New castle disease outbreak in poultry and its control

Dr. Abdul Rehman

Poultry Research Institute, Rawalpindi

Newcastle diseaseFirst identified in Newcastle in 1926Affects all species of birdsMortality up to 100% in chickensWidespread in Asia, Africa, Europe and South

AmericaIn USA, sporadic Newcastle disease (ND) occur

due to importation of infected birds. In 2002 ND outbreak in California, four million

birds were depopulated and cost the U.S. billions of dollars in damage and lost trade.

In Pakistan V-virulent ND appeared in Nov,2011

Clinical History (NDV) Broilers:

Highest economic losses Affected age is 25-35 days, also observed at 8-14

days Layers:

Maximum losses in rearing age, Also caused high mortalities & production losses in

laying birds Broiler breeders: same as in layers Fancy birds:

High mortalities in peacocks, pheasants and pigeons

Clinical signs Respiratory distress Greenish whitish diarrheaTorticollis Reduction in productionMortality up to 100%

Proventicular hemorrhages.

Caecal tonsils hemorrhages

EnteritisTracheitis

Postmortem lesions

ND Losses in BroilersMonth Mortality

(Mill)Av. Rate/Kg (Rs)

Value (Mill Rs.)

Nov,11 0.86 108.03 92.90

Dec,11 3.68 117.58 432.69

Jan,12 8.60 148.19 1274.40

Feb,12 15.48 151.31 2342.27

Mar,12 15.97 136.00 2171.92

TOTAL 44.59 6314.18

Population under report at PRI Million Month Broiler Layer Breeder Total

Nov,11 2.422 3.594 0.129 6.145

Dec,11 2.312 2.872 0.186 5.369

Jan,12 2.069 2.689 0.239 4.997

Feb,12 2.823 2.570 0.208 5.601

Mar,12 2.739 2.473 0.217 5.233

ND Incidence In Punjab

Newcastle disease virus

Genus Avulavirusin family ParamyxoviridaeThe genome is a single-stranded negative-sense

RNA consisting of 15,186 nucleotidesThe genome contains six genes in the order of 3’-

NP-P-M-F-HN-L-5’The virus is enveloped, roughly spherical, with a

diameter around 100-500nm.F and HN proteins form the external envelope

spikes

NDV isolates

Based on severity of disease, NDV isolates are grouped into three pathotypes:

–Lentogenic strainsCause mild or in-apparent respiratory disease

–Mesogenic strainsCause respiratory or nervous signs with

moderate mortality–Velogenic strains

Cause severe intestinal and/or neurologic disease resulting in high mortality –Neurotropic –Viscerotropic

Biological characterization of virus

Isolation & identification of virus Characterization of virus

Mean death time (less than 50 hrs)ICPI (more than 1.5) This indicates it’s a velogenic New castle disease virus Sequencing of M, HN, F genes F gene nucleotide similarity 97 to 100% M gene nucleotide similarity 98.5 to 100% HN gene nucleotide similarity 99.2 to 100%This indicates mutation and close relation with linage

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Contributing factorsIndiscriminate vaccinationClose proximity of farmImproper biosecurity/ managementImproper disposal of dead birdsMorbid Bird’s marketingInsufficient disease diagnostic facilities

ND Surveillance at PRI(Nov,11 to date)

Total no. of sera samples 18847Total no. of tracheal swab 8646Total no. of cloacal swab 20175Total no. of tissue sample 2350Total sample collected

50018

Sample processing Embryo inoculation Virus isolation HAHIRT-PCR

Results (NDV isolated)

Broilers flocks 33Layer flocks 22Rural flocks 12Broiler breeder flocks 05Fancy bird flocks 07Total isolates 79

Research trial on different vaccine regimes Lasota, Mukteswar (live, killed), Velogenic

killed (oil based) were employedMukteswar killed (oil based) and Velogenic

killed (oil based) vaccines prepared in disease section PRI, Rawalpindi

7 groups was made 6 experimental and one unvaccinated control

Experimental Vaccination schedule Group

No. Day of vaccination

Day 1 Day 10 Day 21 Day 28

1 ND+IB (E/D) Lasota (E/D) Lasota (D/W) Velogenic field strain challenge 2 ND+IB (E/D) Mukteswer Live

(E/D)Lasota (D/W)

3 Mukteswer Killed injection + ND+IB (E/D)

Mukteswer Live (E/D)

Lasota (D/W)

4 Velogenic Killed injection + ND+IB (E/D)

Mukteswer Live (E/D)

Lasota (D/W)

5 ND+IB (E/D) Mukteswer Killed injection + Lasota (E/D)

Lasota (D/W)

6 ND+IB (E/D) Velogenic Killed injection + Lasota (E/D)

Lasota (D/W)

7 No vaccine No vaccine No vaccine

HI titers log2Group No. Age in days

Day 1 Day 9 Day 20 Day 27

Group 1 6.2 3.3 3.4 5.0

Group 2 5.5 3.2 4.4 4.7

Group 3 7.3 3.6 3.2 5.5

Group 4 5.4 2.7 3.7 5.9

Group 5 6.3 4.5 4.4 6.2

Group 6 6.2 3.2 3.5 5.6

Group 7 6.6 3.4 2.0 2.2

Protection after experimental challenge Group No. Total no. of

birds at 28 days

Mortality with in 8 days

Total birds survived

% protection

1 43 10 33 76.74

2 42 09 33 78.57

3 43 7 36 83.72

4 42 7 35 83.33

5 43 7 36 83.72

6 42 3 39 92.85

7 42 41 1 2.3

Results Velogenic killed vaccine at 10th day along with

live lasota vaccine gave maximum protection to 92.85 %

Velogenic killed vaccine at day 1st not proved so well as day 10th

Mukteswer killed vaccine at day 10th also gave significant protection 83.72 %

Mukteswer killed vaccine at day first did not prove as much protective

Mukteswer killed vaccine proved well as compared to live vaccine

Conclusion Homologous vaccine gave better result as

compared to Mukteswer and Lasota vaccinesHomologous vaccine may also reduce virus

shedding during infectionHomologous vaccine along with eradication

program may be helpful in the control of current outbreak

Research findings of various organizationsUVAS

Repeatedly isolated and confirmed presence of ND virus in diseased birds

Killed vaccine prepared from local isolate gives almost 100% protections against the challenge from the field virus

NRLPD Virus is closely related to the Malaysian ND virus isolate Protection study showed that clone killed vaccine

prepared from local isolate gave better protectionVRI

Live and Killed vaccine prepared from Mukteswer proved helpful

RecommendationsStrict biosecurity rules must be implementedProper disposal of dead birdsProper dis-infection between the flocksProper litter disposalIt was unanimous opinion that killed vaccine must be included

in the vaccine scheduleRepeated vaccine should be discouraged (Too many)Vaccine prepared from local isolate should only be used for

experimental purposes and should not be used at commercial level

More study work needs to be done to find out the solution to this problem

Regulatory control in poultry sector Maintain farms proximity Biosecurity/ management Sale/ Disposal of birds

Augment Poultry disease diagnostic facilities

Thanks