Institute of Tuberculosis and HIV/AIDS Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China.
Department of Epidemiology, School of Public Health, Fudan University, Shanghai, China.
BMC Infect Dis. 2019 Apr 11;19(1):320. doi: 10.1186/s12879-019-3942-2.
To assess the effect of a contact investigation strategy by assessing the incidence of tuberculosis and the case detection rate among contacts of tuberculosis patients.
The pulmonary tuberculosis incidence among contacts was determined retrospectively from a tuberculosis information management system. For each detection method (symptom examination only, symptom examination plus chest radiography or other alternatives), the detection rate of pulmonary tuberculosis patients among contacts was derived from contact investigation form records.
Sixty-nine cases of pulmonary tuberculosis were identified among a total of 8137 contacts after an average follow-up of 2.6 years (range: 0.25-5.25) during the period from 2010 to 2014. The incidence density was 329/100,000 person-years (PYs), and the 95% confidence interval (CI) was 256-419/100,000 PYs, which was significantly higher than the notification rate during the same period in the general population (29-30/100,000 PYs). The incidence density was higher (p < 0.0001) among male contacts (462/100,000 PYs) than among female contacts (236/100,000 PYs). The incidence density did not differ (p > 0.05) between contacts whose index case was sputum smear positive and those whose index case was sputum smear negative. Contacts who were biologically related family of the index cases exhibited a higher (p < 0.05) incidence density (475/100,000 PYs) than other contacts (281/100,000 PYs). Fifteen of the 69 incident cases were found through contact investigation, corresponding to a case detection rate via contact investigation of 22% (95% CI: 13-33%). The relevance ratio was 288/100,000 (12/4163) by both chest radiography and symptom survey, which was significantly higher than the rate detected by symptom survey alone, of 57/100,000 (2/3486), p = 0.028. The cumulative incidence in the contacts was 761/100,000 (62/8137) within 3 years from the time that the index cases were diagnosed with pulmonary tuberculosis, which was higher than the incidence rate of 210/100,000 (7/3328) recorded after 3 years (p < 0.001).
The contacts were at higher risk of pulmonary tuberculosis than the general population; however, only approximately 22% of the incident cases could be detected through contact investigation. Therefore, the contact investigation strategy must be improved for better detection of potential pulmonary tuberculosis cases.
通过评估结核病患者接触者的结核病发病率和病例检出率来评估接触者调查策略的效果。
从结核病信息管理系统中回顾性确定接触者的肺结核发病率。对于每种检测方法（仅症状检查、症状检查加胸部 X 线检查或其他替代方法），从接触者调查表格记录中得出肺结核患者的检出率。
在 2010 年至 2014 年期间，对 8137 名接触者进行了平均 2.6 年（范围：0.25-5.25）的随访后，共发现 69 例肺结核病例。发病率密度为 329/100000 人年（PY），95%置信区间（CI）为 256-419/100000 PY，显著高于同期一般人群的报告率（29-30/100000 PY）。男性接触者（462/100000 PY）的发病率密度高于女性接触者（236/100000 PY）（p<0.0001）。痰涂片阳性的病例与痰涂片阴性的病例之间的发病率密度无差异（p>0.05）。与索引病例具有生物学关系的家庭接触者的发病率密度（475/100000 PY）高于其他接触者（281/100000 PY）（p<0.05）。69 例发病病例中有 15 例是通过接触者调查发现的，接触者调查的病例检出率为 22%（95%CI：13-33%）。关联比为 288/100000（12/4163），通过 X 射线和症状调查均高于单独通过症状调查的检出率，57/100000（2/3486），p=0.028。从索引病例诊断为肺结核起 3 年内，接触者的累积发病率为 761/100000（62/8137），高于 3 年后记录的 210/100000（7/3328）（p<0.001）。
接触者患肺结核的风险高于一般人群；然而，只有约 22%的发病病例可以通过接触者调查发现。因此，必须改进接触者调查策略，以更好地发现潜在的肺结核病例。
