Question

What is the window phase of an infection? How is this concept important for testing for HIV infection in blood banks?

Answer 1

Window peroid of an infection:

The window period is the time between when a person gets HIV and when a test can accurately detect HIV infection.During the window period a person can be infected with HIV and be very infectious but still test HIV negative. The window period for a 4th generation antigen/antibody test is four weeks.

Concept important for testing for HIV infection in blood banks:

• Antibody tests check for HIV antibodies in blood or fluids from the mouth. HIV antibodies are disease-fighting proteins that the body produces in response to HIV infection.
• Tests selected to screen donor blood and tissue must provide a high degree of confidence that HIV will be detected if present (that is, a high sensitivity is required).
• A combination of antibody, antigen and nucleic acid tests are used by blood banks in Western blot.