Topic 40 - Diseases of farm animals caused by hepatitis E virus

Question 1

Causative agent of hepatitis E

Answer 1

Hepevirus
Family: orthohepevirus A

Question 2

What is very special about clinical signs in case of hepatitis E?

Answer 2

Animals maintain the virus, BUT NO clinical signs.

There is ONLY clinical signs in humans

Question 3

Are hepatitis E enveloped or non-enveloped?

Answer 3

Non-enveloped = good resistance

Question 4

Is hepatitis E a DNA or RNA virus?

Answer 4

RNA virus

Question 5

How to remove hepatitis E from the food?

Answer 5

Boil at 70 °C for 5 min

The virus cannot handle freezing, but this cannot be done in food, as it is not 100% proven

Question 6

Is hepatitis E stenoxen or Euryxen?

Answer 6

Stenoxen, narrow host range
It is species specific

Question 7

Have hepatis E good or bad antigenicity?

Answer 7

Good. Long lasting immunity after infection

Question 8

Laboratory diagnostic tool for hepatitis E:

Answer 8

1st choice :RT-PCR

Question 9

What does RT-PCR stand for?

Answer 9

Reverse Transcription Polymerase Chain Reaction

Question 10

Treatment for hepatitis E:

Answer 10

There is no treatment in case of animals

Humans: supportive care

Question 11

Prevention of hepatitis E:

Answer 11

1. Good hygiene in stable/farm

Question 12

How long does maternal antibodies work in pigs, and at which age is it common to become infected with hepatitis E?

Answer 12

They last until 12 weeks of age, and they are slaughtered at 24 weeks. Gives the virus 3 months to rule

Question 13

How long does maternal antibodies work in rabbits, and at which age is it common to become infected?

Answer 13

They last until 9 weeks of age, and they are slaughtered at 11 weeks. Gives the virus 2 weeks to rule

Question 14

Why is hepatitis E important?

Answer 14

Because it is zoonotic, and there are no significant epidemiological rules applied - because it is a disease not many know of

Question 15

Name a hepatitis disease in chickens:

Answer 15

Chicken big liver and spleen disease

Question 16

Causative agent of Chicken big liver and spleen disease:

Answer 16

Avihepevirus magniiecur

Magniiecur = enlarged liver

Question 17

Susceptible species + age of Chicken big liver and spleen disease:

Answer 17

Chickens over 24 weeks of age

Question 18

Infection route of Chicken big liver and spleen disease:

Answer 18

Per os, through faecal contamination of drinking water

Question 19

Pathogenesis of Chicken big liver and spleen disease:

Answer 19

We have a primary virus replication, then the viraemia takes the virus to the liver and spleen where there is another round of virus replication and we see damages to the liver and spleen as clinical signs and pathological lesions.

Question 20

Site of first virus replication for chicken big liver and spleen disease:

Answer 20

in the intestines

Question 21

How is Chicken big liver and spleen virus shed?

Answer 21

Via faeces

Question 22

Clinical signs of Chicken big liver and spleen disease:

Answer 22

They are not very characteristic. We might see egg drop of 20%, anaemia, premature molting

When other disease are excluded, hepavirus might be considered because the clinical signs are not characteristic

Question 23

Mortality rate of Chicken big liver and spleen disease:

Answer 23

very low. 1% for the first 3-4 weeks, after only 0.25%

Question 24

Pathological lesions in case of Chicken big liver and spleen disease

Answer 24

1. Enlarged liver, with haemorrhages
2. Enlarged spleen
3. Ovarian regression which causes the egg production to decrease

Question 25

Laboratory diagnostics in case of Chicken big liver and spleen disease:

Answer 25

RT-PCR

Serological test can be done to see if the virus is endemic in a flock

Question 26

Treatment of Chicken big liver and spleen disease:

Answer 26

Not an option, but we might try supportive care

Question 27

Prevention measures in case of Chicken big liver and spleen disease:

Answer 27

Prevention is the most important measure!!

1. General epidemiological rules: disinfection, separation of age groups, all-in-all-out
2. Good hygiene, especially of the drinking water