Stresman Gillian H, Baidjoe Amrish Y, Stevenson Jennifer, Grignard Lynn, Odongo Wycliffe, Owaga Chrispin, Osoti Victor, Makori Euniah, Shagari Shehu, Marube Elisabeth, Cox Jonathan, Drakeley Chris, Bousema Teun
Department of Immunology and Infection; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom.
Radboud University Nijmegen Medical Centre, The Netherlands.
J Infect Dis. 2015 Dec 1;212(11):1768-77. doi: 10.1093/infdis/jiv302. Epub 2015 May 27.
Mass screening and treatment currently fails to identify a considerable fraction of low parasite density infections, while mass treatment exposes many uninfected individuals to antimalarial drugs. Here we test a hybrid approach to screen a sentinel population to identify clusters of subpatent infections in the Kenya highlands with low, heterogeneous malaria transmission.
Two thousand eighty-two inhabitants were screened for parasitemia by nested polymerase chain reaction (nPCR). Children aged ≤ 15 years and febrile adults were also tested for malaria by rapid diagnostic test (RDT) and served as sentinel members to identify subpatent infections within the household. All parasitemic individuals were assessed for multiplicity of infections by nPCR and gametocyte carriage by nucleic acid sequence-based amplification.
Households with RDT-positive individuals in the sentinel population were more likely to have nPCR-positive individuals (odds ratio: 1.71, 95% confidence interval, 1.60-1.84). The sentinel population identified 64.5% (locality range: 31.6%-81.2%) of nPCR-positive households and 77.3% (locality range: 24.2%-91.0%) of nPCR-positive individuals. The sensitivity of the sentinel screening approach was positively associated with transmission intensity (P = .037).
In this low endemic area, a focal screening approach with RDTs prior to the high transmission season was able to identify the majority of the subpatent parasite reservoirs.
目前的大规模筛查和治疗未能识别出相当一部分低寄生虫密度感染病例，而大规模治疗使许多未感染个体暴露于抗疟药物之下。在此，我们测试一种混合方法，对一个哨点人群进行筛查，以识别肯尼亚高地疟疾传播率低且不均一地区的亚临床感染聚集情况。
采用巢式聚合酶链反应（nPCR）对2822名居民进行寄生虫血症筛查。对年龄≤15岁的儿童和发热成人也采用快速诊断检测（RDT）进行疟疾检测，并将其作为哨点成员，以识别家庭内的亚临床感染。通过nPCR对所有寄生虫血症个体的感染多样性进行评估，并通过基于核酸序列扩增的方法检测配子体携带情况。
哨点人群中RDT检测呈阳性的家庭更有可能有nPCR检测呈阳性的个体（比值比：1.71，95%置信区间，1.60 - 1.84）。哨点人群识别出64.5%（地区范围：31.6% - 81.2%）的nPCR检测呈阳性的家庭和77.3%（地区范围：24.2% - 91.0%）的nPCR检测呈阳性的个体。哨点筛查方法的敏感性与传播强度呈正相关（P = 0.037）。
在这个低流行地区，在高传播季节之前采用RDT进行重点筛查的方法能够识别出大多数亚临床寄生虫储存宿主。
