Andrews Jason R, Gandhi Neel R, Moodley Prashini, Shah N Sarita, Bohlken Louise, Moll Anthony P, Pillay Manormoney, Friedland Gerald, Sturm A Willem
Division of General Internal Medicine, University of California-San Francisco/San Francisco General Hospital, San Francisco, CA, USA.
J Infect Dis. 2008 Dec 1;198(11):1582-9. doi: 10.1086/592991.
Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) are now major threats in areas of South Africa with a high prevalence of TB and human immunodeficiency virus (HIV) infection. The role of exogenous reinfection as a cause of MDR and XDR TB in these settings has not been determined.
We reviewed data from patients with culture-positive TB who later developed MDR or XDR TB in Tugela Ferry, KwaZulu-Natal, South Africa during 2005-2006. We performed spoligotyping on initial isolates (obtained at the time of treatment initiation) and follow-up isolates obtained from these patients.
We identified 23 patients who developed MDR or XDR TB after being treated for less resistant TB between June 2005 and June 2006. Both initial and follow-up isolates were available for spoligotyping for 17 of these patients. In all cases, the follow-up isolates' spoligotypes differed from those of the initial isolate, indicating exogenous reinfection. Two genotypes (shared type [ST] 34 and ST 60, associated with MDR and XDR TB, respectively) were responsible for 85% of reinfections. All 17 patients had been hospitalized; all 15 whose HIV infection status was known were HIV-infected.
Exogenous reinfection is an important mechanism for the development of MDR and XDR TB. In addition to strengthening TB treatment programs, effective infection control strategies are urgently needed to reduce the transmission of MDR and XDR TB.
耐多药（MDR）和广泛耐药（XDR）结核病目前是南非结核病和人类免疫缺陷病毒（HIV）感染高发地区的主要威胁。在这些地区，外源性再感染作为耐多药和广泛耐药结核病病因的作用尚未确定。
我们回顾了2005年至2006年期间在南非夸祖鲁 - 纳塔尔省图盖拉费里患培养阳性结核病且后来发展为耐多药或广泛耐药结核病患者的数据。我们对初始分离株（在开始治疗时获得）以及从这些患者获得的随访分离株进行了间隔寡核苷酸分型。
我们确定了23例在2005年6月至2006年6月期间接受耐药性较低的结核病治疗后发展为耐多药或广泛耐药结核病的患者。其中17例患者的初始和随访分离株都可用于间隔寡核苷酸分型。在所有病例中，随访分离株的间隔寡核苷酸分型与初始分离株不同，表明为外源性再感染。两种基因型（共享型[ST]34和ST60，分别与耐多药和广泛耐药结核病相关）导致了85%的再感染。所有17例患者均曾住院；已知HIV感染状况的15例患者均感染了HIV。
外源性再感染是耐多药和广泛耐药结核病发生的重要机制。除了加强结核病治疗项目外，迫切需要有效的感染控制策略以减少耐多药和广泛耐药结核病的传播。
