viral respiratory disease

Respiratory Viral Infection in poultry

MEMBER IN INTERNATIONAL NETWORK FOR POULTRY DEVELOPMENTFAO

FAO IRAQ

Dr. Majed H. Mohammed Ph.D.Virology and Moleculat Cell Biology

majed.mohammed@uod.ac

Conclusions

current study revealed that the presence ofbacterial co-infection (E.coli and MG) with the IB viruscomplicated the disease process and increased the mortality ratein the farms that was approximately 60-75% which caused higheconomic losses.

The comparative analysis of the recent genotypes circulating inSlemani with the IB vaccine strains (Massachuset and 4/91)revealed that these vaccines not able to protect farms from IBVinfection, otherwise using of these live virus vaccine may causemutation and spreading of the virus in the flock.

This study indicates the existence of three IBV genotypes (A; Band C) circulating in Slemani, (genotypes group A and group B),

were respiratory types IBV, which were detected from respiratorytissues of the infected chickens, while (genotype group C) was anephropathogenic type IBV which was detected from kidneys ofthe infected chickens.

According to the comparative analysis in the current study the low nucleotide and amino acid similarities were found between the circulating isolates in Slemani and (H120, MA5) Massachusetts and 4/91 vaccine strains. It has been found that genotype group A is (33- 35%) different from all vaccine strains, genotype group B is (32- 35%) different from all vaccine strains while genotype group C is (20%) different from all vaccine strains. The poor relationship in the partial S1 sequence between the three IBV isolates and the vaccinestrains

Center for Food Security and Public Health, Iowa State University, 2008

Influenza Virus

• Family Orthomyxoviridae– “myxo” means mucus

• Three main types– Type A

• Multiple species

– Type B• Humans

– Type C • Humans and swine

Center for Food Security and Public Health, Iowa State University, 2008

Avian Influenza

• Disease based on genetic features and/or severity of disease in poultry– Low pathogenic AI (LPAI)

• H1 to H16 subtypes

– Highly pathogenic AI (HPAI)• Some H5 or H7 subtypes• LPAI H5 or H7 subtypes can mutate

into HPAI

Center for Food Security and Public Health, Iowa State University, 2008

Avian Influenza

• Incubation period: 3-14 days • Birds found dead• Drop in egg production• Neurological signs• Depression, anorexia,

ruffled feathers• Combs swollen, cyanotic• Conjunctivitis and respiratory signs

Center for Food Security and Public Health, Iowa State University, 2008

Post Mortem Lesions

• Lesions may be absent with sudden death• Severe congestion of the musculature• Dehydration• Subcutaneous edema of head

and neck area

Post Mortem Lesions

• Nasal and oralcavity discharge

• Petechiae onserosal surfaces

• Kidneys severely congested• Severe congestion of the

conjunctivae

Treatment

There is no effective treatment for avian influenza. However, good husbandry, proper nutrition, and broad spectrum antibiotics may reduce losses from secondary infections. It must be remembered that recovered flocks continue to intermittently shed the virus.All buildings should be cleaned and disinfected after an infected flock is removed. The poultry litter or manure should be dung before application to cultivated lands.

Newcastle disease virus

NDV also called (avian paramyxovirus type I,

pneumoencephalitis virus & pseudo-fowl pest).ND is contagious and fatal viral disease affecting

most species of birds (chickens, turkeys, pigeons ,parrots ,ducks, geese, quails)and human.

Taxonomy of the NDV : Family: Paramyxoviridae. Subfamily: Paramyxovirinae. Genus: Avulavirus.

Transmission : Direct contact between healthy birds and the

infected bird discharges. Contaminated feed, water, equipment and

clothing. Virus can be picked up on shoes and clothing and

carried from an infected flock to a healthy one. Airborne spread. Contaminated poultry vaccines. Other animals and birds transporting the virus

from farm to farm.

Incubation period :

It varies from (2 to 15) days in poultry depending on the virulence of the strain.

In chickens infected with velogenic isolates; (2 to 6) days.

In some avian species; 25 days. Pathogenesis : The virus replicates in the mucosa of the upper

respiratory and intestinal tracts. Virus spreads via blood to spleen and bone marrow

(viremia) causing infection of other organs: lung ,intestines & C.N.S.

Clinical Signs and Symptoms : Respiratory symptoms. Nervous signs. Digestive symptoms. Drop in egg production with thin, rough-shelled

eggs. Swelling of tissues around eyes and in the neck. Sudden death. In human;(Mild conjunctivitis, influenza-like

symptoms and laryngitis).

Fig2; Coughing and gasping.

Fig3; Mouth discharges.

Fig4; The bird displays torticollis.

Fig8; Diarrhea with green bile pigment and white urates.

Fig9; Square appearance of the head due to bilateral facial edema.

PM and gross les ions :

Inflammation with Petechial hemorrhages on proventriculus mucosa.

Edematous, hemorrhagic, necrotic, and ulcerative areas on Peyer's patches, caecal tonsils.

Edematous, hemorrhagic, or degenerated ovaries.

Fig13; subconjunctival haemorrhages with external lesions.

Fig14; Odema and hemorrhages in the conjunctiva and infraorbital sinus.

Fig15; Accumulation of mucus in the respiratory tract.

Fig16; Mild haemorrhagic lesions in the mucosa of trachea.

Fig17; Congestion and haemorrhages in the pharynx and

proximal trachea.

Fig18; Sever thymus atrophy with extensive haemorrhages.

Fig19; Inflammation with pinpoint heamorrhagic lesions in the proventriculus mucosa.

Fig20; Necrosis of lymphoid tissue at the caecal tonsils.

Fig21; Extensive haemorrahges and ulcers of caecal tonsils mucosa.

Vaccination

GOODVACCINATION

PROGRAMDESIGN

Basics of Vaccination in PoultryElements of a Vaccination Program

Interval betweenSubsequentVaccinations

Route ofVaccination

Age of theFirst Vaccination

Type ofVaccines

Number ofVaccinations

1. Stimulation & Maintenance of Protective Immunity2. Development of Immunologic Memmory

GOODIMMUNE

RESPONSE

Basics of Vaccination in PoultryRequirements for Good Immune Response

No Immune

Suppression

Healthy Birds

Good Administration

Technique

Correct Vaccination Programme

Good Nutrition Correct Vaccine Storage

Correct Vaccine

No Stress

Newcastle Vaccination

Immunity Against ND