新诊断痰涂片阳性肺结核病例家庭密切接触者的活动性肺结核患病率调查

Prevalence of active pulmonary tuberculosis among household contacts of recently diagnosed pulmonary tuberculosis patients with positive sputum-smear

目的 了解新诊断涂片阳性肺结核病例家庭密切接触者的活动性肺结核患病情况。方法 以阜阳市2006年新发现痰涂片阳性肺结核患者为指示病例，追踪其家庭密切接触者，并进行结核菌素、X线胸片和3次痰涂片检查，确定密切接触者中活动性肺结核感染情况。结果 2006年阜阳市共报告1386例新诊断的痰涂片阳性肺结核病例，追踪发现5392名家庭密切接触者。检查家庭密切接触者发现其活动性肺结核患病率为3．76％，家庭密切接触者〈15岁年龄组和≥55岁以上年龄组的活动性肺结核患病率高于其他各年龄组（x^2=15．381，P〈0．01），密切接触者中活动性肺结核患病率随着指示病例的痰检排菌量增多而增高（r=0．998，P〈0．01）。平均每100名指示病例可追踪发现15例新的活动性肺结核病例。结论 对新诊断痰涂片阳性病例家庭密切接触者进行结核病筛查，有利于提高活动性肺结核患者的发现率。

Objective To describe the prevalence of pulmonary tuberculosis （TB） among household contacts of patients recently diagnosed as pulmonary TB. Methods Newly diagnosed pulmonary TB cases in 2006 were used as index cases for searching more active TB cases. All the household contacts were identified and examined with purified protein derivative, chest X-ray and sputum-smear for three times. The prevalence of active TB infection among household contacts was calculated and compared against demographic characteristics. Results A total of 1386 newly diagnosed active TB cases were reported and their 5392 household contacts were screened. The overall prevalence of active pulmonary TB among household contacts was 3.76 %, but significantly higher in the age groups of 〈 15 years or ≥55 years than the other age groups （X^2 = 15.381, P 〈 0.01 ）. The rate of active pulmonary TB in household contacts was significantly associated with the amount of bacteria discharged from index cases （r= 0. 998, P〈 0.01）. Through contact tracing, every 100 index cases could contribute in finding 15 more new active TB cases among household contacts. Conclusion Our results showed that this program could increase the identification of active pulmonary TB case through tracking down the household contacts of newly diagnosed TB cases.