Molecular and clinical characteristics of invasive group A streptococcal infection in Sweden
Molecular and clinical characteristics of invasive group A streptococcal infection in Sweden
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DOI：
10.1086/519936
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发表时间：
2007-08-15
影响因子：
11.8
通讯作者：
Normark, Birgitta Henriques
中科院分区：
文献类型：
--
作者：
Darenberg, Jessica;Luca-Harari, Bogdan;Normark, Birgitta Henriques
背景。侵袭性A组链球菌感染的发生率和严重程度随时间的变化表现出很大的变异性，这至少在一定程度上似乎与A组链球菌在人群中的类型分布有关。2002年4月至2004年12月在瑞典进行了侵袭性A群链球菌感染（746株）的强化监测研究。同时收集咽喉和皮肤无创分离株（773株）进行比较。88%侵袭性疾病患者的临床和流行病学资料与分离物的特征有关，包括T型、emm序列类型和9个超抗原基因的存在，并对所选分离物进行脉冲场凝胶电泳模式比较。年发病率为每10万人3.0例。侵袭性疾病患者中，11%发生链球菌中毒性休克综合征，9.5%发生坏死性筋膜炎。总病死率为14.5%，其中39%的链球菌中毒性休克综合征患者死亡（P < 0.001）。T3/13/B3264集群占侵入性分离株的33%和非侵入性分离株的25%。在这个最普遍的类型集群中，emm 89型和81型占主导地位。脉冲场凝胶电泳、emm分型和超抗原基因谱的综合结果确定了特定emm类型中的亚群，这些亚群比其他同类型的分离株更容易引起侵袭性疾病。这项研究揭示了瑞典侵袭性a组链球菌感染的流行病学变化，出现了以前未描述的新emm类型。结果还表明，一些克隆可能特别容易引起侵袭性疾病。
Background. The incidence and severity of invasive group A streptococcal infection demonstrate great variability over time, which at least, in part, seems to be related to group A streptococcal type distribution among the human population.Methods. An enhanced surveillance study of invasive group A streptococcal infection (746 isolates) was performed in Sweden from April 2002 through December 2004. Noninvasive isolates from either the throat or skin (773 isolates) were collected in parallel for comparison. Clinical and epidemiological data were obtained from 88% of patients with invasive disease and were related to isolate characteristics, including T type, emm sequence type, and the presence of 9 superantigen genes, as well as pulsed-field gel electrophoresis pattern comparisons of selected isolates.Results. The annual incidence was 3.0 cases per 100,000 population. Among the patients with invasive disease, 11% developed streptococcal toxic shock syndrome, and 9.5% developed necrotizing fasciitis. The overall case-fatality rate was 14.5%, and 39% of the patients with streptococcal toxic shock syndrome died (P < .001). The T3/13/B3264 cluster accounted for 33% of invasive and 25% of noninvasive isolates. Among this most prevalent type cluster, emm types 89 and 81 dominated. Combined results from pulsed-field gel electrophoresis, emm typing, and superantigen gene profiling identified subgroups within specific emm types that are significantly more prone to cause invasive disease than were other isolates of the same type.Conclusions. This study revealed a changing epidemiology of invasive group A streptococcal infection in Sweden, with emergence of new emm types that were previously not described. The results also suggest that some clones may be particularly prone to cause invasive disease.