227.302 Virology Test 1

Front 1

The mainadvantage of using virus isolation over the molecular based diagnostic assays such as PCR is that:
A.Virus isolation is quicker than PCR.
B. Virus isolation is cheaper than PCR.
C. Virus isolation requires less sophisticated equiment and fewer skills than more advanced tests such as PCR.
c.Unlike PCR, virus isolation demonstrates the presence of live virus in the sample.
d.Unlike PCR, virus isolation provides immediate definitive identification of the virus, based upon the type of a cytopathic effect (CPE) produced in cell culture.

Back 1

D
PCR tests for the presence of specific nucleotide sequences while virus isolation tries to grow the live virus.

Front 2

Which of these stages in the viral replication cycle is leastlikely to be targeted by antiviral drugs?
A.Adsorption.
B.Attachment.
C.Uncoating.
D.Synthesis.
E.Release.

Back 2

A
Adsorption consists of the nonspecific binding of virus particles to cell membranes. This stage is not targeted by antivirals because it is nonspecific (you can't really prevent particles from randomly bumping into each other).

Front 3

Viruses posses the following characteristics
A. Viruses contain both DNA and RNA.
B.The viral nucleic acids are enclosed within the nucleus inside the viral particle.
C.The viral nucleic acids are used to generate viral mRNA within the host cell.
D.Viruses contain ribosomes, which are released into the host cell and used for viral protein synthesis.
E.All viruses can be cultured in vitroin the appropriate cell culture system.

Back 3

C
All other choices are false (E could be true). All viral DNA or RNA needs to be converted into mRNA so that the sequence can be read by the host cell.

Front 4

Choose the least correct statement regarding the attachment of the virus to the host cell:
A. Attachment is necessary for viral entry into the cell.
B.Attachment step is one of the important determinants for viral tissue tropism and host range.
C.Attachment relies on specific binding between viral and host proteins.
D.Attachment is immediately followed by penetration of the virus into the host cell.
E.Attachment step cannot be blocked as viruses typically use a wide variety of host receptors for attachment and entry.

Back 4

E
All other choices are true. The attachment step relies on the presence of specific receptors which is why many viruses are species specific.

Front 5

The term "viral virulence" relates to:
A.The ability of the virus to cause disease in its natural host species.
B.The ability of the virus to cause cytopathic effects (CPE) in cell culture.
C.The ability of the virus to cause disease in humans.
D.The ability of the virus to spread systemically and infect a variety of tissues.
E.The ability of the virus of cause disease in a specified host.

Back 5

E
This is the definition of virulence

Front 6

Choose the best answer to finish the sentence: Swabs for virological investigation should be collected...
A.Into a commercially available aerobic bacteriological swab -the medium provided with these swabs is suitable for both viral and bacteriological samples.
B.Into a commercially available anaerobic bacteriological swab -the medium provided with these swabs is suitable for both viral and bacteriological samples.
C.Dry into a sterile container (e.g. red top blood tube), so that any viruses present will not be diluted by the medium.
D.Into a viral transport medium, which contains proteins to stabilize the virus and antibiotics to prevent bacterial growth.
E.Into a sterile EDTA blood tube if the swab contains bloody discharge, so that it won't coagulate during transport to the laboratory.

Back 6

D
Placement into a viral transport medium is the only appropriate collection method for virological investigation.

Front 7

The samples for virological investigation should be transported to the laboratory:
A.As soon as possible, preferably within 24 hours of collection. The samples should be put in a freezer immediately after collection and then thawed when ready for transport. The samples should be transported cold with ice packs.
B.As soon as possible, preferably within 24 hours of collection. The samples should be kept cold, but not frozen after collection and during transport.
C.Within a week of collection, providing they are kept in a fridge.
D.As soon as possible, preferably within 24 hours of collection. If the samples are transported to the laboratory soon after collection there is no need to maintain the cold chain during transport.
E.Any time after collection as long as the samples are maintained in the fridge. If the samples were collected using sterile technique all viruses will survive in the fridge for extended periods of time.

Back 7

B
All other choices are not appropriate

Front 8

Which of the following statements about virus size and complexity is most true?
A.The smallest viruses are smaller than viroids
B.The largest viruses are about as complex as Escherichia coli.
C.The largest viruses can replicate independently of living cells.
D.The smallest viruses consist only of protein.
E.The smallest viruses are larger than prions.

Back 8

E
All other choices are false. A prion can be a single protein in a misfolded form while viruses are composed of multiple proteins (and are therefore larger).

Front 9

Which of the following is least usefulas a basis for classifying viruses into families?
A. DNA or RNA genome.
B.Double-stranded or single-stranded genome.
C.Intranuclear or intracytoplasmic inclusion bodies.
D.Helical, icosahedral, or complex structural symmetry.
E.Enveloped or non-enveloped virions.

Back 9

C
All other choices are characteristics used to classify viruses into families. The use of inclusion bodies to classify viruses into families is less useful as the presence of inclusion bodies may vary below the family level.

Front 10

Which of the following stages in the virus replication cycle is the drug Tamiflu thought to target?
A. Adsorption.
B.Attachment.
C.Uncoating.
D.Synthesis.
E.Release.

Back 10

E
Tamiflu (Oseltamivir) is a neuriminidase inhibitor which slows the spread of influenza virus between cells by preventing the release of viral particles.

Front 11

Soluble CD4 has been used experimentally as an anti-HIV drug and may yet prove useful in veterinary medicine. Which of the following stages in the virus replication cycle is it thought to target?
A. Adsorption.
B.Attachment.
C.Uncoating.
D.Synthesis.
E.Release.

Back 11

B
The attachment stage of HIV may be blocked by CD4 derivaties (i.e. receptor analogues or antagonists).

Front 12

Which of the following is the most commonly and widely used method for the cultivation of mammalian viruses?
A.Organ cultures.
B.Experimental animals.
C.Primary cell cultures.
D.Secondary cell cultures.
E.Continuous cell lines.

Back 12

E
Cultivation in cell cultures is the most commonly used method, continuous cell lines are used for most tissue culturing as they can be passaged indefinitely, these are often derived from neoplastic tissue.

Front 13

A cytopathic effect (CPE) is sometimes observed when cultivating viruses in vitro. Which of the following statements about CPE is least correct?
A. Organ cultures.
B.Dead cells, killed by the virus, tend to look large, angular, and paler than surrounding healthy, uninfected cells.
C.It may take weeks for a CPE to develop. Multiple cell passages may have to be done before CPE can be observed.
D.Some kinds of virus grow very well in cell culture but cause no CPE whatsoever.
E.If CPE develops very rapidly, it may be difficult to distinguish it from cytotoxicity due to a toxic substance in the clinical specimen (i.e., the inoculum).

Back 13

E
All other choices are true.

Front 14

Which of the following are viral non-structural proteins? Choose all correct answers (there may be more than one).
A.Integrase.
B.Reverse transcriptase.
C.Hyaluronidase.
D.Hexokinase.
E.Peplomerase

Back 14

A, B
C is an enzyme involved in fertilisation, D is an enzyme involved in glycolysis, and E does not exist.

Front 15

Which of the following statements about viral structureare true? Choose all correct answers (there may be more than one).
A.Structural symmetry facilitates virion self-assembly.
B.Cubic symmetry is a synonym for icosahedral symmetry.
C.Individual virus families contain viruses of helical or icosahedral symmetry, but not both.
D.Virions with complex symmetry have both helical and icosahedral symmetry.
E.Helical symmetry is a feature of the viral nucleocapsid, not of the envelope.

Back 15

A, B, C, E (maybe)
D is not true as complex symmetry is neither helical or icosahedral.

Front 16

Laboratory results of virus isolation are usually available:
A. Within 24-48 hours. This is how long it takes for viral colonies to become visible on agar plates.
B.Within 2-3 days for positive samples, but it may take up to 1 week for negative samples, as these are typically passaged in the appropriate cells 2-3 times before being reported as negative.
C.Within 1-3 weeks for positive samples, but it may take up to one month or longer for negative samples, as these are typically passaged in the appropriate cells 2-3 times before being reported as negative.
D.Within 24-48 hours, as viruses multiply very fast and typically millions of viruses are produced from one infected cell within hours.
E.Within 1 week for negative samples, but it may take longer for positive samples, as the viruses cultured would have to be further identified.

Back 16

C?
It may take up to 3 weeks for cytopathic effects to become evident. Samples are typically passaged 2-3 times.

Front 17

Which of the following statements about viral genomes is least true?
A.Most DNA virus families have double-stranded genomes
B.Some RNA viruses have segmented genomes, but there are no DNA viruses with segmented genomes.
C.There are no known RNA viruses with circular genomes.
D.DNA virus genomes vary in size much more than do RNA virus genomes.
E.There are no known RNA viruses with double-stranded genomes.

Back 17

C
All other choices are true. Hepatitis D virus is one example of an RNA virus with a circular genome.

Front 18

Antiviral drugs inhibit specific steps in viral replication. TRUE/FALSE

Back 18

TRUE
All antiviral drugs act on one of six viral replication steps (no drugs prevent adsorption).

Front 19

Resistance to antiviral drugs is very rare, as viruses cannot change as rapidly as bacteria. TRUE/FALSE

Back 19

FALSE
Viruses can change much more quickly than bacteria which may lead to antiviral resistance.

Front 20

Enveloped viruses are typically fragile and easily killed outside their hosts. TRUE/FALSE

Back 20

TRUE
Viral envelopes are derived from the membranes of infected host cells, these membranes are not meant to be exposed to the external environment.

Front 21

Killed vaccines are safer and as such, killed vaccines are more commonly used in veterinary medicine than live vaccines. TRUE/FALSE

Back 21

FALSE
Killed vaccines are not necessarily safer as they need to be paired with adjuvants. Live vaccines are cheaper which is often an important consideration in veterinary medicine.

Front 22

A single serum sample positive for antibody to a virus indicates that the animal from which the blood was collected had been recently infected with this virus. TRUE/FALSE

Back 22

FALSE
A single serum sample gives no information about the timing of the infection, it only tells us that the animal was exposed to virus in the past. A fourfold rise in titre between acute and convalescent samples suggests recent infection.

Front 23

A large sheep farm in central Otago has had problems with scabby mouth in lambs each year for the last 4 years. They do not vaccinate against scabby mouth on this farm. The most likely explanation for the recurrent, relatively severe problems on this farm is:
a.Persistently-infected ewes are acting as a source of the virus to new lambs each year.
b.The virus is maintained in a rodent population on this farm and is periodically spread to lambs.
c.Rams are transmitting the virus venereally to ewes and the ewes are passing the infection on to their lambs.
The pastures and food troughs are contaminated with the virus, which is surviving outside each winter
d.An unusually hardy virus variant has evolved on this farm.

Back 23

D
Poxviruses are able to survive for long periods in the external environment.

Front 24

Which of the following viruses typically produce only localised infections without systemic spread:
A. Feline panleukopenia virus.
b.Equid herpesvirus type 1.
c.Canine parvovirus.
d.Orf virus.
E. African swine fever virus.

Back 24

D.
All other choices are capable of producing generalised infection

Front 25

Which of the following viruses infect invertebrate hosts?
A.African swine fever virus.
B.Canine adenovirus type 1.
C.Feline herpesvirus type 1.
D.Orf virus.
E.Porcine circovirus type 2.

Back 25

A
As an arbovirus, African swine fever virus replicates within an invertebrate host (a soft tick).

Front 26

A proliferative lesion in the picture below is characteristic of infection with:
A.Herpesviruses.
B.Adenoviruses.
C.Poxviruses.
D.Circoviruses.
E.Parvoviruses.

Back 26

C
The development of small lesions that balloon and combine to become a large wart-like scab (seen in the picture) is characteristic of poxviruses.

Front 27

In general, poxviruses can use the following portals of entry
A.Faecal-oral route.
B.Skin with compromised integrity (e.g. skin abrasions).
C. Respiratory route (via aerosols).
D.Blood via mechanical vectors.
E.Portals listed in b, c, or d.

Back 27

E
Poxviruses spread mainly through skin abrasions, but also through mechanical vectors (i.e. lice with swinepox) or aerosols (i.e. sheep pox).

Front 28

The fish in the picture below is most likely infected with:
A. A fish herpesvirus.
B. An asfarvirus.
C. A circovirus.
D.An iridovirus.
E. A poxvirus

Back 28

D
Lymphocystis (caused by an iridovirus) causes tumour-like lesions on the skin and fins of fish.

Front 29

You are a veterinarian accompanying a large group of sheep that is being shipped from New Zealand to the Middle East in a vessel that has previously been used for the shipment of sheep in other parts of the world. 28 days into the journey, 20% of these sheep have developed fever, generalised, raised skin lesions, and severe systemic illness. So far, about 25% of affected animals have died or required euthanasia on humane grounds. You suspect a viral infection. The most likely differential diagnosis at this stage is:
A. Generalised orf.
B. Ectromelia.
C. Variola.
D. Contagious ecthyma.
E. Sheep pox.

Back 29

E
These signs are consistent with sheep pox infection. Sheep pox would be expected to cause high mortality in New Zealand sheep and ships used to transport sheep from New Zealand and then return are a potential method of entry into New Zealand for the virus.

Front 30

What kind of vaccine is licensed in New Zealand to prevent Orf?
A. Modified live (i.e., attenuated).
B.Adjuvanted, killed whole virus.
C. Adjuvanted, viral subunit.
D. Live, fully virulent virus.
E. Recombinant avipox virus.

Back 30

D
Orf vaccine consists of a live, fully virulent virus, which is applied to lambs by scarification of the inside of the thigh at 1 and 3 months of age.

Front 31

Which of the following poxviruses has an unusually broad host range?
A. Myxoma virus.
B. Lumpy skin disease virus.
C. Variola virus.
D. Swinepox virus.
E. Cowpox virus.

Back 31

E
Most poxviruses are highly host specific, but cowpox has a broad host range.

Front 32

You are called to investigate a drop in production levels at a local poultry farm. When you arrive, you notice a large number of misshapen eggs, as shown in a picture below. Infection with which virus should be on your list of differentials?
A. Poxvirus.
B. Adenovirus.
C. Parvovirus.
D. Herpesvirus.
E. Circovirus.

Back 32

B
The image shows eggs affected by egg drop syndrome, an adenovirus which causes birds to produce weak or thin-shelled eggs.

Front 33

Which of the following are characteristic features of poxviruses? Choose all correct answers (there may be more than one).
A. Enveloped DNA viruses.
B. Intracytoplasmic replication.
C. Long-term carrier state after recovery.
D. Evolve more rapidly than most other viruses.
E. Complex structural symmetry.

Back 33

A, B, E
C occurs with adenoviruses, D occurs with orthomyxoviruses (influenza). Note that B is unusual for DNA viruses but is a unique characteristic of poxviruses.

Front 34

Which of the following poxviral diseases is notknown to be zoonotic? Choose all correct answers (there may be more than one).
A. Cowpox.
B. Pseudocowpox.
C. Bovine papular stomatitis.
D. Parapoxvirus infection of red deer in New Zealand.
E. Monkeypox.

Back 34

D
All other choices are zoonotic

Front 35

Which of the following is the least important reason why it was possible to eradicate smallpox from the world?
A. ONE (1)stable serotype of the virus exists.
B. Smallpox has a long incubation period.
C. Animal reservoir populations are well characterised.
D. Smallpox is easily diagnosed.
E.The period of infectivity begins after the end of the incubation period.

Back 35

C?
All other choices are true.

Front 36

Which of the following viruses is least resistant to adverse environmental conditions:
A. Canine parvovirus.
B. Equid herpesvirus type 1.
C. Orf virus.
D. African swine fever virus.
E.Bovine papillomavirus.

Back 36

B
Herpesviruses are very fragile in the environment. All other choices are very resistant.

Front 37

Orf virus can be transmitted between susceptible animals via fomites. TRUE/FALSE

Back 37

TRUE
Orf is spread by direct contact and fomites

Front 38

Poxviruses typically cause localized skin infections. TRUE/FALSE

Back 38

TRUE
Poxviruses typically cause skin lesions or "pocks" hence the name poxvirus.

Front 39

Some poxviruses can establish viremia followed by generalized disease. TRUE/FALSE

Back 39

TRUE
Viraemia can occur in several types of poxviruses (i.e. cowpox, sheep pox, fowl pox, etc.)

Front 40

Poxviruses do not survive well in the environment.
TRUE/FALSE

Back 40

FALSE
Poxviruses can survive for years in dust or scabs.

Front 41

Orf virus can infect humans. TRUE/FALSE

Back 41

TRUE
Orf is considered zoonotic

Front 42

Myxomatosis causes severe generalised disease in European rabbits, but only localised benign fibromas in American rabbits. TRUE/FALSE

Back 42

TRUE
Local fibromas occur in American rabbits while severe, generalised disease is seen in European rabbits.

Front 43

Which of the following viruses typically produce only localised infections without systemic spread:
A. Feline panleukopenia virus
B. Equid herpesvirus type 1.
C. Canine parvovirus
D. Orf virus
E. African swine fever virus

Back 43

D
All other choices are capable of producing generalised infection

Front 44

Which of the following viruses infect invertebrate hosts?
A. African swine fever virus
B. Canine adenovirus type 1
C. Feline herpesvirus type 1
D. Orf virus
E. Porcine circovirus type 2

Back 44

A.
As an arbovirus, African swine fever virus replicates within an invertebrate host (a soft tick).

Front 45

Choose the least true statement regarding the African swine fever (ASF) virus:
A. In Africa, the virus is maintained in the wild hog populations without any overt clinical disease.
B. The immune response to the virus is unusual in such there is no production of neutralising antibodies, even in survivors.
C. It causes a highly contagious lethal disease of domestic pigs
D. Recovered animals have long-term resistance to disease, however they remain life-long carriers.
E. It is a fragile virus, which does not survive well outside its host. Direct contact with live infected pigs or ticks is necessary for infection.

Back 45

E
ASF is highly resistant to a wide range of pH (4 to 15) and can survive for months to years in refrigerated meat.

Front 46

The most likely route of entry to New Zealand for African swine fever virus is:
A. Through infected mosquitoes
B. Through infected carrier animals that do not display any clinical signs such as sheep.
C. Through infected, frozen pig meat
D. Through infected ticks
E. Through contaminated farm equipment

Back 46

C
Infected frozen pig meat is the most likely route of entry as ASF can survive for prolonged periods of time in refrigerated/frozen meat.

Front 47

Which of the following statements about African swine fever virus is untrue?
A. It is fragile in the environment, relying on intimate contact for transmission
B. It is the only DNA virus biologically transmitted by arthropods
C. Its natural hosts are wild pigs and ticks.
D. It is not closely related to any other virus of veterinary importance
E. No commercial vaccine is yet available

Back 47

A
All other choices are true. African swine fever virus is highly resistant to a wide range of pH (4 to 15) and can survive for months to years in refrigerated meat.

Front 48

Which of the following viruses is leastresistant to adverse environmental conditions:
A. Canine parvovirus
B. Equid herpesvirus type 1
C. Orf virus
D. African swine fever virus
E. Bovine papillomavirus

Back 48

B
Herpesviruses are very fragile in the environment. All other choices are very resistant

Front 49

African swine fever virus is the only DNA virus that is also an arbovirus. TRUE/FALSE

Back 49

TRUE
African swine fever is the only DNA virus that is also an arbovirus. It replicates within and is transmitted by soft ticks.

Front 50

African swine fever virus is present only in Africa. TRUE/FALSE

Back 50

FALSE
African swine fever can sometimes affect Europe as well as Africa

Front 51

An outbreak of African swine fever virus can be successfully controlled by ring-vaccination. TRUE/FALSE

Back 51

FALSE
No vaccination exists for African swine fever

Front 52

You are called to investigate an abortion "storm" that is occurring in a mob of pregnant mares. On close questioning, you learn that several horses have also been recently showing signs of respiratory disease. You also learn that the "colds" and abortions seem to have started soon after two of the mares had been inseminated with semen from a Standardbred stallion that had not been used by the owners before. Which of the following causes should be on the top of your differential list?
A. Equid herpesvirus type 4
B. Equine arteritis virus
C. Equine adenovirus
D. Equine herpesvirus type 2
E. Equine rhinitis virus

Back 52

B
Herpesviruses can cause abortions as well, but arteritis is often transmitted by semen as male stallions can shed the virus in semen for long periods of time without showing any clinical signs.

Front 53

A kitten with upper respiratory disease is most likelyto be infected with which of the following viruses:
A. Feline immunodeficiency virus
B. Feline herpesvirus
C. Feline coronavirus
D. Feline astrovirus
E. Feline infectious peritonitis virus

Back 53

B
The viruses most commonly associated with feline respiratory disease are feline calicivirus (FCV) and feline herpesvirus-1 (FHV-1). Coronavirus and astrovirus cause diarrhoea in cats. FIV and FIP target immune cells in cats.

Front 54

Choose the least correct statement regarding Pseudorabies:
A. It is caused by Suid herpesvirus type 1
B. In dogs, it presents with clinical signs similar to rabies with incoordination, paralysis and convulsions.
C. Adult swine infected with the Pseudorabies virus typically do not develop severe disease, but may abort.
D. Dogs can become infected via ingestion of infected raw pig meat
E. It is a zoonotic disease

Back 54

E
Pseudorabies can be seen in pigs (reservoir host), cattle, dogs, and cats but does not infect humans.

Front 55

Which of the following viruses is least likely to cause neurologic disease in a horse?
A. Equid herpesvirus type 4
B. Equid herpesvirus type 1
C. Borna disease virus
D. Eastern equine encephalitis virus
E. Feline infectious peritonitis virus

Back 55

E
FIP does not affect horses and even if it did, FIP targets macrophages rather than neural cells

Front 56

Which of the following viruses is leastlikely to cause neurologic disease in a horse?
A. Equid herpesvirus type 1.
B. Borna disease virus
C. Western equine encephalitis virus
D. Equine influenza virus
E. West nile virus

Back 56

D
All other choices cause neurologic disease. Equine influenza typically infects the respiratory tract. Clinical disease causes pyrexia, depression, loss of appetite, a repeated dry cough at rest, and enlarged submandibular lymph nodes but no neurologic signs.

Front 57

Which of the following viruses is leastresistant to adverse environmental conditions:
A. Canine parvovirus
B. Equid herpesvirus type 1
C. Orf virus
D. African swine fever virus
E. Bovine papillomavirus

Back 57

B
Herpesviruses are very fragile in the environment. All other choices are very resistant

Front 58

One of the characteristics common to all herpesviruses is their ability to establish latency in their hosts. Choose the beststatement describing the relationship between the host and a herpesvirus in a latent stage:
A. During latency there is a very limited production of progeny viruses
B. During latency there is no production of progeny viruses, but limited transcription of the viral genome can occur
C. All herpesviruses establish latency exclusively in neural tissues
D. Once the virus enters a latent stage, it can be reactivated only if the host becomes re-infected with the same herpesvirus
E. Vaccination against herpesviruses is typically effective in preventing development of latency

Back 58

B
Latency refers to a state in which the viral genome is present in an animal's body but only a few (if any) genes are transcribed and there is no production of infectious virus.

Front 59

Which of the following viruses typically produce only localised infections without systemic spread:
A. Feline panleukopenia virus
B. Equid herpesvirus type 1
C. Canine parvovirus
D. Orf virus
E. African swine fever virus

Back 59

D
All other choices are capable of producing generalised infection

Front 60

Choose the best option from the following. Herpesviruses:
A. Typically cause a short illness followed by recovery and elimination of the virus
B. Stimulate solid (possibly life-long) immunity. Recovered animals are refractory to subsequent herpesviral infections.
C. Establish a life-long infection in their hosts, with a constant low-level production of infectious virus.
D. Are very resistant in the environment and as such, are easily transmitted by fomites over extended areas.
E. Typically establish a life-long infection due to their ability to become latent

Back 60

E
All other choices are false. Latency is a characteristic feature of herpesviruses

Front 61

You are asked to advise on biosecurity measures to control the spread of respiratory viruses in a cattery. Which of the following statements is least correct?
A. Feline calicivirus and Feline herpesvirus are the two most common respiratory viruses of cats.
B. Both viruses are fragile in the environment and don't survive well outside their hosts.
C. Both viruses can be transmitted by aerosol
D. There are vaccines available for both viruses
E. Asymptomatic infections can occur with both viruses

Back 61

B
Herpesvirus is fragile in the outside environment but Feline Calicivirus is not, it persists in contaminated cages and can be spread by handling of cats

Front 62

Which of the following clinical presentations is least typical of herpesviral infection:
A. Encephalitis
B. Ulcerative skin lesions
C. Abortion
D. Upper respiration disease
E. Pancreatitis

Back 62

E
Herpesviruses induce: respiratory disease, abortion, lymphoproliferative changes, ulcerative skin lesions, and nervous system changes

Front 63

One of the characteristics common to all herpesviruses is their ability to establish latency in their hosts. Choose the least true statement describing the effects of latency on diagnosis and control of herpesviral diseases:
A. Detection of latently infected animals is difficult, as these animals appear clinically normal and are not shedding the virus.
B. Latently infected animals can re-activate the virus when stressed. As such, they can develop herpesvirus-associated disease even if not exposed to a source of an infectious virus (e.g. a clinically sick animal).
C. Latently infected animals can be detected by serological testing, as they are always positive for anti-herpesviral antibody, even though they are not shedding the virus.
D. Latently infected animals are not infectious. However, they do become infectious when they re-activate the virus.
E. Vaccination against herpesviruses is typically ineffective in preventing development of latency.

Back 63

C
Serological testing will not detect a latent virus

Front 64

You are presented with a young parrot that has recently lost some of its feathers. The owner also noticed that the bird's beak looks overgrown and shiny. Infection with what virus is mostconsistent with the above clinical signs?
A. Psitaccine parvovirus
B. Avian papillomavirus
C. Psitaccine beak and feather disease virus
D. Avian adenovirus type 1.
E. Gallid herpesvirus type 2

Back 64

C
Both clinical signs are seen in psitaccine beak and feather disease virus

Front 65

A serum sample from a mare that aborted due to a suspected Equid herpesvirus 1 infection tested positive for EHV-1 antibodies in a virus neutralisation test. Choose the incorrect interpretation of this result:
A. The positive result confirms that the mare aborted due to EHV-1 infection
B. The mare might have aborted due to the EHV-1 infection, but in order to confirm a recent EHV-1 infection a four-fold rise in titre between the acute and convalescent serum samples would have to be demonstrated
C. The positive result indicates that the mare has been likely exposed to EHV-1 at some point in the past, but tells us little about the timing of infection
D. It is possible that the mare has never been infected with EHV-1, as the positive serum titre to EHV-1 may have resulted from either vaccination or infection with an antigenically similar virus EHV-4.
E. The mare has been exposed to either EHV-1 or EHV-4 at some point in the past. These two viruses cannot be distinguished serologically in a neutralisation test.

Back 65

A
The presence of antibodies only suggests that the animal was exposed to the virus (or a vaccine) previously and does not indicate that exposure occurred recently (unless you take two samples and there is a four-fold increase in antibody titre).

Front 66

Which of the following is leasttrue of Malignant catarrhal fever in New Zealand?
A. It occurs sporadically
B. It is caused by Alcelaphine herpesvirus type 1.
C. It features a characteristic vasculitis
D. It is most important in farmed red deer
E. It is epidemiologically linked to contact with sheep

Back 66

B
Alcephaline herpesviruses are associated with Wildebeest in Africa and can result in epidemics of cattle. Ovine herpesvirus 2 causes MCF in New Zealand

Front 67

Which of the following is not a well recognised consequence of equid herpesvirus 1 infection?
A. Abortion
B. Encephalomyelitis
C. Upper respiratory disease
D. Genital mucosal ulcerations
E. Perinatal foal mortality

Back 67

D
All other choices are true, genital mucosal ulcerations are a consequence of Equid herpesvirus 3.