title: Increase in HIV diagnoses among men who have sex with men in New Zealand from a stable low period.
abstract: OBJECTIVE
  To describe trends in HIV diagnoses among men who have sex with men (MSM) in New Zealand 1996-2008, and to identify characteristics associated with HIV diagnoses in the resurgent phase.
  
  
  METHODS
  Data collected through routine surveillance of HIV infection, where the mode of transmission included homosexual contact, were analysed over the period 1996-2008.
  
  
  RESULTS
  Annual HIV diagnoses were low during 1996-2000, rose sharply between 2001 and 2005, and remained at an elevated plateau between 2006 and 2008. Over a quarter were attributed to HIV infection acquired overseas (28.6%). Trends in diagnoses of locally acquired HIV infection closely mirrored the trend of three diagnosis phases. Increases in locally acquired HIV occurred among virtually all characteristics of MSM. However, compared with MSM diagnosed in the low phase 1996-2000, individuals diagnosed in the resurgent phase 2001-05 were more likely to be aged 30-39, to have tested HIV-negative within the previous 2 years, to live in the Northern region encompassing Auckland, and to be of non-European ethnicity. The per capita HIV diagnosis rate among MSM was lowest in 1997, at 22.0 per million males aged 15-64, and highest in 2005 at 66.7 per million.
  
  
  CONCLUSIONS
  The increase in HIV diagnoses among MSM in New Zealand was primarily due to an increase in locally acquired HIV infection, which disproportionately affected some groups of MSM. Factors driving this change in local epidemic conditions need to be identified. The rate of new HIV diagnoses among MSM remains low by international standards.
authors.affiliation: Research Unit, New Zealand AIDS Foundation, PO Box 6663, Wellesley Street, Auckland 1141, New Zealand. peter.saxton@otago.ac.nz
authors.forename: Peter J W
authors.initials: PJ
authors.lastname: Saxton
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Dickson
authors.forename: Susan M
authors.initials: SM
authors.lastname: McAllister
authors.forename: Katrina
authors.initials: K
authors.lastname: Sharples
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Hughes
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D058872:Epidemics / Q000706:statistics & numerical data*; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000635:transmission; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D055815:Young Adult