AIDS diagnoses at higher CD4 counts in Australia following the introduction of highly active antiretroviral treatment

Objectives: To assess whether AIDS cases in Australia have been diagnosed a t higher CD4 counts since the widespread availability of highly active anti retroviral treatment (HAART) in mid-1996. Methods: Data on the CD4 count at AIDS diagnosis For AIDS cases diagnosed b etween 1 January 1992 and 31 December 1997, and reported to the National AI DS Registry in Australia by 31 March 1998, were analysed. The median CD4 co unt at AIDS diagnosis, and the proportions of AIDS diagnoses with a CD4 cou nt above 100 cells/mu l, and above 200 cells/mu l, were calculated by the y ear of diagnosis, both for all AIDS-defining illnesses, and for each illnes s separately. Analyses were also stratified by the time interval between HI V and AIDS diagnoses (less than or equal to, or more than, 3 months) becaus e people diagnosed with HIV close to the diagnosis of AIDS would generally not have received any antiretroviral treatment before the diagnosis of AIDS , and so no trends in CD4 counts at the diagnosis of AIDS would be expected in this group. Results: There was an increase in CD4 count at AIDS diagnosis in 1996 and 1 997, although this increase was only apparent for AIDS-defining illnesses o ther than Pneumocystis carinii pneumonia (PCP), and was limited to AIDS cas es diagnosed with HIV more than 3 months before AIDS. In cases of AIDS othe r than PCP, and diagnosed with HIV more than 3 months before AIDS, the medi an CD4 count increased from 50 cells/mu l in 1995 to 80 cells/mu l in 1996 and 134 cells/mu l in 1997. Conclusions: There has been an increase in the CD4 count at AIDS diagnosis for most AIDS-defining illnesses in Australia coincident with the widesprea d availability of HAART. (C) 1999 Lippincott Williams & Wilkins.