Khan Mishal S, Dar Osman, Tahseen Sabira, Godfrey-Faussett Peter
London School of Hygiene and Tropical Medicine, UK.
Trop Med Int Health. 2009 May;14(5):571-5. doi: 10.1111/j.1365-3156.2009.02260.x. Epub 2009 Mar 2.
To investigate whether visual assessment or microscopic grading of the cellular composition of specimens is a better strategy to screen specimen quality for tuberculosis (TB) diagnosis.
About 2643 specimens were collected from TB suspects at the Federal TB centre in Pakistan. Specimens were classified as sputum or saliva visually and microscopically using the criteria proposed by McCarter and Robinson, Van Scoy, Geckler et al., Murray and Washington and Bartlett. The acid-fast bacilli (AFB)-positivity of specimens was also assessed. Results Despite being the least 'technical' and time consuming, visual assessment rejected the lowest proportion of AFB-positive specimens (0.3%). Most microscopic grading criteria, particularly those that considered the squamous epithelial cell count, rejected a large proportion of specimens (30-66%), of which a sizeable fraction contained AFB (6-12%).
Our results indicate that visual assessment by trained technicians is more effective and suitable than microscopic grading for screening specimens for TB diagnosis. TB control resources could be better allocated to optimizing visual screening than investing in more 'strict' microscopic grading tools.
探讨对标本细胞成分进行视觉评估或显微镜分级，哪种方法是筛查用于结核病（TB）诊断的标本质量的更佳策略。
从巴基斯坦联邦结核病中心的结核病疑似患者处收集了约2643份标本。根据McCarter和Robinson、Van Scoy、Geckler等人、Murray和Washington以及Bartlett提出的标准，通过视觉和显微镜检查将标本分类为痰液或唾液。还评估了标本的抗酸杆菌（AFB）阳性情况。结果尽管视觉评估是最不“技术化”且耗时最少的，但它拒收的AFB阳性标本比例最低（0.3%）。大多数显微镜分级标准，尤其是那些考虑鳞状上皮细胞计数的标准，拒收了很大比例的标本（30 - 66%），其中相当一部分含有AFB（6 - 12%）。
我们的结果表明，对于筛查用于结核病诊断的标本，训练有素的技术人员进行视觉评估比显微镜分级更有效且更合适。结核病防控资源可以更好地分配用于优化视觉筛查，而不是投资于更“严格”的显微镜分级工具。
