标题：Evidence for localised HIV related micro–epidemics associated with the decentralised provision of antiretroviral treatment in rural South Africa: a spatio–temporal analysis of changing mortality patterns (2007–2010)
摘要：Background: In this study we analysed the spatial and temporalchanges in patterns of mortality over a period when antiretroviraltherapy (ART) was rolled out in a rural region of north–eastern SouthAfrica.Previous studies have identified localised concentrated HIVrelated sub–epidemics and recommended that micro–level analysesbe carried out in order to direct focused interventions.Methods Data from an ongoing health and socio–demographic surveillancestudy was used in the analysis.The follow–up was dividedinto two periods, 2007–2008 and 2009–2010, representing the timesimmediately before and after the effects on mortality of the decentralisedART provision from a newly established local health centrewould be expected to be evident.The study population at the startof the analysis was approximately 73 000 individuals.Data were aggregatedby village and also using a 2 × 2 km grid.We identified villages,grid squares and regions in the site where mortality rates withineach time period or rate ratios between the periods differedsignificantly from the overall trends.We used clustering techniquesto identify cause–specific mortality hotspots.Findings: Comparing the two periods, there was a 30% decrease inage and gender standardised adult HIV–related and TB (HIV/TB)mortality with no change in mortality due to other causes.There wasconsiderable spatial heterogeneity in the mortality patterns.Areasseparated by 2 to 4 km with very different epidemic trajectories wereidentified.There was evidence that the impact of ART in reducingHIV/TB mortality was greatest in communities with higher mortalityrates in the earlier period.Conclusions: This study shows the value of conducting high resolutionspatial analyses in order to understand how local micro–epidemicscontribute to changes seen over a wider area.Such analyses cansupport targeted interventions.
