The threat of vector-borne diseases to sub-Saharan Africa & how to build resilience in these communities. Prof Steve Lindsay BOVA Second Open Network Meeting UN-Habitat, Nairobi, Kenya 4th April, 2019

Introduction What’s BOVA? The threat of vector-borne diseases in sub-Saharan Africa Importance of working with those in the built environment

Building Out Vector borne diseases BOVA Building Out Vector borne diseases in sub-Saharan Africa

What is the BOVA Network? Interdisciplinary network of researchers and practitioners working on insect-borne diseases and the built environment Aims to establish a new research discipline Vector-borne diseases Built environment

BOVA Network activities Pump-prime funding Global advocacy Yearly open network meetings for information exchange

Who are we? Prof. Steve Lindsay Durham University Prof. Mike Davies The Bartlett, UCL Network directors 20 individuals: representation from both built environment and vector-borne diseases, global north and global south Network Management Board

BOVA Conceptual Framework Network of experts in insect-borne diseases and the built environment Management Board Information exchange Advocacy and sustainability Basic and applied research Capacity building Develop and scale-up products & approaches in the built environment for preventing disease Sustainable & resilient communities free of insect-borne diseases Foundation Action Objectives Goal

What is the burden of insect-borne diseases?

Insect-borne diseases – a major cause of ill health and death in Africa Insect-borne disease risk distribution in Africa Combined global distribution of falciparum and vivax malaria, lymphatic filariasis, dengue, onchocerciasis, cutaneous and visceral leishmaniasis, human African trypanosomiasis and yellow fever WHO 2016, Golding et al 2015

The basic split Rural/Peri-urban = malaria Urban/Peri-urban = dengue & worse

Malaria 200 million malaria cases and 403,000 deaths in Africa in 2017 Africa accounted for 92% of global malaria cases and 93% of malaria deaths in 2017 Typically a rural disease WHO 2018 World Malaria Report 2018

Diseases carried by Aedes mosquitoes Dengue is world’s fastest growing insect-borne disease. Estimated 96 million dengue cases in 2010 Global epidemic of Zika Yellow fever outbreaks in Africa Aedes aegypti, the world’s most efficient vector of viral diseases

Dengue cases reported to WHO Data accessed 27.03.19

Dengue is endemic in 34 African countries in 2012 Were 2012 Paediatrics & International Health, 32 S1 18-21

Overlap between Aedes mosquito and human populations Cities >1M inhabitants Predicted Aedes aegypti distribution in 2015 Nick Golding, unpublished

And for something new…. Anopheles stephensi 2014 2018 Takken & Lindsay (in press) New & Emerging Diseases

What control methods do we currently have? Insecticide-treated bednets Fogging Indoor-residual spraying Larval source management

Declines in malaria attributable largely to mosquito control Between 2000 and 2015 malaria infection prevalence in SSA halved and the incidence of clinical disease fell by 40%, due largely to vector control with long-lasting insecticidal nets and indoor residual spraying. Bednets Drugs Insecticide spraying indoors

Insecticide resistance Below this line = insecticide resistance % of mosquitoes that died when exposed Insects are becoming resistant to the public health insecticides we are using against them Graph shows killing of malaria transmitting mosquitoes (in WHO bioassays) over time when exposed to insecticides typically used on bednets. Less are dying over time. Year Killing of malaria mosquitoes when exposed to two different types of insecticide (deltamethrin (blue) or permethrin (orange)). Source: Ranson and Lissenden 2016

What WHO say….. No significant progress in reducing global malaria [between 2015-2017] The 10 highest burden countries in Africa reported increases in cases of malaria in 2017 compared with 2016.

What is the link between insect-borne diseases & the built environment? Water storage tanks, harbour Aedes mosquitoes Traditional rural housing – open eaves, unscreened doors and windows – allow mosquito vectors to enter Drains with rubbish in them – harbour Culex mosquitoes – lymphatic filariasis, nuisance biting Flooded roads – standing water harbours malaria vectors

Link between insect-borne diseases & the built environment Poorly screened houses Open water containers MALARIA DENGUE Polluted still water Solid waste accumulation Open water storage tanks, harbour Aedes mosquitoes Traditional rural housing – open eaves, unscreened doors and windows – allow malaria mosquito vectors to enter Drains with rubbish in them – harbour Culex mosquitoes – lymphatic filariasis, nuisance biting Flooded roads – standing water harbours malaria vectors NUISANCE BITING DENGUE

What’s the evidence for improvement of the built environment on the reduction of diseases transmitted by insects?

Housing improvements - evidence 80-100% of malaria infections occurs indoors at night Children living in improved housing had about half the odds of having a malaria infection compared to those living in traditional housing. Protection provided by good housing may be similar to insecticide-treated bednets against malaria. House screening can reduce dengue incidence by about three quarters. Source: Tusting et al 2015 and 2017, Bowman et al 2016

Housing improvements - policy RBM / UNDP / UN-HABITAT Consensus statement on housing and malaria

Environmental management - malaria Immature stages of malaria mosquitoes occur in a wide range of waterbodies, but rarely containers Drainage & filling of aquatic habitats will contribute to a reduction in adult mosquitoes

Environmental management – Aedes-borne diseases Immature stages of Aedes occur in water-storage containers, used tyres, solid waste etc Provision of reliable piped water, removal of tyres, waste management etc will reducing the number of adult mosquitoes Community-based environmental management shown to reduce Aedes mosquitoes and dengue infection

Key to reducing poverty

Global Vector Control Response 2017-2030 Broaden collaborations within & beyond the health sector

Find out more about the network! www.bovanetwork.org @bovanetwork

Summary BOVA Network brings together experts in vector-borne diseases with those in the built environment Vector-borne diseases are a major environmental threat to countries & their economies Building out vectors will lead to more resilient cities in the future

Acknowledgments:

Meeting Aims & Objectives Prof Steve Lindsay BOVA Second Open Network Meeting UN-Habitat, Nairobi, Kenya 4th April, 2019

Introduction Information exchange Building the BOVA Network Developing future research proposals

Building the Network Vector-borne disease experts Built environment experts

Community-based approaches Future research Strategic thinking/ policy New tools & approaches Community-based approaches Economics & scale-up Basic research

BOVA can help facilitate future research We will support 1 or 2-day meetings of up to 8 people to hold workshops for writing future research applications £98,400. These will be competitive.