burden of vector borne diseases past, present & future

Burden of Vector Borne Diseases

Dr. Pradip AwateState Surveillance Officer, IDSP,

Maharashtra

Bharati Vidyapith CME 3 AUG 14

Fossil Mosquito

Almost 30 million years old found in geologic strataBharati Vidyapith CME 3 AUG 14

Vector Borne Diseases• Vectors are organisms that transmit pathogens and

parasites from one infected person (or animal) toanother.

• Commonly found in tropical and sub-tropical regions.• Over half the world's population is at risk from vector-borne

diseases such as malaria and dengue.• Vector-borne diseases account for 17% of the estimated

global burden of all infectious diseases.• The most deadly vector-borne disease, malaria.• The world's fastest growing vector-borne disease is

dengue.


VECTOR BORNE

DISEASES

VECTOR BORNE

DISEASES

MalariaMalaria

DengueDengue

ChikungunyaChikungunya

FilariasisFilariasis

Japanese Encephalitis

Japanese Encephalitis

ChandipuraEncephalitisChandipuraEncephalitis

Kala AzarKala AzarCongo Cremean

Hemorrhagic Fever

Congo Cremean

Hemorrhagic Fever

ChagasDiseaseChagasDisease

Trypanosomiasis

Trypanosomiasis

Yellow FeverYellow Fever

Lyme Disease

Lyme Disease

PlaguePlague

DracunculosisDracunculosis


Important VBDs with respect to IndiaSr. No VBD Responsible Vector

1 Malaria Anopheles

2 Dengue Aedes aegypti and Aedes albopictus

3 Chikungunya Aedes aegypti and Aedes albopictus

4 Japanese Encephalitis

Culex tritaeniorhynchus, Culex vishnuiand Culex pseudovishnui

5 ChandipuraEncephalitis & Kala

Azar

Sandfly (genus Phlebotomus )

6 Filariasis Culex quinquefasciatus and Mansonia annulifera/M.uniformis


Malaria


जो जीता वह सकंदर• Alexander the Great was killed by malaria at

the height of his power.• After virtually conquering the entire known

world.• He had set out to subjugate the earth but just

as he was to depart with his army in earlyJune 323 B.C., he contracted Malaria and thevoyage was postponed.

• Malaria, by striking Alexander, had altered thecourse of history.

• Had the military leader survived, he mightwell have succeeded in uniting east and west,fusing Greeks and Asians into a single nation.


Global Malaria Scenario

• In 2010 - 216 million cases of Malaria globally.• 91% - Pf cases.• 81 % from African region.• 13 % from South East Asia Region.• Total Malarial Deaths - - 6,55,000. ( 3% SE

Asia)• Under 5 mortality – 7% deaths due to Malaria


Malaria estimates in Pre-control era

It was estimated in 1947 that out of a population of 340 million in the country, annual malaria incidence was 75 million (nearly 22% of population) with 0.8 million deaths

Epidemics at an interval of 5 to 7 years Economic loss due to malaria to the nation was

estimated at Rs. 7500 crores annually in 1940(Rupee value of the reporting year)


Malaria Epidemics in Pre Independent India

Year Area Affected Deaths

1852Malaria epidemic wiped out the entire village of Ula and then spread

across the Bhagirathi River to Hooghly and continued to devastate populations for many years in Burdwan

1892 Punjab 2,83,223

1900Punjab

Ludhiana, Amballa, Karnal, Gurdaspur & Raya

2,54,580

1908 Punjab - Amristar, Delhi, Palwal, Miani,Gugarat 3,07,316

1920

Bengal

7,30,000

1943 6,80,000

1944 7,63,220Bharati Vidyapith CME 3 AUG 14

3.29

2.07

1.681.36 1.36 1.37

1.1

1995 2000 2005 2008 2009 2010 2011

API

1.56 1.6

1.311.09

0.88

2009 2010 2011 2012 2013

Malaria Cases(Figures in Millions)

Indian Situation

• 27 % Population living in high transmission areas.• 50 % Pf cases • 1000 + deaths every year

• 92 % cases & 97 % deaths are from •NEstates, Chhatisgarh,Jharkhand, MP, Orissa, AP, Maharashtra, Gujarat, Rajasthan,WB & Karnataka


MALARIA ENDEMIC AREA OF THE STATE

API less than 1 API 1 -5 API more than 5

Bharati Vidyapith CME 3 AU

G 14

POST GLOBALIZATION MALARIA

Malaria in the 1990s, presented new features which were not commonly seen before, namely,

Vector resistance to insecticides; pronounced exophilic behaviour of vectors;extensive breeding sites created by development projects, urbanization and industrialization;change in parasite equation in favour of P.falciparumandresistance of P. falciparum to chloroquine and other antimalarial drugs


MALARIA IN MAHARASHTRA 2006-2013

5442067849 67333

93818

139198

96577

58499

43676

133

182

148

227

200118

9680

0

50

100

150

200

250

0

20000

40000

60000

80000

100000

120000

140000

160000

2006 2007 2008 2009 2010 2011 2012 2013

Cases Death


G 14

Dengue


Global Dengue Scenario• World's fastest growing vector-borne disease is dengue, with a 30-fold

increase in disease incidence over the last 50 years.• Over 2.5 billion people – over 40% of the world's population – are now at

risk from dengue.• WHO currently estimates there may be 50–100 million dengue infections

worldwide every year. • Before 1970, only nine countries had experienced severe dengue

epidemics. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific.

• The American, South-east Asia and the Western Pacific regions are the most seriously affected.

• Foot Prints of Dengue in new areas –2010 – First time in France & Croatia2012 – Portugal2013 – Florida (US)

• An estimated 500 000 people with severe dengue require hospitalization each year, a large proportion of whom are children.

• About 2.5% of those affected die.


Determinants of Dengue

Rise

Unplanned Urbanization

Substandard Housing

Inadequate Water Supply

Inadequate Solid Waste & Sewerage

System Increased Population

Density

International trade

(Used tires)

Rapid population movement

Traditional water

storage


G 14

DISTRIBUTION OF GLOBAL DENGUE RISK

High suitability

Low suitabilityUnsuitable or non endemic

75% of the global population exposed to Dengue lives in Asia Pacific region.


G 14

WHEN DENGUE LEADS TOHAVOC…….

Jan – April 2008 1,58,000 Dengue Cases 9000 Admissions 230 deaths Military deployed for

vector control Call for International

aid US $ 1 billion spent. 2010- 1.2 million cases

Dengue major emerging disease in Saudi Arabia, Yemen & Pakistan.

Frequent OBs in urban areas

In 2011 – 300 deaths in Lahore city alone.

Rio De Janerio - Brazil Lahore - Pakistan


G 14

Dengue In India

12561 15535 28292 18860 50222 75454

8096 110

169

301277

0

50

100

150

200

250

300

350

0

10000

20000

30000

40000

50000

60000

70000

80000

2008 2009 2010 2011 2012 2013

Cases Deaths

• 31 States/UTs are Dengue endemic.• All 4 serotypes isolated from India. • DENV-1 & DENV-2 are prevalent.


DENGUE IN MAHARASHTRA

618 743

2255

15741138

4305

5432

24 22 209

25

118

138

0

20

40

60

80

100

120

140

160

0

1000

2000

3000

4000

5000

6000

Yr 2007 Yr 2008 Yr 2009 Yr 2010 Yr 2011 Yr 2012 Yr 2013

Cases Deaths


G 14

8

4

1

10

2

2

2

10

2

3

7

13

12

3

88

42

27

4

2

Dengue Deaths from Rural Maharashtra 2013


Filariasis


HISTORY

6th Century – Susrut recorded Filaria in his ‘Susrut Samhita’ .

7th Century - Madhavkara described signs & symptoms of Filaria in his ‘ Madhava Nidhana’

1709 – Clarke called elephantoidlegs in Cochin as ‘ Malbar Legs’.

Lewis – Discovery of microfilariae in peripheral blood in Kolkata ( 1872).


G 14

LF – GLOBAL BURDEN

World’s second leading cause of long term debility.

LF doesn’t kill but – causes debility imposes severe social & economical burden Destroys marriages & family relationships. Cause & effect of poverty

o 120 million people from 83 countries infected with LF.

o 1/5 World population at risk.o 70 % Infection world wide is from

India, Nigeria, Bangladesh & Indonesia.


G 14

LF - INDIA

20 States250 districts600 million population is at risk. 2010 Survey – 8 Lac cases of Elephantiasis & 4 Lac cases of Hydrocele in India.


G 14

MAHARASHTRA FILARIA SITUATION

Elephantiasis – 43,987Hydrocele - - 28,975Total - 72,968

In Maharashtra, 17 districts are endemic for LF.


G 14

2.86

1.431.23 1.13

0.44 0.46 0.51 0.54 0.43

Maharashtra Mf Rate

1.241.02 0.98

0.64 0.530.65

0.41 0.37 0.410.27

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

India Mf rate

Elimination of Filarisis by 2015

Mass Drug Administration is core strategy to achieve it.

•In Nalganda district of AP,Mf rate is reduced from 17 (2004) to 0.8 in 2009.• 192 out of 250 endemic districts are having below 1 Mf rate in 2011. Bharati Vidyapith CM

E 3 AUG

14

Chikungunya

• Chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952.

• Kolkata outbreak – 1963-64• Chennai Outbreak – 1965 – 3

Lac cases in Chennai City alone.• Return of Chikungunya after 41

years – 16 states involved – 1.39 million cases reported. ( Attack Rate – 45% in some areas)

The name ‘chikungunya’ derives from a word inthe Kimakondelanguage,meaning "to becomecontorted" anddescribes thestooped appearance of sufferers with joint pain


95091

73288

48176

2040215977 18639

2008 2009 2010 2011 2012 2013

Chikungunya Cases In India


Japanese Encephalitis• Japanese encephalitis (JE) is a flavivirus related to

dengue, yellow fever and West Nile viruses, and isspread by mosquitoes.

• JE is the main cause of viral encephalitis in manycountries of Asia with nearly 68 000 clinical casesevery year.

• The case-fatality rate 30%.• Permanent neurologic or psychiatric sequelae can

occur in 30%–50% of those with encephalitis.• 24 countries in the WHO South-East Asia and

Western Pacific regions have endemic JEtransmission, exposing more than 3 billion peopleto risks of infection.


India – JE+ AES Situation

4292

5628 5722

9463 9089 8911

754 882 7911350 1396 1475

2008 2009 2010 2011 2012 2013

Cases Deaths


YEARJE CHANDIPURA AES TOTAL

Cases Deaths Cases Deaths Cases Deaths Cases Deaths

2007 2 0 0 0 0 0 2 0

2008 1 0 4 3 24 13 29 16

2009 8 0 52 15 36 15 96 30

2010 7 1 50 16 29 16 86 33

2011 13 0 11 3 13 11 37 14

2012 11 0 20 1 41 26 72 27

2013 -- -- -- -- 5 5 5 5

Maharashtra – JE, Chandipura & AES Situation


What lies ahead ?

? ?Opportunities Risks

Human Ecology

GlobalizationDemography


Increased Temperature

Rate of blood meal digestion increases

Acceleration the ovarian development & egg- laying

Reduction in duration of the gonotrophic cycle

More frequency of feeding on hosts

Increasing the probability of transmission

•By 2100 it is estimated that average global temperatures will have risen by 1.0–3.50 C.

•This will increase likelihood of many vector-borne diseases in new areas.

What Climate Change will lead to ?


Increased International Travel


Will Yellow Fever Come to India ?• India – Yellow Fever ‘receptive’ area.• Vector – aedes aegypti is found in

abundance.• Climatic condition – favourable• Common monkey in India (

Macacus spp) – susceptible to Yellow Fever

• Missing link is --- Chain of transmission…

• An infected traveler OR mosquito ???


New Research…… New Hope…..Bharati Vidyapith CME 3 AUG 14

No one in the 21st

century should diefrom the bite of a mosquito, a sand fly,a black fly or a tick.

Margaret Chan Director General

World Health Orgnization


burden of vector borne diseases past, present & future

Healthcare