title: Rate of decline of absolute number and percentage of CD4 T lymphocytes among HIV-1-infected adults in Dar es Salaam, Tanzania.
abstract: OBJECTIVE
  To determine the rate of decline of CD4 T lymphocytes among HIV-1-infected individuals.
  
  
  METHODS
  A prospective open cohort study of workers in three hotels in Dar es Salaam.
  
  
  METHODS
  The workers were seen yearly during the study. CD4 T lymphocyte counts were determined using flow cytometry. The CD4 T-lymphocyte slopes were determined using a linear regression model.
  
  
  RESULTS
  During the 9-year study period 682 subjects were selected for lymphocyte subset determinations. Of these, 94 HIV-1-seroprevalent (72%), 77 HIV-1-seroincident (67%) and 325 seronegative (75%) individuals had three or more CD4 T-cell determinations, and were used for calculations of CD4 cell slopes with a mean follow-up period of 71.4, 52.9 and 86.0 months, respectively. The median yearly decline of the CD4 T-lymphocyte counts and percentages among seroprevalent individuals was -21.5 cells/microl and -1.3%; among the seroincident individuals the median decline was -22.0 cells/microl and -1.5%. In seroincident individuals the mean duration to a CD4 T-lymphocyte level corresponding to a definition of AIDS was 13.3 years or 11.8 years for CD4 cell counts or percentages, respectively. HIV-1-seropositive subjects who died had significantly steeper CD4 cell slopes than those who survived.
  
  
  CONCLUSIONS
  The rates of CD4 T-lymphocyte decline in HIV-1-infected individuals in our population are similar to those reported in Europe and north America.
authors.affiliation: Department of Microbiology, Muhimbili University College of Health Sciences, Dar es Salaam, Tanzania.
authors.forename: Willy
authors.initials: W
authors.lastname: Urassa
authors.forename: Mohamed
authors.initials: M
authors.lastname: Bakari
authors.forename: Eric
authors.initials: E
authors.lastname: Sandström
authors.forename: Andrew
authors.initials: A
authors.lastname: Swai
authors.forename: Kisali
authors.initials: K
authors.lastname: Pallangyo
authors.forename: Ephraim
authors.initials: E
authors.lastname: Mbena
authors.forename: Fred
authors.initials: F
authors.lastname: Mhalu
authors.forename: Gunnel
authors.initials: G
authors.lastname: Biberfeld
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003906:Developing Countries; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000276:immunology*; D018023:HIV Seronegativity / Q000276:immunology; D006679:HIV Seropositivity / Q000276:immunology; D015497:HIV-1; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013636:Tanzania