Table 7. Diagnostic criteria for initial immunological failure among study patients on anti-retroviral therapy in (n = 226).

Diagnostic criteria	Frequency	Per cent
Follow-up CD4 cell count dropped by at least 50% from peak value	131	57.96
CD4 cell count persistently below 100/mm 3	17	7.52
Follow-up CD4 cell count dropped to or below baseline	78	34.51
Total	226	100.00