What are the risk factors for cytomegalovirus retinitis?

Although most people are exposed to the CMV retinitis virus in their lives, only certain groups with depressed immune systems are at risk. People with AIDS, particularly those with a low CD4 count, are susceptible, as are those taking drugs that limit the effectiveness of the immune system. People going through major medical procedures like bone marrow or organ transplants have less effective immune systems and become vulnerable, as do people undergoing chemotherapy.