Hamilton M A, DeVries T A, Rubino J R
Montana State University, Bozeman 59717, USA.
J AOAC Int. 1995 Jul-Aug;78(4):1102-9.
The hard surface carrier test (HSCT) recently was proposed as a qualitative test for disinfectant efficacy. A collaborative study of HSCT led to a suggested performance standard of < or = 2 or 3 positive carriers out of 60 tested. Subsequently, it was discovered that HSCT can be used as a quantitative test, because the HSCT protocol requires measurement of inoculum level on some carriers. The data allow estimation of the log10 reduction in number of active bacteria. Producers, consumers, and policymakers will be better able to discuss merits of alternative performance standards if the focus is on log reduction of organisms rather than on number of positive carriers. Data from the collaborative study were reanalyzed from this quantitative viewpoint. If the point estimate of log reduction in LR and the 99% lower confidence limit estimate is LLR, the LR values ranged from 7.0 to 9.0 and the LLR values were greater than 6.0 for all disinfectants except the negative control formulation. The total variance for estimated LR is the sum of interlaboratory and intralaboratory variances. The total variance for LR was 0.095 for Pseudomonas aeruginosa, 0.251 for Staphylococcus aureus, and 0.118 for Salmonella choleraesuis. Percentages of the variance due to interlaboratory variability were 11% for P. aeruginosa, 52% for S. aureus, and 25% for S. choleraesuis. Chances of making false-effective and false-ineffective decisions can be calculated for the quantitative HSCT. The performance standard can be based on LLR.
硬表面载体试验（HSCT）最近被提议作为一种消毒剂效力的定性试验。一项关于HSCT的协作研究得出了一个建议的性能标准，即在60个测试载体中阳性载体≤2个或3个。随后，发现HSCT可作为定量试验，因为HSCT方案要求测量一些载体上的接种物水平。这些数据可用于估计活性细菌数量的对数减少量。如果重点是生物体的对数减少而不是阳性载体的数量，生产商、消费者和政策制定者将能够更好地讨论替代性能标准的优点。从这个定量角度对协作研究的数据进行了重新分析。如果对数减少量（LR）的点估计值和99%的下限置信极限估计值是LLR，除阴性对照制剂外，所有消毒剂的LR值范围为7.0至9.0，LLR值大于6.0。估计LR的总方差是实验室间方差和实验室内方差之和。铜绿假单胞菌的LR总方差为0.095，金黄色葡萄球菌为0.251，猪霍乱沙门氏菌为0.118。实验室间变异性导致的方差百分比，铜绿假单胞菌为11%，金黄色葡萄球菌为52%，猪霍乱沙门氏菌为25%。对于定量HSCT，可以计算做出假有效和假无效决策的概率。性能标准可以基于LLR。
