Transcript Health Effect of Climatic Change: Malaysian Senarios

Health Effect of
Climatic Change:
Malaysian Senarios
Dr Rozlan Ishak
Environmental Health Unit
Disease Control Division
Ministry of Health Malaysia
Situations 50 years ago






Malaria was rampant in Malaysia
460,000 cases a year
High mortality and morbidity
Every parts of the country were under malaria
Even the Island of Penang has malaria
Some urban areas were free from malaria
Health problems






Water supply was inadequate.
Hygiene and sanitation was poor
Latrines were lacking in most parts of the
country.
Bucket latrines was the style of the day.
Infectious disease such as cholera, typhoid,
dysentery, worms infestation were very
common.
Dengue is not a problem!
Mosquito borne diseases
50 years later
Malaria
Malaria in Malaysia from 1961 to 2006
600,000
400,000
300,000
malaria
200,000
100,000
0
19
61
19
70
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Number cases
500,000
Years
Dengue Fever
Dengue Fever In Malaysia from 1980 to 2006
45000
40000
30000
25000
Dengue Fever
20000
15000
10000
5000
0
19
75
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
20
03
20
05
Number of Cases
35000
Years
Viral Encephalitis
Viral Encephalitis in Malaysia from 1980 to 2006
350
250
200
150
100
50
Years
Viral Encephalitis
20
06
20
04
20
02
20
00
19
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
0
19
80
Number of Cases
300
Water Borne Diseases
50 years later
Cholera
Cholera incidence in Malaysia from 1980 to 2006
2500
1500
Cholera
1000
500
Years
20
06
20
04
20
02
20
00
19
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
0
19
80
Number of Cases
2000
Dysentery
Dysentery Incidence in Malaysia from 1980 to 2006
1800
1600
1200
1000
Dysentery
800
600
400
200
0
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Number of Cases
1400
Years
Food Poisoning
Food Poisoning incidence in Malaysia from 1980 to 2006
10000
9000
7000
6000
5000
4000
3000
2000
1000
Years
Food Poisoning
20
06
20
04
20
02
20
00
19
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
0
19
80
Number of Cases
8000
Typhoid
Typhoid incidence in Malaysia from 1980 to 2006
3500
2500
2000
Typhoid
1500
1000
500
0
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Number of Cases
3000
Years
Hepatitis (all forms)
Hepatitis (all form) reported in Malaysia from 1980 to 2006
8000
7000
5000
4000
Hepatitis (all form)
3000
2000
1000
0
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
Number of Cases
6000
Years
Climate Change
Facts !
Global Warming
2100
Climate Change
Pathways
Climate change and health: pathway from driving forces,
through exposures to potential health impact.
Modulating
influences
Adaptive
capacity
 Regional
weather
changes
Population
dynamics
Unsustainable
economic
development
 Heatwaves
Mitigation
measures
 Extreme
Greenhouse
gases (GHG)
emissions
Temperature-related
illness and death
Extreme weatherrelated health effects
Mitigative
capacity
Driving
forces
Health effects
CLIMATE
CHANGE
weather
 Temperature
 Precipitation
Natural
causes
Microbial
contamination
pathways
Air pollution-related
health effects
Transmission
dynamics
Water and food-borne
diseases
Agroecosystems,
hydrology
Socioeconomics,
demographics
Vector-borne and
rodent-borne diseases
Effects of food and
water shortages
Mental, nutritional,
infectious and other
health effects
Health-specific
adaptation
measures
Research
needs
Evaluation of
adaptation
Source: Climate Change and Human Health – Risks and Reponses. Summary (WHO, 2003)
Biological Factors
Biologic response to changes in climate



Global warming and wider fluctuation in weather help to
spread diseases
Temperatures – affect growth, development and survival of
microbes and the vectors
Weather affects the timing and intensity of disease outbreaks
(McMichael et al, 2003)
Biologic response to changes in climate:
Infectious diseases

Warmer environment and mosquitoes
 Boost rate of reproduction
 Increase the number of blood meal
 Prolongs their breeding season
 Shorten the maturation period of microbes
they carry

Heavy downpours
 Drive rodents from burrows: risk of zoonotic diseases
 Create mosquito breeding sites
 Faster fungal growth in houses
 Flush pathogens and chemicals into waterways
 Milwaukee’s cryptosporidiosis outbreak in 1993
 Katrina’s flood 2005: water-borne pathogens and
toxins spread.
 Johor flood 2007 and leptospirosis
Common communicabale diseases sensitive to
climate (WHO, 2004)

Climate is the primary factor in epidemic
Cholera, Malaria

Climate plays significant role

Meningococcal meningitis, leishmaniasis,
dengue, Japanese encephalitis, Rift valley fever,
Ross river virus, St. Louis encephalitis, Murray
valley fever
Infection & Climate: Potential impact on endemic
diseases in Malaysia
Disease
Trans-mission Evidence for
inter-annual
variability
Climateepidemic
link
Strength of
climate
sensitivity
Climateepidemic
relationship
quantified
Cholera
Food & waterborne
*****
Increase in
sea & air
temp.
Sanitation
*****
Malaria
Mosquito
*****
Temp. &
rainfall.
Many others
*****
√
Dengue
Mosquito
****
Temp.,
humidity &
rainfall
***
√
√
Temperature, vectorial capacity of Ann. maculatus and projected
number of malaria cases (Ambu et al. 2003)
Temp
(oC)
Esti. Ma
Esti. A
Esti. N
C
VC
27
20
0.043
10
0.069
28
21
0.043
9.9
0.075
29
22
0.043
9.8
0.081
16000
0.25
30
25
0.050
9.7
0.096
31
27
0.050
9.6
0.12
No. Malaria cases
14000
0.2
12000
10000
0.15
8000
0.1
6000
4000
0.05
2000
32
30
0.050
9.5
0.14
33
35
0.050
9.4
0.17
34
40
0.050
9.3
0.20
0
0
27 28 29 30 31 32 33 34
Temp (oC)
No. of cases
Vectorial Capacity (VC)
Rainfall and dengue outbreak in Malaysia





No. days
examined for
1990 rain
Modification of Mogi et al.
model
Study the threshold of rainfall
actually required to trigger an
outbreak
Dengue incidence and rainfall
data in 1986-1997
Model indicated relatively fewer
raining days are required for
high transmission
Heavy rain flushes off breeding
habitats
Low transmission:
no. raining days
required for an
outbreak
High transmission:
no. raining days
required for an
outbreak
30
2.89
0.47
60
4.57
2.15
90
6.25
3.83
120
7.93
5.51
150
9.61
7.19
180
11.29
8.87
210
12.97
10.55
240
14.65
12.33
270
16.33
13.91
300
18.01
15.59
330
19.69
17.27
360
21.37
18.95
Potential Health
Effects from Global
Warming
Year 2100
Malaria Year 2100
Possible Pattern of Malaria in Worst Cases Senario in Malaysia
from Year 1960 to 2100
600,000
400,000
300,000
200,000
100,000
80
20
60
20
45
20
35
20
25
20
15
20
06
20
00
20
90
19
80
19
70
19
61
0
19
Number of Malaria Cases
500,000
Year
Malaria
With Control measures
Without Control measures
Dengue Fever Year 2100
Dengue Fever In Malaysia from Year 1980 to 2100
700000
500000
400000
300000
200000
100000
Years
Dengue Fever
with Control Measures
Without Control Measures
00
21
80
20
70
20
60
20
50
20
45
20
40
20
35
20
30
20
25
20
20
20
15
20
10
20
06
20
05
20
00
20
95
19
90
19
85
19
80
0
19
Number of Cases
600000
What is our plans?
Thank you
[email protected]