Answer to the comment (for preserving the format):
If I have misunderstood, please let me know. You meant patients who have either HIV or AID right? If so:
AIDS patient: 艾滋病患者
儿童艾滋病患者 (lit: child AIDS patient) or 艾滋病儿童患者 (lit: AIDS child patient)
HIV patient: HIV 患者 (1), 艾滋病病毒患者 (2), 艾滋病病毒感染者 (3), HIV感染者. For specifically referring to children, add "儿童" in front of the terms listed. For example, 儿童 HIV 患者.
(1) Sometimes you will see the English abbr. instead of its full Chinese translation.
(2) I am using "AIDS virus patient" rather than the full name as it is more natural and commonly used as compared to the full form.
(3) 感染者 means "infected person".