Alland D, Kalkut G E, Moss A R, McAdam R A, Hahn J A, Bosworth W, Drucker E, Bloom B R
Department of Medicine, Montefiore Medical Center, North Central Bronx Hospital, N.Y. 10467.
N Engl J Med. 1994 Jun 16;330(24):1710-6. doi: 10.1056/NEJM199406163302403.
The incidence of tuberculosis and drug resistance is increasing in the United States, but it is not clear how much of the increase is due to reactivation of latent infection and how much to recent transmission.
We performed DNA fingerprinting using restriction-fragment-length polymorphism (RFLP) analysis of at least one isolate from every patient with confirmed tuberculosis at a major hospital in the Bronx, New York, from December 1, 1989, through December 31, 1992. Medical records and census-tract data were reviewed for relevant clinical, social, and demographic data.
Of 130 patients with tuberculosis, 104 adults (80 percent) had complete medical records and isolates whose DNA fingerprints could be evaluated. Isolates from 65 patients (62.5 percent) had unique RFLP patterns, whereas isolates from 39 patients (37.5 percent) had RFLP patterns that were identical to those of an isolate from at least 1 other study patient; the isolates in the latter group were classified into 12 clusters. Patients whose isolates were included in one of the clusters were inferred to have recently transmitted disease. Independent risk factors for having a clustered isolate included seropositivity for the human immunodeficiency virus (HIV) (odds ratio for Hispanic patients, 4.31; P = 0.02; for non-Hispanic patients, 3.12; P = 0.07), Hispanic ethnicity combined with HIV seronegativity (odds ratio, 5.13; P = 0.05), infection with drug-resistant tuberculosis (odds ratio, 4.52; P = 0.005), and younger age (odds ratio, 1.59; P = 0.02). Residence in sections of the Bronx with a median household income below $20,000 was also associated with having a clustered isolate (odds ratio, 3.22; P = 0.04).
In the inner-city community we studied, recently transmitted tuberculosis accounts for approximately 40 percent of the incident cases and almost two thirds of drug-resistant cases. Recent transmission of tuberculosis, and not only reactivation of latent disease, contributes substantially to the increase in tuberculosis.
在美国，结核病及耐药性的发病率正在上升，但尚不清楚这种上升中有多少是由于潜伏感染的重新激活，又有多少是由于近期的传播。
我们对1989年12月1日至1992年12月31日期间纽约布朗克斯区一家大型医院确诊为结核病的每位患者的至少一份分离株进行了限制性片段长度多态性（RFLP）分析的DNA指纹识别。查阅了病历和普查区数据以获取相关临床、社会和人口统计学数据。
130例结核病患者中，104例成年人（80%）有完整病历且其分离株的DNA指纹可进行评估。65例患者（62.5%）的分离株具有独特的RFLP模式，而39例患者（37.5%）的分离株具有与至少1例其他研究患者的分离株相同的RFLP模式；后一组中的分离株被分为12个簇。其分离株包含在一个簇中的患者被推断患有近期传播的疾病。分离株呈簇状的独立危险因素包括人类免疫缺陷病毒（HIV）血清学阳性（西班牙裔患者的优势比为4.31；P = 0.02；非西班牙裔患者为3.12；P = 0.07）、西班牙裔种族合并HIV血清学阴性（优势比为5.13；P = 0.05）、耐多药结核病感染（优势比为4.52；P = 0.005）以及年龄较小（优势比为1.59；P = 0.02）。居住在布朗克斯区家庭收入中位数低于20,000美元的地区也与分离株呈簇状有关（优势比为3.22；P = 0.04）。
在我们研究的市中心社区，近期传播的结核病约占发病病例的40%，几乎占耐药病例的三分之二。结核病的近期传播，而非仅潜伏疾病的重新激活，在很大程度上导致了结核病发病率的上升。
