Hamblion Esther L, Le Menach Arnaud, Anderson Laura F, Lalor Maeve K, Brown Tim, Abubakar Ibrahim, Anderson Charlotte, Maguire Helen, Anderson Sarah R
Field Epidemiology Services (Victoria), Public Health England, London, UK.
Field Epidemiology Services (Victoria), Public Health England, London, UK European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Control and Prevention, Stockholm, Sweden.
Thorax. 2016 Aug;71(8):749-56. doi: 10.1136/thoraxjnl-2014-206608.
The incidence of TB has doubled in the last 20 years in London. A better understanding of risk groups for recent transmission is required to effectively target interventions. We investigated the molecular epidemiological characteristics of TB cases to estimate the proportion of cases due to recent transmission, and identify predictors for belonging to a cluster.
The study population included all culture-positive TB cases in London residents, notified between January 2010 and December 2012, strain typed using 24-loci multiple interspersed repetitive units-variable number tandem repeats. Multivariable logistic regression analysis was performed to assess the risk factors for clustering using sociodemographic and clinical characteristics of cases and for cluster size based on the characteristics of the first two cases.
There were 10 147 cases of which 5728 (57%) were culture confirmed and 4790 isolates (84%) were typed. 2194 (46%) were clustered in 570 clusters, and the estimated proportion attributable to recent transmission was 34%. Clustered cases were more likely to be UK born, have pulmonary TB, a previous diagnosis, a history of substance abuse or alcohol abuse and imprisonment, be of white, Indian, black-African or Caribbean ethnicity. The time between notification of the first two cases was more likely to be <90 days in large clusters.
Up to a third of TB cases in London may be due to recent transmission. Resources should be directed to the timely investigation of clusters involving cases with risk factors, particularly those with a short period between the first two cases, to interrupt onward transmission of TB.
在过去20年里，伦敦的结核病发病率翻了一番。为了有效地实施针对性干预措施，需要更好地了解近期传播的风险群体。我们调查了结核病病例的分子流行病学特征，以估计近期传播所致病例的比例，并确定属于聚集性病例的预测因素。
研究人群包括2010年1月至2012年12月期间通报的所有伦敦居民中痰培养阳性的结核病病例，采用24个位点的多间隔重复单位-可变数目串联重复序列进行菌株分型。利用病例的社会人口学和临床特征进行多变量逻辑回归分析，以评估聚集的危险因素，并根据前两例病例的特征评估聚集规模。
共有10147例病例，其中5728例（57%）痰培养确诊，4790株（84%）进行了分型。2194例（46%）聚集在570个簇中，估计近期传播所致比例为34%。聚集性病例更有可能出生在英国，患有肺结核，有过既往诊断，有药物滥用或酒精滥用及监禁史，为白人、印度人、非洲黑人或加勒比族裔。在大的聚集簇中，前两例病例通报之间的时间更有可能<90天。
伦敦多达三分之一的结核病病例可能是近期传播所致。应将资源用于及时调查涉及有危险因素病例的聚集簇，特别是前两例病例间隔时间短的聚集簇，以阻断结核病的进一步传播。
