School of Physics, The University of Western Australia, Crawley, Australia.
Am J Trop Med Hyg. 2011 Nov;85(5):815-7. doi: 10.4269/ajtmh.2011.11-0299.
Malaria control can be improved by rapid, sensitive, low-cost detection of infection. Several such strategies are being pursued. Rapid diagnostic tests can detect infections at parasite densities above 200 μL(-1). Polymerase chain reaction methods can detect low parasite densities, but are slow and prone to contamination under field conditions. Methods that detect hemozoin presence in blood have been proposed as alternatives for rapid detection of infection. In this study, we used a benchtop nuclear magnetic resonance (NMR) device to detect hemozoin. This device could be deployed in malaria-endemic settings. We measured synthetic hemozoin in phosphate-buffered saline and malaria parasites in human blood. The NMR detected hemozoin in suspensions of 4 ng μL(-1) and parasites at densities of 8,000-10,000 μL(-1) (0.2% parasitemia). Thus, our preliminary NMR approach, although providing very rapid measurements, is unlikely to achieve the required sensitivity and specificity for malaria diagnosis, unless a preliminary concentration step is performed.
疟疾控制可以通过快速、敏感、低成本的感染检测来改善。目前正在探索几种这样的策略。快速诊断测试可以在寄生虫密度高于 200 μL(-1)时检测到感染。聚合酶链反应方法可以检测到低寄生虫密度，但在野外条件下速度较慢且容易受到污染。已经提出了检测血液中血色素存在的方法作为快速检测感染的替代方法。在这项研究中，我们使用台式核磁共振（NMR）设备来检测血色素。这种设备可以部署在疟疾流行地区。我们测量了磷酸盐缓冲盐水中的合成血色素和人血中的疟原虫。NMR 在 4ng μL(-1)的悬浮液和 8000-10000 μL(-1)（0.2%疟原虫血症）的寄生虫密度下检测到了血色素。因此，我们的初步 NMR 方法虽然提供了非常快速的测量，但不太可能达到疟疾诊断所需的灵敏度和特异性，除非进行初步的浓缩步骤。
