HIV destroys the immunity of an infected person. As a result, he will develop infections that normally do not affect healthy persons. They are called opportunistic infections as they "seize" the opportunity to cause a problem.
The common infections include respiratory complications such as Pneumocystis pneumonia (PCP), tuberculosis (TB) and mycobacterium avium intracellulare (MAI). The neurological system and gastrointestinal tracts are also commonly affected. e.g. cytomegalovirus infection of the retina and cryptococcus infection of the meninges. Moreover, some viruses can cause cancers such as Kaposi's sarcoma and lymphoma.
- Common HIV-related Complications (published by Department of Health, 2012)
Many of the opportunistic infections can be prevented and treated. However, recurrence is common if the patient remains in an immunodeficiency state. Besides the antiretroviral therapy, the patient generally needs long term maintenance treatment to prevent the opportunistic infections from relapsing until the occurrence of satisfactory immune recovery.