title: Declining HIV prevalence and incidence in perinatal women in Harare, Zimbabwe.
abstract: BACKGROUND
  In several recent papers it has been suggested that HIV prevalence and incidence are declining in Zimbabwe as a result of changing sexual behavior. We provide further support for these suggestions, based on an analysis of more extensive, age-stratified, HIV prevalence data from 1990 to 2009 for perinatal women in Harare, as well as data on incidence and mortality.
  
  
  RESULTS
  Pooled prevalence, incidence and mortality were fitted using a simple susceptible-infected (SI) model of HIV transmission; age-stratified prevalence data were fitted using double-logistic functions. We estimate that incidence peaked at 5.5% per year in 1991 declining to 1% per year in 2010. Prevalence peaked in 1998/9 [35.9% (CI95: 31.3-40.7)] and decreased by 67% to 11.9% (CI95: 10.1-13.8) in 2009. For women <20y, 20-24y, 25-29y, 30-34y and ≥35y, prevalence peaked at 25.4%, 34.2%, 47.1%, 44.0% and 33.5% in 1993, 1996, 1997, 1998 and 1999, respectively, declining thereafter in every age group. Among women <25y, prevalence peaked in 1994 at 28.8% declining thereafter by 69% to 8.9% (CI95: 6.8-11.5) in 2009.
  
  
  CONCLUSIONS
  HIV prevalence declined substantially among perinatal women in Harare after 1998 consequent upon a decline in incidence starting in the early 1990s. Our model suggests that this was primarily a result of changes in behavior which we attribute to a general increase in awareness of the dangers of AIDS and the ever more apparent increases in mortality.
authors.affiliation: Zvitambo Project, Harare, Zimbabwe.
authors.forename: John W
authors.initials: JW
authors.lastname: Hargrove
authors.forename: Jean H
authors.initials: JH
authors.lastname: Humphrey
authors.forename: Agnes
authors.initials: A
authors.lastname: Mahomva
authors.forename: Brian G
authors.initials: BG
authors.lastname: Williams
authors.forename: Henry
authors.initials: H
authors.lastname: Chidawanyika
authors.forename: Kuda
authors.initials: K
authors.lastname: Mutasa
authors.forename: Edmore
authors.initials: E
authors.lastname: Marinda
authors.forename: Michael T
authors.initials: MT
authors.lastname: Mbizvo
authors.forename: Kusum J
authors.initials: KJ
authors.lastname: Nathoo
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Iliff
authors.forename: Owen
authors.initials: O
authors.lastname: Mugurungi
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000401:mortality*; D015497:HIV-1; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D018743:Perinatal Care; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000401:mortality* / Q000821:virology; D015995:Prevalence; D018571:Sentinel Surveillance; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult; D015030:Zimbabwe / Q000453:epidemiology