Meghnath dhimal

NHRC Government of Nepal NHRC

International Conference on Climate Change

Innovation and

Resilience for Sustainable Livelihood, 12-14 January

2015, Kathmandu, Nepal

Meghnath Dhimal

Chief/Senior Research Officer,

Research Section, NHRC

Email: [email protected]

Early Effects of Climate Change on Public

Health in the Hindu-Kush Himalayan Region- a

Case Study of Vector-borne Diseases

NHRC Government of Nepal

Outline of Presentation

Climate change in Hindukush Himalyan region

Health impacts of climate change

Climate change and vector-borne diseases (VBDs)

Materials and methods

Results and Discussion

Conclusions and way forward

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Climate change in Hindukush

Himalyan region

– The Hindu-Kush Himalayan (HKH) region includes

all areas of Nepal and Bhutan, and the mountainous

areas of Afghanistan, Bangladesh, China, India,

Myanmar and Pakistan (ICIMOD 2011).

– The HKH region is particularly vulnerable to climate

change because the rate of warming in the

Himalayas has been reported to have been much

greater than the global average in the last three

decades (Shrestha et al. 2012, Kulkarni et al. 2013,

Shrestha et al. 1999)

NHRC Government of Nepal

Health impacts of climate change

Climate change affects public health mainly by three

pathways:

(1) direct impacts by increasing the frequency of extreme events such as heat, drought and heavy rainfall,

(2) effects mediated through natural systems such as disease vectors, water-borne diseases and air pollution, and

(3) effects that are heavily mediated by human systems such as occupational impacts, under-nutrition, and psycho-social problems (Confalonieri et al. 2007, IPCC 2014)

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Climate change and Vector-borne

diseases (VBDs)

• “Climate change will altered geographical

distribution of vector-bore diseases and poor

regions of the world will be most vulnerable” (IPCC

AR 4 2007, IPCC AR5 2014)

• Shift of disease vectors and disease transmission

from tropical regions into temperate regions and

highlands has been predicted for both observed and

future climate change scenarios (Chen et al. 2011,

Caminade et al. 2014, Liu-Helmersson et al. 2014,

Siraj et al. 2014).

•

Meghnath Dhimal

NHRC Government of Nepal

• At least six major Vector-borne diseases (VBDs),

namely malaria, lymphatic filariasis, Japanese

encephalitis, visceral leishmaniasis (also known

as kala-azar), chikungunya and dengue fever are

endemic in HKH region

• VBDs are climate sensitive because insect

vectors of these diseases are ectothermic and

hence temperature variation affects vectorial

capacity and extrinsic incubation period of

pathogens

Meghnath Dhimal

Climate change and VBDs

NHRC Government of Nepal Meghnath Dhimal

Basic Reproductive Number (Ro)

Rogers et al. 2006

NHRC Government of Nepal Meghnath Dhimal

Mordecali et al. 2013 ,

Ecology Letters

NHRC Government of Nepal Meghnath Dhimal

Fig.: Temperature dependance of malaria risk

Mordecali et al. 2013,

Ecology Letters

NHRC Government of Nepal

• New cases are reported from new areas and

higher altitudes

• Present and projected climate data shows

conducive environment for the transmission of

VBDs especially in highlands of Nepal

• No application of climatic data for understanding

the VBDs transmission in HKH region

Meghnath Dhimal

Rationale for studying climate

change and VBDs

NHRC Government of Nepal

• Study area: Nepal

• Study design: Longitudinal study

• Data collection: Entomological, Diseases ,

Meteorological and behavioral (Knowledge,

Attitude and Practice)

Meghnath Dhimal

Methodology

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Dhimal et al. 2014 Parsites and Vectors

NHRC Government of Nepal

Methods

• Adult mosquitoes collected using BG-Sentinel

and CDC light traps

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NHRC Government of Nepal

Methods contd…

• Indoor resting mosquitoes collected using

aspirator and flashlight in early morning and

evening

Meghnath Dhimal

NHRC Government of Nepal

Methods contd…

• Outdoor resting Anopheles collected from natural outdoor

shelters

Meghnath Dhimal

NHRC Government of Nepal

Methods…

• Larval collection from potential breeding places

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NHRC Government of Nepal

Some Results

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Results

• The vectors of diseases have already been shifted

at least 2,000 m above sea level (Dhimal et al.,

2014a,b.c, Dhimal et al., PLoS Neglected Tropical

Diseases under review).

Meghnath Dhimal

NHRC Government of Nepal

Results

• Significant relationships between climatic

variables and VBDs and their vectors are found

in short-term studies in Nepal

(Dhimal et al 2014b,d,e)

Meghnath Dhimal

NHRC Government of Nepal

Fig 1. Effects of climatic factors on vector abundance

Dhimal et al. 2014b PLoS Neg Trop Dis

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Fig 2. Effect of mean temperature on malaria incidence

Dhimal et al.2014d Malaria Journal

NHRC Government of Nepal

Results

• Knowledge level for prevention and control of

VBDs such as dengue is very low

(Dhimal et al., 2014f).

Meghnath Dhimal

NHRC Government of Nepal

Discussion

• An expansion of autochthonous cases of VBDs to

non-endemic areas including mountain regions is

also observed in Nepal (Pun et al., 2014, Malla et

al., 2008, Pandey et al., 2008, Pandey et al.,

2004, Zimmerman et al., 1997, Thakur et al.,

2012, Impoinvil et al., 2011, Bhattachan et al.,

2009, Partridge et al., 2007).

Meghnath Dhimal

NHRC Government of Nepal

Discussion

• The spatio-temporal distribution pattern of VBDs

in Nepal is in consistent with findings of other countries of HKH regions such as of Bhutan (Dorji et al. 2009, Wangchuk et al. 2013, Bhatia R et al. 2014, Narain 2008,), India (Aditya et al. 2009, Bhatia R et al. 2014), Pakistan (Narain 2008, Bouma et al. 1996) and China (Li et al. 2011)

Meghnath Dhimal

NHRC Government of Nepal

Conclusion and way forward

• We conclude that climate change can intensify

the risk of VBD epidemics in the fragile and

previously non-endemic areas of HKH region.

• We recommend for a regional collaboration for

risk assessment and then extending and scaling-

up VBDs surveillance and control programs in

HKH region to protect the health of both local

people and mountain tourists.

Meghnath Dhimal

NHRC Government of Nepal

Acknowledgement

Ishan Gautam, Natural History Museum, Swoyambhu,

Kathmandu

MandiraLamichhane Dhimal, Biodiveristy and Climate

Research Centre (BiK-F) and Faculty of Social Sciences,

Goethe University, Frankfurt

Bodo Ahrens, Institute for Atmospheric and Environmental

Sciences (IAU), Goethe University, Frankfurt am Main,

Germany

Ulrich Kuch, Institute of Social Medicine, Occupational

Medicine and Environmental Medicine, Goethe University,

Frankfurt am Main, Germany

Nepal Health Research Council (NHRC), Kathmandu

Meghnath Dhimal

NHRC Government of Nepal

Thank you

Meghnath Dhimal