IRIS (immune reconstitution inflammatory syndrome) – illnesses that occur when HIV treatment is started when the CD4 count is very low.

IRIS occurs because the immune system quickly becomes stronger and identifies infections that it was previously too weak to fight.

IRIS can occur in 1 in 4 (25%) people who start with a CD4 count under 50 cells/mm3.

Although the symtoms are serious, IRIS can usually be easily managed.

Common infections related to IRIS include TB and CMV.