title: Distinct HIV discordancy patterns by epidemic size in stable sexual partnerships in sub-Saharan Africa.
abstract: OBJECTIVE
  To describe patterns of HIV infection among stable sexual partnerships across sub-Saharan Africa (SSA).
  
  
  METHODS
  The authors defined measures of HIV discordancy and conducted a comprehensive quantitative assessment of discordancy among stable partnerships in 20 countries in SSA through an analysis of the Demographic and Health Survey data.
  
  
  RESULTS
  HIV prevalence explained at least 50% of the variation in HIV discordancy, with two distinct patterns of discordancy emerging based on HIV prevalence being roughly smaller or larger than 10%. In low-prevalence countries, approximately 75% of partnerships affected by HIV are discordant, while only about half of these are discordant in high-prevalence countries. Out of each 10 HIV infected persons, two to five are engaged in discordant partnerships in low-prevalence countries compared with one to three in high-prevalence countries. Among every 100 partnerships in the population, one to nine are affected by HIV and zero to six are discordant in low-prevalence countries compared with 16-45 and 9-17, respectively, in high-prevalence countries. Finally, zero to four of every 100 sexually active adults are engaged in a discordant partnership in low-prevalence countries compared with six to eight in high-prevalence countries.
  
  
  CONCLUSIONS
  In high-prevalence countries, a large fraction of stable partnerships were affected by HIV and half were discordant, whereas in low-prevalence countries, fewer stable partnerships were affected by HIV but a higher proportion of them were discordant. The findings provide a global view of HIV infection among stable partnerships in SSA but imply complex considerations for rolling out prevention interventions targeting discordant partnerships.
authors.affiliation: Infectious Disease Epidemiology Group, Weill Cornell Medical College--Qatar, Cornell University, Qatar Foundation--Education City, Doha, Qatar.
authors.forename: Hiam
authors.initials: H
authors.lastname: Chemaitelly
authors.forename: Ide
authors.initials: I
authors.lastname: Cremin
authors.forename: Jim
authors.initials: J
authors.lastname: Shelton
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Hallett
authors.forename: Laith J
authors.initials: LJ
authors.lastname: Abu-Raddad
mesh_terms: D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012111:Residence Characteristics; D012725:Sexual Behavior / Q000706:statistics & numerical data; D012747:Sexual Partners; D055815:Young Adult