Laboratory diagnosis of virus infections

Question 1

What are the approaches to viral diagnosis?

Answer 1

Virus isolation
Electron microscope
Principle of immunofluorescence
PCR
Serology

Question 2

Advantages and Disadvantages of virus isolation

Answer 2

Advantage: Sensitive, Catch all, Generates isolate for further study, detects viable virus, and adaptation for rapid result
Disadvantage: Slow, need technical skills, not applicable to all viruses

Question 3

Advantages and Disadvantages of EM

Answer 3

A: catch all, cost saving, rapid technique when +, detects unculturable and non viable viruses
D: requires skilled staffs, poor sensitivity if low abundance, maintenance is costly

Question 4

Advantages and Disadvantages of immunofluorescence

Answer 4

A: rapid, sensitive for some viruses
D: requires skilled staffs, not catch all, dependent on high quality specimen

Question 5

Advantages and Disadvantages of pcr

Answer 5

A: highly sensitive, can be modified to detect specific virus types, rapid
D: costly, target seq must be known and highly conserved

Question 6

Advantages and Disadvantages of serology

Answer 6

A: IgG is an indicator of past infection, IgM is an indicator of recent infection, rapid, can be non invasive
D: cross reactivity