Bärnighausen Till, Tanser Frank, Newell Marie-Louise
Africa Centre for Health and Population Studies, University of KwaZulu-Natal , Mtubatuba, South Africa.
AIDS Res Hum Retroviruses. 2009 Apr;25(4):405-9. doi: 10.1089/aid.2008.0211.
To understand the dynamics of the HIV epidemic and to plan HIV treatment and prevention programs, it is critical to know how HIV incidence in a population evolves over time. We used data from a large population-based longitudinal HIV surveillance in a rural community in South Africa to test whether HIV incidence in this population has changed in the period from 2003 through 2007. We observed 563 seroconversions in 8095 individuals over 16,256 person-years at risk, yielding an overall HIV incidence of 3.4 per 100 person-years (95% confidence interval 3.1-3.7). We included time-dependent period dummy variables (in half-yearly increments) in age-stratified Cox regressions in order to test for trends in HIV incidence. We first did regression analyses separately for women and men. In both regressions, the coefficients of all period dummy variables were individually insignificant (all p > or = 0.338) and jointly insignificant (p = 0.764 and p = 0.111, respectively). We then did regression analysis using the pooled data on women and men, controlling for sex and interactions between sex and age. Again, the coefficients of the eight period dummy variables were individually insignificant (all p > or = 0.387) and jointly insignificant (p = 0.701). We show for the first time that high levels of HIV incidence have been maintained without any sign of decline over the past 5 years in both women and men in a rural South African community with high HIV prevalence. It is unlikely that the HIV epidemic in rural South Africa can be reversed without new or intensified efforts to prevent HIV infection.
为了解艾滋病毒流行的动态并规划艾滋病毒治疗和预防方案,了解人群中的艾滋病毒发病率如何随时间演变至关重要。我们使用了南非一个农村社区基于人群的大型纵向艾滋病毒监测数据,以检验该人群在2003年至2007年期间的艾滋病毒发病率是否发生了变化。在16256人年的观察期内,我们在8095名个体中观察到563例血清转化,总体艾滋病毒发病率为每100人年3.4例(95%置信区间3.1 - 3.7)。我们在按年龄分层的Cox回归中纳入了随时间变化的时期虚拟变量(以半年为增量),以检验艾滋病毒发病率的趋势。我们首先分别对女性和男性进行回归分析。在这两个回归中,所有时期虚拟变量的系数单独来看均无统计学意义(所有p≥0.338),联合起来也无统计学意义(分别为p = 0.764和p = 0.111)。然后我们使用女性和男性的汇总数据进行回归分析,同时控制性别以及性别与年龄之间的相互作用。同样,八个时期虚拟变量的系数单独来看均无统计学意义(所有p≥0.387),联合起来也无统计学意义(p = 0.701)。我们首次表明,在南非一个艾滋病毒高流行率的农村社区,过去5年中男性和女性的艾滋病毒高发病率一直保持,且没有任何下降迹象。如果不采取新的或强化的艾滋病毒感染预防措施,南非农村地区的艾滋病毒流行不太可能得到扭转。