アメーバ性大腸炎

Current Trends and Diagnosis of Amebic Colitis

要旨　アメーバ性大腸炎は，STDの代表的な疾患の1つで最近，増加傾向を示している．その原因は，以前から指摘されている男性同性愛者間の感染者のほか，性風俗を介する異性間感染者の増加が大きな要因と推測される．当院で経験した19例での分析では，異性間感染が11/19（58％），同性愛者間感染3/19（16％），海外での感染6/19（32％）などであった．19例中2例（11％）に肝膿瘍を認めた．病変の分布は盲腸19/19（100％），直腸12/19（63％）に多く，診断は内視鏡所見から疑われ，粘液の鏡検，生検組織診断，血清抗体価で確定診断され，その診断率はそれぞれ88％，79％，71％であった．3者を組み合わせることで診断率の向上が期待される．

　The incidence rate of amebic colitis, a major sexually transmitted disease（STD）, has been increasing in recent years. As noted previously, this is due to an increase in the rate of infection among male homosexuals as well as an increase in infections between the sexes through the commercial sex trade. Infection was between the sexes in 11 of 19 patients（58％）with this disease treated at our hospital, while three of the infections were between members of the same sex. Six of the 19 cases（32％）were infected overseas. Two of the patients（11％）presented with complications associated with liver abscess. The lesions were seen most commonly in the appendix（100％）and the rectum（63％）, which was suspected from diagnosis relying only on endoscopic findings, and a definite diagnosis was then made based on microscopic examination of the mucus obtained by biopsy using forceps, histological examination, and serum antibody value. The diagnosis rates using these methods were 88％, 79％, and 71％, respectively. The diagnostic rate can be improved by a combination of these methods.