Virology (week 7)

They cause a wide variety of clinical disease

The virus is highly stable in the environment, surviving years without a host

The virus is resistant to pH

The virus causes latent infection

Non-enveloped, spherical, single stranded positive sense RNA

Enveloped, spherical, single stranded positive sense RNA

Enveloped, spherical, single stranded DNA

Enveloped, spherical, double stranded positive sense RNA

Non-enveloped, spherical, double stranded positive sense RNA

Respiratory and/or gastrointestinal epithelium

Respiratory and/or myocaridal epithelium

Bone marrow and lymph nodes

Respiratory and/or circulatory system endothelium

Second most common cause of diarrhoea in calves

Most common cause of diarrhoea in calves

Most common cause of abortions in cattle

Leads to infertility in cattle

Less than 2 weeks old – diarrhoea lasts 4-5 days

Less than 10 weeks old – diarrhoea lasts 2-10 days

Less than 2 weeks old – diarrhoea lasts 2-10 days

Around 7 months old- diarrhoea lasts 4-5 days

Faecal–oral route of transmission

Droplet transmission

Vector transmission

Venereal transmission

Fomite transmission

Fluid absorption and digestion of disaccharides is reduced

Build up of fibrosis tissue due to damage, resulting in gut motility being reduced

Fluid absorption and digestion of fats is reduced

Fluid absorption increases causing oedema

Feline infectious peritonitis virus (FIPV)

Feline panleukopaenia

Feline Herpesvirus

Feline adenovirus

FECV causes a mild or inapparent enteritis while FIPV is a sporadic, fatal disease of young cats

FIPV causes a mild or inapparent enteritis while FECVV is a sporadic, fatal disease of young cats

FECV is always asymptomatic in domestic cats while FIPV is a sporadic, fatal disease of young cats

FIPV is always asymptomatic in domestic cats while FECV is a sporadic, fatal disease of young cats

Shed in faeces and oronasal secretions, transmission by inhalation, or ingestion

Shed in urine, transmission ingestion

Shed in papules on the skin, transmission by direct contact

Transmission by vectors

Primarily respiratory transmission by aerosol (shed from respiratory tract for several weeks) and recovered from faeces and eggs

Primarily faecal-oral route

Vector transmission

Venereal transmission

In young birds

In adult birds

In aged birds

In embryos, causing death

Virus isolation (egg inoculation) and serology (neutralisation, ELISA, HI)

Virus isolation (egg inoculation) and bacterial culture

Bacterial culture and PCR

Physical examination

Yes, live and killed vaccines are available

Yes, a live vaccine is available only

No vaccines are available

A vaccine was available until the virus mutated in 2015

Inhalation and ingestion - faecal oral route or via aerosol

Fomite spread

Vector borne transmission

Ingestion- oral route

Variable (depending on the virus)

Not contagious but are infectious

Highly contagious

Enveloped ss + sense RNA viruses with an Icosahedral capsid

Non-enveloped ss + sense RNA viruses with an Icosahedral capsid

Enveloped ds + sense RNA viruses with an Icosahedral capsid

Enveloped ss - sense RNA viruses with an Icosahedral capsid

Non-enveloped ss - sense RNA viruses with an Icosahedral capsid

Confined to Western hemisphere

Confined to the Northern hemisphere

Confined to Europe

Confined to the Southern hemisphere

up to 9 days

up to 13 days

up to 2 days

up to 21 days

Arthropod borne viruses.
“Viruses that replicate in their haematophagous arthropod hosts and transmitted to vertebrate host by biting”

Arboviruses – Arachnid borne viruses.
“Viruses that replicate in their haematophagous arachnid hosts and transmitted to vertebrate host
by biting”

Amphibian borne viruses.
“Viruses that replicate in their haematophagous amphibian hosts and transmitted to vertebrate host by biting”

Aquatic borne viruses.
“Viruses that replicate in their haematophagous aquatic hosts and transmitted to vertebrate host by biting”

Enveloped, ss + sense RNA viruses

Non-enveloped, ss + sense RNA viruses

Enveloped, ds + sense RNA viruses

Enveloped, ss - sense RNA viruses

Stable in meat products for weeks/months. Enabled re-introduction and spread

Stable in the air for weeks/months. Enabled re-introduction and spread

Not stable in the environment, reintroduction occurred with an accidental release from a laboratory in Germany

Stable in milk products for weeks/months. Enabled re-introduction and spread

Reproductive failure (abortion, stillbirths, weak young, otherwise inapparent infection of young)

Fever, Lethargy and Recovery or Hyperexcitable and Death

GIT dysfunction

Total organ necrosis

Reproductive failure (abortion, stillbirths, weak young, otherwise inapparent infection of young)

Fever, Lethargy and Recovery or Hyperexcitable and Death

GIT dysfunction

Respiratory disease (oronasal discharge)

Acute disease – bovine virus diarrhoea
Chronic disease – mucosal disease (persistent infection)

Acute disease –mucosal disease (persistent infection)
Chronic disease – bovine virus diarrhoea

Acute disease – death
Chronic disease – mucosal disease (persistent infection)

Acute disease – bovine virus diarrhoea
Chronic disease – Asymptomatic shedding

Infection of susceptible adult cattle usually of little consequence unless pregnant (transplacental spread common)

Asymptomatic infection in the feotus

Abortion of the feotus if infection late in gestation (> 125 days)

Profuse watery diarrhoea, Nasal discharge, salivation Ulcerative lesions, death

CNS dysfunction, death

Heart failure

Asymptomatic

In tonsils, spread to lymph and endothelial cells

In epithelial cells

In the GIT

Haemorrhages, DIC, thrombosis of small vessels

CNS dysfunction

Reproductive dysfunction