1. 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

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

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

4. 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

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

6. 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

7. 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

8. What is the burden of insect-borne diseases?

9. 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

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

11. 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

12. 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

13. Dengue cases reported to WHO
Data accessed

14. Dengue is endemic in 34 African countries in 2012
Were 2012 Paediatrics & International Health, 32 S

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Nick Golding, unpublished

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

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

18. 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

19. 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

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

21. 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

22. 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

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

24. 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

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

26. 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

27. 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

28. Key to reducing poverty

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

30. Find out more about the network!
@bovanetwork

31. 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

32. Acknowledgments:

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

34. Introduction Information exchange Building the BOVA Network
Developing future research proposals

35. Building the Network Vector-borne disease experts
Built environment experts

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

37. 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.