Martínez-Lirola Miguel, Alonso-Rodriguez Noelia, Sánchez M Luisa, Herranz Marta, Andrés Sandra, Peñafiel Teresa, Rogado M Cruz, Cabezas Teresa, Martínez Juan, Lucerna M Angeles, Rodríguez Manuel, Bonillo Magdalena Del Carmen, Bouza Emilio, García de Viedma Darío
Servicio de Microbiología, Hospital Gregorio Marañón, Madrid, Spain.
Clin Infect Dis. 2008 Jul 1;47(1):8-14. doi: 10.1086/588785.
An increase in the incidence of tuberculosis (TB) in immigrants has changed the socioepidemiologic scenario in Spain. It is generally assumed that TB in immigrants is the result of importation of infection, but the role of recent transmission is rarely considered. Standard contact tracing is not suitable for the survey of transmission in this complex scenario.
During the study period (2003-2006), we genotyped 356 (90.4%) of 394 isolates from patients with microbiologically confirmed TB in Almería, the province with the highest percentage of TB cases among immigrants in Spain. The epidemiologic survey of TB transmission was performed by active data collection using standardized interviews of the patients with TB and subsequent interviews of the clustered patients (who were clustered on the basis of the restriction fragment-length polymorphism types of their isolates) to identify transmission locations (supported by nominal and/or photographic recognition by the clustered patients).
Of all 356 genotyped isolates, 131 (36.8%) were clustered, suggesting recent transmission. The difference between the clustering rate for immigrants (32.8%) and that for native patients (41.6%) was not statistically significant (P = .087); of the 45 clusters, 15 (33.3%) involved only immigrants, 17 (37.8%) involved only autochthonous patients, and 13 (28.9%) involved both immigrants and autochthonous patients. The advanced system to investigate the clustered patients succeeded in detecting links in 10 of the 12 clusters that involved >4 patients, whereas the conventional approach, based on contact tracing, could detect links in only 2 clusters.
Recent transmission among immigrants and transmission permeability between the immigrant and autochthonous populations were found. Epidemiologic strategies that combine universal genotyping and refined surveys of the clustered patients are needed to investigate transmission patterns in complex scenarios.
移民中结核病（TB）发病率的上升改变了西班牙的社会流行病学状况。一般认为移民中的结核病是感染输入的结果，但很少考虑近期传播的作用。标准的接触者追踪不适用于这种复杂情况下的传播调查。
在研究期间（2003 - 2006年），我们对来自阿尔梅里亚394例微生物学确诊结核病患者的356株菌株（90.4%）进行了基因分型，阿尔梅里亚是西班牙移民中结核病病例百分比最高的省份。通过对结核病患者进行标准化访谈并随后对聚集患者（根据其菌株的限制性片段长度多态性类型进行聚集）进行访谈来积极收集数据，以确定传播地点（得到聚集患者的名义和/或照片识别支持），从而开展结核病传播的流行病学调查。
在所有356株基因分型菌株中，131株（36.8%）呈聚集性，提示近期传播。移民的聚集率（32.8%）与本地患者的聚集率（41.6%）之间的差异无统计学意义（P = 0.087）；在45个聚集组中，15个（33.3%）仅涉及移民，17个（37.8%）仅涉及本地患者，13个（28.9%）涉及移民和本地患者。用于调查聚集患者的先进系统成功地在涉及>4名患者的12个聚集组中的10个中检测到了联系，而基于接触者追踪的传统方法仅在2个聚集组中检测到联系。
发现了移民之间的近期传播以及移民与本地人群之间的传播渗透性。需要结合普遍基因分型和对聚集患者进行精细调查的流行病学策略来研究复杂情况下的传播模式。
