目的了解2009年驻京部队入伍新兵结核感染及发病情况,评价酶联免疫斑点试验(ELISPOT)在检测结核分枝杆菌感染中的应用价值。方法2009年907例驻京部队入伍新兵,行胸部X线检查、PPD皮肤试验和ELISPOT检测。PPD皮肤试验阴性者,接种卡介苗7个月后抽查110例,再进行PPD皮肤试验和ELISPOT检测。随访18个月了解结核病发病情况。结果907例入伍新兵中,PPD皮肤试验和ELISPOT的阳性率分别为50.2%和30.7%。452例PPD阴性和455例PPD阳性者中,分别有132例(29.2%)和146例(32.1%)ELISPOT阳性,两者的一致率为51.4%(466/907)。65.6%的PPD阳性者和27-8%的ELISPOT阳性者[斑点形成细胞(SFC)12.2±21.2]有卡介苗接种;21.3%的PPD阳性者和35.9%的ELISPOT阳性者(SFC18.3±34.6)没有卡介苗接种。PPD皮肤试验阴性的新兵接种卡介苗7个月后抽查的110例中,8s例(7%3%)PPD皮肤试验阳性、21例(19.1%)强阳性,21例(19.1%)ELISPOT阳性、13例(11.8%)强阳性;两者的一致率为38.2%(42/110)。12例新兵发现胸片异常,其中12例(100%)PPD皮肤试验阳性,6例(s0%)ELIsPoT阳性。随访18个月,均未发现发展为结核病。结论驻京部队入伍新兵的结核感染率低于既往报道,提示卡介苗接种能部分保护人群抵抗结核感染,ELISPOT技术能够更有效地筛查结核感染。
Objective To investigate Mycobacterium tuberculosis infection and incidence of tuberculosis in the recruits of army stationed in Beijing Military command, and evaluate the value of enzyme-linked immunospot (ELISPOT) assay for detection of mycobacterial infections. Methods From December 2009 to February 2010, a total of 907 new recruits to the army were examined by chest radiography, purified protein derivative(PPD) skin test and ELISPOT assay with recombinant CFP-10/ESAT-6 fusion protein (rCFP-10/ESAT-6) as a stimulus. The PPD-negative recruits were vaccinated with BCG vaccine, and 110 were retested with PPD skin test and ELISPOT 7 months later. The recruits were followed up for 18 months to find out whether they would develop active tuberculosis. Results The prevalence of latent tuberculosis infection (LTI), as estimated by PPD skin test and ELISPOT assay, was 50.2% and 30.7%, among new recruits, respectively. Of 452 PPD-negative and 455 PPD-positive volunteers, 132(29.2%) and 146(32.1%) were ELISPOT positive, respectively. Overall agreement between tests was 51.4% (466/907). About 65.6% of PPD- positive volunteers and 27.8% of ELISPOT-positive volunteers (SFC 12.2 ± 21.2) had received BCG vaccination with scars on their arms. About 21.3% of PPD-positive volunteers and 35.9% of ELISPOT-positive volunteers (SFC 18.3± 34.6) had not received vaccination with no scar on their arms. Of 1 i0 PPD-negative recruits who received BCG vaccination, 77.3% PPD skin test turned to positive, 19.1% turned to strongly positive, 7 months later, and 19.1% were ELISPOT-positive, 11.8% were ELISPOT-strongly positive. Overall agreement between tests was 38.2% (42/100). No one developed active tuberculosis during 18-month follow-up. Conclusions The M. tuberculosis infection rate in army recruits in China is lower than that previously reported. BCG vaccination could partly protect the population against the infection of M. tuberculosis. ELISPOT technique may he a more accurate method for scree