Cabezos J, Bada J L
Unidad de Enfermedades Tropicales e Importadas, Centro de Atención Primaria Drassanes, Barcelona.
Med Clin (Barc). 1993 Jun 12;101(3):91-4.
The diagnosis of paludism is important because of the severity of the clinical picture caused by Plasmodium falciparum, the increasing number of travellers to endemic zones and the emigration from these zones. A comparative study of the QBC techniques (staining with acridin orange and observation with ultraviolet light) and the thick film with Giemsa staining was carried out.
The QBC and thick film were performed parallelly for 17 months in a total of 623 samples pertaining to subjects from endemic zones of paludism (emigrants, immigrants and travellers).
Of the 623 samples studied 49 were positive for paludism by both techniques. Ten were positive with only the thick film and six were positive only with QBC. The sensitivity of QBC versus thick film was 83% and specificity 98.9%. The time used to determine diagnosis with the QBC technique ranged from 6 to 12 minutes from withdrawal of the sample, while with the thick film the time spent was more than 2 hours. The cases positive by thick film and negative with QBC corresponded to patients with very low parasitation. The intensity of parasitation was difficult to determine quantitatively by QBC.
Although the QBC technique has the advantage of speed it is inexact with respect to the quantification of parasitemia. Moreover, it is less sensitive than the thick film in patient with very low parasitations and cannot thus substitute the thick film.
由于恶性疟原虫所致临床症状的严重性、前往疟疾流行区旅行者数量的增加以及来自这些地区的移民，疟疾的诊断至关重要。开展了一项关于QBC技术（吖啶橙染色及紫外线观察）与吉姆萨染色厚血膜的对比研究。
对来自疟疾流行区的受试者（移民、侨民和旅行者）的623份样本，并行进行QBC和厚血膜检测，共持续17个月。
在研究的623份样本中，两种技术检测均为疟疾阳性的有49份。仅厚血膜检测阳性的有10份，仅QBC检测阳性的有6份。QBC相对于厚血膜的敏感性为83%，特异性为98.9%。使用QBC技术从采集样本到确定诊断的时间为6至12分钟，而厚血膜检测耗时超过2小时。厚血膜检测阳性而QBC检测阴性的病例为疟原虫寄生率极低的患者。通过QBC难以定量确定疟原虫寄生强度。
尽管QBC技术具有速度优势，但在疟原虫血症定量方面并不准确。此外，对于疟原虫寄生率极低的患者，其敏感性低于厚血膜，因此不能替代厚血膜。
