title: Risk factors influencing HIV infection incidence in a rural African population: a nested case-control study.
abstract: BACKGROUND
  Risk factors influencing the incidence of human immunodeficiency virus (HIV) infection were investigated in a case-control study nested within a community-randomized trial of treatment of syndromic sexually transmitted infections (STIs) in rural Tanzania.
  
  
  METHODS
  Case patients were persons who became HIV positive, and control subjects were randomly selected from among persons who remained HIV negative. For each sex, we obtained adjusted odds ratios (ORs) and population-attributable fractions (PAFs) for biomedical and behavioral factors.
  
  
  RESULTS
  We analyzed 92 case patients and 903 control subjects. In both sexes, the incidence of HIV infection was significantly higher in subjects with an HIV-positive spouse than in those with HIV-negative spouse (men: OR, 25.1; women: OR, 34.0). The incidence of HIV infection was significantly higher in those who became positive for herpes simplex virus type 2 (HSV-2) (men: OR, 5.60; women: OR, 4.76) and those who were HSV-2-positive at baseline (men: OR, 3.66; women: OR, 2.88) than in subjects who were HSV-2 negative. In women, living elsewhere (OR, 3.22) and never having given birth (OR, 4.27) were significant risk factors. After adjustment, the incidence of HIV infection was not significantly associated with a history of injections or STIs in either sex.
  
  
  CONCLUSIONS
  HSV-2 infection was the most important risk factor for HIV infection, which highlights the need for HSV-2 interventions in HIV infection control, and there were particularly strong associations with recent HSV-2 seroconversion. The PAF associated with having an HIV-positive spouse was low, but this is likely to increase during the epidemic.
authors.affiliation: London School of Hygiene and Tropical Medicine, UK. jim.todd@lshtm.ac.uk
authors.forename: James
authors.initials: J
authors.lastname: Todd
authors.forename: Heiner
authors.initials: H
authors.lastname: Grosskurth
authors.forename: John
authors.initials: J
authors.lastname: Changalucha
authors.forename: Angela
authors.initials: A
authors.lastname: Obasi
authors.forename: Frank
authors.initials: F
authors.lastname: Mosha
authors.forename: Rebecca
authors.initials: R
authors.lastname: Balira
authors.forename: Kate
authors.initials: K
authors.lastname: Orroth
authors.forename: Stephane
authors.initials: S
authors.lastname: Hugonnet
authors.forename: Mar
authors.initials: M
authors.lastname: Pujades
authors.forename: David
authors.initials: D
authors.lastname: Ross
authors.forename: Awene
authors.initials: A
authors.lastname: Gavyole
authors.forename: David
authors.initials: D
authors.lastname: Mabey
authors.forename: Richard
authors.initials: R
authors.lastname: Hayes
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004196:Disease Outbreaks; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology*; D006558:Herpes Genitalis / Q000150:complications*; D018258:Herpesvirus 2, Human; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012424:Rural Population; D012725:Sexual Behavior; D012747:Sexual Partners; D013636:Tanzania / Q000453:epidemiology