title: Spatial epidemiology of HIV-hepatitis co-infection in the State of Michigan: a cohort study.
abstract: BACKGROUND
  Acquired immunodeficiency syndrome (AIDS) is a continuing global public health threat affecting millions of individuals. In 2009, 33.3 million people worldwide were living with human immunodeficiency virus (HIV) infection. HIV-infected individuals are at an increased risk of acquiring hepatitis B and hepatitis C viral (HBV, HCV)infections because of shared transmission routes. The purpose of this study was to identify geographical clusters of HIV-(HBV/HCV) co-infection in the State of Michigan.
  
  
  METHODS
  Retrospective cohort data on HIV-infected individuals were matched to all hepatitis B and C cases in Michigan during the period of January 1, 2006 through December 31, 2009. A prevalence map of HIV infection was created and spatial clusters of HIV-hepatitis B or C co-infection were detected using GeoDa's bivariate local Moran's I and SaTScan's discrete Poisson model.
  
  
  RESULTS
  A bivariate cluster of high prevalence HIV and hepatitis B or C was identified in the Detroit Metropolitan Area and surrounding counties. A Poisson cluster of HIV-hepatitis B or C co-infection was identified, relative risk (RR) = 1.38 (p = 0.029) in the western and northwestern counties of Lower Michigan, controlling for sex, race, and AIDS status.
  
  
  CONCLUSIONS
  This study identified elevated HIV-hepatitis B or C co-infection unexplained by sex, race or AIDS status in counties outside of the Detroit Metropolitan Area where HIV prevalence was highest in Michigan. The findings from this study may be used to target future public health policy and healthcare interventions for HIV-hepatitis co-infection in these areas.
authors.affiliation: a Department of Epidemiology & Biostatistics , Michigan State University , East Lansing , MI , USA.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Butt
authors.affiliation: b Department of Geography , Michigan State University , East Lansing , MI , USA.
authors.forename: Sue
authors.initials: S
authors.lastname: Grady
authors.affiliation: c Program in Public Health, Michigan State University , East Lansing , MI , USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Wilkins
authors.affiliation: d Body Art, Viral Hepatitis & HIV Analysis Unit, HIV/STD/VH/TB Epidemiology Section , Michigan Department of Community Health Lansing , East Lansing , MI , USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hamilton
authors.affiliation: a Department of Epidemiology & Biostatistics , Michigan State University , East Lansing , MI , USA.
authors.forename: David
authors.initials: D
authors.lastname: Todem
authors.affiliation: a Department of Epidemiology & Biostatistics , Michigan State University , East Lansing , MI , USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Gardiner
authors.affiliation: a Department of Epidemiology & Biostatistics , Michigan State University , East Lansing , MI , USA.|e Departments of Large Animal Clinical Sciences and Epidemiology , 165 Food Safety and Toxicology Center, Michigan State University , East Lansing , MI , USA.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Saeed
mesh_terms: D016000:Cluster Analysis; D015331:Cohort Studies; D060085:Coinfection / Q000453:epidemiology* / Q000821:virology; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000453:epidemiology* / Q000821:virology; D006509:Hepatitis B / Q000150:complications / Q000453:epidemiology* / Q000821:virology; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D016012:Poisson Distribution; D015995:Prevalence; D011634:Public Health; D012189:Retrospective Studies; D013997:Time Factors
keywords: HIV and hepatitis co-infection; HIV/AIDS; cluster analysis; hepatitis