 |
The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
| ArticleTitle |
Epidemiological Evaluation of Mycobacteria Isolates in a City Hospital during the 30 Years from 1981 to 2010 |
| Language |
J |
| AuthorList |
Yuji Arai1), Kae Iwata1), Ayumi Hiishi1), Mayumi Togashi1), Akiko Anan1), Yayoi Ito1), Hisako Nakamura1), Naoyuki Yazawa1), Setsuko Tazawa2), Kenji Marumo3) |
| Affiliation |
1) Division of Clinical Laboratory, Fujigaoka Hospital, Showa University
2) Department of Clinical Pathology, Fujigaoka Hospital, Showa University
3) Department of Microbiology and Immunology, School of Medicine, Showa University |
| Publication |
J.J.C.M.: 22 (4), 263-271, 2012 |
| Received |
June 14, 2012 |
| Accepted |
October 2, 2012 |
| Abstract |
The aim of this study was to evaluate the long-term trend in mycobacterial isolation based on microbiological laboratory data in a Japanese city hospital without the word for tuberculosis patients. Seven hundred fifty and 1,059 cases of Mycobacterium tuberculosis and nontuberculous mycobacteria (NTM), respectively, were isolated in Showa University Fujigaoka Hospital during the 30 years (1981 through 2010). The mean isolation rates of smear-positive M. tuberculosis and NTM were 46 and 18%, respectively. The main NTM isolation comprised 65% of M. avium complex (MAC), 4% of M. chelonae, 3% of M. kansasii, and 3% of M. fortuitum. The isolation rate of smear-positive M. tuberculosis with a high discharge of ≥Gaffky no. 5 in sputum during the most recent ten years (2001 through 2010) significantly increased, compared with that during the past ten years (1981 through 1990) (p=0.017, by chi-square test). M. tuberculosis infection afflicted patients ranging widely in age from 16 to 88 years old, whereas NTM infection afflicted mostly older patients. Analysis by 3rd-degree polynomial fitting of the annual isolation frequency of M. tuberculosis showed that the frequency had not changed at the study period, whereas that of MAC had increased until 2004 and then decreased. In investigating the underlying diseases, we found that 36% of tuberculosis patients suffered kidney diseases including those requiring artificial hemodialysis treatment, diabetes mellitus and malignant tumor, whereas 51% of MAC-infected patients mainly showed malignant tumor, bronchiectasis and bronchitis. These findings suggested that mycobacterial infections were associated with aging, lung lesions and decline of immune capacity, and that the isolation frequency of M. tuberculosis in the hospital did not significantly change at a period of 30 years including the enforcement period of direct observed therapy short-course (DOTS) during the 11 years (2000 through 2010), showing the necessary of mycobacterial survey in many city hospitals without the word for tuberculosis patients. |
| Keywords |
Mycobacterium tuberculosis, nontuberculous mycobacteria (NTM), Mycobacterium avium complex (MAC), smear-positive, underlying diseases |
|
