1. or Climate Risk Management in Health
Amazon Malaria Initiative / Amazon Network for the Surveillance of Anti-malarial Drug Resistance
Bogota, Colombia, March 17–19, 2009
“Climate Change and Malaria”
or Climate Risk Management in Health
Stephen Connor, International Research Institute for Climate & Society (IRI),
The Earth Institute at Columbia University, New York .
PAHO/WHO Collaborating Centre on early warning systems for malaria and other climate sensitive diseases

2. Into climate sensitive development sectors…
how can we get the knowledge benefit from recent advances in climate science and observation
Into climate sensitive development sectors…
…to more effectively manage the associated risks affecting vulnerable populations?
…sooner rather than later … (e.g. MDG timeframe 2015)

3. Climate Change…… ^T 0.74ºC circa 100 years

4. And rainfall circa 100 years?
Long term trend: 18% Variance
Inter-decadal variability: 27% Variance
Inter-annual variability: 55% Variance
Example: observed rainfall variability in the Sahel
long-term variability (linear trend),
decadal variability (after removing the linear trend)
inter-annual variability (after removing the linear and decadal trends)

5. Malaria has also changed greatly in the past 100 years….
Americas: USA – malaria declined as a result of changes in land use and ‘eradication’ which was declared in 1949 – occasional ‘import’ malaria
Guyana 1940s: 40,000 cases/1965: 22 cases/ ,017 cases – down again today
Europe: decline as a result of land use change/eradication – some resurgence >WWII.
Eradication declared during 1950s and 1960s – occasional ‘import’ malaria
Asia: India 1940s:circa 70 million cases/late 1950s circa 100,000/1970s >20 million
Sri Lanka – 1940s: circa 2 million case/ cases/ massive resurgence – but down again today
Africa: Not included in the Global Eradication Campaign – though notable examples
e.g. Swaziland 0 cases in resurgence 1978 on – but down again today
Malar ia
T i m e

6. Clearly its more complex…multi faceted…
Malaria vs
poverty

7. So does climate have a role to play ?
Climate may impact on health through a number of mechanisms
directly through cold or heat stress – aggravating conditions such as heart disease and respiratory conditions,
- and indirectly, for example through:
a) food security - nutritional status and immuno-suppression,
b) water source quality and water-borne disease
c) infectious diseases – malaria being a good example

8. Where (CS) disease is not adequately controlled …
Where (CS) disease is not adequately controlled …. Then climate information is relevant to informing on:
Seasonality in endemic disease
Shifts in the spatial distribution of endemic and epidemic disease
Changes in risk of epidemic disease
> Epidemic Early Warning Systems

9. Climate and infectious disease ……
Using Climate to Predict Infectious Disease Epidemics. WHO 2005
Diseases include:
Inter-annual variability:
Sensitivity to climate#:
Climate variables:
Influenza
* * * * *
* *
<T
Meningitis
* * * *
* * *
>T,<H,>R
Leishmaniasis
>T,>R
R.V. Fever
>R,<T
Cholera
>T
Malaria
>R,T,H
Dengue
.. bacterial, viral and protozoan ..
..other candidates, e.g some respiratory diseases not included here….
… must remember socio economic factors very important…

10. Demand for integrated early warning systems …
Integrated MEWS gathering cumulative evidence for early and focused epidemic preparedness and response (WHO 2004)
Climate
Env-Info
Monitoring
and Surveillance

11. Demands for evidence-based health policy
Before using climate information in routine decision making health policy advisors need:
Evidence of the impact of climate variability on their specific outcome of interest, and
Evidence that the information can be practically useful within their decision frameworks, and
Evidence that using climate information is a cost-effective means to improving health outcomes.
…. A case study >>>>

12. An example: Malaria and MEWS in Botswana
Policy Changes
Botswana straddles the southern margins of malaria transmission in sub-Saharan Africa.
The incidence of malaria varies considerably from district to district across the country – showing a general north-south decreasing pattern from more stable to less stable malaria.
In Botswana the incidence of malaria also varies considerably from year to year – and as such malaria is considered to be ‘unstable’ and prone to periodic epidemics (MoH 1999)

13. Vulnerability monitoring
Example in practice: Botswana …
Routine assessment of drug efficacy in sentinel sites, susceptibility of the vector to insecticides, coverage of IRS achieved each season
Regular assessment of drought-food security status from SADC Drought Monitoring Centre - disseminates the information to the epidemic prone DHTs
Recognises need for extra vigilance among its most vulnerable groups, including those co-infected with HIV, TB, etc.

14. Seasonal Climate Forecasting
Example in Botswana ….. SCF offers good opportunities for planning and preparedness. NMCP strengthens vector control measures and prepares emergency containers with mobile treatment centres
Lead-time 5 months
Evidence of impact of climate variability on specific outcome of interest (Thomson, et al. Nature. 2006)

15. Environmental monitoring
Example in Botswana …ENV monitoring enables opportunities to focus and mobilise more localised response, i.e. vector control and location of emergency treatment centres….
Lead-time 1 to 2 months
Evidence of impact of climate variability on specific outcome of interest (Thomson, et al. AJTMH. 2005)
Adjusted malaria anomalies

16. Case surveillance
Example in Botswana .. Of a number of indicators (WHO 2004) the NMCP uses case thresholds defined for three levels of alert …
Threshold unconfirmed cases/week >>> Action Plan 1.
Threshold unconfirmed cases/week >>> Action Plan 2.
Threshold unconfirmed cases/week >>> Action Plan 3.

17. RBM: Southern African Regional MEWS activities
Evidence for practical application within a decision making framework (DaSilva, et al. MJ 2004).
Evidence for using environmental monitoring (Thomson, et al. AJTMH 2005)
Evidence for using seasonal forecasting (Thomson, et al. Nature 2006).
Evidence of timing/effectiveness (Worrall, et al. TMIH 2007; Worrall, et al. 2008)

18. The 2005/06 season in Southern Africa…..
A ‘test case’ for MEWS in the Southern Africa region
A ‘wet year’ following three ‘drought’ years (like 96/97) when major regional epidemics had occurred
“Classic post-drought epidemics” have occurred periodically in Southern Africa’s history

19. Demonstrated progress…..

20. And for application of the approach elsewhere ?
.. growing interest/demand from other countries/regions:
in West Africa (malaria and meningitis)
in South East Asia (malaria, dengue and respiratory)
in Colombia (malaria & dengue)
in East Africa (malaria, meningitis cholera & RVF)

21. Climate Risk Management for Health
Clearly we must take steps to mitigate Climate Change. However……
learning to manage climate risk on a year to year basis is undoubtedly our best method of adapting to climate change
A society that manages current climate risks – is less vulnerable - more resilient – giving it greater adaptive capacity to face the many risks associated with climate change.

22. Need to:
Improve understanding of climate-environment-disease-interaction
…. to build knowledge base for risk management
Invest in effective control now & face the future with lower disease burden
Develop “more broadly informed surveillance systems” to sustain advances in control and ultimately elimination/eradication

23. Thank you for your attention
PAHO/WHO Collaborating Centre on early warning systems for malaria and climate sensitive diseases

25. e.g. Seasonal climate and endemic malaria ….
Due to poor epidemiological data in sub-Saharan Africa - climate data often used to help model and map the distribution of disease.
Temporal information useful for developing seasonal disease calendars for control planning purposes
Climate suitability for endemic malaria
= 18-32ºC + 80mm + RH>60%

26. e.g. the impact of climate trends….
30 year drought >?
Changes in malaria
<endemicity (Faye et al 1995)
Changes in meningitis
>southward extension of ‘Meningitis Belt’ >epidemic frequency (Molesworth et al 2003)
Very important consideration when establishing baselines

27. e.g. Climate anomalies and epidemic malaria ….
Desert fringe malaria … e.g. Botswana

28. But - what is an epidemic?
More cases than expected at a particular place and time ?
Where R0 temporarily goes above 1 ?
‘True epidemics’ – infrequent (possibly cyclical) events in areas where the disease does not normally occur – e.g. warm arid/semi arid zones and beyond the highland-fringe.
Unusually high peak in seasonal transmission
Neglect/breakdown of control – ‘resurgent outbreaks’ with subsequent increase in endemicity level
Epidemics in complex emergencies – transmission exacerbated by population movement and political instability – may include the above – and may be ‘triggered’ by a climate anomaly
introduction of exotic vector (? rare ?)
The apparently simple question what is an epidemic? Comes up time and time again. The simple definition of “more cases than expected at a particular place and time” – or “when r0 rises above 1” is not considered sufficient to help understand the variety of situations which control services have to deal with.
In view of this WHO’s Technical Support Network on Epidemic Prevention and Control have recently suggested the a range of definitions to characterize particular circumstances:
~ True epidemics – infrequent, but possibly cyclical, events in areas where the disease does not normally occur – e.g. the warm arid and semi arid zones
~ Unusual seasonal transmission – where the peak in seasonal transmission is higher than expected
~ Resurgent outbreaks – where previously controlled malaria emerges as a result of control breakdown or neglect
A further definition is required for epidemics in complex emergencies – where transmission is unusually high as a result of populations movements and political instability – may include components of the above and may be triggered by a climate anomaly