A definite diagnosis of symptomatic HIV infection (i.e. HIV infection causing disease) can be made if both of the following are present:
- Confirmation of HIV infection by ELISA or PCR testing
- Clinical signs and symptoms common in HIV infection (Remember that young infants do not have symptoms as they cannot give a history.)
Additional blood tests showing a weakened or damaged immune system help to confirm the diagnosis of symptomatic HIV infection but are not essential. Therefore, when laboratory tests of immune function are not available, a diagnosis of illness due to HIV infection can still be made on clinical signs and symptoms together with blood tests confirming HIV infection.