title: Transitions from injection-drug-use-concentrated to self-sustaining heterosexual HIV epidemics: patterns in the international data.
abstract: BACKGROUND
  Injecting drug use continues to be a primary driver of HIV epidemics in many parts of the world. Many people who inject drugs (PWID) are sexually active, so it is possible that high-seroprevalence HIV epidemics among PWID may initiate self-sustaining heterosexual transmission epidemics.
  
  
  METHODS
  Fourteen countries that had experienced high seroprevalence (<20%) HIV epidemics among PWID and had reliable data for injection drug use (IDU) and heterosexual cases of HIV or AIDS were identified. Graphs of newly reported HIV or AIDS cases among PWID and heterosexuals were constructed to identify temporal relationships between the two types of epidemics. The year in which newly reported cases among heterosexuals surpassed newly reported cases among PWID, aspects of the epidemic curves, and epidemic case histories were analyzed to assess whether it was "plausible" or "highly unlikely" that the HIV epidemic among PWID might have initiated the heterosexual epidemic in each country.
  
  
  RESULTS
  Transitions have occurred in 11 of the 14 countries. Two types of temporal relationships between IDU and heterosexual HIV epidemics were identified, rapid high incidence transitions vs. delayed, low incidence transitions. In six countries it appears "plausible" that the IDU epidemic initiated a heterosexual epidemic, and in five countries it appears "highly unlikely" that the IDU epidemic initiated a heterosexual epidemic. A rapid decline in incidence among PWID after the peak year of new cases and national income were the best predictors of the "highly unlikely" initiation of a heterosexual epidemic.
  
  
  CONCLUSIONS
  Transitions from IDU concentrated epidemics to heterosexual epidemics are common in countries with high seroprevalence among PWID though there are distinct types of transitions. Interventions to immediately reduce HIV incidence among PWID may reduce the likelihood that an IDU epidemic may initiate a heterosexual epidemic.
authors.affiliation: The Baron Edmond de Rothschild Chemical Dependency Institute, Beth Israel Medical Center, New York, New York, United States of America. ddesjarlais@chpnet.org
authors.forename: Don C
authors.initials: DC
authors.lastname: Des Jarlais
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Feelemyer
authors.forename: Shilpa N
authors.initials: SN
authors.lastname: Modi
authors.forename: Kamyar
authors.initials: K
authors.lastname: Arasteh
authors.forename: Bradley M
authors.initials: BM
authors.lastname: Mathers
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
authors.forename: Holly
authors.initials: H
authors.lastname: Hagan
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000635:transmission / Q000821:virology; D003140:Communicable Disease Control; D058872:Epidemics; D005260:Female; D014943:Global Health; D015658:HIV Infections / Q000453:epidemiology / Q000209:etiology / Q000635:transmission*; D006679:HIV Seropositivity / Q000453:epidemiology; D020010:Heterosexuality; D006801:Humans; D008297:Male; D015819:Substance Abuse, Intravenous / Q000150:complications*; D013997:Time Factors