1. Olds (2nd exam)

Question 1

In the Philippines, how is African swine fever mostly spread from pig to pig?

Answer 1

Mostly spread via truck drivers that go farm-to-farm to buy pigs.

Additionally:
1) direct contact
2) infected meat (swill)
3) indirect contact (fomites).

Question 2

Define SMEDI.

Answer 2

Stillbirth
Mummification
Embryonic Death
Infertility

Question 3

Rank all of the enveloped DNA (sally) virus families according to genome size

[ PIAHH ]

Answer 3

DNA Enveloped

1. Pox (130-375)
2. Irido (135-503)
3. Asfar (170-190)
4. Herpes (125-240)
5. Hepadna (3-4)

Question 4

Rank all of the naked DNA virus families according to genome size

[ APP CP ]
app cellphone

Answer 4

DNA Naked

1. Adeno (26-45)
2. Papilloma (7-8)
3. Polyoma (5)
4. Parvo (4-6)
5. Circo (2)

Question 5

Rank all of the enveloped RNA virus families according to genome size

[ CF PAR FR ]
cafe para for real

Answer 5

RNA Enveloped

1. Corona (31-38)
2. Filo (19)
3. Paramyxo (13-18)
4. Arteri (13-16)
5. Rhabdo (11-15)
6. Flavi (10-12)
7. Retro (7-13)

Question 6

Rank all of the naked RNA virus families according to genome size

[ R PCAB ]

Answer 6

RNA Naked

1. Reo (19-32)
   2. Picorna (7-9)
   3. Calici (7-8)
2. Astro (6-7)
   5. Birna (5-6)

Question 7

Give 3 reasons why CPV2 spread very fast all over the world in 1978.

Answer 7

1) High viral shedding due to efficient feco-oral transmission – dogs shed up to 10^7 virus particles per gram of feces

2) Low minimum infectious dose near universal susceptibility of dog populations worldwide – only 10 virus particles needed to infect another dog.

3) Extremely resistant in the environment or virus stability due to being a naked virus.

CPV2 was first recognized in 1978, making it a new disease. Therefore, vaccines are not yet
available and proper treatment/control is not yet discovered/studied.

Question 8

Why do geldings and foals (before 6 months of age) not become carriers when they are infected by EVA (Equine Viral Arteritis)?

Gelding = castrated male horse

Answer 8

Carrier status is testosterone-dependent, and geldings and foals have very low or undetectable testosterone levels.

Question 9

Explain the unique replication strategy of viruses under Order Nidovirales.

Answer 9

Production of nested set of 3’ co-terminal subgenomic mRNAs

(basta ang nasa 5’ end ay non-structural proteins tapos nasa 3’ end puro structural proteins)

ILLUSTRATE

Question 10

Draw and describe why parvoviruses cause more severe enteric infections than coronaviruses.

Answer 10

Parvoviruses attack the intestinal crypts, which is more destructive since enterocytes arise from these crypts.

Coronaviruses attack the intestinal villi, which can be replenished since enterocytes from the crypts are continuously pushed upwards for cell turnover.

Question 11

Describe the unique morphological structures of the following viruses: (a) Poxvirus
(b) Coronavirus
(c) Rhabdovirus
(d) Filoviruses

Answer 11

(a) Pox = brick-shaped
(b) Corona = crown-like
(c) Rhabdo = bullet-shaped
(d) Filo = long, filamentous, branched, U-shaped, 6-shaped, circular

Question 12

What were the events leading up to Edward Jenner’s creation of the world’s first successful vaccine?

Answer 12

Edward Jenner noticed that milkmaids do not get sick by smallpox AND discovered that cows suffered from cowpox

He is also first to describe canine distemper & vaccine for pox.

Question 13

Give 3 general clinical signs of FIP (Feline infectious Peritonitis).

Answer 13

1. Progressive abdominal distention
2. Anorexia
3. Chronic fever
4. Malaise
5. Weight loss
6. Inverted letter D-shaped pupil due to infiltration of the iris

Question 14

Maternal antibodies protect against disease, but not against subclinical infections. T or F?

Answer 14

TRUE

Maternal Ab from colostrum (milk) of mother
- Day 1-2: bloodstream & gut
- Day 3 onwards: gut only

Question 15

Explain Coggin’s test

Answer 15

Coggin’s Test is used to diagnose Equine Infectious Anemia/ Swamp Fever

+: presence of Ab➡️Ab binds to Ag➡️immunoprecipitation (line)

-: no Ab

Question 16

(A) Explain how the nasal turbinates of swine act as physical/physiological barriers against viruses,

(B) and give 2 pathogens that may damage these turbinates.

Answer 16

Bordetella bronchiseptica and Pseudorabies destroy the turbinate of the nose of the pig.

Unwanted pathogens and particles get swirled in the turbinate and sticks to the nasal mucous to prevent them from entering the body, upon infection with Bordetella bronchiseptica, these turbinates get destroyed, and the pathogens when inhaled just come right in.

Question 17

List down the steps of a typical viral replication cycle.

[ AEU PACR ]

Answer 17

1. Attachment
2. Entry
3. Uncoating
4. Production of viral protein and nucleic acid
5. Assembly
6. Cell death/lysis
7. Release