.1186/1475-2875-9-356 2009 Doi: 10.1016/j.pt.2009.01.005 Doi: 10.4269/ajtmh.2009.09-0192 2008 Doi: 10.1186/1475-2875-7-158 Doi: 10.1016/j.anbehav.2008.01.014 Doi: 10.1186/1756-3305-1-45 2007 Doi: doi:10.1242/jeb.005033 Doi: 10.1371/journal.pmed.0040229 2006 Doi: 10.1186/1475-2875-5-62 2005 Doi: 10.1016/j.tree.2005.02.003 Doi: 10.1186/1475-2875-4-49 2) Patents 2) Patent applications A joint patent application has been granted between the University of Glasgow and Ifakara Health Institute for the mosquito trap we co-developed Patent application title: "IInsect Trap". https://www.ipo.gov.uk/p-ipsum/Case/ApplicationNumber/GB1708369.2. U. K. I. P. Office. UK, University Court of the University of Glasgow Ifakara Health Institute. 2552073. 3) Mentorship and funding support for early career scientists I have co-sponsored the Wellcome Trust Fellowships for several early career scientists from the Ifakara Health Institute 2020: 2020: Supervisor, Scottish Funding Council Global Challenges Research Fund Master's Fellowship "Strengthening capacity for laboratory colonization of the major African malaria vector Anopheles funestus". Awarded to Mr Emmanuel Hape (£31,845, 2020-2021) Sponsor, Wellcome Trust International Intermediate Fellowship "Demonstrating impact of mosquito-assisted larviciding autodissemination) as a complementary malaria intervention in rural Tanzania". Principal Investigator: Dr. Dickson Lwetoijera, Ifakara Health Institute, Tanzania (£634,780, 2020-2025) 2019: Sponsor and supervisor. Wellcome Trust International Master's Fellow "Combining house-screening and odour-baited mosquito traps for sustainable control of malaria transmission in low-income communities dominated by Anopheles funestus "" Principal Investigator: Ms. Doreen Siria, Ifakara Health Institute, Tanzania (£120,000, 2019-2021) 2013: Sponsor and supervisor. Training Fellow in International Health and Tropical Medicine "Understanding the potential for malaria vector behavioural adaptations" Principal Investigator: Dr. Nicodem Govella, Ifakara Health Institute, Tanzania (£348,602, 2014-2017) Sponsor. Intermediate Fellow in International Health and Tropical Medicine. "Targeting residual malaria vectors in communities where insecticidal bed nets are already widely used". Dr. Fredros Okumu, Ifakara Health Institute, Tanzania (£660,705, 2014-19) 2010: Sponsor and supervisor, Wellcome Trust Training Fellowship in Public Health and Tropical Medicine, "Evolutionary and ecological response of African malaria vectors to insecticide- treated nets: vector population replacement?" Principal Investigator: Dr Kija Ng'habi, Ifakara Health Institute, Tanzania. (£285,864, 2010-2013) 4) Postgraduate student training I have supervised the postgraduate training of severa; students from the Ifakara Health Institute Ms. Christina Makunga, PhD:Ms. Christina Makunga, PhD: Malaria control in Tanzania: exploring human behaviors, activities, and risk. 2021-Ongoing Ms. Najat Kahamba, PhD: The dry season ecology of the malaria vector Anopheles funestus in ecology. 2020-ongoing Mr. Joel Odero. PhD: Population genetics of Anopheles funestus in Tanzania. 2020-ongoing.3 Mr. Halfan Ngowo, PhD: Quantifying the ecology and control of Anopheles funestus 2019- ongoing. Mr. Halfan Ngowo, M.Sc: Investigating the seasonal abundance and biting behaviours of primary and secondary malaria vectors in Tanzania. 2015-2016 Dr. Deodatus Maliti (University of Glasgow), PhD: Ecological determinants of African malaria vector behaviour and their implications for control. Dr. Issa Lyimo (University of Glasgow), PhD: The ecological determinants of host choice in Anopheline mosquitoes and its consequences for malaria parasite transmission, 2007-2010. *Ms. Valeliana Mayagaya (University of Dar es Salaam), MSc:The impacts of host species composition on malaria vectors and transmission risk in Kilombero Valley, Tanzania, 2007-2010. Dr. Kija Ng'habi (Wageningen University, Netherlands), PhD: Ecological, behavioural and genetic determinant of gene flow in African malaria mosquitoes, 2006-2010. 5) Additional funding 2021 Co-applicant, Bill and Melinda Gates Foundation "Infrared Spectroscopy for Mosquito Characterization" (Total= $3,800,000; UoG Component: $1,300,000; 2021-2024) 2020: Co-applicant, Bill and Melinda Gates Foundation "Population biology and genomics studies on Anopheles funestus in Tanzania". (Total = $2,821,000, , UoG Component: $440,766, 2020-2022) Principal Investigator with African Research Leader Dr. Nicodem Govella, MRC African Research Leaders Award, "Integrating intervention targetable behaviours of malaria vectors to optimize interventions selection and impact" (Total £703,302, 2020-2024) 2017: Co-applicant, Bill and Melinda Gates Foundation, "Anopheles funestus gene flow studies and rearing methods" (Total $2million, HMF Component: £164,600, 2017-2019) Principal Investigator, MRC Global Challenges Research Fund Foundation Award, "Development of a new tool for malaria mosquito surveillance to improve vector control" (£659,977, 2017-2019) Co-applicant, USAID Grand Challenges to Combat Zika, "Affordable, scalable , low technology Transluthrin emanators for protection against Zika transmission in low-income countries" (Total: £1,385,460 HMF Component: £73,827, 2016-2018) Co-applicant, NERC- DFID Understanding the Impacts of the Current El Nino call. "Impact of El Niño on malaria vector dynamics in Tanzania: observation, improvement and unleashing forecasting potential" (£232,828, HMF Component: £8121, 2016-2017) 2011: Co-applicant, NIH RO1 Grant: "Ecological and genetic determinants of malaria transmitting behaviors in the African vector Anopheles arabiensis", (Total $2,459,000 USD, HMF Component: £638,000, 2011-2016) Co-applicant, European Union FP7 Call for Africa Programme, "African Vector Control: New tools", (Total €12 million, HMF Component: £515,651, 2011-2016) 2009: Principal Investigator, Royal Society International Travel Grant, "Semi-field systems for the study of vector ecology", (£1500) Co-applicant, UBS Optimus Foundation Grant, "Road-testing Innovative Surveillance Technologies for Rabies in Southern Tanzania" (780,000 Swiss Francs, 2009-2011)
Start Year 2006
 
Description National Institute of Medical Research Tanzania 
Organisation National Institute for Medical Research, Tanzania
Country Tanzania, United Republic of 
Sector Public 
PI Contribution Sharing of data on malaria vector surveillance from across Tanzania
Collaborator Contribution Sharing of information from routine malaria surveillance activities
Impact N/A
Start Year 2020
 
Description National Institute of Medical Research Tanzania 
Organisation National Institute for Medical Research, Tanzania
Country Tanzania, United Republic of 
Sector Public 
PI Contribution Sharing of data on malaria vector surveillance from across Tanzania
Collaborator Contribution Sharing of information from routine malaria surveillance activities
Impact N/A
Start Year 2020
 
Description Display at the COP 26 Conference in Glasgow 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact This display was presented as part of the GreenZone programme at the COP 26 conference held in Glasgow, Nov 9th 2021. The aim of this display was to highlight the anticipated impacts of climate change on insect vector-borne disease, and the research being conducted on this topic at the University of Glasgow.
The display was themed around a series of case studies from collaborative research being undertaken by our team at the University of Glasgow and our international partners.
1) The transmission of avian malaria to wild birds in Scotland
2) Malaria vector ecology and control in Africa
3) Land use change and its role in driving the spread of monkey malaria to humans in South East Asia
Through a combination of high impact images from our ongoing collaborative research on these topics, posters with simple infographics and a captioned video display; the display highlighted how climate change and its associated impacts on humans and land use is expected to increase the global burden of vector-disease. The display was attended by members of the public, school groups, and attendees at the COP26 conference.
Year(s) Of Engagement Activity 2021
URL https://www.gla.ac.uk/explore/sustainability/events/index.html/event/12227