Rao P, Mohamedali F Y, Temmerman M, Fransen L
Commission of European Community, Brussels, Belgium.
Sex Transm Infect. 1998 Jun;74 Suppl 1:S17-22.
Sexually transmitted diseases (STDs) enhance HIV transmission, and improved management of STD in primary health care decreases HIV incidence. In resource poor countries, those responsible for planning and managing STD control programmes need to be able to analyse the STD situation in their setting and the interventions which are therefore likely to be most cost effective. However, the data required for such decision making are often not available in developing countries. This paper presents an operational model, developed as a practical tool to support planning, monitoring, and evaluation of STD intervention strategies in settings where data are unavailable or inadequate.
The operational model is based on the approach developed for estimating the effectiveness of control measures in tuberculosis programmes. Using available data, the model takes a step by step approach. It begins with analysis of the total male and female population, the proportion of men and women aged 15-49 years, and the proportion of these who are sexually active. Subsequent steps analyse numbers with STDs, and loss of cases to the health system at each stage between infection and cure. The model was tested in Nairobi, Kenya using available demographic, epidemiological, and public health data; no original data were collected. Data for the total population of Nairobi were not available to illustrate all the steps in the model. For these steps, relevant information was taken where available from a specific study population using a large STD referral centre.
Despite the lack of precise data for Nairobi, the model highlighted sex imbalances in population, which has potential implications for STDs. It also showed significant disparities in terms of public health policy--for example, between the number of people infected with STDs and the number who have symptoms, and between the number with symptoms and those who seek treatment from public health facilities. It also showed differences between the numbers who attend a health facility, and those that are correctly diagnosed and treated, and, of these, the proportion that are cured.
Even where data are incomplete or not available, the model can be a useful tool for analysis. Application of the model, as the Nairobi example illustrates, provides a useful starting point in terms of determining both general and specific determinants of STDs, identifying problems, highlighting significant sex differences, and indicating where it might be appropriate to focus interventions. The model showed that, in Nairobi, only a small proportion of STD cases are removed from the reservoir of infection in the community through curative services, that cases are lost to the health services at every step, and therefore that interventions are required at every step to achieve comprehensive STD control. It highlights the need for strategies to prevent infections, to identify and treat those with and without symptoms, to motivate those who are aware of their infection to seek treatment, and to improve the effectiveness of partner notification and treatment. Finally, the model points to areas where data are inadequate and where STD control programmes need to concentrate information collection efforts.
性传播疾病（STD）会增加艾滋病毒的传播，而在初级卫生保健中改善性传播疾病的管理可降低艾滋病毒的发病率。在资源匮乏的国家，负责规划和管理性传播疾病控制项目的人员需要能够分析其所在地区的性传播疾病状况以及可能最具成本效益的干预措施。然而，发展中国家往往没有此类决策所需的数据。本文介绍了一种操作模型，该模型是作为一种实用工具开发的，用于在数据不可用或不足的情况下支持性传播疾病干预策略的规划、监测和评估。
该操作模型基于为评估结核病控制措施效果而开发的方法。利用现有数据，该模型采用逐步推进的方法。它首先分析男性和女性总人口、15至49岁男性和女性的比例以及其中性活跃者的比例。后续步骤分析性传播疾病患者数量以及在感染到治愈的每个阶段卫生系统中病例的流失情况。该模型在肯尼亚内罗毕使用现有的人口统计学、流行病学和公共卫生数据进行了测试；未收集原始数据。内罗毕总人口的数据无法获取以说明该模型的所有步骤。对于这些步骤，从一个大型性传播疾病转诊中心的特定研究人群中获取了可用的相关信息。
尽管内罗毕缺乏精确数据，但该模型突出了人口中的性别失衡，这对性传播疾病可能有潜在影响。它还显示了在公共卫生政策方面的显著差异——例如，性传播疾病感染者数量与有症状者数量之间、有症状者数量与从公共卫生设施寻求治疗者数量之间的差异。它还显示了就诊于卫生机构的人数、被正确诊断和治疗的人数以及其中治愈的比例之间的差异。
即使数据不完整或不可用，该模型也可以是一种有用的分析工具。如内罗毕的例子所示，应用该模型在确定性传播疾病的一般和特定决定因素、识别问题、突出显著的性别差异以及指出可能适合集中干预的领域方面提供了一个有用的起点。该模型表明，在内罗毕，通过治疗服务仅一小部分性传播疾病病例从社区感染源中被清除，病例在每一步都流失于卫生服务系统，因此需要在每一步采取干预措施以实现全面的性传播疾病控制。它强调了需要采取预防感染的策略、识别和治疗有症状和无症状者、激励知晓自身感染的人寻求治疗以及提高性伴通知和治疗的有效性。最后，该模型指出了数据不足的领域以及性传播疾病控制项目需要集中信息收集工作的地方。
