Singh Neeru, Mishra A K, Shukla M M, Chand S K, Bharti Praveen Kumar
Malaria Research Centre (ICMR) RMRCT Campus, India.
BMC Infect Dis. 2005 Jun 21;5:50. doi: 10.1186/1471-2334-5-50.
Malaria presents a diagnostic challenge in most tropical countries. Rapid detection of the malaria parasite and early treatment of infection still remain the most important goals of disease management. Therefore, performance characteristics of the new indigenous ParaHIT f test (Span diagnostic Ltd, Surat, India) was determined among ethnic tribal population in four districts of different transmission potential in central India to assess whether this rapid diagnostic test (RDT) could be widely applied as a diagnostic tool to control malaria. Beyond diagnosis, the logical utilization of RDTs is to monitor treatment outcome.
A finger prick blood sample was collected from each clinically suspected case of malaria to prepare blood smear and for testing with the RDT after taking informed consent. The blood smears were read by an experienced technician blinded to the RDT results and clinical status of the subjects. The figures for specificity, sensitivity, accuracy and predictive values were calculated using microscopy as gold standard.
The prevalence of malaria infection estimated by RDT in parallel with microscopy provide evidence of the type of high, low or no transmission in the study area. Analysis revealed (pooled data of all four epidemiological settings) that overall sensitivity, specificity and accuracy of the RDT were >90% in areas of different endemicity. While, RDT is useful to confirm the diagnosis of new symptomatic cases of suspected P. falciparum infection, the persistence of parasite antigen leading to false positives even after clearance of asexual parasitaemia has limited its utility as a prognostic tool.
The study showed that the ParaHIT f test was easy to use, reliable and cheap. Thus this RDT is an appropriate test for the use in the field by paramedical staff when laboratory facilities are not available and thus likely to contribute greatly to an effective control of malaria in resource poor countries.
在大多数热带国家，疟疾的诊断颇具挑战。快速检测疟原虫并尽早治疗感染仍是疾病管理的最重要目标。因此，在印度中部四个具有不同传播潜力地区的部落人群中，对新型国产ParaHIT f检测（印度苏拉特Span诊断有限公司）的性能特征进行了测定，以评估这种快速诊断检测（RDT）是否可作为控制疟疾的诊断工具广泛应用。除诊断外，合理利用RDT还可监测治疗效果。
在获得知情同意后，从每例临床疑似疟疾病例采集指尖血样本，用于制备血涂片并进行RDT检测。血涂片由一名对RDT结果和受试者临床状况不知情的经验丰富的技术人员阅片。以显微镜检查为金标准，计算特异性、敏感性、准确性和预测值。
RDT与显微镜检查并行估计的疟疾感染患病率为研究地区高传播、低传播或无传播类型提供了证据。分析显示（所有四种流行病学背景的汇总数据），在不同流行程度地区，RDT的总体敏感性、特异性和准确性均>90%。虽然RDT有助于确诊疑似恶性疟原虫感染的新症状病例，但即使无性疟原虫血症清除后，寄生虫抗原持续存在导致假阳性，这限制了其作为预后工具的效用。
该研究表明，ParaHIT f检测易于使用、可靠且廉价。因此，在没有实验室设施的情况下，这种RDT是辅助医务人员在现场使用的合适检测方法，很可能对资源匮乏国家有效控制疟疾做出巨大贡献。
