Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, United Kingdom.
PLoS Med. 2010 Jul 6;7(7):e1000301. doi: 10.1371/journal.pmed.1000301.
As international efforts to increase the coverage of artemisinin-based combination therapy in public health sectors gather pace, concerns have been raised regarding their continued indiscriminate presumptive use for treating all childhood fevers. The availability of rapid-diagnostic tests to support practical and reliable parasitological diagnosis provides an opportunity to improve the rational treatment of febrile children across Africa. However, the cost effectiveness of diagnosis-based treatment polices will depend on the presumed numbers of fevers harbouring infection. Here we compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites.
We assembled first administrative-unit level data on paediatric fever prevalence, treatment-seeking rates, and child populations. These data were combined in a geographical information system model that also incorporated an adjustment procedure for urban versus rural areas to produce spatially distributed estimates of fever burden amongst African children and the subset likely to present to public sector clinics. A second data assembly was used to estimate plausible ranges for the proportion of paediatric fevers seen at clinics positive for P. falciparum in different endemicity settings. We estimated that, of the 656 million fevers in African 0-4 y olds in 2007, 182 million (28%) were likely to have sought treatment in a public sector clinic of which 78 million (43%) were likely to have been infected with P. falciparum (range 60-103 million).
Spatial estimates of childhood fevers and care-seeking rates can be combined with a relational risk model of infection prevalence in the community to estimate the degree of parasitemia in those fevers reaching public health facilities. This quantification provides an important baseline comparison of malarial and nonmalarial fevers in different endemicity settings that can contribute to ongoing scientific and policy debates about optimum clinical and financial strategies for the introduction of new diagnostics. These models are made publicly available with the publication of this paper.
随着国际社会加大力度在公共卫生部门普及青蒿素联合疗法,人们对不分青红皂白地继续将其用于治疗所有儿童发热的做法表示担忧。快速诊断检测手段的出现为在整个非洲改善对发热儿童的合理治疗提供了机会。然而,基于诊断的治疗政策的成本效益将取决于假定患有感染的发热人数。在此,我们计算了在非洲可能到公共卫生机构就诊的发热人数,以及这些发热者中估计有多少人感染恶性疟原虫疟疾寄生虫。
我们首先汇编了儿科发热流行率、寻求治疗率和儿童人口的行政单位一级数据。这些数据在地理信息系统模型中进行了组合,该模型还结合了城市与农村地区的调整程序,以便对非洲儿童的发热负担以及可能到公共部门诊所就诊的发热子集进行空间分布估计。第二项数据汇编用于估计在不同流行地区的诊所中,有多少比例的儿科发热者的疟原虫检测呈阳性。我们估计,在 2007 年非洲 0-4 岁儿童中,6.56 亿发热者中,有 1.82 亿(28%)可能在公共部门诊所接受治疗,其中 7800 万(43%)可能感染恶性疟原虫(范围 6000-1.03 亿)。
可以将儿童发热和寻求治疗率的空间估计与社区中感染流行率的关系风险模型相结合,以估计到达公共卫生机构的发热者的寄生虫血症程度。这种量化为不同流行地区的疟性和非疟性发热提供了重要的基线比较,有助于正在进行的关于引入新诊断方法的最佳临床和财务策略的科学和政策辩论。这些模型在本文发表的同时公开发布。