title: Epidemiology of HIV in the United States and Canada: current status and ongoing challenges.
abstract: OBJECTIVE
  To determine the status of the HIV epidemic in the United States and Canada.
  
  
  METHODS
  We used data on AIDS and HIV diagnoses for 1996-2005 reported to the United States and Canadian national surveillance systems to determine trends in AIDS and HIV (33 US states only) diagnoses and to identify population groups most affected by HIV. HIV incidence for Canada was determined using back-calculation methods. We also determined the proportion of persons diagnosed late (HIV diagnosis within 12 months before AIDS diagnosis).
  
  
  RESULTS
  AIDS diagnosis rates were higher in 2005 among blacks (54.1 per 100,000) and Hispanics (18.0) compared with whites (5.9) in the United States and among blacks (4.7) and aboriginal peoples (4.9) compared with whites (0.7) in Canada. Since 2001, HIV diagnoses increased among men who have sex with men in both countries and in Canada, increased among persons from HIV-endemic countries and where heterosexual contact was the only identified risk of transmission. Overall, HIV incidence remained relatively stable in Canada during that period. A large proportion of persons were diagnosed late in the disease process (United States, 54.3%; Canada, 64.2%).
  
  
  CONCLUSIONS
  Rates of HIV transmission remain a challenge in both the United States and Canada as overall diagnosis rates have not decreased in recent years. Renewed prevention efforts are needed to further reduce the high HIV diagnosis rates among racial/ethnic minorities and to decrease HIV transmission among men who have sex with men.
authors.affiliation: Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. ixh1@cdc.gov
authors.forename: H Irene
authors.initials: HI
authors.lastname: Hall
authors.forename: Jennifer
authors.initials: J
authors.lastname: Geduld
authors.forename: David
authors.initials: D
authors.lastname: Boulos
authors.forename: Philip
authors.initials: P
authors.lastname: Rhodes
authors.forename: Qian
authors.initials: Q
authors.lastname: An
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Mastro
authors.forename: Robert S
authors.initials: RS
authors.lastname: Janssen
authors.forename: Chris P
authors.initials: CP
authors.lastname: Archibald
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005006:Ethnicity; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012725:Sexual Behavior; D014481:United States / Q000453:epidemiology; D055815:Young Adult