20: astro, hepe, toga, flavi

Question 1

Astroviridae:

- genus

Answer 1

Avastrovirus, Mamastrovirus genus

Question 2

Astroviridae:

• Morphology
• Biological properties
• Antigenic porperties
• Diagnosis

Answer 2

Morphology:
- linear, +ssRNA genome
- ~30nm icosahedral capsid
- non enveloped
Resistance: good (50 °C 60 min, pH3)

Biological properties:

• Baltimore IV.
• stenoxen – host specific
• self-limiting gastroenteritis

Antigenic properties: good antigens

Diagnosis:

• isolation – CPE ø
• IF, AGID, PCR

Question 3

Avastrovirus genus:

Answer 3

(Astroviridae)

• Chicken nephritis
• Duck hepatitis (2), Turkey astroviruses (PEMS)

Question 4

Mamastrovirus genus:

Answer 4

(Astroviridae)

- Bovine-, porcine-, ovine-, feline-, human gastroenteritis

Question 5

Hepeviridae:

- genus

Answer 5

(hepatitis E)

Orhohepevirus, Piscihepevirus genus

Question 6

Hepeviridae:

• Morphology
• Biological properties
• Antigenic porperties
• Diagnosis

Answer 6

Morphology:
- linear, +ssRNA genome
- ~40nm icosahedral capsid
- no envelope
Resistance: good (56 °C 60 min, pH rezistant)
sensitive: cold store (-70 - +8 °C), iodine disinfectants

Biological properties:

• Baltimore IV. – subgenomic mRNS-s
• stenoxen – genetically host specific, but some are zoonotic

Antigenic properties: good antigens

Diagnostics:

• isolation – complicated
• ELISA, RT-PCR

Question 7

Orthohepevirus genus:

Answer 7

(Hepeviridae)
- Orthohepevirus A, C, D
--> Hepatitis E
human, swine, wild boar, rabbit, deer, mongoose, camel
rat, ferret
bat
worldwide
zoonoses, food-safety!

• Orthohepevirus B
• -> Chicken big liver and spleen disease

Question 8

Piscihepevirus genus

Answer 8

(Hepeviridae)

- trout, salmon - orphan(?)

Question 9

Non-assigned hepeviruses:

Answer 9

moose, fox, kestrel, little egret

Question 10

Togaviridae:

- genera

Answer 10

Alpha-, Rubivirus genus

Question 11

Togaviridae:

• Morphology
• Biological properties
• Antigenic porperties
• Diagnosis

Answer 11

Morphology:
- linear, +ssRNA genome
- ~40nm icosahedral capsid
- enveloped – 70 nm
Resistance: weak: 37°C, pH 6-8

Biological properties:

• Baltimore IV.
• CPE ø, HA
• Alphavirus – zoonosis
• -> arboviruses – mosquito transmission

Antigenic properties:

• good antigens
• cross-reactions within genera

Diagnosis:

• clinical signs, IF
• serology: ELISA, IF, VN, HAI

Question 12

Alphavirus genus:

Answer 12

(Togaviridae)
(alpha – group A arboviruses)

• Eastern, Western, Venezuelan equine encephalitis
• -> horse, human – America: CNS signs
• -> bird reservoir, mosquito transmission
• Chikungunya (Africa, India, Indonesia)
• -> human – joint pains, fever, rash, hemorrhage
• O’nyong nyong (Africa)
• -> human – fever, rash
• Ross river fever (Australia, New Guinea, Fiji)
• -> human- fever, arthritis, rash
• Getah virus (South-East Asia)
• -> horse encephalitis (Japan)
• Sindbis virus (Africa, Mediterranean, Scandinavia)
• -> human: Ockelbo, Pogosta disease, Karelian fever
• Semliki forest virus (Africa)

Question 13

Rubivirus genus:

Answer 13

(Togaviridae!, 2019: Matonaviridae!)

Rubella

• -> human – fever, rash
• -> fetopathy: deafness, blindness, mental retardation

Question 14

Flaviviridae:

- genera

Answer 14

Flavi-, Pesti-, Hepaci-, Pegivirus genus

Question 15

Flaviviridae:

• Morphology
• Biological properties
• Antigenic porperties
• Diagnosis

Answer 15

Morphology:
- linear +ssRNA genome
- ~40nm icosahedral capsid
- enveloped – 50 nm
Resistance: weak (37°C, pH 6-8; Pestivirus: pH 3-9)

Biological properties:

• Baltimore IV. – single polyprotein precursor
• CPE: not typical or no, Flavivirus: HA
• Flavivirus:
• -> arboviruses – mosquito or tick
• -> zoonoses! – fever, hemorrhage, rash, encephalitis, hepatitis

Antigenic properties:

• good antigens
• cross reactions within genera

Diagnosis:

• clinical signs, histopathology, IF, PCR
• serology: ELISA, IF, PRNT

Question 16

Flavivirus genus:

Answer 16

(Flaviviridae)

• Tick borne encephalitis viruses (human, goat! – Europe, Asia)
• Louping ill (sheep meningoencephalitis – Europe)
• Yellow fever (human – tropics)
• Dengue fever (1-4) – (human – Asia, Africa)
• Japanese encephalitis (human, swine, horse, cattle – Far East)
• Murray Valley encephalitis (sheep, human – Australia)
• St. Louis encephalitis (horse, human – USA)
• West Nile virus (human, horse, bird – worldwide)
• Usutu virus (Africa, Europe – wild birds)
• Israel turkey encephalomyelitis virus (Israel, South Africa)
• Wesselsbron disease (sheep abortion – Asia, Africa)
• Zika virus – (human – rash, fever, joint pain, microcephalia)

Question 17

Pestivirus genus:

Answer 17

(Flaviviridae)
pest

• Classical swine fever – Hog cholera
• -> swine – haemorrhage, fever – high morbidity and mortality
• Bovine viral diarrhoea (BVD)
• -> calf diarrhoea, immunosuppression, tolerated infections
• -> Mucosal disease (MD) – mucosal erosions, fatal
• -> foetopathy, cerebellar hypoplasia
• Border disease
• -> sheep fetopathy – „hairy shaker” lamb

Question 18

Hepacivirus genus:

Answer 18

(Flaviviridae)

• Hepatitis C virus
• -> human serumhepatitis,
• -> chronic infection, cirrhosis
• „Non-primate hepaciviruses”
• -> Canine hepacivirus
• -> Equine hepacivirus

Question 19

Pegivirus genus:

Answer 19

(Flaviviridae)

• Hepatitis G – human (orphan)
• Horse, bat, chimpanzee, rodent pegiviruses (orphan)