Questions and Answers
What is the term for the circulation of viruses through the whole body, usually in the blood or lymph?
Viraemia
Which of the following organs is typically affected during the secondary viraemia of a blood-borne virus?
Liver
What is the route of transmission of Canine Parvovirus?
Faecal-oral transmission
What is the term for the initial replication of a virus in cells at the site of entry?
Signup and view all the answers
What is the site of major pathology during a viral infection?
Signup and view all the answers
What is the difference between acute and persistent viral infection?
Signup and view all the answers
What is a necessary condition for a cell to be infected by a virus?
Signup and view all the answers
Which type of cells does Canine parvovirus need to infect?
Signup and view all the answers
What can affect the disease severity of a viral infection?
Signup and view all the answers
How does Rabies virus reach the central nervous system (CNS) after infection?
Signup and view all the answers
What is the role of the salivary gland in the transmission of Rabies virus?
Signup and view all the answers
Why does the immune system of the host have a reduced ability to detect and respond to Rabies virus infection in the brain?
Signup and view all the answers
What is the primary function of the keratinized layer of skin in relation to viral infections?
Signup and view all the answers
Which of the following immune cells is NOT typically recruited to sites of inflammation in the skin?
Signup and view all the answers
What is the term for the spread of viruses from the initial site of infection to other parts of the body through the bloodstream?
Signup and view all the answers
Which of the following is NOT a route of transmission for viruses?
Signup and view all the answers
What is the term for the process by which viruses change to infect other hosts?
Signup and view all the answers
Which of the following immune responses is NOT specific to a particular tissue or site?
Signup and view all the answers
What is the primary reason why viruses cause pathology in hosts?
Signup and view all the answers
What determines the viral fitness of a virus?
Signup and view all the answers
What is the term for the damage to host cells caused by a virus?
Signup and view all the answers
Why do emerging viruses not have to evolve to become less pathogenic?
Signup and view all the answers
What is the term for the process by which a virus is released from an infected host?
Signup and view all the answers
What is the site of entry and exit for FMDV?
Signup and view all the answers
What is the primary factor that influences the ease of transmission and dose of insect-borne viruses in a livestock population?
Signup and view all the answers
Which of the following factors is NOT a viral factor that influences whether infection results in disease?
Signup and view all the answers
What is the characteristic of latent infections that allows the virus to reactivate in certain circumstances?
Signup and view all the answers
Which of the following climatic conditions is likely to facilitate the flying of midges, increasing the transmission of insect-borne viruses?
Signup and view all the answers
What is the outcome of an acute viral infection in a host?
Signup and view all the answers
Which of the following Practices is likely to increase the risk of transmission of insect-borne viruses in a livestock population?
Signup and view all the answers
Study Notes
Viral Infection and Pathogenesis
- Viruses cause disease and pathology, which may be necessary for transmission
- Viral fitness is determined by survival and transmission
Stages of Viral Infection
- Entry into host through various routes (e.g., skin, respiratory tract, gastrointestinal tract)
- Local replication at site of entry
- Primary viraemia
- Replication at secondary site(s)
- Secondary viraemia
- Target organ replication
Mechanisms of Viral Pathology
- Direct effects: cytopathic effects (CPE) damage to host cells, resulting in cell death
- Indirect effects: virus-induced immune response, inflammation, and tissue damage
Viral and Host Factors Influencing Disease
- Viral factors: tropism, virulence, and level of replication
- Host factors: susceptibility, immune response, and genetics
Types of Viral Infection
- Acute infection: rapid, self-limiting infection cleared by the immune system
- Persistent infection: virus persists at low levels following recovery, with potential to reactivate
Latent Infection
- Virus persists in immune-privileged sites (e.g., neurons)
- Limited viral protein synthesis and infectious virus production
- Latency-associated transcripts reduce MHC expression and block apoptosis
Transmission of Viruses
- Faecal-oral transmission (e.g., FMDV)
- Salivary transmission (e.g., rabies)
- Blood-borne transmission (e.g., H5 avian influenza)
- Vector-borne transmission (e.g., insect-borne viruses)
Defences Against Viral Infection
- Physical barriers (e.g., skin, mucosal surfaces)
- Innate immune system (e.g., macrophages, neutrophils, natural killer cells)
- Adaptive immune system (e.g., antibodies, cytotoxic T cells)
Environmental Factors Influencing Viral Transmission
- Climatic conditions (e.g., high rainfall, temperature)
- Nutrition and feed (e.g., pasture, animal feed)
- Stocking density and animal husbandry practices
- Veterinary policy (e.g., vaccination programs)
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
