緩徐に進行したA群β溶血性連鎖球菌による細菌性筋膜炎の1例

Abstract

A群β溶血性連鎖球菌は，咽頭炎および侵襲性感染症を含む様々な疾患を引き起こすヒト適応病原体である．侵襲性感染症としては劇症型溶血性連鎖球菌感染症，壊死性軟部組織感染症は有名であるが，いずれも発病から病状の進行が非常に急激かつ劇的であり，数十時間以内に軟部組織壊死を含め多臓器に障害をきたし死に至ることも多い疾患である．今回我々は，血液培養，筋膜に付着する膿瘍の培養から，A群β溶血性連鎖球菌を検出したにも関わらず，臨床経過が緩徐で，全身状態も比較的安定していた細菌性筋膜炎と考えられる4歳男児例を経験した．経過からは壊死性あるいは劇症型の臨床像とは合致せず，起因菌となったA群溶連菌株の病原因子について一部検討した．A群溶連菌による軟部組織感染症を疑う症例では，常に壊死性あるいは劇症化の病像を想定し，それらの徴候が察知されれば躊躇せず外科的介入を行うことが最重要であるが，起因菌株によっては，本症例のように非劇症型・非壊死性の病型もあることを認識したい．

Group A Hemolytic Streptococcus is a human-adapted pathogen that causes a variety of diseases，including pharyngitis and invasive infections．As invasive infections，severe invasive hemolytic streptococcal infections and necrotizing soft tissue infections are well known，but in both cases the progression of the disease state from onset is quite abrupt and dramatic，and within several tens of hours tissue necrosis including soft tissue necrosis is often a disorder of multiple organs leading to death．We detected group A β-hemolytic streptococci from the culture of abscess attached to the fascia and blood culture in a 4-year-old boy suspected of having bacterial fasciitis, but did not match the clinical picture of necrotizing or fulminant type. The clinical course was slow and general state was also relatively stable. We examined the pathogenic factors of group A streptococcus strains which became the causative bacteria．In cases suspected to be soft tissue infection caused by Group A streptococcus，it is important to assume a pathological condition of necrosis or fulmination and to perform surgical intervention without hesitation if these signs are detected．However，depending on the causative strain，we need to be aware of the possibility of non-dramatic and non-necrotizing disease types as in this case．