Background: WHO recommends initiating combination antiretroviral treatment at the minimal CD4 cell threshold of 350 cells/μl. In sub-Saharan Africa, the time for a recently infected patient to reach this threshold is unclear.
Method: We estimated the probability of reaching different CD4 cell thresholds over time in the ANRS 1220 cohort of HIV-1 seroconverters in Côte d'Ivoire. CD4 cell slopes were estimated using a mixed linear model. Probabilities of crossing the 350 and 500 cells/μl CD4 cell thresholds were estimated by the Kaplan–Meier method.
Results: Between 1997 and 2009, 304 recent seroconverters have been enrolled in the Primo-CI cohort (62% men, median baseline age 29 years and median time since the estimated date of seroconversion 9 months). The probability of having a first CD4 cell count below 500 cells/μl was 0.57, 0.72, 0.79 and 0.84 at study entry, 2, 4 and 6 years, respectively. For a first CD4 cell count below 350 cells/μl, these figures were 0.29, 0.40, 0.55 and 0.67. The time for 75% of patients to reach the threshold was 3.0 years for 500 cells/μl and 7.0 years for 350 cells/μl.
aProgramme PAC-CI, Abidjan, Côte d'Ivoire, France
bInserm U897, France
cUniversité Victor Segalen Bordeaux 2, ISPED, Bordeaux, France
dCeDReS Laboratory, University Hospital of Treichville, Abidjan, Côte d'Ivoire.
Received 8 December, 2010
Revised 4 February, 2011
Accepted 24 February, 2011
Correspondence to Dr Albert K. Minga, Programme PAC-CI, 18 BP 1954, Abidjan 18, Côte d'Ivoire. Tel: +225 21 355278/07 087661; fax: +225 21 355995; e-mail: firstname.lastname@example.org