title: Disparities in sexually transmitted disease rates across the "eight Americas".
abstract: BACKGROUND
  The purpose of this study was to examine rates of 3 bacterial sexually transmitted diseases (STDs; syphilis, gonorrhea, and chlamydia) in 8 subpopulations (known as the "eight Americas") defined by race and a small number of county-level sociodemographic and geographical characteristics. The eight Americas are (1) Asians and Pacific Islanders in specific counties; (2) Northland low-income rural white; (3) Middle America; (4) Low-income whites in Appalachia and Mississippi Valley; (5) Western Native American; (6) Black middle America; (7) Southern low-income rural black; and (8) High-risk urban black.
  
  
  METHODS
  A list of the counties comprising each of the eight Americas was obtained from the corresponding author of the original eight Americas project, which examined disparities in mortality rates across the eight Americas. Using county-level STD surveillance data, we calculated syphilis, gonorrhea, and chlamydia rates (new cases per 100,000) for each of the eight Americas.
  
  
  RESULTS
  Reported STD rates varied substantially across the eight Americas. STD rates were generally lowest in Americas 1 and 2 and highest in Americas 6, 7, and 8.
  
  
  CONCLUSIONS
  Although disparities in STDs across the eight Americas are generally similar to the well-established disparities in STDs across race/ethnicity, the grouping of counties into the eight Americas does offer additional insight into disparities in STDs in the United States. The high STD rates we found for black Middle America are consistent with the assertion that sexual networks and social factors are important drivers of racial disparities in STDs.
authors.affiliation: From the Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. hbc7@cdc.gov
authors.forename: Harrell W
authors.initials: HW
authors.lastname: Chesson
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Kent
authors.forename: Kwame
authors.initials: K
authors.lastname: Owusu-Edusei
authors.forename: Jami S
authors.initials: JS
authors.lastname: Leichliter
authors.forename: Sevgi O
authors.initials: SO
authors.lastname: Aral
mesh_terms: D001061:Appalachian Region / Q000453:epidemiology; D044466:Asian People / Q000706:statistics & numerical data; D044383:Black People / Q000706:statistics & numerical data; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000635:transmission; D005006:Ethnicity; D005260:Female; D006069:Gonorrhea / Q000453:epidemiology* / Q000635:transmission; D006297:Health Services Accessibility / Q000706:statistics & numerical data; D054625:Healthcare Disparities / Q000706:statistics & numerical data*; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data; D008297:Male; D044468:Native Hawaiian or Pacific Islander / Q000706:statistics & numerical data; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D017678:Sex Distribution; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D013587:Syphilis / Q000453:epidemiology* / Q000635:transmission; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American