Cambanis A, Ramsay A, Wirkom V, Tata E, Cuevas L E
St Elizabeth General Hospital, Shisong, Kumbo, Cameroon.
Int J Tuberc Lung Dis. 2007 Jan;11(1):40-5.
St. Elizabeth Hospital, rural North-west Cameroon, an area with high tuberculosis (TB) and human immunodeficiency virus (HIV) incidence.
To measure the time spent during routine sputum smear microscopy and assess whether reexamining slides for 10 min translates into higher case detection of smear-positive cases.
A prospective observational study over a 6-month period with three components: 1) timing of routine sputum smear examination; 2) blinded reexamination of all slides for 10 min and results compared with initial readings; and 3) blinded re-examination, by the original microscopists, of a portion of false-negative slides mixed with true negatives for 10 min.
A total of 204 patients submitted 612 sputum specimens for screening. The median routine examination time was 2 min 6 seconds (interquartile range 1:30-2:30). A 10 min examination significantly increased the number of positive smears from 82 to 116 (P = 0.0083), and overall case detection from 28 to 48 patients (P = 0.011). On review by the original readers, more than half of the false-negative slides were reported as positive after 10 min.
Sputum smear microscopy has low sensitivity if performed too quickly, and 10 min re-examination significantly increases case detection. Ensuring that smears are examined for the recommended duration may be a simple and low-cost way to improve case detection.
圣伊丽莎白医院位于喀麦隆西北部农村地区，该地区结核病（TB）和人类免疫缺陷病毒（HIV）发病率较高。
测量常规痰涂片显微镜检查所需时间，并评估对玻片进行10分钟的重新检查是否能提高涂片阳性病例的检出率。
一项为期6个月的前瞻性观察性研究，包括三个部分：1）常规痰涂片检查的时间；2）对所有玻片进行10分钟的盲法重新检查，并将结果与初始读数进行比较；3）由原显微镜检查人员对一部分与真阴性混合的假阴性玻片进行10分钟的盲法重新检查。
共有204名患者提交了612份痰标本进行筛查。常规检查的中位时间为2分6秒（四分位间距为1:30 - 2:30）。10分钟的检查显著增加了阳性涂片数量，从82例增加到116例（P = 0.0083），总体病例检出率从28例增加到48例（P = 0.011）。在原检查人员复查时，超过一半的假阴性玻片在10分钟后报告为阳性。
痰涂片显微镜检查如果进行得太快，敏感性较低，10分钟的重新检查显著提高了病例检出率。确保按照推荐的时间进行涂片检查可能是一种简单且低成本的提高病例检出率的方法。
