Egwang T G, Slocombe J O
Can J Comp Med. 1981 Jul;45(3):243-8.
Haemonchus contortus eggs were extracted from sheep feces and known numbers were added to helminthologically sterile bovine feces to provide samples with seven, 30 and 60 eggs per gram (epg). At 60 epg, dilution techniques (modified Cornell-McMaster and modified McMaster) tended to overestimate the number of eggs and more eggs were recovered (mean of 121 and 88% respectively) with these techniques than with centrifugal concentration procedures (modified Cornell-63% and Wisconsin- 69%). At 30 epg, all techniques were comparable (modified Cornell-McMaster 67%, modified McMaster 63%, modified Cornell and Wisconsin 64%). At 7 epg, the Wisconsin (61%), modified Cornell (60%) and Cornell-McMaster (94%) techniques were comparable and better than the modified McMaster technique (16%). At all levels of epg, the modified Cornell and Wisconsin techniques recovered eggs from 100% of the samples. The Cornell-McMaster and modified McMaster techniques recovered eggs from 90 and 100% of samples at 60 epg; 40 and 100% at 30 epg; and 21 and 11% at 7 epg. With a gravitational concentration procedure, the Standard Vial, no more than 16% of the eggs at any level of epg were recovered and at 7 epg eggs were recovered from only one-half of the samples. Five gravitational concentration techniques were assessed over 66 to 490 epg. The Ovassay, Fecalyzer and modified Standard Vial techniques were comparable in efficiency (28%, 25% and 24% respectively), but the Standard Vial technique was less efficient (11%). Introduced into diagnostic parasitology was the concept of predictive values which is the proportion of samples that a technique correctly identifies as being negative for parasite eggs. At 7 epg this was calculated to be zero for the modified Cornell-McMaster, modified McMaster and Standard Vial techniques and 100 for the Wisconsin and modified Cornell techniques.
从绵羊粪便中提取捻转血矛线虫卵，并将已知数量的虫卵添加到经蠕虫学检测无菌的牛粪中，以制备每克含7、30和60个虫卵（epg）的样本。在每克60个虫卵的情况下，稀释技术（改良康奈尔-麦克马斯特法和改良麦克马斯特法）往往会高估虫卵数量，与离心浓缩法（改良康奈尔法-63%，威斯康星法-69%）相比，使用这些技术回收的虫卵更多（分别为121%和88%）。在每克30个虫卵时，所有技术的效果相当（改良康奈尔-麦克马斯特法67%，改良麦克马斯特法63%，改良康奈尔法和威斯康星法64%）。在每克7个虫卵时，威斯康星法（61%）、改良康奈尔法（60%）和康奈尔-麦克马斯特法（94%）效果相当，且优于改良麦克马斯特法（16%）。在所有虫卵水平下，改良康奈尔法和威斯康星法能从100%的样本中回收虫卵。康奈尔-麦克马斯特法和改良麦克马斯特法在每克60个虫卵时能从90%和100%的样本中回收虫卵；每克30个虫卵时分别为40%和100%；每克7个虫卵时分别为21%和11%。采用重力浓缩法（标准小瓶法），在任何虫卵水平下回收的虫卵均不超过16%，在每克7个虫卵时，仅从一半的样本中回收虫卵。对5种重力浓缩技术在每克66至490个虫卵的范围内进行了评估。Ovassay法、粪便分析仪法和改良标准小瓶法的效率相当（分别为28%、25%和24%），但标准小瓶法效率较低（11%）。诊断寄生虫学引入了预测值的概念，即一种技术正确识别为寄生虫卵阴性的样本比例。在每克7个虫卵时，改良康奈尔-麦克马斯特法、改良麦克马斯特法和标准小瓶法的预测值经计算为零，而威斯康星法和改良康奈尔法为100。
