Temporal and Spatial trends of Bluetongue in India

Dr. M.Senthil Murugan (Student MVSc. , EDM)Dr. Bhoj R Singh, Principal Scientist (VM)

I/C Epidemiology; Centre for Animal Disease Research and Diagnosis

Indian Veterinary Research Institute, Izatnagar-243122, Bareilly, UP, India. 

TeleFax  +91-581-2302188

Temporal and Spatial distribution

Temporal distribution

distribution of disease in relation to time,

e.g. occurrence of disease incidents in different seasons

Spatial distributiondistribution of

disease in relation to position in space,

e.g. Incidence of disease in specified geographical areas

Saunders Comprehensive Veterinary Dictionary, 3 ed. © 2007

Blue Tongue - Indian Scenario

Endemic in India

22 serotypes are recorded in India out

of 26 serotypes of BTV

Morbidity and mortality – High in

Sheep, low in Goats

Cattle and Buffaloes – Seroprevalence

is evident without clinical disease (Prasad

et.al . 1992)

Major Vectors

MidgesSouth IndiaCuliciodes brevitarsisCulicoides imicola(Ilango et.al 2006)

North IndiaCulicoides oxistomaCulicoides monocoli(Maheswari, 2012)

Vector Breeding placesManure pitsBiogas slurry

wasteIncessant rain in

rainy seasonWind based

movement of midges

Serotypes reported in India

Through Virus Isolation (11)

1,2,3,4,8,9,15,16,17,18,23

Through detection of Neutralising antibodies(11)

5,6,7,10,11,12,13,14,15, 19,20

StateSerotypes

Neutralizing Ab’s

Virus Isolation

J&K - 23

Himachal 4 3,4,9,16,17

Harayana 2,8,12,16 1,4

Rajastan - 1

UP 23 9,8,13

UK - 23

MP 18,23 23

Gujarat 1,2,3,5,8,9,10,11,12,13,15,16,17,20

6

Maharashtra

2,3,4,5,5,7,8,10,12,13,16

1,9,16,18,4,17

Andhra 4,6,12,13,14,17,18,19

2,9,15

Karnataka 1,2,4,12,16,17,20 18,23

TN 1,3,4,5,6,7,11,12,14,15,16,17,19,20

1,2,3,16,23Newer Concepts in Animal Diseases, 2011, IVRI

Blue Tongue Serotypes in India

Srinivasalu ., et al 2004

BT Outbreaks in India

Source: IBVNet, 2005

Incidence of BT, DAHF, Govt of India

2001-

2002

2003-04

2004-05

2006-07

2008-09

2009-10

2010-11

2011-12

2012-13

0

50000

100000

150000

200000

250000

300000

At-tack

2001-2002

2003-04

2004-05

2006-07

2008-09

2009-10

2010-11

2011-12

2012-13

0

200

400

600

800

1000

1200

1400

Outbreak

SeasonalityCyclical occurrenceJune to September

South-western monsoon

October to December North eastern Monsoon

Monsoon leads to High Vector population

Overall Morbidity 9.3%Mortality 2.7%CFR 28.8% (Srinivasalu et.al 2004)

Month wise outbreak in Karnataka( Source: PDADMAS 2010-11)

Higher incidence in

winter months

November and

December

Moist soil after flood

with ideal wind

speed- large scale

breeding of

Culicoides

Prevalence of BTV antibodies in Sheep and Goats

Northern India- Harayana, H.P, J&K, Punjab, Rajastan, UP

Central India– M.PWestern India– Gujarat,

MaharashtraSouthern India– Andhra,

Karnataka, Kerala and T.NNorth Eastern India– No

reports (Prasad et.al 2000)

(Bitew.,et.al, 2013, African J. Biotech)

Seroprevalence in Cattle and Buffaloess

First Reported in Annual Report of

IVRI,1978

3.7% Cattle positive for BTV

23% •Native

71.9% •Exotic

70% •Cattle

37.5 %

•Buffaloes

Punjab Andhra Pradesh

Srinivasalu., et.al 2004

Seroprevalence in Cattle and Buffaloes

Currently Seroprevalence has been (Sub clinical) reported in North Eastern States too.

Joardar SN, et.al Vet.World, 2013Rev.Sci.Tech.Off.Int.Epiz:1992 Prasad

et.al

58.2 %

31.79 %

70 %

Why endemic in India?

22 serotypes reported

Clinical signs not reported in Goat, Cattle, Buffalo

and deer RESERVOIR??

Seroprevalence in Camels, Deers and Elepahant (Prasad

et.al,1992)

Knowledge of fauna & biology of Culicoides spp. is

poorly known in India.

Vaccines – Not very good have Poor immunogenicity Prasad,et.al 1992

Periodic Hyper Endemicities are associated with

MonsoonPoor flock nutritionHigh parasitic burdenLack of affordable veterinary careSheep rearing in poorest areas in

India as major source of incomePoor immunogenicity of the

inactivated vaccines Ilango et.al 2006

How BTV reached India? 1964 – BTV reported in Maharashtra ,U.P –

Movement of infected animals/Vector form Paksitan?

It is probable because India shares long border with Pakistan.

Import of cattle, Sheep and Goat for cross breeding?

1973 – outbreak in Hisar in Russian Merino

1975- outbreak in CSBF, Hisar - Corridale Sheep – Indo Australian project

1974 - outbreak in Dorset breed, Andhra

Srinivasalu et.al 2004

Prasad,et.al 1992

Prevention and Control Effective vaccination may reduce

incidence

Many Countries eradicated BT

and possible in India. (UK 2008)

Restricting animal movement

Insecticide sprays,

Habitat removal - Vector

Timely announcement of satellite

based weather forecasting and

educating sheep farmers

Community Participation

Bhanuprasad., et al 2009

Vaccines in IndiaTechnology

transferred from IVRI, July 2012.

BTV serotypes are 1, 2, 10, 16 and 23

Under All India Network Project on Blue Tongue, ICAR, efforts are concentrated on developing effective vaccine