13. Haemorrhagic nephritis and enteritis of geese.

Question 1

Virus family and info?

Answer 1

• Family: Polyomaviridae
• 40-55 nm diameter, Icosahedral shape
• Non-enveloped: Very strong resistance, Infectious for month in the environment
• Double stranded, linear DNA genome (5 kbp)
• 5-9 proteins
• 3 structural proteins VP1, VP2 and VP3 (VP1 is the main, sometimes VP4 can be detected)
• Replication associated proteins (T-proteins)
• Use a viral transcriptase
• Good antigens, but hidden, and no cross protection
• Stenoxen (except birds), Oncogene ;(Mainly in mammals,in birds its an acute virus)
• Latent (integration in the chromosome of the cell)
• In tissue culture: microtumor
• Persistent
• Haemagglutination
• 4 genuses ʹ
• alpha: Bat, monkey, human
• beta : Human, monkey seal, elephant, rodent
• gamma: birds
• delta: human
• Polyomavirus: different signs in animals
• Mouse (wild): Persistent in the kidney
• House mouse: Multiplex tumor
• Hamster: Epithelial tumor in hair follicules
• Rat: Parotid tumor
• Rabbit: Vacuolization in the kidney epithelia
• Cattle: Persistent in the kidney
• Monkey: Persistent in the kidney and lymphoid cells
• Human: Persistent, in case of immunosuppression: leukoencephalopathy, nephropathy,
• haemorrhagic cystitis and tumor

Question 2

HNEG occurrence and epidemiology?

Answer 2

Haemorrhagic nephritis enteritis of geese (HNEG)

• 1969: Hungary

• Spread with Derzsy hyperimmune sera
• Later in Germany, Southern France and spread further
• 2000: goose haemorrhagic polyomavirus (GHPV)
• Isolation: embryonate eggs chorio allantois-membranes and goose primer kidney epithelial cells
• Cytopathic: graininess and vesicles
• Haemaggluttination: chicken red blood cells
• Duck can be seropositive, carrier
• Muscovy duck, hybrids and wild goose susceptible but remain symptomless with high virus titres

Question 3

Pathogenesis?

Answer 3

Pathogenesis (same like PARVO)

1. Intake: per os, intranasal ➝ direct contact, infected food, water
2. Replication: lymphoid tissues around throat (dividing cells)
3. Viraemia: virus replication in blood endothelium, bursa, kidney and intestinal epithelium, B cells
4. Virus shedding in faeces and urine

• Germinative infection has not been demonstrated
• After infection can give yolk immunity
• After infection can stay persistent carrier
• Vertical and horizontal transmission

Question 4

Clinical signs?

Answer 4

Clinical signs

• Mainly 3-10 weeks old
• Incubation period: 6-7 days
• Clinical signs appear few hours before death
• Shaking of neck and head, lethargy, diarrhoea and coma
• Mortality depends on age (4-67%) but can be 100% in goslings
• Chronic cases ➝ uric acid crystals
• Elderly shed the virus without symptoms

Question 5

Pathology?

Answer 5

Pathology: similar to derzsy

• Oedema of tissues under the skin
• Ascites
• Haemorrhagic nephritis and necrosis in tubular epithelia ➝ low levels of replication, consequence of blood endothelium necrosis
• Gout
• Hepatitis serosa
• Necrotising haemorrhagic enteritis
• Haemorrhages around the body (also in the brain)

Question 6

Histopathology?

Answer 6

Histopathology

• Interstitial nephritis
• Epithelial necrosis in the kidney
• Necrotizing enteritis
• Liver cell-degeneration and hepatitis

Question 7

Diagnosis and differential diagnosis?

Answer 7

Diagnosis

• Virus detection: Kidney, liver, spleen
• IF, (EM,) PCR
• (Isolation is not easy ʹ can do in embryonated egg/ Choroallantois membrane which is not easy which
• is why we prefer PCR or IF)
• Serology: ELISA, HAG, Sera

Differential diagnosis:

1. Derzsy
2. Circovirus
3. (Marek, NDV, influenza)

Question 8

Prevention?

Answer 8

Prevention

• Epidemiology
• Vaccine (inactivated BFDV)
• Farm-specific vaccine to breeders
• Subunit vaccine (VP1)
• Protocol of using the vaccine
• Before hatching: 2 and 6 weeks before
• Breeders: 3 weeks old and 6 weeks old