Lesson 4

Question 1

Laboratory diagnosis for viral diseases is performed to:

Answer 1

1. Confirm the viral etiology of diseases for which antiviral chemotherapeutic agents are available.
2. Screen blood donors for blood-borne viral pathogens, such as hepatitis B and C, human immunodeficiency virus (HIV), etc., to prevent transmission of infection by transfusion of blood and blood-borne products contaminated by viruses.
3. Define the viral disease process.
4. Perform seroepidemiological studies of viral infections.
5. Monitor and detect epidemics of serious virus infections, such as influenza, encephalitis, and poliomyelitis, etc., earlier so as to initiate appropriate control measures to prevent further spread of these diseases.

Question 2

Laboratory procedures used in diagnosis

Answer 2

1. demonstration of virus-induced cytopathic effects (CPEs) in the cells
2. direct detection of viruses
3. virus isolation and viral assays
4. detection of viral proteins and other enzymes
5. detection of viral genome
   viral serology