Peto Heather M, Pratt Robert H, Harrington Theresa A, LoBue Philip A, Armstrong Lori R
Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, Sexually Transmitted Disease, and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Clin Infect Dis. 2009 Nov 1;49(9):1350-7. doi: 10.1086/605559.
Almost one-fifth of United States tuberculosis cases are extrapulmonary; unexplained slower annual case count decreases have occurred in extrapulmonary tuberculosis (EPTB), compared with annual case count decreases in pulmonary tuberculosis (PTB) cases. We describe the epidemiology of EPTB by means of US national tuberculosis surveillance data.
US tuberculosis cases reported from 1993 to 2006 were classified as either EPTB or PTB. EPTB encompassed lymphatic, pleural, bone and/or joint, genitourinary, meningeal, peritoneal, and unclassified EPTB cases. We excluded cases with concurrent extrapulmonary-pulmonary tuberculosis and cases of disseminated (miliary) tuberculosis. Demographic characteristics, drug susceptibility test results, and risk factors, including human immunodeficiency virus (HIV) status, were compared for EPTB and PTB cases.
Among 253,299 cases, 73.6% were PTB and 18.7% were EPTB, including lymphatic (40.4%), pleural (19.8%), bone and/or joint (11.3%), genitourinary (6.5%), meningeal (5.4%), peritoneal (4.9%), and unclassified EPTB (11.8%) cases. Compared with PTB, EPTB was associated with female sex (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.7-1.8) and foreign birth (OR, 1.5; CI, 1.5-1.6), almost equally associated with HIV status (OR, 1.1; CI, 1.1-1.1), and negatively associated with multidrug resistance (OR, 0.6; CI, 0.5-0.6) and several tuberculosis risk factors, especially homelessness (OR, 0.3; CI, 0.3-0.3) and excess alcohol use (OR, 0.3; CI, 0.3-0.3). Slower annual decreases in EPTB case counts, compared with annual decreases in PTB case counts, from 1993 through 2006 have caused EPTB to increase from 15.7% of tuberculosis cases in 1993 to 21.0% in 2006.
EPTB epidemiology and risk factors differ from those of PTB, and the proportion of EPTB has increased from 1993 through 2006. Further study is needed to identify causes of the proportional increase in EPTB.
美国近五分之一的结核病病例为肺外结核；与肺结核（PTB）病例数的年度下降相比，肺外结核（EPTB）病例数年度下降速度较慢且原因不明。我们利用美国国家结核病监测数据描述了EPTB的流行病学特征。
将1993年至2006年报告的美国结核病病例分为EPTB或PTB。EPTB包括淋巴、胸膜、骨和/或关节、泌尿生殖、脑膜、腹膜及未分类的EPTB病例。我们排除了合并肺外-肺结核病例和播散性（粟粒性）结核病例。比较了EPTB和PTB病例的人口统计学特征、药敏试验结果及危险因素，包括人类免疫缺陷病毒（HIV）感染状况。
在253,299例病例中，73.6%为PTB，18.7%为EPTB，其中包括淋巴（40.4%）、胸膜（19.8%）、骨和/或关节（11.3%）、泌尿生殖（6.5%）、脑膜（5.4%）、腹膜（4.9%）及未分类的EPTB（11.8%）病例。与PTB相比，EPTB与女性（比值比[OR]为1.7；95%置信区间[CI]为1.7 - 1.8）和外国出生（OR为1.5；CI为1.5 - 1.6）相关，与HIV感染状况相关性几乎相同（OR为1.1；CI为1.1 - 1.1），与多重耐药（OR为0.6；CI为0.5 - 0.6）及几种结核病危险因素呈负相关，尤其是无家可归（OR为0.3；CI为0.3 - 0.3）和过量饮酒（OR为0.3；CI为0.3 - 0.3）。从1993年至2006年，EPTB病例数的年度下降速度慢于PTB病例数的年度下降速度，这使得EPTB在结核病病例中的占比从1993年的15.7%增至2006年的21.0%。
EPTB的流行病学特征和危险因素与PTB不同，且从1993年至2006年EPTB的占比有所增加。需要进一步研究以确定EPTB占比增加的原因。
