Microbiology: Virology - Pathogenesis & Lab Diagnosis of Viral Infections

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What is the stage of the infectious disease cycle where the host is infectious but does not exhibit clinical signs?

Latent period

Infectious period

Subclinical infectious period (correct)

Incubation period

Which of the following best describes the relationship between pathogenicity and virulence?

Pathogenicity and virulence are synonymous terms that refer to the potential of a virus to cause disease in a host.

Pathogenicity is a measure of the virus's ability to enter and replicate within host cells, while virulence is a measure of the host's ability to mount an immune response.

Pathogenicity refers to the ability of a virus to infect a host, while virulence describes the host's immune response to the virus.

Pathogenicity is a qualitative measure of a virus's ability to cause disease, while virulence is a quantitative measure of the severity of the disease caused. (correct)

What is the term used to describe the range of tissues that a virus can infect?

Tissue specificity

Tissue tropism (correct)

Tissue susceptibility

Tissue affinity

Which of the following factors can influence a virus's tissue tropism?

All of the above Signup and view all the answers

Why are highly virulent avian influenza strains able to infect a wider range of tissues in birds compared to mammals?

Avian influenza viruses can replicate more efficiently in the intestinal tract of birds. Signup and view all the answers

What is the stage of the infectious disease cycle where the host exhibits clinical signs of the disease?

Clinical period Signup and view all the answers

Which of the following patterns of infection is characterized by the virus remaining in the host's body in a dormant state, with periodic reactivation and shedding of the virus?

Latent infection Signup and view all the answers

Which of the following patterns of infection is characterized by the virus remaining in the host's body without causing any clinical signs, but with the potential to reactivate and cause disease?

Persistent asymptomatic infection Signup and view all the answers

What type of cell cultures are transformed and immortal?

Continuous cell lines Signup and view all the answers

Which type of cell culture can grow for up to 100 generations?

Diploid cell strains Signup and view all the answers

What are the three main types of cell cultures used for viral diagnosis?

Primary, diploid, and continuous Signup and view all the answers

What is the purpose of using immunoassays or molecular assays in viral diagnosis?

To detect noncytopathic infected cells Signup and view all the answers

What is the main limitation of using respiratory fluids for viral diagnosis?

Not suitable for feces and vesicle fluid Signup and view all the answers

Which of the following is a key step in the laboratory diagnosis of viral infections?

All of the above Signup and view all the answers

What is the purpose of interpreting positive laboratory test results in the context of the clinical history and signs?

To ensure the accuracy of the laboratory test Signup and view all the answers

What is the main advantage of using continuous cell lines for viral diagnosis?

They are transformed and immortal Signup and view all the answers

What is a potential consequence of mutations in the HA that allow it to be cleaved by furins?

Development of cancer Signup and view all the answers

What is one of the pathogenesis mechanisms associated with host cell damage?

Immune suppression Signup and view all the answers

Which method is used for the detection and identification of viral nucleic acids?

Detection of viral antigens Signup and view all the answers

What are the advantages of using electron microscopy for diagnosing viral infections?

Rapid diagnosis Signup and view all the answers

What is a disadvantage associated with electron microscopy in diagnosing viral infections?

Low sensitivity Signup and view all the answers