Kao A S, Ashford D A, McNeil M M, Warren N G, Good R C
Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30033, USA.
J Clin Microbiol. 1997 Jul;35(7):1847-51. doi: 10.1128/jcm.35.7.1847-1851.1997.
The increase in numbers of cases of tuberculosis in the United States has placed greater demands on mycobacteriology laboratory workers to produce rapid and accurate results. The greater number of specimens generated by the increased emphasis on detecting the disease has placed these workers at greater risk of laboratory-acquired infection. We surveyed 56 state and territorial public health laboratories to determine the status of existing tuberculin skin testing (TST) programs and to evaluate the frequency of probable laboratory-acquired tuberculosis for each responding mycobacteriology laboratory. Probable laboratory-acquired infections were determined by each laboratory's evaluation of occupational positions, duties, and employee histories and review of medical records. Two-step TST for new employees was routinely practiced in only 33% of responding laboratories, and mycobacteriology laboratorians were found to be most frequently screened when they were compared to employees of other departments. Of 49 (88%) responding laboratories, 13 reported that 21 employees were TST converters from 1990 to 1994. Seven of these 21 employees were documented to have laboratory-acquired infections based on evaluations by their respective laboratories. Based on Centers for Disease Control and Prevention guidelines, converters are categorized on the basis of both a change in the size of the zone of induration and the age of the person being tested. By the definitions in the guidelines, 14 mycobacteriologists were identified as recent converters, 7 of whom were > or = 35 years of age and 4 of whom were exposed in the laboratory within a 2-year period. Inadequate isolation procedures, the high volume of specimen handling, and faulty ventilation accounted for these laboratory-associated infections. These results suggest that more frequent periodic evaluations based on documented TST conversions for workers in mycobacterial laboratories should be performed, since this population is at increased risk of becoming infected with Mycobacterium tuberculosis. Although general assessments are necessary to accurately and effectively evaluate the risk of tuberculosis transmission, they are especially important for those working in high-risk areas within a public health laboratory.
美国结核病病例数量的增加，对分枝杆菌学实验室工作人员提出了更高要求，即要快速且准确地得出检测结果。由于更加强调疾病检测而产生了更多的标本，这使得这些工作人员面临更高的实验室获得性感染风险。我们对56个州和地区的公共卫生实验室进行了调查，以确定现有结核菌素皮肤试验（TST）项目的状况，并评估每个参与调查的分枝杆菌学实验室可能发生实验室获得性结核病的频率。每个实验室通过评估职业岗位、职责、员工病史以及查阅医疗记录来确定可能的实验室获得性感染情况。仅33%的参与调查实验室对新员工常规进行两步TST检测，并且发现与其他部门的员工相比，分枝杆菌学实验室技术人员接受筛查的频率最高。在49个（88%）参与调查的实验室中，有13个报告称在1990年至1994年期间有21名员工TST结果出现转化。根据各自实验室的评估，这21名员工中有7名被记录为发生了实验室获得性感染。根据疾病控制与预防中心的指南，结果转化者是根据硬结区域大小的变化以及被检测者的年龄进行分类的。按照指南中的定义，有14名分枝杆菌学家被确定为近期结果转化者，其中7名年龄≥35岁，4名在2年内在实验室有过接触。隔离程序不完善、标本处理量过大以及通风不良是这些实验室相关感染的原因。这些结果表明，对于分枝杆菌实验室的工作人员，应根据有记录的TST结果转化情况更频繁地进行定期评估，因为这一人群感染结核分枝杆菌的风险增加。尽管进行全面评估对于准确有效地评估结核病传播风险是必要的，但对于在公共卫生实验室高风险区域工作的人员而言尤为重要。
