Vulnerability assessment of malaria from the viewpoint of climate change in India

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Vulnerability assessment of malaria from the
viewpoint of climate change in India

• Ramesh C Dhiman
• Deputy Director (Senior Grade)
• National Institute of Malaria Research
• Delhi-110054
• dhimanrc_at_icmr.org.in

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CLIMATE CHANGE

• Climate change poses a major, and largely
  unfamiliar, challenge.
• It is a newer challenge to ongoing efforts to
  protect human health

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Climate Change is caused by

• Human actions increase atmospheric
  concentration of energy trapping gases thereby
  amplifying the natural green house effect
  leading to climate change.
• Green House Gases are
• CO2 ( from fossil fuel forest burning ).
• Methane (from irrigated agriculture, animal
  husbandry oil extraction),
• Nitrous Oxide etc.

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Projection of Global WarmingInter- governmental
Panel on Climate Change -III Assessment Report

• Year Temp ( )
  Precipitation ()
• 2020 1.4 0.30 C
  2 1
• 2050 2.5 0.40 C
  3 1
• 2080 3.8 0.50 C
  7 3
• 
  
  
  
  

Rise in sea level up to 0.88 m may submerge
coastal areas Effect of sea level rise already
witnessed in Orissa
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Potential Impacts of Climate Change on Health
Weather related mortality Infectious
diseases Altered food productivity
associated pest and diseases Air quality
respiratory illnesses
Heat Strokes Skin Diseases Eye Diseases Floods ,
Storms leading to deaths, Injury ,Psychological
distress Loss of PH infrastructure
Climate Change Temperature
Precipitation Sea Level
Geographic range and incidence of Vector Borne
diseases, Changed incidence of Diarrhoeal
Diseases
Malnutrition , Hunger , Impaired child growth and
development
Asthma Respiratory diseases
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Other Infectious Diseases Likely to be Affected
by Climate Change

• Hantavirus
• Leptospirosis
• Diarrohea due to floods droughts
• Typhoid
• SARS

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Vector Borne Diseases in India
Reported cases in 2005 1
Report of NFCP Units
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Malaria Epidemiological Triangle
Environment
Analogy Development of pathogens in insect
vectors is affected by climatic
conditions
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Relationship of Temp. RH with Malaria Parasite
and Mosquito Development
10 11 12 13
Maximum temp. for mosquito survival
Minimum temp. for parasite development
Optimum temp.
14 15 16 17 18 19
25 26 27
40 oC
Relative Humidity 40 60 70 80
Minimum T required for transmission P
vivax 14.5-16 C P
falciparum16-18 C
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Effect of Rise in Temperature on Disease Vectors

• Rate of development (from egg to adults) will be
  faster
• Rate of digestion of blood meal will be faster.
• Frequency of feeding will be faster
• Frequency of egg laying will increase.
• Density of mosquitoes will increase.
• Survival affected by RH.
• Gonotrophic cycle and Longevity for sporogony
  reduced at higher temperature
• Death of mosquitoes at 40C

Gonotrophic cycle, daily survival and man biting
rates are crucial factors for vectorial capacity
of vectors
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Climatic Determinants for P. vivax Development
and Transmission
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Average duration of sporogony of human Plasmodia
At 16 C , 55 days are required for completion of
sporogony
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Impact of Temperature on Sporogony
Up to November
Degree days required for Pv 104C for Pf114
C Rainfall in 1993 was103.1cm while in 1994,
137.9 cm
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Endemicity of Malaria in India ( 2006)

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Malaria Vulnerability Assessment in India from
Climate Change

• Northern states such as
• J K, H.P, Punjab Haryana, Uttarakhand,
  U.P., NE states etc are more vulnerable to
  climate change
• Southern states such as Karnataka, Kerala, T.N
  and A.P are less vulnerable to climate change

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Distribution of vectors of malaria in India
Spatial extension of vectors may be affected
Role of An. subpictus and An Annularis need to
be assessed
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Current Transmission windows of malaria ( 2004)
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Projected Shift in Transmission Windows of
Malaria in view of Climate Change
a. Baseline 2004
b. TWs by 2080
Increase in TWs in Northern and NE states
reduction in Orissa, AP and TN is expected
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PRECIS Surface Temperature, Baseline
IITM Pune
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PRECIS Surface Temperature, A2 ( 2071-2100)
Baseline (1961-1990)
P vivax season
P falciparum season
IITM Pune
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Season- wise impact of projected rise in
temperature on malaria transmission
Transmission windows may widen in
October-February Extension in P falciparum
transmission more than P vivax From March to
May , chances of reduction in Trans windows
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Possible changes in Transmission Windows of
malaria
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However, Vulnerability depends on

• Population scenarios
• Agricultural practices
• Food availability
• Economic scenarios
• Local environmental conditions
• Pre-existing health status and intervention
  capacities

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Adaptation assessments

• Shift in transmission months of VBDs - plan of
  intervention measures accordingly.
• To develop tools for early warning for seasonal
  forecasts.
• Strengthening of surveillance and EDPT
• To improve health seeking behaviour, reach of
  health facilities to public
• To identify adaptive capacity of society
• Plan public health interventions and allocate
  resources
• Community use of Insecticide treated nets.
• Estimating the co-incidental benefits and costs
  of mitigation and adaptation
• Adaptation strategies must be considered to
  reduce disease burden , injuries, disabilities
  and deaths

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Adaptation measures Possible tools for early
Warning

• Meteorological
  Variables
• El Nino Southern Oscillation Rainfall
• 
  
• Satellite derived Normalized Difference
• Vegetation Index ( NDVI)
• Ecological changes detected by Remote
• sensing

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Relationship Between Malaria and Met. Parameters
Banaskantha district ( Gujarat)
Correlation between Rainfall and malaria
incidence with Two months lag was significant
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Relationship Between Malaria and Met. Parameters
Bikaner district ( Rajasthan) 1988-2002
Rainfall two months prior was found as an
important indicator for early warning
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Relationship Between Malaria and Met. Parameters
Tumkur district ( Karnataka)
No correlation was found between met parameters
and malaria incidence
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Initiatives taken by Govt of India

• Indias 1st National Communication Project to
  UNFCC/GEF ( 2000-2002) for vulnerability
  assessment adaptation measures in view of
  climate change.
• IInd National Communication Project, MoEF
  launched in Feb 2008
• Prime Ministers Expert Committee on Climate
  Change is reviewing the issue.
• Climate Change is an imp. issue for XIth Plan.

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Research needs

• To examine evidence from the associations between
  climate variability and Malaria occurrence in
  high land areas.
• Establishing baseline relationships between
  weather and malaria in different paradigms.
• To find methods for early detection of
  already-emerging infectious disease and impacts
  of long-term climate change.
• To generate data on the impacts of T, RH on
  vector development in vector specific domains.
• To develop predictive models to estimate the
  future burden of malaria and other VBDs under
  projected climate change scenarios.
• To find out the adaptive needs of the society for
  addressing climate change issue
• Evaluation of adaptation options
• .

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• Thanks