Tracking Trichophyton tonsurans through a large urban child care center:: Defining infection prevalence and transmission patterns by molecular strain typing
Tracking Trichophyton tonsurans through a large urban child care center:: Defining infection prevalence and transmission patterns by molecular strain typing
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DOI：
10.1542/peds.2006-2065
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发表时间：
2006-12-01
期刊：
影响因子：
8
通讯作者：
Gaedigk, Andrea
中科院分区：
文献类型：
--
作者：
Abdel-Rahman, Susan M.;Simon, Steve;Gaedigk, Andrea
目标。在北美，疣毛癣菌是儿童皮肤真菌病最常见的原因，在其他国家也越来越常见。这项调查的目的是深入了解结核菌感染的自然过程。患者和方法。这项为期2年的前瞻性纵向研究评估了所有在一个托儿中心就读的学龄前儿童。每月收集每个儿童的头皮培养，并在每次就诊时记录疾病症状的存在。根据2个基因座中存在的稳定序列变异（2个长度变异，8个单核苷酸多态性，10个碱基对插入，14个碱基对缺失）的组合来确定皮肤真菌的基因型。在24个月内，共收集了446名儿童的3541份头皮培养物。每月22%至51%的头皮培养呈阳性，贡献1390个真菌培养，其中1048个可分型。在有多个可分型菌株的儿童中，51%的儿童完全携带同一菌株，37%的儿童显示单一优势菌株，短暂获得次级菌株，12%的儿童在每个可分型培养中携带不同菌株。同一菌株在随后几个月持续存在的概率为0.898，不太可能是偶然出现的。特异性、显性和短暂性T - surans携带者的症状性疾病发生率有显著差异。在老年人中，有症状的疾病似乎是病原体获得的结果，携带者可以追溯到一个指标病例，与此相反，在学龄前人群中，感染是地方性的，有症状的疾病似乎代表了头皮上持续存在的单一菌株的激活。
OBJECTIVES. Trichophyton tonsurans is the single most common cause of pediatric dermatophytoses in North America and is observed with increasing frequency in other countries. This investigation was designed to gain insight into the natural course of T tonsurans infection.PATIENTS AND METHODS. This 2-year prospective, longitudinal study evaluated all preschool-aged children attending a single child care center. Scalp cultures were collected monthly from each child in attendance, and the presence of disease symptoms recorded at each visit. Dermatophyte genotype was assigned based on the combination of stable sequence variations (2 length variants, 8 single-nucleotide polymorphisms, a 10-base pair insertion, a 14-base pair deletion) present in 2 gene loci.RESULTS. A total of 3541 scalp cultures were collected from 446 children during 24 months. Twenty-two percent to 51% of scalp cultures per month were positive, contributing 1390 fungal cultures of which 1048 were typeable. Among children with multiple typeable isolates, 51% exclusively carried the same strain, 37% demonstrated a single predominant strain with secondary strains transiently acquired, and 12% harbored a different strain of T tonsurans with each typeable culture. The probability that the same strain persisted in subsequent months was 0.898 and unlikely to have arisen by chance. Rates of symptomatic disease were significantly different between exclusive, predominant, and transient carriers of T tonsurans.CONCLUSIONS. In contrast to dermatophyte infections in older individuals, where symptomatic disease seems to be a consequence of pathogen acquisition and carriers can be traced to an index case, in this preschool-aged population infection was endemic, and symptomatic disease seemed to represent activation of a single strain that persisted on the scalp.