Kawano Kimiko, Okada Mika, Kura Fumiaki, Amemura-Maekawa Junko, Watanabe Haruo
Miyazaki Prefectural Institute for Public Health and Environment.
Kansenshogaku Zasshi. 2007 Mar;81(2):173-82. doi: 10.11150/kansenshogakuzasshi1970.81.173.
In July 2002, a large outbreak of legionellosis occurred in a bathhouse with spa facilities in Miyazaki Prefecture. Among the visitors, 295, including suspected cases had pneumonia and/or symptoms of fever, coughing, etc. Of these, 37% were hospitalized and 7 died. Clinical samples from 95 mainly inpatients were collected and microbiologically tested at our laboratory. Legionella pneumophila serogroup (SG) 1 was isolated from 3 of 24 in sputum culture, and none of the 3 had been treated effectively with antibiotics at sputa collection. L. pneumophila antigen in urine was detected by using enzyme immunoassay and/or immunochromatographic kits in 23 of 75 patients. Serum antibodies to L. pneumophila SG1 and Legionella dumoffii were detected in 5 each of 66 patients--9 cases including a case at mixed infection-by microplate agglutination test and/or indirect immunofluorescence assay. At our laboratory, 32 were diagnosed with legionellosis. In this outbreak, 14 were diagnosed at other laboratories, resulting in 46 confirmed cases. Urine antigen was detected more frequently by Binax NOW immunochromatographic assay than by Biotest EIA-31% versus 16% of cases tested. Both assays detected urine antigen only in samples collected within 4 weeks after onset. Antigen concentration in urine enhanced sensitivity-58% and 51%-and extended the period of antigen detection beyond 5 weeks. Both antibody titers to L. pneumophila SG1 and L. dumoffii in more than 90% of sera collected within 3 weeks after onset were < 1:16. The rate of serum antibody titer to > or = 1:128 within 3 weeks was 1.6%, during 4 to 6 weeks less than 10%, and after 7 weeks or more 8 to 25%. After an administrative report was published, L. pneumophila DNA in sputa was detected in 5 of 17 patients by nested PCR, resulting in extra 3 cases. Altogether, urinary antigen detection and PCR were more effective in laboratory diagnostic tests than culture and serology. Culture combined with molecular epidemiology is critical, however, for confirming the source of infection.
2002年7月，宫崎县一家设有水疗设施的澡堂爆发了大规模军团病疫情。在到访者中，包括疑似病例在内，有295人出现肺炎和/或发热、咳嗽等症状。其中，37%的人住院治疗，7人死亡。我们实验室收集了95名主要住院患者的临床样本并进行了微生物检测。在痰液培养的24份样本中，有3份分离出嗜肺军团菌血清型（SG）1，这3人在采集痰液时均未接受有效的抗生素治疗。在75名患者中，有23人通过酶免疫测定法和/或免疫层析试剂盒检测出尿液中的嗜肺军团菌抗原。通过微孔板凝集试验和/或间接免疫荧光测定法，在66名患者中有5人检测出针对嗜肺军团菌SG1和杜莫夫军团菌的血清抗体——包括1例混合感染病例在内共9例。在我们实验室，32人被诊断为军团病。在此次疫情中，其他实验室诊断出14例，确诊病例共计46例。与Biotest酶免疫测定法相比，Binax NOW免疫层析测定法检测尿液抗原的频率更高——检测病例的比例分别为31%和16%。两种检测方法均仅在发病后4周内采集的样本中检测到尿液抗原。尿液中的抗原浓度提高了检测灵敏度——分别为58%和51%——并将抗原检测时间延长至5周以上。在发病后3周内采集的血清中，超过90%的样本针对嗜肺军团菌SG1和杜莫夫军团菌的抗体滴度均<1:16。发病后3周内血清抗体滴度≥1:128的比例为1.6%，4至6周时低于10%，7周及以后为8%至25%。一份行政报告发布后，通过巢式聚合酶链反应在17名患者中的5份痰液中检测出嗜肺军团菌DNA，新增3例确诊病例。总体而言，在实验室诊断检测中，尿液抗原检测和聚合酶链反应比培养和血清学检测更有效。然而，培养结合分子流行病学对于确定感染源至关重要。
