投稿分類 微生物

主委發表種類: 口頭

投稿標題(中): 台灣地區環境供水系統中退伍軍人菌血清型態調查

投稿標題(英): Investigation of Legionella Speciation And Serotype From Environmental Water System In Taiwan

投稿摘要: 前言:
Legionella is a bacterium that is widespread in nature and can be found in environmental water sources such as rivers, lakes and reservoirs, usually in low concentration. From the natural source, it passes into sites that constitute a manmade reservoir (channeled water in towns, water systems in individual buildings, etc.). Numerous reports have demonstrated that the major sources for Legionnaires’ disease (LD) are the potable water systems of large buildings including hospitals, nursing homes, and hotels. Legionella is a common cause of hospital acquired pneumonia, especially for immunocompromised patients. Legionella pneumophila is the species that accounts for almost all of the cases reported.
方法:
Total of 5,162 water samples were collected and processed during 2017 ~ 2020 period from environmental surveillance in Taiwan. Sample concentration by filtration of 250 mL water was used to increase the yield of Legionella bacteria. A standardized processing and enumeration, latex agglutination test, and direct fluorescent antibody assay were used for serotyping of L. pneumophila.
結果:
Among the Legionella positive samples (n=440), the isolation rate of L. pneumophila was 91.8%(404/440); L. pneumophila serogroup 1 (Lp 1) was 40.2% (177/440), Lp 6 comprised 24.3% (107/440) followed by Lp 3 (5.7%, 25/440), Lp 2 (3.2%, 14/440), Lp 5 (1.4%, 6/440) and Lp 7 (0.5%, 2/441). Legionella species comprised 8.2% (36/440). When compared with water source, Lp 1 isolation rate was 39.4% (134/340) in potable water system, Lp 1 isolation rate was 67.2% (43/66) in cooling towers.
討論:
Taiwan’s CDC laboratory began to survey and monitor Legionella bacteria from clinical specimens of the case since 2002 till 2018, Legionella pneumophila serogroup 1 (Lp1) remained the most recurrent serogroup which was 86.4% (412/477) (Taiwan CDC). Obviously, the positive rate of Lp1 (40.2%) from environmental water system was lower than the clinical samples (86.4%). For LD with Legionella other than Lp 1, PCR and culture laboratory diagnostic capability should be established to detect Legionnaires’ disease in addition to Legionella pneumophila serogroup 1 urinary antigen test . This underscores a pressing need for the development of more inclusive Legionella rapid diagnostics tests. This study provides useful fundamental data for programs of continuous monitoring of L. pneumophila, which will make a significant contribution to the prevention of LD and to epidemiological surveys in the event of outbreaks in Taiwan.
結論:
Most of clinical microbiology laboratories in Taiwan are unable to culture L. pneumophila from clinical specimens. There is still a need to develop antigen-based assays that can diagnose infections with all species and serogroups of Legionella. Furthermore, it is very important that, during this covid-19 pandemic, this report is aimed at hospitals, hotels, other accommodation sites including campsites, cruise ships etc. that it is relevant to all public, residential and office buildings with similar water systems. Review risk assessment and to reflect current water system usage and other systems or equipment are necessary to prevent LD.

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