title: Spatial patterns of HIV prevalence and service use in East Zimbabwe: implications for future targeting of interventions.
abstract: Focusing resources for HIV control on geographic areas of greatest need in countries with generalized epidemics has been recommended to increase cost-effectiveness. However, socioeconomic inequalities between areas of high and low prevalence could raise equity concerns and have been largely overlooked. We describe spatial patterns in HIV prevalence in east Zimbabwe and test for inequalities in accessibility and uptake of HIV services prior to the introduction of spatially-targeted programmes.
  
  
  
  8092 participants in an open-cohort study were geo-located to 110 locations. HIV prevalence and HIV testing and counselling (HTC) uptake were mapped with ordinary kriging. Clusters of high or low HIV prevalence were detected with Kulldorff statistics, and the socioeconomic characteristics and sexual risk behaviours of their populations, and levels of local HIV service availability (measured in travel distance) and uptake were compared. Kulldorff statistics were also determined for HTC, antiretroviral therapy (ART), and voluntary medical male circumcision (VMMC) uptake.
  
  
  
  One large and one small high HIV prevalence cluster (relative risk [RR] = 1.78, 95% confidence interval [CI] = 1.53-2.07; RR = 2.50, 95% CI = 2.08-3.01) and one low-prevalence cluster (RR = 0.70, 95% CI = 0.60-0.82) were detected. The larger high-prevalence cluster was urban with a wealthier population and more high-risk sexual behaviour than outside the cluster. Despite better access to HIV services, there was lower HTC uptake in the high-prevalence cluster (odds ratio [OR] of HTC in past three years: OR = 0.80, 95% CI = 0.66-0.97). The low-prevalence cluster was predominantly rural with a poorer population and longer travel distances to HIV services; however, uptake of HIV services was not reduced.
  
  
  
  High-prevalence clusters can be identified to which HIV control resources could be targeted. To date, poorer access to HIV services in the poorer low-prevalence areas has not resulted in lower service uptake, whilst there is significantly lower uptake of HTC in the high-prevalence cluster where health service access is better. Given the high levels of risky sexual behaviour and lower uptake of HTC services, targeting high-prevalence clusters may be cost-effective in this setting. If spatial targeting is introduced, inequalities in HIV service uptake may be avoided through mobile service provision for lower prevalence areas.
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.
authors.forename: Robin
authors.initials: R
authors.lastname: Schaefer
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.|Biomedical Research and Training Institute, 10 Seagrave Road, Harare, Zimbabwe.
authors.forename: Simon
authors.initials: S
authors.lastname: Gregson
authors.affiliation: Biomedical Research and Training Institute, 10 Seagrave Road, Harare, Zimbabwe.
authors.forename: Albert
authors.initials: A
authors.lastname: Takaruza
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Rhead
authors.affiliation: Biomedical Research and Training Institute, 10 Seagrave Road, Harare, Zimbabwe.
authors.forename: Tidings
authors.initials: T
authors.lastname: Masoka
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.
authors.forename: Nadine
authors.initials: N
authors.lastname: Schur
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.
authors.forename: Sarah-Jane
authors.initials: SJ
authors.lastname: Anderson
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.|Biomedical Research and Training Institute, 10 Seagrave Road, Harare, Zimbabwe.
authors.forename: Constance
authors.initials: C
authors.lastname: Nyamukapa
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006297:Health Services Accessibility; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011203:Poverty; D015995:Prevalence; D012424:Rural Population; D012725:Sexual Behavior; D014195:Travel; D047568:Unsafe Sex; D055815:Young Adult; D015030:Zimbabwe / Q000453:epidemiology
keywords: HIV clustering; Spatial heterogeneity; Zimbabwe; equity; targeted interventions