为了掌握中专学生结核菌感染的情况，从1990年开始，每年对入学新生全部进行旧结核菌素（OT）试验，结果报告如下。1材料和方法结核菌素为卫生部生物制品研究所生产供给。用1：2000的旧结核菌素0．1ml接种于受检者的左前臂中的下1／3处皮内。注射后48-72小时看结果，其强弱分度 In order to grasp the situation of tuberculosis infection in secondary school students, from the beginning of 1990, all incoming students will be subjected to the old tuberculin (OT) test each year. The results are reported below. 1 Materials and methods Tuberculin is produced and supplied by the Institute of Biological Products of the Ministry of Health. A 1:2000 old tuberculin 0.1 ml was inoculated into the skin of the lower third of the subject’s left forearm. 48-72 hours after injection to see the results, the strength of the indexing