Potterat J J, Zimmerman-Rogers H, Muth S Q, Rothenberg R B, Green D L, Taylor J E, Bonney M S, White H A
STD/HIV Program, El Paso County Department of Health and Environment, Colorado Springs, CO 80910, USA.
Am J Epidemiol. 1999 Dec 15;150(12):1331-9. doi: 10.1093/oxfordjournals.aje.a009965.
To identify factors that influence individual and group transmission of Chlamydia, the authors conducted community-wide contact tracing of chlamydia cases in Colorado Springs, Colorado, from mid-1996 to mid-1997. Case patients identified persons with whom they had had contact during the 6 months preceding diagnosis; contacts were actively sought and offered DNA amplification testing. Sexual contact networks were used to identify "source cases" and "spread cases," permitting estimation of the basic reproduction number (R0) for individuals and groups. Network and epidemiologic factors influencing R0 were assessed using univariate and multivariate procedures. Of 1,309 case patients, 1,131 (86%) were interviewed, and 2,409 contacts were identified. The 1,131 interviewed cases yielded 623.9 computed spread cases, for an overall R0 of 0.55. Few subgroups analyzed yielded a mean R0 exceeding unity-an observation in keeping with routine surveillance information which suggests that chlamydia incidence is declining in Colorado Springs. Concurrency, a network measure of simultaneous partnerships, was the most powerful predictor of transmission. Direct estimation of basic reproduction numbers for chlamydia using contact tracing techniques is feasible and can produce useful data with which to prioritize control efforts, evaluate interventions, and gauge the place of chlamydia on the epidemic continuum.
为了确定影响衣原体个体传播和群体传播的因素，作者于1996年年中至1997年年中在科罗拉多州科罗拉多斯普林斯市对衣原体病例进行了全社区范围的接触者追踪。病例患者需指出在诊断前6个月内与之有过接触的人；积极寻找这些接触者并为其提供DNA扩增检测。利用性接触网络来识别“源头病例”和“传播病例”，从而估计个体和群体的基本繁殖数（R0）。使用单变量和多变量方法评估影响R0的网络和流行病学因素。在1309例病例患者中，1131例（86%）接受了访谈，共识别出2409名接触者。1131例接受访谈的病例产生了623.9例计算得出的传播病例，总体R0为0.55。分析的少数亚组中，平均R0超过1的情况很少见——这一观察结果与常规监测信息一致，表明科罗拉多斯普林斯市的衣原体发病率正在下降。同时性伴侣关系的网络指标——并发率，是传播的最有力预测因素。使用接触者追踪技术直接估计衣原体的基本繁殖数是可行的，并且可以产生有用的数据，用于确定控制工作的优先级、评估干预措施以及衡量衣原体在流行连续体中的位置。
