Virology
Which of the following statements about Porcine parvovirus (PPV) is least correct?
Abortions due to PPV are usually accompanied by enteritis and upper respiratory disease in pregnant sows.
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. Infection with which virus should be on your list of differentials?
Adenovirus
Which of these stages in the viral replication cycle is least likely to be targeted by antiviral drugs?
Adsorption
Which of the following viruses infect invertebrate hosts?
African swine fever virus
You are working as a small animal veterinarian and have seen several cases of canine parvovirus disease over the past two months. You are concerned about the efficacy of your puppy vaccination schedule and decide to test sera from several of your client's dogs for antibodies against Canine parovirus type 2 (CPV-2). The following results come back from the laboratory: CPV-2 haemagglutination inhibition (HI) titres: Dog 1 - 160 Dog 2 - 5000 Dog 3 -320 Dog 4 - 40
All dogs can be considered protected against infection with CPV-2 as all dogs have anti-CPV-2 antibodies
Infection of a non-immune, pregnant cow with Bovine viral diarrhoea virus between 180 and 190 days post-conception would be most likely to lead to which of the following consequences?
An antibody positive, virus-free, normal calf is born.
A fish with lots of wart like masses all over it is most likely infected with:
An iridovirus.
d. Evolve more rapidly than most other viruses.
Animal reservoir populations are well characterised
Which of the following statements about antigenic change in influenza A viruses is least true?
Antigenic drift d. leads to a rapid change in a subtype
Which of the following statements about antigenic change in influenza A viruses is least true?
Antigenic drift occurs as a result of reassortment of the 8 segments in the virus genome.
Retroviruses:
Are easily inactivated by common disinfectants and do not survive well outside the host.
The samples for virological investigation should be transported to the laboratory:
As soon as possible, preferably within 24 hours of collection. The samples should be kept cold, but not frozen after collection and during transport.
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?
Attachment
Choose the least correct statement regarding the attachment of the virus to the host cell:
Attachment step cannot be blocked as viruses typically use a wide variety of host receptors for attachment and entry.
You are working as an aid veterinarian in a developing country and are bitten by a 3-month-old puppy brought by its owners for its free rabies vaccination. What would be the best way to deal with this accident?
Because of the possibility of rabies exposure, you had been vaccinated against rabies before you went on the aid trip. The puppy is young, so unlikely to haverabies, as rabies typically has a long incubation period. As such, you clean the bite, vaccinate the puppy and forget about the incident.
Infection with the Bovine viral diarrhoea (BVD) virus at around two months of gestation is most likely to result in:
Birth of a persistently infected calf, which may occasionally clear the virus in the first few months of life.
The picture below shows a horse that presented with sudden onset of severe neurological signs. The horse is unable to stand and has to be supported in a sling. Which of the viral infections is unlikely to be the causative agent of this horse's problems?
Borna disease virus
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?
Both viruses are fragile in the environment and don't survive well outside their hosts.
Which of the following statements about Bovine parainfluenza type 3 (BPiV-3) virus is least true?
Bovine PI-3 virus infection provokes a strong, long-lasting immune response in both sheep and cattle.
Which of the following viruses is least likely to cause abortion or congenital defects in cattle:
Bovine coronavirus
You are called to help with an outbreak of diarrhoea in a mob of 1-week old calves. The calves are depressed, dehydrated and show watery yellow diarrhoea. Older animals seem unaffected. The majority of calves recover in about 4-5 days, but there are some mortalities. Which viral agents are most likely to be involved in this outbreak?
Bovine coronavirus or rotavirus
Which of the following viruses is least likely to cause abortion or congenital defects in cattle
Bovine coronavirus.
Abortion is the least common clinical presentation of infection with
Bovine immunodeficiency virus.
Abortion is the least common clinical presentation of infection with:
Bovine immunodeficiency virus.
You are called to examine several young cattle with severe papillomatosis. The farmer would like to know whether or not he can use a vaccine to prevent warts in his cattle. Choose the best answer.
Bovine papillomatosis is typically a self-limiting disease. Efficacy of any vaccination has been difficult to prove. There are no commercially available vaccines against Bovine papillomaviruses.
a cow has ulcerative lesions in its mouth. Which of the following viruses are least likely to have caused these lesions?
Bovine parainfluenza type 3 virus
Which of the following statements regarding bunyaviruses is least true?
Bunyaviruses survive well outside their hosts and are difficult to disinfect.
Parvoviruses
Can survive extremely well outside their hosts and remain infectious for weeks to months
Transmissible spongiform encephalopathies
Cause progressive neurological disease in a number of animal species
The velogenic form of Newcastle disease in poultry
Causes clinical signs that are indistinguishable from clinical signs of pathogenic avian influenza infection. As such, diagnosis has to be confirmed through laboratory testing.
An outbreak of porcine Post-weaning Multisystemic Wasting Syndrome (PMWS) has recently been detected in the North Island of New Zealand. Which of the following statements about PMWS and Porcine circovirus type 2 (PCV-2) is least accurate, given our current understanding of the disease?
Certain genetic strains of PCV-2 are known to be more likely to cause PMWS.
Which of the statements below regarding prions is least true?
Certain genotypes of sheep are associated with resistance to scrapie.
Which of the following virus families are very small viruses that require actively dividing cells for replication? Choose all correct answers (there may be more than one).
Circoviridae Parvoviridae
Which of the following is the least practical and effective measure you could take to help eradicate Equine viral arteritis (EVA) virus from a country in which it has become established?
Compulsory serological testing of all breeding mares to detect carriers.
Which of the following is the most commonly and widely used method for the cultivation of mammalian viruses?
Continuous cell lines
Which of the following statements about coronaviruses is correct?
Coronaviruses typically cause mild respiratory or gastrointestinal infections in several species
Which poxvirus has an unusually broad host range?
Cowpox virus
Currently-available Feline calicivirus (FCV) vaccines do not provide complete protection against this virus. The most likely reason for this is:
Cross-protection between vaccinal strains and strains present in the community is incomplete.
Highly pathogenic avian influenza (HPAI) is very much in the news lately. In rich countries, farm and government workers handling large numbers of chicken carcasses during an HPAI outbreak (i.e., cullers) are encouraged to take an anti-influenza drug, such as oseltamivir. Yet some cullers and other workers choose not to do so. From the list below, and thinking from a national and international perspective, select the most important underlying reason why cullers should be required to take an anti-influenza drug while working with HPAI carcasses.
Cullers may be incubating human influenza while working
Paramyxovirus infected cells may show which of the following useful diagnostic features:
Cytoplasmic inclusion bodies. Multinucleated giant cells. Haemadsorption.
Which of the following factors play a role in the spread of the Bluetongue viruses?
Density of cattle and sheep
Which statement related to Feline infectious peritonitis (FIP) is least true?
Diagnosis of FIP can be confirmed based on virus isolation from faeces.
What is the least useful test for the diagnosis of canine parvoviral enteritis
Direct and light microscopic inspection of the faeces.
One of the characteristics common to all herpesviruses is their ability to establish latency in their hosts. Choose the best statement describing the relationship between the host and a herpesvirus in a latent stage:
During latency there is no production of progeny viruses, but limited transcription of the viral genome can occur.
Which of the following statements are true of alphaherpesviral latency? Choose all correct answers (there may be more than one).
During latency, virus particles cannot be detected during any routine diagnostic test. Because of latency, measurement of antiviral antibodies is uninformative. There may be no viral protein whatsoever in the host's body during latency. Latency is most often achieved in nerve ganglia and lymphocytes.
Which of the following viruses is LEAST resistant to adverse environmental conditions
EHV 1
Which of the following viruses is least resistant to adverse environmental conditions:
EHV 1
List features of poxviruses
Enveloped DNA viruses. Intracytoplasmic replication Evolve more rapidly than most other viruses.
You are called to investigate an abortion "storm" that is occurring in a mob of heavily-pregnant mares. On close questioning, you learn that a 'new' mare has recently been introduced from another part of the country. Which of the following herpesviral causes should be at or near the top of your differential list?
Equid herpesvirus type 1.
What virus is LEAST likely to cause neurogenic disease in a horse?
Equine Influenza virus
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?
Equine arteritis virus
You are asked to comment on whether or not your client's adult cat should be vaccinated against Feline infectious peritonitis (FIP). Choose the least correct statement from the options below.
FIP usually occurs as a result of mutation of feline enteric coronavirus, and vaccination will have no effects on that process
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.
False
About 60% of human common colds are caused by coronaviruses.
False
African swine fever (ASF) is exotic to New Zealand, but Classical swine fever (CSF) is a common infection in New Zealand pigs.
False
African swine fever virus is present only in Africa.
False
Arboviruses are mechanically transmitted by arthropods
False
Bovine parainfluenza type 3 (PI-3) is a common cause of abortions in cattle.
False
Canine parvovirus infection is extremely unlikely to be a cause of gastroenteritis in a 12 week-old puppy that had been vaccinated twice against parvovirus at 6 and 9 weeks of age.
False
Coronaviruses generally grow very well in cell culture, producing a strong cytopathic effect.
False
Coronaviruses have the smallest genomes of the known RNA viruses.
False
Coronaviruses mutate and evolve relatively slowly compared with most other RNA viruses
False
Equine influenza is a common cause of equine respiratory disease in New Zealand.
False
Feline immunodeficiency virus (FIV) is most often transmitted via prolonged direct contact, for example via grooming.
False
Feline infectious peritonitis (FIP) and Feline enteric coronavirus (FEC) are two antigenically distinct coronaviruses of cats.
False
Following EHV-1 infection, horses develop a life-long immunity to re-infection, but the latent virus can still be re-activated.
False
Herpesviruses stimulate solid (possibly life-long) immunity. Recovered animals are refractory to subsequent herpesviral infections.
False
Herpesviruses typically cause a short illness followed by recovery and elimination of the virus.
False
Immunity to Feline calicivirus is stronger and longer lasting than immunity to Feline panleukopenia virus following either vaccination or natural infection.
False
Infection with the African horse sickness virus in Zebras is typically fatal.
False
Internal haemorrhages are typical of severe disease following infection with Canine parvovirus type 1 (CPV-1) infection
False
Killed vaccines are safer and as such, killed vaccines are more commonly used in veterinary medicine than live vaccines.
False
Mammalian coronaviruses have a tropism for ectodermal cells.
False
Mucosal disease results from infection of young cattle with a more virulent strain of the Bovine viral diarrhoea (BVD) virus.
False
Mucosal immunity plays little role in protection from infection with rotaviruses.
False
Poxviruses do not survive well in the environment.
False
Rabies virus belongs to the genus Vesiculovirus of the family Rhabdoviridae
False
Resistance to antiviral drugs is very rare, as viruses cannot change as rapidly as bacteria.
False
Sheep serve as maintenance hosts for Bluetongue viruses.
False
The levels of maternally derived antibodies against canine parvovirus are similar in all puppies from the same litter.
False
The most important route of spread of infection with the Equine Viral Arteritis virus is horizontally through direct contact.
False
The natural reservoir for Equine encephalitis viruses are horses
False
The velogenic biotype of Newcastle disease virus is endemic in New Zealand.
False
There are three known serotypes of the Bluetongue virus.
False
Vaccination against EHV-1 is protective against the neurological form of disease.
False
Vesicular stomatitis is often associated with profound hypocalcaemia.
False
An outbreak of African swine fever virus can be successfully controlled by ring-vaccination
False - no vaccination exists
A kitten with upper respiratory disease is most likely to be infected with what virus
Feline herpesvirus
A kitten with upper respiratory disease is most likely to be infected with which of the following viruses:
Feline herpesvirus
Which of the following is most often associated with transmission of the Feline immunodeficiency virus (FIV) between cats?
Fighting
Which of the following is not a well recognised consequence of equid herpesvirus 1 infection?
Genital mucosal ulcerations
Which of the following statements about Rinderpest is least true?
Global eradication is very unlikely to be successful
What strain of influenza A virus caused enormous concern in Southeast Asia around 2007?
H5N1.
Which of the following disease manifestations is least typical of herpesvirus infections in mammals?
Hepatitis.
Which of the following virus families are large viruses that are fragile in the environment?
Herpesviridae
Which of the following features of the Foot-and-mouth disease (FMD) virus is least likely to contribute to the rapid spread of the virus?
High stability of the virus in wide range of pH.
What is the most important advantage of a "high titre, low passage" vaccine against CPV-2, as compared with a more conventional modified live vaccine?
High titre, low passage vaccines 'break through' maternally transferred passive immunity earlier than do more conventional vaccines
Which of the following statements about Borna disease virus is least true?
Horses infected with BDV invariably develop fatal neurological disease.
A cytopathic effect (CPE) is sometimes observed when cultivating viruses in vitro. Which of the following statements about CPE is least correct?
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).
Which of the following statements regarding ecology of Influenza viruses is least true?
Immunity following infection with a given H subtype of influenza virus is strong and long-lasting, but does not cross-protect against other H subtypes.
Which of the following best describes similarity between coronaviral diarrhoea and rotaviral diarrhoea in young calves?
In both cases mature villous cells, rather than crypt cells, are targeted.
Which of the following is the most significant point of similarity between coronaviral diarrhoea and rotaviral diarrhoea in young calves?
In both cases mature villous cells, rather than crypt cells, are targeted.
From the point of view of viral pathogenesis, there are some interesting parallels between mucosal disease of cattle and feline infectious peritonitis. From the list below, select the most accurately stated point of similarity.
In both cases, a low pathogenicity 'precursor' virus persists in the host and later mutates to become highly pathogenic
Which ONE (1) of the following statements about Feline immunodeficiency virus (FIV) is LEAST correct?
In high density cat populations FIV is commonly transmitted via grooming.
Which of the following statements is least true of adenoviruses in general?
Infection is associated with intracytoplasmic inclusion body formation.
Which of the following are viral non-structural proteins? Choose all correct answers (there may be more than one).
Integrase Reverse transcriptase
Choose the best answer to finish the sentence: Swabs for virological
Into a viral transport medium, which contains proteins to stabilize the virus and antibiotics to prevent bacterial growth.
Which of the following is least useful as a basis for classifying viruses into families?
Intranuclear or intracytoplasmic inclusion bodies.
Which of the following measures is least likely to prevent introduction of BVD-virus to a BVD-negative herd?
Introduce only BVD-antibody negative animals to the herd.
Which ONE (1) of the following is the LEAST likely route of introduction of the Porcine reproductive and respiratory syndrome (PRRS) virus into New Zealand?
Introduction via infected arthropod eggs.
You are involved in containing a Foot-and-mouth disease (FMD) virus outbreak in the UK. Which of the measures below would you consider least effective in trying to stop the spread of the virus?
Isolation of infected animals in a fenced paddock, with at least 50 meters clearance around the perimeter of the paddock.
During the recent outbreak of Equine influenza in Australia a recombinant Canarypox influenza vaccine was used to help contain the outbreak and eradicate Equine influenza from Australia. The main advantage of this type of vaccine over other available vaccines was:
It allows for serological differentiation between vaccinated and infected animals.
Choose theLEAST true statement regarding the African swine fever (ASF) virus:
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
Choose the LEAST correct statement regarding Pseudorabies:
It is a zoonotic disease
Which of the following is least true of Malignant catarrhal fever in New Zealand?
It is caused by Alcelaphine herpesvirus type 1.
Which of the following statements about African swine fever virus is untrue?
It is fragile in the environment, relying on intimate contact for transmission
Which of the following statements about Hendravirus is untrue?
It is unusually hardy (resistant) in the environment for a paramyxovirus.
One of your clients has adopted a stray female cat, which turned out to be pregnant. The client wants to know whether or not her newly adopted cat should be vaccinated against Feline panleucopenia. Choose the best answer:
It would be best to vaccinate the queen with a killed vaccine, as such vaccines do not have a potential of crossing the placenta and causing foetal death or abnormalities.
Which of the following statements about Nipahvirus (Nipavirus) is least true?
Its closest relative among the paramyxoviruses is Turkey rhinotracheitis virus.
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:
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.
What kind of vaccine is licensed in New Zealand to prevent Orf?
Live, fully virulent virus.
Which statement about Maedi/Visna virus infection is least correct?
Maedi presents a common problem in New Zealand sheep, while Visna is rarely seen.
You are working as a veterinarian in the USA and are called to examine a horse that is depressed and not eating well. You discover severe lesions in its mouth (pictured below). Several other horses on the same property showed similar lesions. Infection with which virus(es) should be on the top of your list of differential diagnoses?
Malignant catarrhal fever virus. Foot-and-mouth disease virus. Vesicular stomatitis virus.
The most likely reason why we so infrequently observe canine parvovirus type 2 (CPV-2)-associated myocarditis in very young puppies is that:
Much of the adult canine population is now immune: maternally transferred passive immunity protects puppies at the critical, early life stage.
Which of the following statements about Newcastle disease virus and its pathotypes is most true?
New Zealand only has lentogenic, avirulent strains of the virus.
Which virus typically only produce localised infections without systemic spread:
Orf virus
Which of the following clinical presentations is least typical of herpesviral infection
Pancreatitis.
Which of the following virus families have been proven to cause carcinomas?
Papillomaviridae
One of your clients has several heifers affected by multiple warts. You explain that the likely cause of warts is a papillomavirus infection. The client has heard that it's possible to use an autogenous vaccine prepared from formalin-treated wart tissue to treat warts. He asks your opinion on the subject. Considering your knowledge of papillomaviruses, choose the best answer:
Papillomavirus warts usually regress spontaneously and so it is difficult to assess the effectiveness of a vaccine.
A proliferative lesion that presents as a sore around the mouth is characteristic of infection with:
Poxviruses
For bovine spongiform encephalopathy, which of the following is the least important difference between PrPSC and PrPC?
PrPSC polymerises more efficiently than PrPC.
Which of the following factors is least likely to affect the spread of the Bluetongue viruses?
Presence of horses
Which of the following factors are least important determinants of whether or not an arbovirus transmitted by midges will become established following inadvertent introduction to the new geographical area?
Presence of other arboviruses.
Which of the following factors is least likely to contribute to difficulties associated with control of prion diseases (spongiform encephalopathies)?
Prion proteins are easily transmitted between different animal species
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 most consistent with the above clinical signs?
Psitaccine beak and feather disease virus.
Which of the following diseases/disorders can be caused by a circovirus? Choose all correct answers (there may be more than one).
Psittacine beak and feather disease in young birds. Anaemia in 2-3 week old chicks
The results of a parvovirus haemagglutination inhibition (HI) test done on the sera of three six week old puppies are as follows: Puppy A 1:20, puppy B 1:540, and puppy C 1:160. If you were to vaccinate all three puppies with a single dose of a vaccine containing attenuated live canine parvovirus, which of the puppies would be most likely to develop immune response to the vaccine that would be protective against subsequent challenge with virulent parvovirus?
Puppy A. It has the lowest levels of maternal antibody and as such it is most likely to respond to vaccination by mounting an active immune response.
Which of the following is not a feature of circoviruses
Rapidly cleared from the body after infection resolves
Retroviruses, in general, evolve rapidly and exhibit unusually frequent antigenic change. Which of the following is the least important reason for this?
Recombination with endogenous retroviruses occurs frequently.
Which of the following stages in the virus replication cycle is the drug Tamiflu thought to target?
Release
Which of the statements below regarding the ecology of terrestrial rabies is least true?
Reservoir hosts can shed the Rabies virus for prolonged periods of time (weeks to months
Which statement related to the reservoir hosts for rabies is least true?
Reservoir hosts maintain the rabies virus in the populations, as they do not become sick following infection, but still shed the virus in their saliva.
Mucosal disease
Results from co-infection of a persistently infected calf with a cytopathic strain of Bovine viral diarrhoea (BVD) virus. Results from a mutation of a non-cytopathic strain of the BVD virus in persistently infected calves
Which of the following measures is least likely to be effective in minimizing the economic effects of Bovine viral diarrhea (BVD) infection in a herd?
Separation of persistently-infected animals from the rest of the herd in a designated paddock.
Which of the following statements about Borna disease virus is least true?
Several rodent reservoir hosts have been characterised.
Which of the following statements regarding Foot-and-mouth disease (FMD) virus is least true?
Shedding of the FMD virus begins after development of clinical signs.
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:
Sheep pox
Which of the following statements about Vesicular stomatitis virus (VSV) is least true?
Similarly to the foot-and-mouth disease virus, VSV does not affect horses
In general, poxviruses can use the following portals of entry:
Skin with compromised integrity (e.g. skin abrasions). Respiratory route (via aerosols). Blood via mechanical vectors
What is the most common form of Creutzfeldt-Jakob disease?
Sporadic
Transmissible spongiform encephalopathies may be:
Sporadic, infectious, and genetic
Which of the following statements about influenza A viruses is least true?
Spread mostly by aerosols in birds and mammals.
Influenza A viruses share all of the following features, except
Spread predominantly by respiratory aerosols in birds and mammals.
Which of the following statements about viral structure are true? Choose all correct answers (there may be more than one).
Structural symmetry facilitates virion self-assembly. Cubic symmetry is a synonym for icosahedral symmetry. Individual virus families contain viruses of helical or icosahedral symmetry, but not both. Virions with complex symmetry have both helical and icosahedral symmetry.
You are called to investigate a problem on one of your client's pig farms. The farmer reports increased numbers of lame pigs and a decrease in food intake. On arrival, you examine several pigs, which appear slightly depressed. Several of the pigs are febrile and some show vesicles and ulcers in the mouth and interdigital spaces. Infection with which virus(es) would be consistent with such a clinical picture?
Swine vesicular disease virus. Foot-and-mouth disease virus. Vesicular stomatitis virus.
Which of the following diseases is not caused by an arbovirus?
Swinepox
You are investigating a problem on a 600-cow dairy farm. The farmer reports an increase in the number of cows that return to oestrus following mating, a decrease in milk production and an increased number of abortions. The farmer wants to know whether or not he has a problem with Bovine viral diarrhoea (BVD) in his herd. What initial testing options could you suggest to the farmer to determine the BVD status of the herd?
Test composite milk samples for the presence of BVD antigen.
The term "viral virulence" relates to:
The ability of the virus of cause disease in a specified host.
You are involved in organising veterinary field clinics in Africa, as part of voluntary humanitarian work. At one of such clinics, you are presented with a donkey that shows unusual behaviour - it seems very pruritic around its anus and it repeatedly tries to bite at its right hind leg. The owner reports that the donkey started to behave strangely two days ago and it seems to be getting worse. Choose the most likely explanation for the donkey's behaviour and the best choice of action:
The donkey displays clinical signs that are suggestive of rabies. It is best to treat it as potentially rabid and take all the appropriate precautions. The donkey should be euthanized, or isolated and kept under observation.
What is the most significant difference between new variant Creutzfeldt-Jakob disease and other 'classical' forms of the disease?
The new variant form is associated with a longer course of illness.
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:
The pastures and food troughs are contaminated with the virus, which is surviving outside each winter
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:
The positive result confirms that the mare aborted due to EHV-1 infection.
You are presented with a 9-week-old German shepherd puppy "Lucky". Lucky was vaccinated at the age of 6 weeks with a multivalent vaccine containing an attenuated strain of canine parvovirus, and is due for his second shot. However, yesterday Lucky seemed less playful, and has since lost his appetite and developed pasty pale faeces. ON examination, Lucky seemed quiet, but responsive, his temperature was 39.2 C, with slightly elevated heart rate and respiratory rate. You've performed a parvo "snap" test on a fecal sample from Lucky, which gave a strong positive result. Choose the most likely interpretation of the test result and the best course of action.
The puppy is most likely in the very early stages of parvovirus infection. The best option would be to keep it in the hospital on IV fluids overnight and re-address the treatment plan the following morning, depending on the progression of clinical signs.
Which of the following statements about virus size and complexity is most true?
The smallest viruses are larger than prions.
What would you expect to be the most likely reason for a false negative result when using in-practice diagnostic test kits for the detection of canine parvovirus antigen in faeces?
The test is done too late, specific antiviral antibodies block viral epitopes.
Viruses posses the following characteristics:
The viral nucleic acids are used to generate viral mRNA within the host cell.
The term "highly pathogenic avian influenza virus" relates to:
The virulence of the virus to chickens.
Prompt post-exposure vaccination of humans against rabies can be protective. Given our current understanding of rabies pathogenesis, which of the following is the most plausible explanation for this?
The virus remains accessible to immune attack for a period after exposure, while it remains at the bite site. Once the virus enters neurons it becomes less accessible to the immune system
Prompt post-exposure vaccination of humans against rabies can be beneficial, i.e., protective. Given our current understanding of rabies pathogenesis, which of the following is the most plausible explanation for how post-exposure rabies vaccination can protect?
The virus remains accessible to immune attack for a period after exposure. Later, virus enters cells of the nervous system where it is more difficult for the immune system to access.
Which of the following is the most significant point of similarity between canine distemper virus and Rinderpest virus?
There is only one serotype for each of these virus species.
You are called to examine and provide advice about a group of young cattle, several of which have multiple cutaneous papillomas. Which of the following advisory comments is most accurate?
These papillomas are most likely to regress spontaneously over a period of months.
Which of the following feature is least applicable to Paramyxovirdidae
They can undergo rapid genetic change through the exchange of the genomic segments
Most young rabbits up to 8 weeks of age are resistant to rabbit calicivirus disease (RCD). From what is known so far, what is the most plausible and precise explanation for this observation?
They do become infected and mount an immune response, but, for reasons that remain unclear, they do not become seriously ill as a consequence.
Most young rabbits up to 8 weeks of age are resistant to rabbit calicivirus disease (RCD). From what is known so far, what is the most plausible and precise explanation for this observation?
They do become infected and mount an immune response, but, for reasons that remain unclear, they do not become seriously ill as a consequence.
Which of the following characteristics of morbilliviruses is least true?
They induce strong, but short-lasting immune responses
Which of the following features is least applicable to members of Paramyxoviridae?
They replicate in the cell nucleus.
An inquisitive client who breeds dogs asks your advice upon the wisdom (or otherwise) of vaccinating 6 week-old puppies against canine distemper using a measles virus vaccine. Which of the following pieces of advice is least valuable?
This approach will work best if the bitch (dam) was herself vaccinated with a measles vaccine after she was 12 weeks of age.
The most likely route of entry to New Zealand for African swine fever virus
Through infected, frozen pig meat.
People working on commercial pig farms are often required to be vaccinated against a seasonal human flu virus. The most important justification for this requirement is:
To minimize possibility of recombination between human and animal influenza viruses in a human host
African swine fever virus is the only DNA virus that is also an arbovirus.
True
Antiviral drugs inhibit specific steps in viral replication.
True
Aphtoviruses, such as the foot-and-mouth disease virus, are unstable in pH below 7.0 and can be easily disinfected by acidic solutions.
True
Approximately half a million cattle deaths occur in South America each year, as a consequence of bat-associated rabies.
True
Avian influenza viruses replicate predominantly in the gastrointestinal track of infected birds and are spread via faecal-oral route
True
Bovine coronavirus can cause diarrhoea in people.
True
Canine adenovirus type 1 (CAV-1) can be excreted in urine of recovered dogs for a prolonged period of time.
True
Coronaviruses are moderately fragile in the environment, surviving 1-2 days at room temperature.
True
Endogenous retroviral sequences are present in most, if not all, mammalian genomes.
True
Endogenous retroviruses are typically non-pathogenic.
True
Enveloped viruses are typically fragile and easily killed outside their hosts.
True
Equine sarcoids have been shown to contain Bovine papillomavirus sequences
True
Feline infectious peritonitis, transmissible gastroenteritis and some cases of puppy diarrhoea are caused by coronaviruses.
True
Foot-and-mouth disease (FMD) in cattle is clinically indistinguishable from infection with the Vesicular stomatitis virus.
True
Foot-and-mouth disease virus is easily destroyed by low pH.
True
Haemagglutinin of the influenza viruses is one of the determinants for viral virulence
True
Immunity to Canine parvovirus disease following natural infection is most likely life-long.
True
Immunosuppression is an important clinical feature seen in chickens infected with Infectious bursal disease virus (IBDV).
True
Infection with the Aujeszky's disease virus causes fatal meningoencephalitis in cattle, sheep, dogs, foxes, and rabbits.
True
Infectious Foot-and-mouth disease virus can be carried by wind over long distances.
True
Internal haemorrhages are typical of severe disease following infection with the Canine adenovirus type 1 (CAV-1) infection
True
Living in rodent-infested places is a risk factor for hantavirus infection.
True
Many members of the Paramyxoviridae family engender strong immune responses.
True
Morbilliviruses induce strong, long-lasting immunity in survivors of infection.
True
Most coronaviruses are monotypic (meaning that they have one serotype per species).
True
Most coronaviruses cause mild disease in adults and more severe disease in newborn animals.
True
Most coronaviruses cause mild disease in adults, but more severe disease in newborn animals.
True
Myocarditis associated with Canine parvovirus type 2 (CPV-2) infection is rarely seen now, because most puppies have some level of maternal immunity to CPV-2 during the first few weeks of life.
True
Myxomatosis causes severe generalised disease in European rabbits, but only localised benign fibromas in American rabbits.
True
Numerous important fish diseases are caused by members of the rhabdoviridae family.
True
Only stallions can become permanent shedders of the Equine viral arteritis (EVA) virus.
True
Orf virus can be transmitted between susceptible animals via fomites.
True
Orf virus can infect humans.
True
Paramyxovirus infection may cause both intranuclear and intracytoplasmic inclusion bodies to form.
True
Parvoviruses can remain infectious in faecal material for weeks to months.
True
People can become infected with hantaviruses through contact with rodents or rodent-infested places.
True
Pigs are considered "amplifier" hosts for the foot-and-mouth disease virus.
True
Pigs possess both human and avian types of receptors for influenza viruses.
True
Poxviruses typically cause localized skin infections.
True
Rabies virus causes progressive neurological disease, which is invariably fatal in all warm-blooded animals
True
Rhabdoviruses are fragile in the environment, but will survive in cool, damp places.
True
Rift valley fever virus can cause abortions in a variety of species, including humans.
True
Rotaviruses are common causes of diarrhoea in young animals of many species.
True
Some cats are able to mount effective immune response to the Feline leukemia virus (FeLV) and clear infection with this retrovirus.
True
Some members of the Paramyxoviridae family are haemagglutinators.
True
Some poxviruses can establish viremia followed by generalized disease
True
The 'naked' RNA of a coronavirus is infectious.
True
The African horse sickness virus is an arbovirus.
True
There are many serotypes of the Bluetongue virus, with little cross-protection between them.
True
Typically, papillomavirus infections in cattle cause development of warts, which disappear spontaneously after 4 to 6 months.
True
Velogenic Newcastle disease and highly pathogenic avian influenza are clinically indistinguishable
True
Viruses in the Paramyxoviridae family characteristically cause syncytium formation in cell cultureTrue
True
Viruses of the Paramyxoviridae family have two kinds of surface glycoprotein.
True
Choose the best option from the following. Herpesviruses
Typically establish a life-long infection due to their ability to become latent.
The main advantage of using virus isolation over the molecular based diagnostic assays such as PCR is that:
Unlike PCR, virus isolation demonstrates the presence of live virus in the sample.
Which of the following is least likely to help control rotavirus diarrhoea in a group of calves?
Vaccination of calves
Which of the following statements about alphaviruses is least true?
Vaccines have not yet been developed to protect against alphaviruses.
Which of the following vesicular viruses can infect both pigs and cattle?
Vesicular stomatitis virus and Foot-and-mouth disease virus.
Which ONE (1) of the following is the MOST likely route of introduction of the Bluetongue virus to New Zealand?
Via viraemic cattle or wild ruminants with mild or inapparent disease.
Many arboviruses have evolved to be able to infect a wide range of vertebrate hosts. Which of the following is the most likely reason for this?
Virus-infected vectors of a given species may bite more than one vertebrate species.
You are working in an equine hospital in central USA and are caring for a horse with severe neurological disease, which has been diagnosed as a West Nile virus (WNV) infection. Your veterinary nurse is concerned about the risk of catching the disease from this horse. Choose the best answer
West Nile virus is a zoonotic disease, but it is transmitted by infected mosquitoes, not by direct contact with the infected horse.
Which of the following statements about viral genomes is least true?
Which of the following statements about viral genomes is least true?
Laboratory results of virus isolation are usually available:
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.
Consider this list of possible reasons for false positive and false negative diagnostic test results, some of which are relevant when testing cats for feline retroviral infections: Healthy 10wk kitten with infected mother recently vaccinated recently infected over-whelming end stage disease very mild disease Which of these could plausibly cause a false negative result in a conventional 'in-practice' test for feline immunodeficiency virus?
very mild disease
