Hazel Ashley, Marino Simeone, Simon Carl
School of Natural Resources and Environment, University of Michigan, Dana Building, 440 Church Street, Ann Arbor, MI 48109, USA Department of Anthropology, Stanford University, 450 Serra Mall, Building 50, Stanford, CA 94305, USA
School of Medicine, Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48109-0620, USA.
J R Soc Interface. 2015 May 6;12(106). doi: 10.1098/rsif.2015.0067.
Neisseria gonorrhoeae (GC) remains a serious burden in many high-sexual-activity, undertreated populations. Using empirical data from a 2009 study of GC burden among pastoralists in Kaokoveld, Namibia, we expand the standard gonorrhoea transmission model by using locally derived sexual contact data to explore transmission dynamics in a population with high rates of partner exchange and low treatment-seeking behaviour. We use the model to generate ball-park estimates for transmission probabilities and other parameter values for low-level (i.e. less than approx. 1200 copies/20 µl PCR reaction) asymptomatic infections, which account for 74% of all GC infections found in Kaokoveld in 2009, and to describe the impact of asymptomatic, low-level infections on overall prevalence patterns. Our results suggest that GC transmission probabilities are higher than previously estimated, that untreated infections take longer to clear than previously estimated and that a high prevalence of low-level infections is partially due to larger numbers of untreated, asymptomatic infections. These results provide new insights into the natural history of GC and the challenge of syndromic management programmes for the eradication of endemic gonorrhoea.
淋病奈瑟菌（GC）在许多性活动频繁但治疗不足的人群中仍然是一个严重的负担。利用2009年纳米比亚考科韦尔德牧民中淋病负担研究的经验数据，我们通过使用当地得出的性接触数据，扩展了标准的淋病传播模型，以探索在伴侣更换率高且寻求治疗行为低的人群中的传播动态。我们使用该模型对低水平（即每20微升PCR反应少于约1200拷贝）无症状感染的传播概率和其他参数值进行大致估计，此类感染占2009年在考科韦尔德发现的所有淋病感染的74%，并描述无症状、低水平感染对总体流行模式的影响。我们的结果表明，淋病传播概率高于先前估计，未治疗的感染清除所需时间比先前估计的更长，且低水平感染的高流行率部分归因于大量未治疗的无症状感染。这些结果为淋病的自然史以及根除地方性淋病的症状管理计划所面临的挑战提供了新的见解。
