Viruses Flashcards

Question

Describe the host range of myxoma virus

Answer 1

Myxamatosis Wild rabbits in Americas = mild disease European rabbits = generalised disease

Answer 2

Mechanical transmission by insect vectors Released as a form of population control

Answer 3

Attenuated myxoma vaccine Vaccination with rabbit fibroma virus

Answer 4

Conjunctivitis Gelatinous swellings Severe generalised disease **No typical pox lesions** (Localised benign fibroma in American wild rabbits)

Answer 5

Poxviridae

Answer 6

Chickens (Most bird species have their own pox virus, e.g. pidgeonpox, turkeypox)

Answer 7

mechanical transmission by insects

Answer 8

Severe disease with proliferative lesions in young birds Pox lesions on comb, wattle, feet, vent, +/- respiratory tract

Answer 9

Attenuted fowlpox or pigeonpox vaccines Vector control

Answer 10

Upper respiratory tract infection Conjunctivitis

Answer 11

Some serotypes: Upper respiratory tract infections; pneumonia Some serotypes: keratoconjunctivitis

Answer 12

Some can cause respiratory disease (experimental innoculation)

Answer 13

Subclinical or mild respiratory disease Severe disease in young Arab SCID foals: fatal pneumonia

Answer 14

Most apathogenic. Respriatory disease (may resemble mild infectious laryngeotrachetis) Decreased egg production ``` Immunosuppressed birds (infectious bursal disease): Inclusion body hepatitis, moderate mortality \<10% in 5-10w.o chicks ``` Haemmorhagic enteritis in turkeys

Answer 15

Adenovirus | (Canine adenovirus 1)

Answer 16

Dogs, foxes

Answer 17

Encephalitis

Answer 18

- hepatitis/hepatic necrosis - upper respiratory tract infection - chronic interstitial & glomerulo- nephritis - vascular damage, petechial haemorrhage, oedma - "blue eye" = corneal odema (AB-AG complexes) - inclusion bodies Mortality may reach 100%

Answer 19

- present in secretions during acute phase - present in urine \> 6 months

Answer 20

- shed in urine \>6m (and secretions, acute phase) - persists in environment at least a week Close contact and possible ingestion usual method of infection Rarely, aerosols (respiratory disase)

Answer 21

- attenuated canine adenovirus 2 vaccine - inactivated canine adenovirus 1 vaccine - immunity is cross-protective

Answer 22

Mild respiratory disease +/- fatal bronchopneumonia Role in Kennel Cough

Answer 23

- Virus gains entry to basal cells (stratum basale) - only DNA present - causes proliferation of intermediate cell layers (stratum granulosum) -\> papilloma lesions ("warts") - virus particles shed in exfoliated keratinised cells (stratum corneum)

Answer 24

Most benign Some associated with carcinomas (cervical, laryngeal, skin)

Answer 25

Papillomas on nose and face of young horses Spontaneous regression with immunity

Answer 26

Oral papallomas. Usually benign, some evidence of neoplastic transformation Also on feet of greyhounds Spontaneous regression

Answer 27

Lesions most common on ears, face, vulva. May undergo neoplastic transformation

Answer 28

Lesions usually on udder, genital skin. Some neoplastic transformation

Answer 29

1,2,3,5,6: cutaneous papillomas, may be extensive and coalescing (esp young animals) Papillomas on penis of bulls 5, 6: Papillomas and fibropapillomas on teats of cows 4: Papillomas of alimentary tract Neoplastic transformation associated with grazing brachenfern

Answer 30

Equine sarcoids

Answer 31

Inactivated autogenous vaccines But spontaneous regression common, so difficult to evaluate worth

Answer 32

Infection possible via any route, especially ingestion Virus in blood in acute phase, may be spread by biting insects Virus excreted in urine, faeces, saliva, and in utero for many months Highly contagious

Answer 33

Affinity for rapidly dividing cells (foetal, GIT, bone marrow) enteritis, diarrhoea, leucopenia Foetal death/cerebellar hypoplasia Secondary bacterial infection probably important in pathogenesis

Answer 34

Attenuated and inactivated vaccines Attenuated vaccines should not be used on pregnant cats

Answer 35

severe haemorrhagic enteritis, leucopenia, (myocarditis) especially young dogs

Answer 36

Transmission via fecal-oral route Shed for 1-2 weeks

Answer 37

No - Virus extremely resistant in environment, including to a range of pH, temperatures - Virus shed in very large quantities - Low infective dose (only a few virus particles needed for infection)

Answer 38

Tentative diagnosis based on clinical signs Rapid, commercially available serological tests to confirm presence of antigen (robust, due to large number of viral particles shed) PCR limited availability

Answer 39

Attenuated or inactivated vaccines Inactivated vaccine used in pregnant bitches Cross-react between subtypes, strongly immunogenic -\> solid immunity

Answer 40

Not pathenogenic for young or adult pigs Spread across placenta, variety of breeding abnormalities: death, mummifcation, malformation, stilllbirths Disease occurs in gilts seronegative at the time of first mating

Answer 41

Antigen detection in foetal tissue (Antibody detection of little value because disease is widespread)

Answer 42

Attenuated and inactivated vaccines Gilts can be purposely infected prior to pregnancy

Answer 43

Circoviridae

Answer 44

In parrots: species variability Cockatoos suceptible, lorikeets resistant abonormalities of feathering, beak and feet hepatitis diarrhoea immunosuppression

Answer 45

Circoviridae

Answer 46

Horizontal and vertical transmission Breeders infected during lay produce infected eggs for ~6 weeks

Answer 47

Vertically infected chicks become diseased at about 10 days old ~60% mortality Stunted growth, anemia, immunosuppression Secondary skin infections, especially fungal

Answer 48

Virulent vaccine in drinking water

Answer 49

apathogenic

Answer 50

Post-weaning multisystemic wasting syndrome (~6w.o) Case fatality 10% Respiratory disease

Answer 51

Good husbandry (environmental factors important in pathogenesis) Removal of affected animals Elimination of infectious agents PCV2 vaccine

Answer 52

Recently discovered in dogs in the US vasculitis, histocytic inflamation, thrombocytopenia

Answer 53

Close contact, venerial, short-distance droplets in production systems

Answer 54

relatively fragile Except Mareks, very resistant

Answer 55

Characteristically produce latent infections Virus undergoes retrograde transport along peripheral nerves to ganglia During latent phase, viral DNA is found in the ganglia Factors (e.g. stress, fever, UV, corticosteroid therapy) trigger the reactivation of the virus, which undergoes anterograde transport along peripheral nerves

Answer 56

Yes - can screen population using antibody detection tests (relatively cheap) - remove carriers (AB+) - fragile virus with no long-term environmental reservoirs

Answer 57

Herpesvirdiae | (Bovine herpesvirus 1)

Answer 58

respiratory disease conjunctivitis genital disease (infectious pustular vulvovaginitis) Exotic strain causes abortion

Answer 59

Multifactorial Pathogen exposure to \>4 viruses and \>3 bacteria Bovine herpesvirus 1 Bovine viral diarrhoea virus Bovine respiratory syncytial virus Bovine coronavirus Bovine adenovirus Bovine parainfluenza virus 3 Environmental factors Stress, climate, transport, food, density, etc Peak incidence of disease 21 days after being moved to a new feedlot

Answer 60

- live attenuated bovine herpesvirus 1 vaccine - detection and removal of infected animals

Answer 61

fatal neurological disease in calves

Answer 62

(Bovine herpesvirus 2) Vesicles on teats and udder predispostion to mastitis loss of production

Answer 63

- generalised disease, invariably fatal - erosive lesions of GIT - respiratory lesions - mucopurulent naso-occular discharge - lymphoproliferation and lymphocyte infiltration - vasculitis - corneal opacity - neurological sins

Answer 64

Carried asymptomatically by wildebeast and sheep Sporadic transmission to cattle, deer via contact or infected pastures

Answer 65

No vaccine available Control contact with wildbeast/sheep/infected pasture?

Answer 66

Type 1.1 and 1.2a Infectious bovine rhinotracheitis (Type 2b endemic) Porcine herpesvirus 1 (Aujeszky's disease)

Answer 67

Herpeviridae | (Porcine herpesvirus 1)

Answer 68

- subclinical/mild respiratory disease in adult pigs - abortion - generalised fatal disease in piglets (100% mortality)

Answer 69

fatal meningioencephaltis and pruritis in sheep, cattle, dogs, cats (pseudorabies, "mad itch")

Answer 70

Herpeviridiae | (Equine herpesvirus 3)

Answer 71

Ulcerative lesions on penis/vulva

Answer 72

Herpeviridae | (Equine herpesvirus 4)

Answer 73

respiratory disease, especially in young foals

Answer 74

Herpeviridae | (Equine herpesvirus 1)

Answer 75

abortion respiratory disease fatal generalised disease in neonates encephalomyelitis

Answer 76

Killed/recombinant vaccine

Answer 77

Mostly apathogenic possible immunosuppression

Answer 78

Herpeviridae | (Feline herpesvirus 1)

Answer 79

upper respiratory tract disease responsible for 40% of cat flu rhinitis oculo-nasal discharge inappetance confjunctivitis keratatis +/- secondary bacterial pneumonia generalised disease in neonates

Answer 80

Live attenuated vaccine not 100% protective

Answer 81

management of clincal signs reduce stress prevent/treat secondary bacterial infections nucleotide analogues (famcyclovir)

Answer 82

1&2: fatal disease in young (1-7 y.o) lethargy and inappetance death may occur \<24 hours

Answer 83

generalised, severe disease in neonatal pups (fading puppy syndrome) multifocal necrosis in multiple organs can die in 24-48 hours Unlikely after 4w.o -\> mature thermoregulation occasional vesicular lesions on external genetalia of adults

Answer 84

In chickens, esp 4-18m.o respiratory tract disease (coughing, sneezing, naso-ocular discharge, dyspnoea, haemorrhagic trachetis) up to 70% mortality

Answer 85

Live attenuated vaccine

Answer 86

Herpeviridae Chickens

Answer 87

esp. 12-24w.o neoplastic transformation of T cells lympho-proliferative lesions tumours in nerve tissue, spleen, liver neurological signs paresis/paralysis high case fatality

Answer 88

Non-pathogenic in chickens

Answer 89

Non-pathogenic herpesvirus in turkeys

Answer 90

Cross-protective attentuated Mareks disease vaccine or turkey herpesvirus Imperfect ("leaky") vaccine -\> evolution of virulence

Answer 91

Shedd in of enveloped, infectious particles from feather follicles into environment Highly resistant in environment Infection via inhalation

Answer 92

stomatitis, cold sores occasional encephalitis

Answer 93

genital lesions

Answer 94

infectious mononucleosis (glandular fever)

Answer 95

Chickenpox (initial infection) Shingles (recurring infection)

Answer 96

Rodents, pigs Dead-end hosts: sheept, cattle, cats, dogs

Answer 97

Pigs infected through oral and nasal mucosa Excrete virus for ~13 weeks Other animals infected through abrasions in skin, contact with infected pigs or rats

Answer 98

Attenutated vaccine

Answer 99

Very fragile in environment, transmission by close contact with body fluids

Answer 100

Produce persistent, progressive lifelong infections

Answer 101

Detection of antibodies Virus not detectable until ~disease period

Answer 102

1. possess viral oncogene -\> rapid oncogenesis replication deficient virus requires "helper virus" for replication 2. affect cellular oncogene -\> slow oncogenesis e. g. activation or increased transcription of cellular oncogenes if inserted in genome near an oncogene (occurs by chance)

Answer 103

Retroviruses (oncovirus)

Answer 104

- horizontal or vertical Vertical: chick is persistently viremic but antibody negative Sporadic development of tumours \> 4mo Horizontal: adults mount immune response, clear tumour. EXCEPTION to lifelong infection Horizonally infected chicks may become carriers

Answer 105

Genetic resistance Avian leucosis-free flocks No vaccine available

Answer 106

Retrovirus (oncovirus)

Answer 107

Depends on age and dose Older cats: usually clear infection (immune response) Young cats: persistent viremea, development of clinical signs, Px 2-3 years

Answer 108

Older cats: clinically unaffected Persistently viremic (esp young) cats: (**FeLV-A + ...**) * *FeLV-B** - lymphoid and myeloid leukaemia - lymphosarcoma * *FeLV-C** - bone marrow aplasia and anaemia * *FeLV-T** - immunosuppression less commonly, - reproductive failure - glomerulonephritis - osteosclerosis (abnormal hardening of bone)

Answer 109

Shed in saliva and other excretions/secretions Infection by prolonged close contact (e.g. sharing bowls, mutual grooming), via ingestion Prevalence highest in multi-cat households and catteries

Answer 110

Detection of FeLV antigen Immunofluoresence, ELISA, rapid antigen detection tests

Answer 111

Recombinant vaccine Cats should be tested to ensure antibody-negative prior to vaccination Test & remove effective in catteries

Answer 112

Retrovirus (oncovirus) | (Bovine leukaemia virus)

Answer 113

Persistant lymphocytosis Non-regenerative anaemia Infiltration of lymphoblastic lymphocytes producing diffuse or nodular enlargement of many organs Small proportion: lymphosarcoma

Answer 114

Blood transfer between animals

Answer 115

Antibody test (gel diffusion test) and culling of AB+ animals

Answer 116

Often no clincial signs May be decreased egg laying and hatchability

Answer 117

In chickens reticuloendothelial tumours runting feathering defects immunodepression

Answer 118

Pulmonary adenomatosis (Jaagsiekte)

Answer 119

- viral genome inserted into host DNA, hidden from immune system - high mutagenic rate (no proofreading), difficult for immune system to eliminate - infect lymphocytes and monocytes, leading to immune dysfunction

Answer 120

Visna-maedi

Answer 121

Destruction of CD4+ T (helper) cells leading to severe immunosuppression and opportunistic infection Progression to AIDS

Answer 122

Maedi: slowly progressive pnuemonia Visna: slowly progressive demyelination Death

Answer 123

Retrovirus (Lentivirus)

Answer 124

Chronic lesion in mammary gland, lung, brain, and joints Cachexia

Answer 125

Retroviruses (lentivirus)

Answer 126

fever, anaemia, abnormal iron metabolism, gammaglobulin immunosuppression, cachexia acute death (unusual for lentiviruses) or recurrent periods of disease with progressive debilitation

Answer 127

mechanimal transmission by biting insects (flies, mosquitos)

Answer 128

immunosuppression, opportunisitic infections anaemia lymphadenopathy lethargy febrile episdes

Answer 129

transmitted via biting/fighting

Answer 130

Killed vaccine Keeping cats indoors

Answer 131

detection of antibodies in serum vaccine causes AB+ response, PCR for detection of pro-virus-DNA in blood samples now available

Answer 132

Many cats live long lives Only a small percentage develop AIDS (poor prognosis)

Answer 133

Yes - fragile in environment, no reservoir - testing for antibodies detects carriers, can be culled

Answer 134

- mechanical (no replication in arthropod) or biological (replication in arthropod host; arboviruses) - both have replication in vertebrate host - some arboviruses can only be transmitted by arthropod host; some can also be transmitted by direct contact between vertebrate hosts

Answer 135

Endemic cycle: between arthropod and maintenence vertebrate host; no disease in either species; usually restricted to a geographic location Epidemic cycle: spillover into "unusual" vertebrate host; disease; usually associated with high numbers of arthropod vectors

Answer 136

Arthropod host: mosquitoes Eastern, Western EE: maintenence host = birds Venezualan EE: maintenence host = mammals Dead end host = horses and **humans**

Answer 137

Eastern, western, venuzualan equine encephalitis

Answer 138

Eastern, Western, Venuzualan equine encephalitis

Answer 139

Vaccination of horses Control of mosquito populations

Answer 140

Endemic: mosquito-bird Amplifying host: pigs Unusual hosts: horses, people

Answer 141

encephalitis in horses, people reproductive problems (stillbirths, abortion) in pigs

Answer 142

Yellow fever Japanese B encephalitis West Nile virus

Answer 143

Japanese B Encephalitis Murray Valley Encephalitis Dengue West Nile virus West Nile-Kunjin virus

Answer 144

Endemic: bird-mosquito Unusual hosts: horses, peole, domestic animals

Answer 145

Encephalitis in horse and people

Answer 146

Endemic: mosquito - non-human primates Now: mosquito - human (millions of cases annually)

Answer 147

Bite by infected mosquitos Complicated pathogenesis 4 serotypes, not cross-protective Infection with \>1 serotype facilitates disease

Answer 148

Rash, arthragia, haemorrhagic fever

Answer 149

Endemic: mosquito-bird Causes disease in humans, horses, some bird species Seroconversion with no disease in many species

Answer 150

rash, arthralgia, (rarely) encephalitis in people encephalitis in horses and some bird species

Answer 151

Endemic: mosquito-bird Mutated strain: causes disease in horses and people

Answer 152

Encephalitis in horses and people caused by mutated strain with additional virulence factors

Answer 153

1. Virus diarrhoea 2. Reproductive problems 3. Mucosal disease

Answer 154

Cytopathic Non-cytopathic

Answer 155

Mild GIT erosions diarrhoea immunosuppression respiratory disease May be mild or subclinical

Answer 156

Infection with cytopathic or non-pathogenic Bovine Virus Diarrhoea Virus Acute disease High incidence rate but low case fatality rate

Answer 157

Reproductive problems in naive dams infected with cytopathic or non-pathogenic strains embryonic death, abortion, calves with cerebellar hypoplasia +/- Bovine virus diarrhoea

Answer 158

Severe erosion of the GIT and digits Depression, fever, profuse diarrhoea

Answer 159

Specific pattern of infection with bovine virus diarrhoea virus Low incidence, but invariably fatal Naive dam infected with non-pathogenic strain at 40-120 days of gestation Foetus becomes immunotolerant (does not recognise as non-self) Persistent infection, AB -ve Infection with exogenous cytopathic strain, or mutation of non-cytopathic strain -\> cytopathic 6-18 m.o Mucosal disease

Answer 160

If infected at (day) of gestation Day 0-40: embryonic loss Day 40-120: Persistently infected, immunotolerent calf (Ag +ve, AB -ve) -\> Mucosal disease 6-18mo Day 90- 160: Congenital abnormalities (Ag, AB variable) Day 140-280: clinically normal, or small weak calf (Ag -ve, AB +ve)

Answer 161

abortion developmental abnormalities (hairy shaker lamb) neurological signs in lambs altered birth coat

Answer 162

Highly contagious, high incidence, high case fatality -\> explosive Strains vary from mild to severe

Answer 163

leucopenia immunosuppression haemorrhages (petichiae, ecchymoses)and skin discolouration vomiting, diarrhoea neurological signs, encephalitis abortion, congenital defects

Answer 164

Serological testing (skin or blood samples) for Ag +ve, AB =ve (persitently infected animals) Killed or attenuated live vaccines in some countries

Answer 165

Swine fever (hog cholera)

Answer 166

Detection of viral antigen (immunofluorescence, antige ELISA) Slaughter

Answer 167

No - Africa, Europe, Asia

Answer 168

Endemic cycle: ticks - warthogs and native pigs Disease in domestic pigs Biological transmission by ticks; direct contact

Answer 169

Warthogs, wild pigs: no disease Domestic pigs: fever, haemorrhages, dystentery, death

Answer 170

Infection by oral or respiratory route

Answer 171

2 types of peplomers (H, N); 8 segments of RNA Virus undergoes antigenic drift: small spontanous mutations reduce Ag-AB binding, decreased immune response and efficacy of vaccine Virus also undergoes antigenic shift: genetic reassortment of RNA fragments between viruses -\> change in RNA for H or N -\> new subtype; results in epidemics, ABs do not recognise new subtype

Answer 172

H binds to SA (sialic acid) receptors on tracheal epithelium - Avians express SA-alpha2,3 - Humans express SA-alpha2,6 - Pigs express both in 1:1 ratio - Pigs infected by two subtypes -\> genetic shift (reassortment) -\> new subtype that can affect humans Recent concern that some avian influenzas can directly affect humans, bypassing pig

Answer 173

children, pregnant women, some chronic conditions most at risk severe disease and death from viral pneumonia

Answer 174

- all subtypes present - range from asymptomatic to severe (fowl plague) - species differences in pathogenicity

Answer 175

respiratory distress, cyanosis, nervous signs, diarrhoea, haemorrhage, rapid death

Answer 176

Killed vaccine containing current strain, protective 6-9 months

Answer 177

H7N7(equi 1) H1N1 Swine flu (has been isolated in Aus, but no disease) H5N1 Avian influenza

Answer 178

Control avian disease with quarentine, culling, vaccination Vaccination of humans for human strains Protection of people at high risk with PPE and antivirals Mass culling probably not a solution due to economic and production importance of poultry in many countries

Answer 179

fever, naso-ocular discharge, cough +/- secondary bacterial infection, pneumonia

Answer 180

vaccination: inactivated bivalent vaccine (both subtypes) recombinant canarypox vaccine (no booster required) subunit vaccine containing H & N Not fully protective, boosters 6-9 months

Answer 181

highly contagious, spreads rapidly, self-limiting

Answer 182

respiratory disease ranging from mild, to severe + pneumonia; fever, cough.

Answer 183

H3N8 equine influnza virus tranmitted to dogs, become host adapted in USA Probably multiple transmission events from horses to dogs Dog-Dog transmission still in question (no evidence in UK or Aus)

Answer 184

respiratory disease and distress, cough, pyrexia, anorexia and emaciation +/- secondary bacterial infection Mortality highest in piglets from non-immune sows

Answer 185

Shipping fever + calf pneumonia in cattle summer pneumonia in sheep +/- secondary bacterial infection Possibly apathogenic in pigs, horses, dogs

Answer 186

Upper respiratory tract infection Role in kennel cough in dogs

Answer 187

calf pneumonia and respiratory disease in feedlots

Answer 188

Rinderpest (globally eradicated, 2011) Velogenic Newcastle disease (but outbreaks from mutated lentogenic strains in 1990s) Nipah virus (AB/virus detected, but no disease)

Answer 189

severe disease, high incidence, high case fatality in cattle Mild disease in cattle, buffalo, game animals, sheep, goats

Answer 190

inflammation, haemorrhage, erosions, necorsis of digestive mucosal membranes, diarrhoea, death

Answer 191

canids (dog, foxes), racoon, panda, ferrets, minks, large felids, red panda, civits, hyena

Answer 192

pyrexia, repiratory disease (pneumonia, bronchitis), conjunctivitis, gastroenteritis, encephalitis +/- secondary bacterial infection

Answer 193

Demyelinating encephalitis: within months of recovery (autoimmune) "Old dog" encephalitis: years after recovery (slow, persistent viral replication) Neurological signs, loss of proprioception

Answer 194

Paramyxovirus

Answer 195

Paramyxovirus (Morbillivirus)

Answer 196

aerosol infection \> viremia, infection of lymphoid tissue, fever \> virus in connective tissue If AB response insufficient \> infection of epithelial cells (respiratory, conjunctiva, GIT) \> Death OR \> Recovery \> late sequelae \> demyelinating encephalitis or old dog encephalitis

Answer 197

Very effective, live attenuated vaccine Usually combined with parvovirus & canine adenovirus 2 +/- parainfluenza virus 2 & *B. bronchiseptica* in some countries, attenuated measles vaccine used to avoid MAB interference Vaccination of other species (fox, lion)

Answer 198

severe, generalised disease (sometimes confused with fowl plague) in chickens, turkeys, pigeons, parrots, +/- other avians respiratory, intestinal, nervous signs haemorrhagic enteritis and tracheitis, encephalitis, hepatic necrosis and haemorrhage

Answer 199

Paramyxovirus (Morbillivirus)

Answer 200

Only one serotype, BUT Lentogenic: can only replicate in epithelial cell, no disease Mesogenic: moderate disease Velogenic: can replicate in many cell types - severe disease, high case fatality, highly virulent. Varies by 2 amino acids from lentogenic strain --- Viscerotropic: prediliction for GIT Pneumotropic: prediliction for resp. tract

Answer 201

In endemic countries, vaccination with lentogenic strain (selected for heat stability) In exotic locations, slaughter

Answer 202

pathogenesis depends on AB response infection via droplets severe pathology with secondary bacterial infection

Answer 203

Respirtory route

Answer 204

Paramyxovirus (Henipavirus)

Answer 205

Reservoir host: fruit bats (no disease) \>50 spillover events into horses Occasional spillover into humans

Answer 206

Reservoir host in bats Requires coordinted set of events for spillover to horses; bats rarely shed virus; does not last long in environment To date, zoonotic transmission from horses-\> humans; no evidence of transmission from bats -\> humans

Answer 207

Bats: no disease Horses: acute onset, pyrexia, severe respiratory signs, pulmonary oedema, neurological signs Humans: respiratory and neurological signs; 4/7 deaths

Answer 208

Limit horses grazing under fruit trees Horse vaccination (recombinant with Nipah): 2 initial doses 21 days appart, yearly boosters

Answer 209

PCR. New variant recently discovered, not detected by current PCR -\> updating assays

Answer 210

Paramyxovirus (Henipavirus)

Answer 211

Fruit bats Pigs Humans

Answer 212

Bats: no disease Pigs: encephalitis, respiratory signs Humans: 75% fatality

Answer 213

Infected eating fruit or palm juice contaminated with urine or saliva of infected bats human-human transmission

Answer 214

Rhabdovirus (Lyssavirus)

Answer 215

Non-specific: broad host range affecting warm-blooded animals

Answer 216

Transmission by bite, break in skin, rarely by aerosol \> replication in muscle fibres \> enters nerve and slowly migrates to CNS (incubation period weeks - 6 months) \> fatal encephalitis and neurological signs (disease course ~1 week) \> travels down nerves to saliva \> shedding of virus in saliva

Answer 217

Paralytic rabies: usually herbivores Furious rabies: usually carnivores

Answer 218

Rabies Vesicular stomatitis

Answer 219

Urban rabies maintained in domestic dog populations (Africa, Asian, Latin America). Transmitted between dogs, then to people Sylvatic rabies maintained in wild animal (fox, skunk, raccoon, mongoose) species: Europe, north and south America. Transmitted between bats and wild species. Human infection is known to come from bats. Other species questionable human transmission Different species with slightly different genetic differences

Answer 220

Histological staining for Negri (intracytoplasmic) inclusion bodies. Essentially pathognomonic, but such a serious disease, confirmed with other tests Immunofluorescent staining of brain section using labelled anti-rabies antibodies (conclusive) PCR and sequencing to determine origin/stain

Answer 221

1. vaccinate domestic animals, esp. dogs, cats 2. Kill/vaccinate wildlife vectors (requires resources; cultural implications e.g. culling in Buddhist countries) 3. Control stray feral dog and cat populations (requires resources) 4. Surveillance programs to monitor incidence and distribution 5. Public education regarding pet vaccinations and interactions with wild animals

Answer 222

Developing countries - vaccine dervived from neural tissue, can cause allergic (often fatal) encephalitis Live attenutated or inactivated diploid vaccines for domestic animals and people Live recombinant vaccina virus/vaccine baits used to vaccinate wildlife in some countries

Answer 223

Prophylactic vaccination for at-risk people, domestic animals, wildlife Post exposure: wash and disinfect wound Vaccinated people: series of 2 doses vaccination Unvaccinated people: antiserum (1/2 dose given at wound site) + series of 5 vaccinations

Answer 224

Early: may be vague, non-descript symptoms Later: Shaking, speech difficulties, severe anxiety, vomiting, agitiation, muscle tremors, paralysis, encephalitis

Answer 225

Rhabdovirus (Lyssavirus)

Answer 226

Prodromal phase Paralysis of pharyngeal muscles impacting deglutition -\> appearing to cause excessive salivation Paralytic (herbivores) Aggression, loss of fear response in carnivores Fatal encephalitis Disease is often fatal even in bats

Answer 227

Causes disease in fruit bats and insectivorous bats, also caused disease in some horses and can be zoonotic Does not appear to cause infection or disease in other species

Answer 228

Bats: paresis/paralysis, aggression, self-mutilation, other CNS signs, often found moribund or dead Horses: neurological signs, progressive ataxia, pyrexia

Answer 229

Rabies vaccination and post-exposure protocol (96% shared DNA)

Answer 230

Rhabdovirus

Answer 231

Similar to FMD: causes vescicular lesions on mouth, snout, feet; rupture to leave ulcerative areas

Answer 232

pigs, horses, cattle, zoonotic

Answer 233

Arthropod vectors (probably mechanical)

Answer 234

Rhabdoviruses

Answer 235

Biological transmission by mosquitos and culicoides species

Answer 236

fever, depression, odema, lameness, decreased milk yield, recumbency, abortion related to immune response: better immune system -\> more signs Usually spontaneous regression in days (\<2 weeks) 2% mortality

Answer 237

Attenuated live and inactivated vaccines available, but not often used as only lasts 6-12 months and disease course is acute with low morbidity

Answer 238

Smallpox - globally eradicated Buffalopox Cowpox Sheepox/Goatpox Lumpy skin disease

Answer 239

Coronavirus (in chickens)

Answer 240

Young birds (1-4w.o): gasping, coughing, nasal exudates, respiratory distress, mortality 25-30(-70)% Older birds: milder signs, drop in egg production, lay abnormal eggs Post mortem: mucosal thickening, exudate in nasal passages, trachea, bronchi

Answer 241

live attenuated vaccines in water, by spray, or by eyedrops Vaccine failure from emergence of new antigenic varients

Answer 242

detection of viral antigens or RNA in tracheal tissue virus culture in eggs -\> dwarfed, curled embryos

Answer 243

Coronavirus

Answer 244

In pigs: villous atrophy, profuse diarrhoea, vomiting, dehydration, death Most severe in piglets \< 3w.o \<=100% mortality

Answer 245

Transmissible gastroenteritis Porcine epidemic diarrhoea

Answer 246

detection of viral antigen or RNA in intestinal tissue Pathology -\> villous atrophy

Answer 247

Live attenuated vaccines Vaccination of pregnant sows confers MAB to piglets

Answer 248

watery diarrhoea, sometimes vomiting, mortality in piglets \<3w.o \<=100% Adult pigs with mild or no signs

Answer 249

Vaccination in some countries

Answer 250

Only affects young pigs depression, incoordination, hyperaesthesia vomiting, anorexia, wasting mortality \<=100%

Answer 251

No vaccine Disease not usually seen in endemic herds -\> piglets protected by MAB

Answer 252

Coronavirus

Answer 253

Coronavirus

Answer 254

Coronavirus

Answer 255

effusions in peritoneal and pleural cavities granulomas and necrosis in visceral organs immunosuppression usually in cats \< 2yo usually fatal

Answer 256

Complex pathogenesis: host to feline enteric coronavirus -\> quasispecies variant with tropism changed from enteric epithelium to macrophages immunological basis: defective cell-mediated immunity -\> uncontrolled viral replication -\> production of non-protective AB -\> immune mediated vasculitis

Answer 257

Vaccine available, BUT Experimental infection of immunocompetent cats -\> no disease So questionable efficacy. May have higher disease rates if vaccinated Cross-reacts serologically with feline enteric coronavirus, so antigen detection tests of questionable usefullness

Answer 258

enteric and respiratory coronaviruses Gastroenteritis, may be subclinical In young pups: Severe clinical signs - vomiting, anorexia, depression, diarrhoea Low case fatality rate

Answer 259

Rapid antigen detection tests, sometimes combined with tests for canine parvovirus Some labs have developed PCR tests

Answer 260

Inactivated vaccine, questionable efficacy

Answer 261

Neonatal diarrhoea \< 3w.o Winter dysentery and respiratory disease in cows

Answer 262

Neonatal calves most at risk -\> vaccinate dams, ensure sufficient colostrum intake

Answer 263

fever, cough, pneumonia, diarrhoea 10% mortality (\>750 deaths/8100 cases)

Answer 264

Coronavirus

Answer 265

Epidemiological associations with wildlife meats Chinese rufous horseshoe bats natural reservoir

Answer 266

Severe respiratory disease, 40% mortality (\>800 deaths/\>2000 cases)

Answer 267

Coronavirus

Answer 268

Dromedary camels reservoir host Isolated in bats from Hong Kong Humans

Answer 269

More than 2.5 million deaths worldwide 2% case fatality rate

Answer 270

- change in virus with expanded host range and increased virulence (but viruses have been mutating forever) - disruption to ecosystems, changing behaviours or mixing of species - Changes in wildlife trade, e.g. market structure, use of wild animals

Answer 271

Disease seen in pigs in USA between 1932-1956 (now eradicted) Vesicular disease, similar to FMD Same as San Miguel sea lion virus Probably resulted from feeding pigs marine mammals

Answer 272

Calcivirus

Answer 273

Upper respiratory tract infection (rhinitis, fever, conjunctivitis) ulcerative glossitis Sometimes pneumonia and death, esp. kittens Some virulent strains cause systemic infections with facial and limb oedema, alopecia, and ulceration of feet (rare)

Answer 274

Feline calcivirus (40%) Feline herpesvirus (40%) Chlamydia (20%)

Answer 275

No - Many serotypes, leading to vaccination failure - Shed from oropharynx for \>1y after recovery (carrier animals) - Resistant in environment

Answer 276

Attenuated vaccines available, but vaccination failures not uncommon (many serotypes)

Answer 277

hepatic necrosis, disseminated intravascular coagulopathy, lung congestion and oedema, enlarged spleen, peracute death (6-24hr) Only occurs in rabbits \>2mo. Innate property of young rabbits, immature hepatocytes and enzymes do not support viral replication, possible altered clotting factors. May die from starvation if dam dies. If survive, no disease, AB+ve

Answer 278

killed vaccine used to protect pets, farmed, and lab rabbits Used as a form of biological control in some countries Accidentally released into Australia after trials on neighbouring islands, illegally released in NZ -\> reduced impact, needed to be released out of breeding season to prevent persistance in young rabbits. Effective in more arid regions

Answer 279

Picornavirus (Apthovirus)

Answer 280

Cloven-hoofed animals including cattle, deer, sheep, goats, pigs rarely, humans

Answer 281

Cows, pigs: fever, depression, loss of production vesicles on tongue, gums, snout, feet, teats Sheep and goats with mild or subclincal infections

Answer 282

Loss of production, but less significant in endemic areas Significant impacts on international trade

Answer 283

- short incubation period - high concentrations of virus shed in aerosols, esp. pigs; can be transmitted long distances on wind; - infection via respiratory route - virus can be shed before clinical signs observed - small infectious dose

Answer 284

- large amounts of virus shed into environment, can travel long distances on wind - can be shed before clinical signs observed - rapid replication cycle (short incubation period) - small infective dose - many serotypes & subtypes, short-lived immunity -\> vaccination problems - extremely resistant in environment at neutral pH (resistant to detergents and dessication)

Answer 285

- 7 serotypes: A, O, C, SAT1, SAT2, SAT3, Asia1 - Many subtypes per serotype (\> 80 total) - Immunity to one serotype does not protect against others - Immunity to one subtype may or may not protect against others - Need correct subtype in inactivated vaccines to protect against local strains - short-lived immunity, boosters required /6m

Answer 286

- strict control for importation of animal products/swill feeding to pigs - strict quarantine measures - slaughter of affected animals - +/- ring vaccination - alert authorities if suspect vesicular disease - monitoring/surveillence

Answer 287

foot lesions; snout lesions uncommon

Answer 288

Picornavirus

Answer 289

Picornavirus

Answer 290

13 strains, variable in pathological effects: - asymptomatic - neurological disease comparible to polio in humans (encephalmyelitis, tremors, convulsions, ataxia, paralysis) - reproductive problems in naive pregnant animals (stillbirts, mummification, embryonic death, infertility) - pneumonia, myocarditis, pericarditis

Answer 291

Picornavirus

Answer 292

Paralysis and death in young chickens (2-3wo) drop in egg production in adult birds

Answer 293

horizontal or vertical transmission

Answer 294

Vaccination of pullets (before lay) - \> No vertical transmission - \> Chicks protected by maternal antibodies

Answer 295

cattle, horses, people

Answer 296

upper respiratory tract disease (common cold)

Answer 297

maintained in rodents pigs + other species including monkeys, kangaroos

Answer 298

Pigs: acute myocarditis and sudden death (mortality \<=100% in young pigs) Sudden death in monkeys, kangaroos

Answer 299

Picornavirus

Answer 300

Orthoreovirus Orbivirus Rotavirus

Answer 301

Reovirus (Orbivirus)

Answer 302

arbovirus (biological transmission by Culicoides) Multifactorial: age, stress, rough terrain; sheep vs cattle proportions (preferred host = cattle) Non-contagious between sheep; severity depends on strain of virus and breed of sheep Cattle important amplifying hosts (viremia ~4 months)

Answer 303

Can be prolonged, progressive disease Variability in clinical signs - catarrhal (mm) inflammation of digestive and respiratory tracts with erosions) - fever, swollen lymph nodes - mucopurulent nasal discharge; swelling of nose and mouth - damage to small blood vessels - odema, cyanosis, haemorrhage - distension of tongue - coronitis (hyperaemia, red-\>purple swelling of coronary band) - muscle degeneration, loss of condition, emaciation - congenital abnormalities - Postmortem: yellow/gelatinous/haemorrhagic SQ, thoracic, abdominal oedema -

Answer 304

Usually asymptomatic or mild disease congenital defects from in utero infection

Answer 305

arbovirus \>20 serotypes, not cross protective 11 strains present in Aus; mostly low virulence; this may be changed with changing climactic factors and spread of cattle into sheep areas

Answer 306

Live attenuated or killed vaccines used in some countries (need to know local serotype of prevelance) Attenuated viruses can cause congenital defects Concerns about genetic reassortment of vaccine and field strains (killed vaccines may be safer, but less effective)

Answer 307

peracute - acute, very severe, often fatal disease of horses, donkeys, mules acute dyspnoa, pulmonary oedema, haemorrhage, profuse nasal discharge; may be confused with Hendra

Answer 308

Reovirus (Orbivirus)

Answer 309

Arbovirus (culicoides)

Answer 310

9 serotypes -\> polyvalent vaccine

Answer 311

-Detection of viral antigen (complement fixation test, ELISA) or viral RNA (PCR) in samples of vesicular fluid or tissues

Answer 312

Some strains of Bluetongue African horse sickness

Answer 313

diarrhoea in neonatal animals, depression dehydration or secondary bacterial infection

Answer 314

piglets, calves, foals, lambs, mice, babies

Answer 315

large amounts shed in excretions highly stable in environment

Answer 316

detection of viral antigen in faeces (serological assays) detection of viral RNA in PCR

Answer 317

Ensure sufficient colostrum intake killed vaccines for dams (sows and cows)

Answer 318

Birnavirus | (Bi = 2, (ds)RNA, virus)

Answer 319

Viral replication in Bursa of Fabricius (decreased size) -\> immunosuppression decreased response to pathogens and vaccination depression, ruffled feathers, diarrhoea, trembling, muscular, renal and intestinal lesions; esp chicks 2-6 wo

Answer 320

Live attenuated and killed vaccines Outbreak of virulent strains in some countries not effectively controlled by vaccination -\> serious economic losses

Answer 321

Bunyaviruses

Answer 322

Arbovirus (Cullicoides)

Answer 323

No disease in adult hosts Foetal abnormalities: Arthrogryposis (fixed flexion or extension of joints), hydroencephaly, encephalitis

Answer 324

Mosquitos -\> Cattle, sheep, goats

Answer 325

Endemic to QLD, disease rarely seen (dams infected prior to pregnancies) Outbreak into naive populations in NSW

Answer 326

detection of AB in pre-colostral sera of neonate; or rising titre levels in dam Detection of virus or components not viable, because foetus clears virus prior to birth

Answer 327

Bunyavirus

Answer 328

arbovirus (culicoides)

Answer 329

cattle, sheep, other ruminants

Answer 330

congenital abnormalites, stillbirths, production losses

Answer 331

Bunyavirus

Answer 332

Arbovirus (mosquitoes) with transovarial transmission Humans infected via mosquito or contaminated blood (e.g. autopsy, slaughter)

Answer 333

Mosquitos -\> cattle, sheep, goats, most domestic animals, **zoonotic**

Answer 334

hepatitis, encephalitis, abortion disease and death in humans

Answer 335

Schamallenberg virus Rift Valley fever

Answer 336

Range of signs - asymptomatic - fever, oedema, respiratory signs, abortion, necrosis of small arteries

Answer 337

aerosols, semen

Answer 338

removal of carrier stallions, vaccinations virus present in Australia, but no disease seen (non-virulent strain)

Answer 339

Arteriviruses

Answer 340

Porcine respiratory and reproductive syndrome Equine viral arteritis is present in Australia, but does not cause disease

Answer 341

abortion, neonatal deaths, respiratory disease in young piglets

Answer 342

Killed and live attenuated vaccines in endemic countries

Answer 343

long incubation period (years) slowly progressive, fatal disease caused by an unconvential agent minimal inflammatory response and no immune response brain lesions including deposition of amyloid-like material, vacuolation of neurons

Answer 344

PrP^c = normal protein of unknown function, formed by alpha-helicies PrP^Sc = abnormal protein; beta-pleated sheets; less soluable; resistant to proteases; extremely resistant and difficult to inactivate; stable at a wide range of pH, after boiling, standard autoclaving, most disinfectants, formalin fixation, UV irradiation, ether/alcohol treatment

Answer 345

- autoclaving at 132ºC for 90 min - hot solutions of sodium hydroxide - high concentrations of sodium hypochlorite (NOT a guarentee of inactivation)

Answer 346

**Externally aquired:** Ingestion of PrP^Sc -\> absorbed through intestines, into lymph nodes * *Internally aquired:** 1. Mutation of gene encoding PrP^C -\> PrP^Sc 2. Spontaneous incorrect folding of protein *all processes lead to PrP^Sc in the brain* **Conversion** PrP^Sc induces conversion of PrP^C to PrP^Sc -\> exponential accumulation -\> aggregation of deposits and fibrils -\> disruption of brain function

Answer 347

Host species may be resistant to prions of some species, but not others Species barrier depends on amino acid sequence and shape of proteins

Answer 348

Depends on molecular and biological properties 1. amino acid sequence (reflective of host species) 2. banding pattern on Western blot 3. Bioassays: intracerebral innoculation of mice - incubation period and mortality pattern - distribution of brain lesions - infectivity titre

Answer 349

None - Prion

Answer 350

Sheep, goats More common in sheep

Answer 351

pruritis, decreased wool quality progressive neurological disease: ataxia, tremors, apprehension, increased excitability, paralysis emaciation, death

Answer 352

Scrapie Bovine spongiform encephalopathy Transmissible mink encephalopathy Creuztfeld-Jacob disease Kuru

Answer 353

Usually by oral route; possibly in neonatal period by exposure to foetal fluids and contaminanted milk Pastures may remain contaminated for years (forever?) Susceptibility associated with certain PrP alleles

Answer 354

histopathology of brain (vacuolation, degeneration of neurons) EM for fibrils immunoblotting (no detectable serological response)

Answer 355

None: prion

Answer 356

Cows -\> CJD in humans

Answer 357

progressive neurological disease: hindlimb incoordination, locomotory disturbances, abnormal gait and carriage of head Marked behavioural changes: temperment changes, aggression, loss of herd heirarchy, erratic behaviour and abnormal responses emaciation, death

Answer 358

significant association with eating meat and bone meal, following changes to the processing regie: dose dependent horizontal transmission does not appear to occur, maternal transmission considered minimally important

Answer 359

1. National surveillance: targeted sampling of 400 cows and 450 sheep per year 2. ruminant feed ban: ban on feeding restricted animal material, including blood, bone, meat, fish, poultry, feathermeals to ruminants 3. Quarantine measures: importation of meat and bone meal, cattle, sheep = prohibitied 4, Be prepared: preparedness and response capability

Answer 360

None: prion

Answer 361

severe wasting, trembling, ataxia

Answer 362

Horizontal transmission occurs through prion in saliva

Answer 363

None: prion

Answer 364

Occurs in humans, PNG, as a result of cannabalistic rituals involving consumption of human brains . Transmission via ingestion. Decline in incidence since cannibalism abandoned

Answer 365

1. Sporadic CJD 2. New variant CJD

Answer 366

Humans of all nationalities and ethnic groups, usually \> 50 years old

Answer 367

Mutation of PrP^Cgene to produce PrP^Sc protein Spontaneous misfolding Transmission by: Iatrogenic transmission Corneal transplants Growth hormones harvested from cadavers

Answer 368

Neurological signs: sensory disturbance, sleeping disorders, dementia, motor disturbances, coma, death

Answer 369

Symptoms: psychiatric (e.g. depression/anxiety) cf neurological Pathology: lesions more florid (elaborate) Age of affected people: 19-45 y.o (cf \>50) Epidemiology: likely associated with eating BVD-contaminanted tissues (rather than spontaneous mutation or misfolding)

Answer 370

Presents in a different demographic and with different clinical signs to sporadic CJD Began ~10 years after BSE described Bioassays show similarities to BSE -\> removal of neural tissue now mandated before entering food chain