A review of the microbiology, immunology, and clinical implications of Chlamydia trachomatis infections

Using an agent-based sexual-network model to analyze the impact of mitigation efforts for controlling chlamydia

Chlamydia trachomatis (Ct) is the most reported sexually transmitted infection in the United States, with a major cause of infertility, pelvic inflammatory disease, and ectopic pregnancy among women. Despite decades of screening women for Ct, rates increase among young African Americans (AA). We create and analyze a heterosexual agent-based network model to help understand the spread of Ct. We calibrate the model parameters to agree with survey data showing Ct prevalence of 12% of the women and 10% of the men in the 15-25 year-old AA in New Orleans, Louisiana. Our model accounts for both long-term and casual partnerships. The network captures the assortative mixing of individuals by preserving the joint-degree distributions observed in the data. We compare the effectiveness of intervention strategies based on randomly screening men, notifying partners of infected people, which includes partner treatment, partner screening, and rescreening for infection. We compare the difference between treating partners of an infected person both with and without testing them. We observe that although increased Ct screening, rescreening, and treating most of the partners of infected people will reduce the prevalence, these mitigations alone are not sufficient to control the epidemic. The current practice is to treat the partners of an infected individual without first testing them for infection. The model predicts that if a sufficient number of the partners of all infected people are tested and treated, then there is a threshold condition where the epidemic can be mitigated. This threshold results from the expanded treatment network created by treating an individual's infected partners' partners. Although these conclusions can help design future Ct mitigation studies, we caution the reader that these conclusions are for the mathematical model, not the real world, and are contingent on the validity of the model assumptions.

Chlamydia in colposcopy clinics: to screen or not to screen?

The objective of the study was to assess the prevalence of Chlamydia trachomatis in our colposcopy clinic. A total of 337 consecutive patients newly referred to the colposcopy clinic between May and November 2003 were screened for chlamydia trachomatis. All our patients were referred by their GPs and none of the patients had had a recent chlamydia test performed. Four patients screened positive, overall giving a prevalence of 1.2% [95% CI 0.04-2.36%]. Three of those with positive results were in the 21 - 30 year age group (139 in the group, which equals 2.2% prevalence [95% CI 0 - 4.6%]). The fourth positive result was in the group over the age of 60. None of those screened in the other age groups was positive (< or =20, 31 - 40, 41 - 50, 51 - 60 years). Numbers screened in each of those groups were: 14, 115, 53 and 12, consecutively. Our study, though small in sample size, supports the view that the prevalence of chlamydia is not high in all colposcopy clinic attenders. Women younger than 30 years old are more likely to be infected than older women; hence opportunistic screening should target this age group. The prevalence rate may be low due to the enzyme linked immunosorbent assay giving a poor detection rate for chlamydia screening.

Reactive and undifferentiated arthritis in North Africa: use of PCR for detection of Chlamydia trachomatis

Little is known about the possible role of Chlamydia in patients with reactive or unclassified arthritis in North Africa. This study used polymerase chain reaction (PCR) to survey this population. In addition, we compared the results in three different laboratories for PCR analyses for Chlamydia trachomatis (Ct) in synovial fluid (SF) and tissue (ST) from these North African patients with reactive arthritis (ReA), undifferentiated arthritis (UA), and in rheumatoid arthritis (RA) and osteoarthritis (OA). Eight ReA (six posturethritic, two postenteritic), 23 UA, 13 OA, and 12 RA patients were studied in Algeria, Morocco, and Tunisia. Serum, SF, and ST were obtained from each patient. Ct-PCR was performed in the three different laboratories and compared to Ct-serology [microimmunofluorescence (MIF) and anti-hsp60 enzyme-linked immunosorbent assay (ELISA)] performed in one laboratory. The rate of Ct-PCR positivity in SF/ST was low: none out of the eight ReA and three out of 23 UA patients. In the controls, Ct DNA was detected in two OA SF and in one RA SF. There was no concordance for Ct-PCR positivity between the three laboratories. MIF suggested previous Ct infection (IgG-positive) in two out of five posturethritic ReA, none out of one postenteritic ReA, one out of 17 UA, and nine out of 21 RA/OA patients tested. No MIF-positive patient was PCR-positive from SF or ST. However, anti-hsp60 IgG was detected in all four out of four patients positive by PCR and in 11 out of 44 PCR-negative patients (p = 0.002). In this multinational comparative study, the rate of Ct-PCR-positive synovial specimens in North African ReA/UA patients was low. Concordance among the three PCR testing laboratories was poor indicating the need for test standardization. All Ct-PCR-positive patients were found positive by anti-hsp60 IgG serology.

Reasons for testing women for genital Chlamydia trachomatis infection in the Calgary region

OBJECTIVE

To determine the clinical reason(s) for screening women with varying degrees of risk for genital Chlamydia trachomatis (CT) in the Calgary region.

DESIGN

Women aged 15 to 75 years were enrolled at various patient care locations. Pertinent risk factors for genital CT infection were recorded and a gynecological examination was performed. Two endocervical swabs and a first-void urine sample were collected for CT detection using two different nucleic acid amplification test methods.

SETTING

Calgary is an urban region that provides healthcare services to a population of almost one million people. Microbiology services are provided by Calgary Laboratory Services through a centralized regional laboratory service.

MAIN RESULTS

504 women with a mean age of 28.1 +/-SD 8.22 years were enrolled. Two hundred ninety-one women (57.8%) were at high risk for acquiring genital CT infection. Twenty-eight (5.6%) tested positive for CT infection and almost all of these women (26 of 28, 93%) had risk factors for acquiring infection. Of the high-risk women, 9.8% were CT positive versus only 1.3% of women at low risk (P=0.0001). Only two of 152 (1.3%) women older than 30 years had genital CT infections. Although most women were asymptomatic, those with laboratory-confirmed CT infection were more likely to have genitourinary symptoms. Three hundred forty-three of 476 (72%) women who did not have genital CT infection had no risk factors, and screening was done as part of a routine gynecological examination for other purposes (prenatal visit, Pap smear).

CONCLUSION

Women without risk factors are being screened routinely for genital CT infection as part of a routine gynecological examination done for other reasons. Elimination of the routine screening of low-risk women older than 30 years of age would decrease the current regional utilization of CT tests by as much as one-third.

Identification of human T cell targets recognized during Chlamydia trachomatis genital infection

The specificity of the human T cell response to Chlamydia trachomatis was investigated by stimulating lymphocytes from 16 case patients with urogenital infection by use of a size-fractionated serovar D lysate. Considerable heterogeneity was found among case patients, and multiple protein fractions were recognized in each specimen. Mass spectrometry analysis of the 30-42-kDa T cell-stimulating region identified 10 C. trachomatis proteins. Of these, CT583, CT603, and CT610 were identified as strong antigens that induced significantly higher levels of IFN- gamma secretion in PBMCs from case patients, compared with PBMCs from control donors. All 3 proteins were recognized in specimens from case patients infected with serovars D-F, the most prevalent serovars. McDonald-Kreitman and Tajima's D tests involving clinical isolates from the same samples showed evidence for frequency-dependent selection on ct583. We predict that CT583 is a target of acquired protective immune responses in humans.

Distribution study of Chlamydia trachomatis serovars among high-risk women in China performed using PCR-restriction fragment length polymorphism genotyping

This was one of the first epidemiological studies in China focused on genital Chlamydia trachomatis serotype distribution in high-risk female populations using omp1 gene-based restriction fragment length polymorphism analysis. One thousand seven hundred seventy cervical swab samples from women attending sexually transmitted disease clinics and female sex workers in six cities in China (Shenzhen and Guangzhou in southern China, Nanjing and Shanghai in eastern China, and Nanning and Chengdu in southwestern China) were subjected to serovar genotyping. The proportion of omp1 genes successfully amplified in 240 C. trachomatis plasmid-positive samples was 94.2% (226/240). Serotypes E (n = 63; 27.9%), F (n = 53; 23.5%), G (n = 28; 12.4%), and D (n = 25; 11.1%) were most prevalent. Though there was no significant difference in the geographic distribution of C. trachomatis, serotype E was predominant in the South (32.1%) and East (27.1%), while serotype F was predominant in the Southwest (28.3%). Serotype F infection was associated with young age and single status. Serovar G was associated with lower abdominal pain; 47.5% of asymptomatic patients were infected with serovar E. These results provide information on distribution of genital C. trachomatis serotypes among high-risk women in China and indicate that high-risk women, including those who are asymptomatic, can be infected with multiple serovars of C. trachomatis, revealing exposure to multiple sources of infection. Although the scope for generalizations is limited by our small sample size, our results showing clinical correlations with genotypes are informative.

Clinic-based evaluation of Clearview Chlamydia MF for detection of Chlamydia trachomatis in vaginal and cervical specimens from women at high risk in China

OBJECTIVES

To determine the performance of a rapid Chlamydia trachomatis (CT) test (Clearview Chlamydia MF) compared to the current "gold standard" (Roche Amplicor CT assay) test, and to assess acceptability of the tests to patients.

METHODS

A total of 1497 women at sexually transmitted diseases (STD) clinics or re-education centres in six urban cities (Shanghai, Nanjing, Shenzhen, Guangzhou, Chengdu and Fuzhou) in China participated in the study. Three vaginal and three cervical swabs were collected from each participant. Rapid CT tests were performed locally on the first vaginal and cervical swabs and the results were read independently by two staff members. The second and third swabs were randomised for performing the Roche CT assay at the National STD Reference Laboratory. Acceptability of the rapid tests to patients was determined by asking patients in clinics about their willingness to wait for the results.

RESULTS

The prevalence of CT was 13.2% (197/1497), as determined by the Roche assay with cervical specimens. CT was detected in 78 vaginal and 127 cervical specimens by the rapid test and the positive rates determined with cervical specimens were significantly higher than those with vaginal specimens (p<0.001). There was good agreement between the results read by two independent staff for either vaginal or cervical specimens (both kappa = 0.98, p<0.001). Sensitivities for vaginal and cervical specimens were 32.8% and 49.7%, respectively, and specificities were 99.2% and 97.9%, respectively. The positive predictive value was 85.7% for vaginal and 78.4% for cervical specimens. The vast majority of the patients (99.1%) were willing to wait up to two hours for the results.

CONCLUSION

Clearview Chlamydia MF, while yielding a rapid result and requiring minimal laboratory facilities, had unacceptably low sensitivity compared to a nucleic acid amplification test. Rapid tests yielding results within one hour are generally accepted by the clients.

[Respiratory infection due to Chlamydia trachomatis in infants. Clinical presentation and outcome in 18 patients]

BACKGROUND

Among other diseases, Chlamydia trachomatis causes epididymitis and prostatitis in men and urethritis, cervicitis and pelvic inflammatory disease in women. In children, it most usually causes conjunctivitis and is also responsible for lower respiratory tract disease, occasionally requiring hospital admission.

OBJECTIVE

To draw attention to this disease, which is usually overlooked and which can be potentially serious.

METHODS

We retrospectively reviewed the medical records of infants aged less than 6 months with symptoms of lower respiratory tract disease in whom C. trachomatis antigen was detected by enzyme immunoassay.

RESULTS

We identified 18 patients with C. trachomatis between 1993 and 2002. Of these, 17 patients required hospital admission and five required monitoring in the pediatric intensive care unit. The mean length of hospital stay was 9.6 days. Three patients were immigrants. The mean age at admission was 6.6 weeks. Apnea occurred in five infants. Chest x-ray showed interstitial infiltrates in five infants. Sixteen patients were treated with erythromycin and all made a complete recovery.

CONCLUSIONS

Although lower respiratory tract disease caused by C. trachomatis is usually managed on an outpatient basis, it sometimes requires hospital admission or even management in the intensive care unit. Therefore, C. trachomatis infection should be ruled out in infants aged less than 6 months with clinical symptoms of lower respiratory tract disease for which no other pathogen can be found.

Update on the impact of Chlamydia trachomatis infection on male fertility

With approximately 90 million cases annually, infection with Chlamydia trachomatis is the most prevalent sexually transmitted bacterial disease in the world. Considering that these infections are often asymptomatic and cause major complications like acute pelvic inflammatory disease, ectopic pregnancy, infertility or infant pneumonia, the estimated costs for diagnosis and treatment in the USA amounts to 2.2 million US dollars for each 500 cases. Therefore, there is a high need for correct, quick and cost-effective diagnosis and treatment of this urogenital tract infection. New innovative therapies provide good results with regard to efficacy and patients' compliance. The success rates of treatments are at least 95%. However, the occurrence of antibiotic resistance should not be ignored and new treatment schemes must be developed. The state-of-the-art of diagnosis and treatment of chlamydial infections as well as the pathophysiology is discussed in this review. In conclusion, infections with C. trachomatis is an important public health problem, especially in third world and developing countries, and more socio-economic studies linking secondary prevention of chlamydial infections, infertility and adverse pregnancy outcome are needed to understand more of its aetiology. In addition, diagnosis and treatment should be improved. Data in men revealed that past infections but not present infections are more related to male infertility. There is still controversial results. In future studies, function of the seminal vesicles and evaluation of the antioxidant capacity should be taken into account when role of C. trachomatis infection on male fertility is assessed.

Prevalence and determinants of Chlamydia trachomatis infections in women from Bogota, Colombia

OBJECTIVES

Chlamydia trachomatis infection in the cervix and uterus has been hypothesised to be a co-factor for cervical cancer. We performed a cross sectional study in Bogota, Colombia, where cervical cancer rates are high, to determine the prevalence and determinants of C trachomatis infection, and in particular its association with human papillomavirus (HPV).

METHODS

1829 low income sexually active women were interviewed and tested for C trachomatis, using an endogenous plasmid PCR-EIA, and for 37 HPV types, using a general primer GP5+/6+ mediated PCR-EIA.

RESULTS

The overall prevalence of C trachomatis was 5.0%, and it did not differ substantially between women with normal (5.0%) and those with abnormal (5.2%) cervical cytology. Women infected with any HPV type (15.1%) had a slightly increased risk of being simultaneously infected with C trachomatis (adjusted OR 1.3, 95% CI: 0.8 to 2.4). This association was stronger when multiple HPV infections (adjusted OR 2.5, 95% CI: 1.1 to 5.9) were present. No other lifestyle or reproductive characteristics were clearly associated with risk of C trachomatis infection.

CONCLUSIONS

HPV infected women, particularly women with multiple HPV infections, are at increased risk of being infected with C trachomatis.

Inhibition of chlamydial infectious activity due to P2X7R-dependent phospholipase D activation

Chlamydia trachomatis survives within host cells by inhibiting fusion between Chlamydia vacuoles and lysosomes. We show here that treatment of infected macrophages with ATP leads to killing of chlamydiae through ligation of the purinergic receptor, P2X(7)R. Chlamydial killing required phospholipase D (PLD) activation, as PLD inhibition led to rescue of chlamydiae in ATP-treated macrophages. However, there was no PLD activation nor chlamydial killing in ATP-treated P2X(7)R-deficient macrophages. P2X(7)R ligation exerts its effects by promoting fusion between Chlamydia vacuoles and lysosomes. P2X(7)R stimulation also resulted in macrophage death, but fusion with lysosomes preceded macrophage death and PLD inhibition did not prevent macrophage death. These results suggest that P2X(7)R ligation leads to PLD activation, which is directly responsible for inhibition of infection.

Chlamydia pneumoniae and severity of asthma

A substantial increase in the prevalence of asthma in the Western world during the last few decades has led to a continuous search for novel factors that might be involved in the development of the disease. We carried out a study to clarify whether there is a relationship between severity of asthma and Chlamydia pneumoniae-specific titres at the group level and whether antibodies to the 60 kDa chlamydial heat shock protein (chsp60) are associated with asthma. A total of 116 (31 men, 85 women) consecutive asthma patients from a chest clinic were recruited and divided into 3 groups according to the severity of the disease: there were 13 asthmatics with severe, 54 with moderate and 49 with mild asthma. In addition, 50 (31 men, 19 women) consecutive blood donors were enrolled to serve as a control group. Sera for the measurements of specific IgG, IgA and IgM antibodies using a microimmunofluorescence test and of chsp60 using an enzyme immunoassay were obtained upon enrolment and also 3-4 months later from the asthma patients. Severe and moderate asthma were found to be strongly associated with elevated IgA antibody levels to C. pneumoniae [odds ratio (OR) 5.58, 95% confidence interval (CI) 1.31-23.72 for severe and OR 5.65, 95% CI 2.05-15.53 for moderate asthma] in a logistic regression model. Furthermore, in women, the occurrence of elevated IgA antibody levels and the age-adjusted geometric mean titres of IgA antibodies were significantly higher among the asthmatics than the controls (p = 0.003 and 0.04, respectively). Antibodies to chsp60 occurred more frequently and in higher concentrations among the asthmatics than the controls, although the differences did not reach significance. In conclusion, severe and moderate asthma were significantly associated with elevated IgA antibody levels to C. pneumoniae suggestive of chronic infection. Antibodies to chsp60 did not prove to be a useful marker of such an infection among the asthmatics studied here.

Evaluation of sequential testing strategies using non-amplified and amplified methods for detection of Chlamydia trachomatis in endocervical and urine specimens from women

Nucleic acid amplification tests (NAAT) are more sensitive than other methods for the diagnosis of Chlamydia trachomatis (CT) genital infections. Two unique sequential testing strategies that employed two different commercial NAAT methods to detect CT in a population of women with widely varying infection risk were evaluated. Specimens from 504 women aged 15 to 75 years were studied. Two endocervical swabs and a urine sample were collected from each woman. One swab was initially tested using the Access enzyme immunoassay (EIA) (Beckman). An aliquot from the EIA extraction was subsequently amplified using the COBAS AMPLICOR CT assay (PCR) (Roche). The second swab was initially tested using the PACE 2 CT hybridization assay (Gen-Probe). An aliquot was pipetted off prior to performing the PACE 2 assay and also amplified using the AMP-CT assay (TMA) (Gen-Probe). Urine samples were tested for CT using both NAAT methods. True CT infections were defined as any woman that was confirmed to be positive on both NAAT results from endocervical swabs. The results of all other CT assays were compared against this expanded gold standard. 28 women were confirmed to have CT infection giving an overall prevalence of 5.6%; low-risk women had a rate of 1.3% while high-risk women had a rate of 9.8%. NAAT methods have a higher sensitivity for detecting CT cervicitis when swabs are tested compared to urine. The positive predictive value of NAAT is decreased when testing low risk women. Limited automation makes it difficult to test a high volume of samples (i.e., > 100 swabs and/or urines) using either of these NAAT methods and continue to provide same day results. Laboratories performing CT testing must define the female population served so that appropriate diagnostic strategies can be employed.

Chlamydial antibodies in an elderly Finnish population

The characteristic feature of Chlamydia is its tendency to cause chronic infections. It has been hypothesized that prior exposure to C. pneumoniae may lead to chronic infection and the development of associated chronic cardiopulmonary disease. Few studies have so far addressed the occurrence of chlamydial antibodies in an elderly, unselected population. This information is important for the development of possible treatment strategies. Chlamydial antibodies were analysed from 1179 serum samples obtained from 481 men and 698 women, aged 64 y and over, who participated in an epidemiological survey carried out in a Finnish rural district. Specific IgG and IgA antibodies were measured by the microimmunofluorescence (micro-IF) test. The criterion for seropositivity was defined as a titre of > or =32 for both IgG and IgA, independently of each other. C. pneumoniae IgG antibodies occurred in 91% of the men and 75% of the women. The respective figures for C. pneumoniae IgA antibodies were 57% and 28%. The geometric mean titres (GMT) rose with increasing age and were higher in men than in women. The prevalences of C. trachomatis IgG antibodies were 13% in men and 18% in women, and for IgA antibodies, 2% and 1%, respectively. C. psittaci antibodies were rare. Only 3% of the men and women were IgG seropositive, whereas the respective figures for IgA seropositivity were 0.4% and 0.1%. C. pneumoniae antibodies indicative of recurrent or chronic infection were common in the elderly. The geometric mean titres correlated positively with age and were higher in men than in women. Other chlamydial antibodies occurred in low titres.

Asthma, atopy and Chlamydia pneumoniae antibodies in adults

BACKGROUND

Factors involved in the development of inflammation and asthma in nonatopic subjects have remained largely obscure, although there is some evidence to suggest that certain infections may play a role.

OBJECTIVE

We investigated the association between serological evidence of Chlamydia pneumoniae infection and asthma in adults, and the possible modifying effect of the patients' atopic status on this association.

METHODS

Four hundred and thirty consecutive patients who attended the hospital between 1992 and 1993 with symptoms suggestive of asthma, rhinitis or allergy were enrolled. Diagnostic procedures including lung function measurements and skin-prick tests were performed in all patients. The patients with established asthma (n = 332) were divided into those with recent asthma (n = 224, onset 1985 onward) and longstanding asthma (n = 108, onset before 1985). The controls (n = 98) comprised all subjects who did not meet the criteria of asthma. Serum immunoglobulin (Ig)G, IgA and IgM antibodies to C. pneumoniae were measured by the microimmunofluorescence test.

RESULTS

In women, the prevalences of elevated IgG (a titre of >/= 128) and IgA (>/= 32) antibody levels and the age-adjusted geometric mean titres (GMT) of IgG and IgA antibodies were invariably highest among subjects with nonatopic longstanding asthma. Elevated IgG titres in women occurred in 11% of controls, in 28% of nonatopic recent onset asthmatics, and in 43% of asthmatics with nonatopic longstanding disease; for men the respective figures were 33, 50 and 64%. Logistic regression analysis controlling for age, sex and smoking showed that asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae (odds ratio 3.3, 1.6-6.8 for longstanding asthma, 2.3, 1. 2-4.4 for recent asthma, and among women only 4.2, 1.6-10.9 for longstanding asthma, and 3.0, 1.3-7.2 for recent asthma). When the atopics and nonatopics were analysed separately, an even stronger relationship in the nonatopics was obtained for longstanding asthma (6.0,2.1-17.1). In contrast, the relationship between atopic asthma, either recent or longstanding, and elevated IgG titres was not significant, indicating that asthma per se does not predispose to C. pneumoniae infection.

CONCLUSIONS

Asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae, and this association was strongest for nonatopic longstanding asthma.

Antisperm antibodies and microorganisms in genital secretions--a clinically significant relationship?

In asymptomatic infertility patients, no significant relationship was found between the presence of antisperm antibodies (ASA) in serum and in semen samples (IgG and/or IgA ASA), differentiated with the mixed antiglobulin reaction (MAR), and the microbial colonization of ejaculates covering a broad spectrum of microorganisms. Likewise, there was no significant association of ASA with microbial findings in patients' female partners, who also presented without symptoms of genital tract infection and were screened at the same time. Furthermore, ASA in semen (IgG and IgA) were not significantly related to several potential markers of subclinical male sexual gland infection or inflammation (leukocytes, PMN elastase, albumin, C3c) evaluated in aliquots of the same ejaculates used for immunological testing.

Chlamydia trachomatis in adolescents: a review

Genital infections caused by Chlamydia trachomatis represent the most prevalent bacterial sexually transmitted disease in the United States. An estimated 3-4 million cases annually necessitate the expenditure of more than $2 billion in health care costs per year. The ramifications of infection with this organism have significant reproductive complications. The objective of this paper is to provide the reader with a review of Chlamydia trachomatis in general with particular focus on those areas that are pertinent to the adolescent population. The authors hereby provide an overview of the clinically pertinent microbiology, epidemiology, risk factors, selective screening protocols, diagnostic methods, clinical manifestations, and sequelae of C. trachomatis.

Current methods of laboratory diagnosis of Chlamydia trachomatis infections

Infections caused by Chlamydia trachomatis are probably the most common sexually transmitted diseases in the United States. Commonly unrecognized and often inadequately treated, chlamydial infections can ascend the reproductive tract and cause pelvic inflammatory disease, which often results in the devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. C. trachomatis infections are also known to increase the risk for human immunodeficiency virus infection. The obligate intracellular life cycle of C. trachomatis has traditionally required laboratory diagnostic tests that are technically demanding, labor-intensive, expensive, and difficult to access. In spite of these historical challenges, however, laboratory diagnosis of C. trachomatis has been a rapidly advancing area in which there is presently a wide array of commercial diagnostic technologies, costs, manufacturers. This review describes and compares the diagnostic methods for C. trachomatis infection that are currently approved for use in the United States, including the newest DNA amplification technologies which are yet to be licensed for commercial use. Issues to consider in selecting a test for purposes of screening versus diagnosis based on prevalence, performance, legal, social, and cost issues are also discussed.

Chlamydia trachomatis detected in cervical smears from Copper-T users by DFA test

OBJECTIVE

This study was carried out to determine the prevalence of Chlamydia trachomatis (CT) antigen in endocervical smears from women using the Copper-T200 (Cu-T) intrauterine device and comparing them with nonusers.

METHODS

The direct fluorescent antibody (DFA) test was used to detect the CT antigen (CT Ag).

RESULTS

A total of 422 women between 17 and 42 years of age was evaluated. Out of these 71 (16.8%) were positive for CT Ag. Among Cu-T users (n = 222), 14.0% were positive. The duration of Cu-T use varied from 6 to 80 months. Among nonusers (n = 200), the DFA test was positive in 20.0% (p = 0.11, NS). However, as a whole, symptoms related to genital tract infection were significantly more common in Copper-T users than in nonusers (p < 0.02) and signs were relatively more common in Cu-T users but not significantly so (p = 0.16). Similarly, as a group, symptoms as well as signs were significantly more common in all DFA-positive cases than in all negative cases (p < 0.02). Among Cu-T users, symptoms were relatively more common, and signs were significantly more common, in women positive for CT Ag than in the negative cases (p < 0.04). There were two cases of mild pelvic inflammatory disease (PID) diagnosed clinically, one in a Copper-T user, and the other a nonuser, both being positive by the DFA test.

CONCLUSION

There was no correlation between the duration of Copper-T use and percent positivity for CT Ag. Although milder genital tract symptoms and signs were more common in women with chlamydial cervicitis, clinically PID appears to be uncommon (0.5%). PID in this study was not related to Copper-T use but related to chlamydial cervicitis in this group of women with low risk sexual behavior.

Prevalence and serovar distribution of asymptomatic cervical Chlamydia trachomatis infections as determined by highly sensitive PCR

The prevalence rates and serovar distributions of Chlamydia trachomatis cervical infections were investigated in two different groups of women. Group I consisted of 393 asymptomatic young women (aged 17 to 30 years) who were invited to participate in a C. trachomatis screening program. Group II consisted of 734 randomly selected patients (aged 17 to 68 years) attending an inner-city gynecological outpatient clinic. C. trachomatis was detected in cervical scrapes by PCR specific for endogenous plasmid. These plasmid PCR-positive samples were subsequently subjected to genotyping by C. trachomatis-specific omp1 PCR-based restriction fragment length polymorphism analysis (J. Lan, J. M. M. Walboomers, R. Roosendaal, G. J. van Doornum, D. M. MacLaren, C. J. L. M. Meijer, and A. J. C. van den Brule, J. Clin. Microbiol. 31:1060-1065, 1993). The overall prevalence rates of C. trachomatis found in patients younger than 30 years were 9.2 and 11.8% in groups I and II, respectively. A clear age dependency was seen in group II, with the highest prevalence rate (20%) found in patients younger than 20 years, while the rate declined significantly after 30 years of age (5.9%). In women younger than 30 years, the genotyping results showed that serovars E, I, and D (in decreasing order) were frequent in group I, while serovars F, E, and G (in decreasing order) were predominantly found in group II. The study shows that C. trachomatis infections are highly prevalent in asymptomatic young women. The different serovar distributions found most likely reflect the different compositions of the study groups, but additional analysis of the case histories of individual patients suggests that certain serovars might be associated with symptomatic (i.e., serovar G) or asymptomatic (i.e., serovars D and I) infections.

Genital tract infections in women

The future holds promise of new, more accurate diagnostic tests; more effective therapies; and development of better barriers and eventual vaccines. GTI is, however, and for the foreseeable future will continue to be a major health care problem for women, requiring careful surveillance, management, and ongoing education for both patient and provider.

Detection of Chlamydia trachomatis in semen by antibody-enzyme immunoassay compared with polymerase chain reaction, antigen-enzyme immunoassay, and urethral cell culture

OBJECTIVE

To compare the results obtained by four different techniques for the detection of Chlamydia trachomatis in the male genital tract.

DESIGN

Prospective study.

SETTING

Andrology unit of a university hospital.

PATIENTS

Male infertility patients.

INTERVENTIONS

Analysis of semen samples and urethral swabs for the presence of C. trachomatis by recombinant antibody-enzyme-linked immunosorbent assay (rELISA), polymerase chain reaction (PCR), antigen-enzyme immunoassay (EIA) and McCoy cell culture.

MAIN OUTCOME MEASURE

Detection of C. trachomatis.

RESULTS

In 57 of 205 semen samples (27.8%) immunoglobulin A-antibodies against C. trachomatis were found. In contrast, only 1 of 56 semen samples (1.8%) was positive for C. trachomatis-DNA by PCR, only 1 of 139 semen samples (0.7%) was positive by antigen-EIA, and only 4 of 173 urethral swabs (2.3%) grew C. trachomatis in cell culture.

CONCLUSIONS

The discrepancy of positive results found by the antibody-rELISA and direct methods for the detection of C. trachomatis indicates successful eradication of the microorganism in > 90% of antibody-positive men. Therefore, detection of antibodies against C. trachomatis in seminal plasma appears to be of limited diagnostic value.

Detection of Chlamydia trachomatis in semen of artificial insemination donors by the polymerase chain reaction

OBJECTIVE

To assess the feasibility of detecting Chlamydia trachomatis in cryopreserved donor semen by a specific, direct polymerase chain reaction (PCR).

DESIGN

Cryopreserved donor semen was tested for the presence of C. trachomatis by a specific PCR, directly applied to semen without prior DNA purification.

SETTING

Tertiary care fertility center in a teaching hospital and university-based laboratory for molecular pathology.

PARTICIPANTS

Cryopreserved semen from 30 donors was investigated. These semen samples had previously given negative results in cell culture for C. trachomatis. Two different ejaculates of each donor, cryopreserved with an interval of 2 years, were retrospectively analyzed.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

The presence of C. trachomatis as demonstrated by PCR.

RESULTS

In 3 of 30 donors C. trachomatis was detected in both ejaculates, whereas in 2 additional donors only one of the two samples tested positive. Additional samples from 2 positive donors, together with samples from 3 negative donors, were studied more extensively, to test the reproducibility and reliability of PCR results. All ejaculates of the donors, previously positive for C. trachomatis by PCR, indeed appeared to be positive, whereas the samples of the negative donors remained negative.

CONCLUSIONS

The direct PCR is a reliable, sensitive, and valuable method for detection of C. trachomatis in semen. The incidence of contamination of donor semen with C. trachomatis in the donor population in this study stresses the need for rigorous screening of donor semen before artificial insemination, preferably using a sensitive method such as the PCR.