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Saudi Journal of Kidney Diseases and Transplantation
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Year : 2012  |  Volume : 23  |  Issue : 2  |  Page : 316-320
Frequency of Chlamydia trachomatis among male patients with urethritis in northeast of Iran detected by polymerase chain reaction

1 Microbiology and Virology Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
2 Minimally Endoscopic Invasive Surgery Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

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Date of Web Publication28-Feb-2012


Planning for appropriate preventive measures against Chlamydia trachomatis, a common cause of sexually transmitted disease, requires knowledge of prevalence of infection so that interventions can be targeted in a cost-effective manner. This study was performed on 178 male patients presenting with urethritis in the Mashhad province to determine the prevalence of chlamydial infection in Northeast Iran. A cotton swab and first voided urine specimen were collected according to standard procedures. Polymerase chain reaction (PCR) tests were used for the detection of C. trachomatis in the specimens collected and the results were analyzed using SPSS program. Results showed that 10.6% of male patients in this group were infected with C. trachomatis. This study provides strong evidence that prevalence of Chlamydia in the Northeast Iran is high and suggests that Chlamydia screening as a routine part of STD investigations is highly necessary in this area.

How to cite this article:
Ghazvini K, Ahmadnia H, Ghanaat J. Frequency of Chlamydia trachomatis among male patients with urethritis in northeast of Iran detected by polymerase chain reaction. Saudi J Kidney Dis Transpl 2012;23:316-20

How to cite this URL:
Ghazvini K, Ahmadnia H, Ghanaat J. Frequency of Chlamydia trachomatis among male patients with urethritis in northeast of Iran detected by polymerase chain reaction. Saudi J Kidney Dis Transpl [serial online] 2012 [cited 2021 Dec 3];23:316-20. Available from: https://www.sjkdt.org/text.asp?2012/23/2/316/93165

   Introduction Top

Today, sexually transmitted diseases (STDs) are a major and ever-expanding public health problem and they cause great social concern as well as economic drain in many forms. While other STDs such as syphilis and gonorrhea are on the decline due to prompt detection and treatment, in many parts of the world, their place has been taken by other infectious agents such as Chlamydia trachomatis. [1] In particular, genital chlamydial infections in males are currently recognized as the leading cause of non-gonococcal urethritis and epididymitis, which can contribute to male infertility or sub-fertility. [2],[3] Appropriate preventive measures should be taken to prevent the spreading and consequences caused by this infections. Effec­tive prevention requires knowledge of preva­lence of infection in order to target interven­tions in a cost-effective manner. [4] Although pri­mary prevention of this infection through avoidance of multiple sex partners and use of condoms is the most desirable approach, fur­ther prevention through early detection and treatment of infected individuals plays an im­portant role as well. [5],[6] As the chlamydial in­fection can be easily treated, the incidence of complications can be considerably reduced if it is diagnosed and treated early and promptly. Therefore, the programs for screening and sub­sequent early treatment are necessary. [7] To im­plement such a successful program, one must have comprehensive knowledge of the preva­lence of chlamydial infections in the population. This study was performed to determine the prevalence of chlamydial infections among male patients with urethritis in Mashhad in the northeast region of Iran.

   Materials and Methods Top

Study population and specimen

After obtaining approval from local ethical committee and getting informed consent, every subject attending the STD clinic of Ghaem University Hospital in Mashhad from Sep­tember 2005 to September 2007 was included in this study. During the period of this study, we identified 178 male patients presenting with urethritis (urethral discharge or ≥4 polymor-phonuclear leukocytes per high power field in a Gram-stained urethral smear). The subjects were examined by the physician and a ques­tionnaire was completed. The demographic characteristics of these patients were reviewed and data on clinical and paraclinical findings were collected.

The first voided urine was collected and also a cotton swab was inserted 1 cm into the ure­thra and rotated before withdrawal from each subject. The swab was placed in a sterile col­lection tube containing 1 mL of phosphate-buffered saline and transported to the mole­cular laboratory for further processing. Upon arrival, the swab was vortexed thoroughly, and then the buffer was centrifuged completely at 3200 rpm for 30 min and the supernatant was removed. Simultaneously, 5 mL of first void urine was centrifuged at 3200 rpm for 30 min. The sediment was washed with distilled water and resuspended in 200 μL of 1% sodium dodecyl sulfate solution.

PCR assay

We used polymerase chain reaction (PCR) assays as the diagnostic tool as PCR has now become the most reliable diagnostic tool in the case of suspected chlamydial infections. [8] Nucleic acid was extracted from 0.2 mL of each sedi­ment using spin column-based DNA isolation kit (Qiamp DNA Mini kit; Qiagen GmbH, Hilden, Germany) according to the manufac­turer's instructions. This procedure has been shown to be suitable for the extraction of DNA from urine specimens because of the high DNA yield and the removal of PCR inhibitors.

PCR assays were performed with approxi­mately 100 ng of total DNA using two diffe­rent sets of oligonucleotide primers for identi­fication of C. trachomatis endogenous plasmid (Chromosome Sequence Gen-Bank Accession #AE001273). It is estimated that ten copies of endogenous plasmid are present per elemen­tary body. [9] Both sets of oligonucleotide primers (upstream 5′-GGACAAATCgTATCTCGG-3′ and downstream 5′-GAAACCAACTCTACG-CTG-3′) and (upstream 5′-GCTAGAGCGGC-ATGCTACAT-3′ and downstream 5′-CGCTT-GCACGAAGTACTCTG-3′) amplify a species-specific, 517-bp fragment with all known C. trachomatis serovars. [10]

The reactions were performed over 38 cycles, consisting of denaturation at 95°C for 1 min, annealing at 57°C for 1 min, and extension at 72°C for 1 min, followed by a final extension step of 5 min at 72°C. The reaction conditions were as follows: 2.5 mM MgCl2, 15 pmol of each oligonucleotide primer (Isogen Life Science, Maarssen, The Netherlands), 1.2 U Taq polymerase (Genet Bio, Chungnam, Korea), and 200 μM each of dNTP (dATP, dCTP, dGTP, and dTTP) (Boehringer Mannheim Corp, Indianapolis, USA). All amplifications were performed in a 50 μL volume with a thermal cycler (Touchgene, Gradient).

The process was evaluated by amplification of a 500-bp fragment of the human ß-globin gene as a quality control measure. Positive and negative control reactions were also included in each batch of amplifications. The positive control consisted of DNA extracted from a C. trachomatis confirmed positive culture. Nega­tive controls consisted of DNA extracted from urine of healthy subject and blank tubes con­taining just distilled water.

PCR products were analyzed in 1% agarose gel and were visualized by ethidium-bromide (ETBr) under UV light. The assay was consi­dered positive when one of the PCR products was present. Precautions to avoid cross-conta­mination and false-positive results were taken in every assay. [11]

Statistical analyses were performed in this study using the Chi-square test with the level of significance defined as a P value of 0.05 or less (SPSS 11.5).

   Results Top

A total of 178 men attending the clinic for STDs were tested by PCR for C. trachomatis. All these men were Iranians and their ages ranged from 18 to 58 years (mean ± standard deviation = 27.6 ± 7.4). By this method, 19 specimens among 178 specimens were diag­nosed as positive, making the prevalence of chlamydial infection as 10.6%. The distribu­tion of PCR-positive subjects according to age is shown in [Table 1].
Table 1: Age distribution of subjects positive for  Chlamydia trachomatis Scientific Name Search  by PCR.

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Most of the men (131 of 178) were between 20 and 30 years of age and 73.7% of all the infections were in this age group. Fifty-eight patients attending with urethritis were married while the other subjects were single or di­vorced, and only four patients among the married subjects were infected with Chlamydia (P < 0.05). All of these men were symptomatic because specimens were obtained from attendees to STD clinic who presented with urethritis.

   Discussion Top

The prevalence of C. trachomatis, as deter­mined in several areas of the world, varies according to the geographic area, age, and behavioral pattern of patients, and it is parti­cularly on the increase among adolescents. [1],[12],[13],[14] Overall prevalence of chlamydial infection in general population was 4.19% in the United States compared with 2.6% in China, an Asian country. [13],[15] According to another report, the prevalence of C. trachomatis genital infections was much higher among the female attendees to STD clinics. [16] According to two studies performed in Tehran, Iran, 8.8 and 8.4% of male patients attending the STD clinics for urethritis were infected by Chlamydia. [17],[18] Our previous study conducted during 2000-2003, which used only standard bacterial culture as the diagnostic tool, also showed that in North­east Iran, the prevalence of chlamydial infec­tions in male attendees to STD clinics for urethritis was 9.3%, which is even higher than that reported earlier. [19] This study which used PCR as a more reliable diagnostic tool has shown even higher prevalence of chlamydial infection in the same geographic region. The present study emphasizes that most patients with chlamydial infection belong to the young and sexually active age group of 20-30 years. Although many people still believe that the prevalence of STDs, including C. trachomatis genital infection in Iran, is lower than that in the western world because of the socially con­servative attitudes of Iranian people toward free sexual attitudes, our results show strong evidence that C. trachomatis infection exists with a high prevalence rate in our region.

These findings strongly point to the necessity of Chlamydia screening and treatment in Iran, as recommended for western countries. [20] Therefore, screening for genito-urinary chla-mydial infections should form a routine part of STD investigations. [21] This strategy should be further emphasized because chlamydial infec­tion usually produces far less severe symptoms than other causes of urethritis, and so the in­fection could go undetected for a very long time with the patient not realizing until secon­dary or tertiary problems arise. [22],[23] One should be aware that untreated chlamydial infection can cause both short- and long-term severe consequences. [7] Strong evidence is now availa­ble that Chlamydia screening and treatment not only reduces the prevalence of lower genital tract infection, but also decreases the incidence of costly complications in the affec­ted people.

Although some factors such as technician experience, specimen collection, and labora­tory procedures might influence the result of PCR examination, we have tried to minimize the potential effect of these factors by strict adherence to the study protocol. However, some variability may be possible and further study on a larger group of general population will be of benefit.

This study provides strong evidence that C. trachomatis infection does exist with a high prevalence rate in northeast region of Iran and Chlamydia screening as a routine part of STD investigations seems necessary.

   Acknowledgment Top

The authors would like to thank the Research Deputy of Mashhad University of Medical Sciences for their great help and support (Project Code 83034).

   References Top

1.World Health Organization. Global prevalence and incidence of selected curable sexually transmitted diseases: overview and estimates. Geneva: WHO, 2001.  Back to cited text no. 1
2.Bradshaw CS, Tabrizi SN, Read TR, et al. Etiologies of non-gonococcal urethritis: bacteria, viruses, and the association with oro-genital exposure. J Infect Dis 2006;193(3):336-45.  Back to cited text no. 2
3.Holmes KK, Hansfield H, Wang SP, et al. Etiology of non-gonococcal urethritis. N Engl J Med 1975 292:1199-2005.  Back to cited text no. 3
4.Gift TL, Blake DR, Gaydos CA, Marrazzo JM. The cost-effectiveness of screening men for Chlamydia trachomatis: a review of the literature. Sex Transm Dis 2008;35(11 Suppl): S51-60.  Back to cited text no. 4
5.Kilic D, Basar MM, Kaygusuz S, Yilmaz E, Basar H, Batislam E. Prevention and treatment of Chlamydia trachomatis, Ureaplasma urea-lyticum, and Mycoplasma hominis in patients with non-gonococcal urethritis. Jpn J Infect Dis 2004;57(1):17-20.  Back to cited text no. 5
6.Brook MG, Bell C. Screening for non-gono-coccal urethritis. Int J STD AIDS 2004;15 (1):69.  Back to cited text no. 6
7.Mayer BM, Berger RE. Sexually Transmitted Diseases in Male. In: Tanagho EA, McAninch JW, eds. Smith's General Urology, 17 th edition, New York, LANGE Mc Graw Hill Clinical Medicine, International Edition, 2008; 259-65.  Back to cited text no. 7
8.Davies PO, Ridgway GL. The role of poly-merase chain reaction and ligase chain reaction for the detection of Chlamydia trachomatis. Int J STD AIDS 1997;8:731-8.  Back to cited text no. 8
9.Palmer L, Falkow S. A common plasmid of Chlamydia trachomatis. Plasmid 1986;16:52-62.  Back to cited text no. 9
10.Kluytmans JA, Goessens WH, Mouton JW, et al. Evaluation of Clear view and Magic Lite Tests, Polymerase Chain Reaction, and cell Culture for Detection of Chlamydia trachomatis in Urogenital specimens. J Clin Microbiol 1993; 31(12):3204-10.  Back to cited text no. 10
11.Kwok S, Higuichi R. Avoiding false positives with PCR. Nature 1989;339:237-38.  Back to cited text no. 11
12.Gauschino S, De Seta F. Update on Chlamydia trachomatis. Ann NY Acad Sci 2000;900:293-300.  Back to cited text no. 12
13.Parish WL, Laumann EO, Cohen MS, et al. Population-based study of chlamydial infection in China: a hidden epidemic. JAMA 2003; 289(10):1265-73.  Back to cited text no. 13
14.Satterwhite CL, Joesoef MR, Datta SD, Wein-stock H. Estimates of Chlamydia trachomatis infections among men: United States. Sex Transm Dis 2008;35(11 Suppl):S3-7  Back to cited text no. 14
15.Miller WC, Ford CA, Morris M, et al. Preva­lence of chlamydial and gonococcal infections among young adults in the United States. JAMA 2004;291(18):2229-36.  Back to cited text no. 15
16.Bunnell RE, Dahlberg L, Rolfs R, et al. High prevalence and incidence of sexually trans­mitted diseases in urban adolescent females despite moderate risk behavior. J Infect Dis 1999;180:1624-31.  Back to cited text no. 16
17.Darougar S, Jones BR, Cornell L, et al. Chlamydial urethral infection in Teheran. A study of male patients attending an STD clinic . Br J Vener Dis 1982;58(6):374-6.  Back to cited text no. 17
18.Naser B. Prevalence of chlamydia trachomatis in attendance to STD clinics of Tehran University of Medical Sciences, 1992, doctoral thesis, upublished data.  Back to cited text no. 18
19.Ghanaat J, Afshari JT, Ghazvini K, Malvandi M. Prevalence of genital Chlamydia in Iranian males with urethritis attending clinics in Mashhad. East Mediterr Health J 2008;14(6): 1333-7.  Back to cited text no. 19
20.La Montagne DS, Patrick LE, Fine DN, Marrazzo JM. Re-evaluating selective screening criteria for Chlamydial infection among women in the US Pacific Northwest. Sex Transm Dis 2004; 31(5):283-9.  Back to cited text no. 20
21.Gift TL, Blake DR, Gaydos CA, Marrazzo JM. The cost-effectiveness of screening men for Chlamydia trachomatis: a review of the lite­rature. Sex Transm Dis 2008;35(11 Suppl): S51-60.  Back to cited text no. 21
22.Tebb KP, Shafer MA, Wibbelsman CJ, et al. To screen or not to screen: prevalence of C. trachomatis among sexually active asymp­tomatic male adolescents attending health maintenance pediatric visits. J Adolesc Health 2004;34(3):166-8.  Back to cited text no. 22
23.Rietmeijer CA, Hopkins E, Geisler WM, Orr DP, Kent CK. Chlamydia trachomatis posi-tivity rates among men tested in selected venues in the United States: a review of the recent literature. Sex Transm Dis 2008;35(11 Suppl):S8-18.  Back to cited text no. 23

Correspondence Address:
Kiarash Ghazvini
Assistant Professor, Microbiology and Virology Research Center, Mashhad University of Medical Sciences, Ghaem Hospital, Ahmad Abad Avenue, 9176699199 Mashhad
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