Jpn.J.Infect.Dis., 52, 1999
Laboratory and Epidemiology Communications
Distribution of Serovars of Chlamydia trachomatis in Nagano Prefecture, Japan
Michiko Takeuchi*, Satoko Ono1, Motoyasu Sugase2, Sadashi Shiga3 and Toshikatsu Hagiwara3
Nagano Research Institute for Health and Pollution, 1978, Amori-Komemura, Nagano, 380-0944, 1Nagano City Health Office, 3791-7 Kawaishinden, Nagano, 2Department of Obstetrics and Gynecology, Nagano Red Cross Hospital, 1512-1, Wakasato, Nagano, and 3National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-Ku, Tokyo
Communicated by Shigetou Suzuki
(Accepted July 21, 1999)
Chlamydia trachomatis is a sexually transmitted pathogen.
In women, this pathogen can cause cervicitis, perisalpingitis,
pelvic peritonitis, perihepatic inflammation, etc. C. trachomatis
is classified into 15 serovars, namely, A, B, Ba, C, D, E, F,
G, H, I, J, K, L1, L2, and L3(1). Sub-serovars, such as Da, Ia,
L2a, etc, have also been reported (2).
The Department of Obstetrics and Gynecology of Nagano Red Cross Hospital has derived a collection of C. trachomatis isolates. These isolates which were derived from patients treated at this hospital from 1992-1998. The patients included pregnant women who underwent routine medical check-ups as well as women having urogenital symptoms. Cervical smears were examined by using IDEIA CLAMYDIA (Kyowa Medics, Tokyo) which detects the LPS antigen, or AMPLICORE Chlamydia trachomatis (Nippon Roch, Tokyo) which detects Chlamydia DNA. There were a total of 374 specimens that were positive for either test. These specimens were used for the isolation of C. trachomatis , following the standard procedures (3). C. trachomatis was isolated from 250 of the specimens. The isolates were further replicated by means of the centrifuge-adsorption method. Eighty-two isolates were expanded to titers suffcient enough for serotyping by micro-IF method (3).
Serovars D, E, F, and G comprised 68.3% of the isolates (Fig. 1). The result was consistent with a previous report by Hagiwara et al. (4). A similar pattern has been reported in other developed countries (5-7). Serovars D and E are antigenically similar and distinct from serovars F and G. In our study, serovars D and E and serovars F and G were detected at similar frequencies, which is in agreement with results reported by Poole and Lamont (5). However, Rodriguez et al.(6) and Morre et al. (7) reported that the frequency of the former group was twice as high as that of the latter. It was noted that serovars B (known to cause trachoma) and K were relatively frequent (7.3% and 9.8%, respectively), unlike results reported from other studies (5-7).
Figure 2 shows the frequency of the four serovars among the total isolates examined during 1992-1998. The frequency of the four serovars was 76.2-85.7% from 1992-1994, but it tended to decrease from 1995-1998 (63% from 1997-1998).
Table 1 shows the age distribution of patients classified according to isolated serovars. Serovar E, which comprised about 50% of the isolates, was isolated from patients younger than 40. Serovars F and G tended to be frequent in older age groups.
Figure 3 summarizes symptoms observed in patients infected with each serovar. In this figure, asymptomatic patients were either pregnant women or women who consulted the infertility outclinic of the hospital. Clinical symptoms produced by different serovars appeared different, for example, vaginal discharge was more frequent in cases of infection with serovar I. However, an association of symptoms with particular serovars could not be established because of tne small number of cases, particularly of serovars B, H, I, and K.
REFERENCES
*Corresponding Author :Fax:+81-26-224-3415
Go to JJID Homepage Go to JJID 52 (3)