Asymptomatic Chlamydia trachomatis infections among sexually active men

The prevalence of Chlamydia trachomatis in the population living in Roma settlements: a comparison with the majority population

BACKGROUND

We aimed to study the occurrence of Chlamydia trachomatis infection in the population living in Roma settlements and to compare the obtained results with the prevalence in the majority population.

METHODS

We examined 340 people for the presence of bacterium C. trachomatis, 208 of them were Roma (66 men, 142 women) and 132 were from the majority population (75 men, 57 women). Respondents were aged 18-55 years (mean age = 33.44, STD = 9.57). The occurence of C. trachomatis was detected by direct proof of the pathogen by polymerase chain reaction (PCR).

RESULTS

Of 340 respondents included in the study, 22 (6.5%) showed positivity for C. trachomatis infection, 15 of them were Roma (7.2%) and 7 non-Roma (5.3%). The highest positivity was detected in Roma women (8.5%), while positivity in both non-Roma women and men was 5.3%, and in Roma men 4.5%. We did not confirm any significant contribution of age, gender or ethnicity to the occurrence of C. trachomatis infection.

CONCLUSIONS

Despite the increased number of people with risk factors in the Roma community, no significant difference in the occurrence of C. trachomatis infection was found. Neither age nor gender contributes to the probability of C. trachomatis infection. Nevertheless, there are other health consequences which might be more pronounced among the population living in Roma settlements due to barriers to the health care and their lower ability to benefit from health care services provided.

Development status and future prospects for a vaccine against Chlamydia trachomatis infection

Chlamydia trachomatis continues to be the most commonly reported sexually transmitted bacterial infection in many countries with more than 100 million new cases estimated annually. These acute infections translate into significant downstream health care costs, particularly for women, where complications can include pelvic inflammatory disease and other disease sequelae such as tubal factor infertility. Despite years of research, the immunological mechanisms responsible for protective immunity versus immunopathology are still not well understood, although it is widely accepted that T cell driven IFN-g and Th17 responses are critical for clearing infection. While antibodies are able to neutralize infections in vitro, alone they are not protective, indicating that any successful vaccine will need to elicit both arms of the immune response. In recent years, there has been an expansion in the number and types of antigens that have been evaluated as vaccines, and combined with the new array of mucosal adjuvants, this aspect of chlamydial vaccinology is showing promise. Most recently, the opportunities to develop successful vaccines have been given a significant boost with the development of a genetic transformation system for Chlamydia, as well as the identification of the key role of the chlamydial plasmid in virulence. While still remaining a major challenge, the development of a successful C. trachomatis vaccine is starting to look more likely.

Molecular Diagnosis of Sexually Transmitted Chlamydia trachomatis in the United States

Chlamydia, with its Chlamydia trachomatis etiology, is the most common bacterial sexually transmitted infection in the United States and is often transmitted via asymptomatic individuals. This review summarizes traditional and molecular-based diagnostic modalities specific to C. trachomatis. Several commercially available, FDA-approved molecular methods to diagnose urogenital C. trachomatis infection include nucleic acid hybridization, signal amplification, polymerase chain reaction, strand displacement amplification, and transcription-mediated amplification. Molecular-based methods are rapid and reliable genital specimen screening measures, especially when applied to areas of high disease prevalence. However, clinical and analytical sensitivity for some commercial systems decreases dramatically when testing urine samples. In vitro experiments and clinical data suggest that transcription-mediated amplification has greater analytical sensitivity than the other molecular-based methods currently available. This difference may be further exhibited in testing of extragenital specimens from at-risk patient demographics. The development of future molecular testing could address conundrums associated with confirmatory testing, medicolegal testing, and test of cure.

Management of Chlamydia trachomatis genital tract infection: screening and treatment challenges

Chlamydia trachomatis is a prevalent sexually transmitted infection that can lead to serious reproductive morbidity. Management and control of C. trachomatis is a challenge, largely due to its asymptomatic nature and our incomplete understanding of its natural history. Although chlamydia screening programs have been implemented worldwide, several countries have observed increasing rates of reported chlamydia cases. We reviewed the literature relating to the long-term complications of C. trachomatis, as well as screening strategies, treatment, and prevention strategies for reducing chlamydia in the population. Articles from 1950-2010 were identified through a Medline search using the keyword "Chlamydia trachomatis" combined with "screening", "pelvic inflammatory disease", "endometritis", "salpingitis", "infertility", "ectopic pregnancy", "urethritis", "epididymitis", "proctitis", "prostatitis", "reinfection", "cost-effectiveness", "treatment", "vaccines", or "prevention". Progression of C. trachomatis varies, and recurrent infections are common. Currently, there is limited evidence on the effectiveness of chlamydia screening. Higher quality studies are needed to determine the efficacy of more frequent screening, on a broader range of sequelae, including infertility and ectopic pregnancy, in addition to pelvic inflammatory disease. Studies should focus on delineating the natural history of recurrent infections, paying particular attention to treatment failures. Furthermore, alternatives to screening, such as vaccines, should continue to be explored.

Lymphogranuloma venereum in human immunodeficiency virus-infected individuals in New York City

Lymphogranuloma venereum (LGV), or chlamydial proctitis, is a classic sexually transmitted disease with prominent gastrointestinal manifestations. The disease has received little attention in recent years, especially in relation to human immunodeficiency virus (HIV) infection. However, outbreaks of LGV have been reported in several large cities in Europe and the United States over the past few years, occurring in both HIV-infected and -uninfected individuals, and the reports have been largely limited to the sexually transmitted disease literature. We recently diagnosed four cases of chlamydial proctitis in HIV-infected individuals, who had different clinical presentations but very similar endoscopic and histopathologic features, as well as prompt and complete response to therapy. It is important for gastroenterologists to recognize that LGV may be reemerging as a relevant clinical entity, because of its similarity to inflammatory bowel diseases and its response to treatment with antibiotics.

Risk factors for genital chlamydial infection

OBJECTIVE

To discuss the occurrence of genital chlamydia in developed countries and review the literature assessing the potential risk factors for this sexually transmitted disease.

DATA SOURCES

A MEDLINE search was performed for all English citations from 1985 to 2000 that contain the keywords "Chlamydia trachomatis", "chlamydial infections", "risk factors" and "sex behaviour". All relevant references cited in articles that were obtained from the search were also included.

DATA EXTRACTION

ALL ARTICLES OBTAINED FROM THE ABOVE SOURCES WERE EXAMINED, AND WERE INCLUDED IN THE REVIEW IF THEY MET THE FOLLOWING CRITERIA: primary study examining sociodemographic or behavioural risk factors associated with genital chlamydial infection using multivariate analysis; study subjects 12 years of age and older; and study setting in a developed country.

DATA SYNTHESIS AND CONCLUSIONS

Genital chlamydial infection has become the most commonly reported bacterial infection in North America over the past decade. Thirty-eight cross-sectional studies and six cohort studies were included in the present review. Most studies demonstrated that young men and women are at higher risk of being infected with chlamydia than older subjects. Chlamydia seems to be found in a diverse group of people, and unlike gonorrhea, is not concentrated in low income, minority core groups with high rates of partner change. However, a number of studies have shown that communities with well-established control programs are beginning to demonstrate this pattern. There is no clear evidence that chlamydia is associated with type of partners, contraceptive use, or age at first intercourse. Future research should follow this sexually transmitted disease as it evolves through the epidemiological stages to ensure that preventive and treatment services are reaching those people who are most likely to be infected.

Chlamydial serology: comparative diagnostic value of immunoblotting, microimmunofluorescence test, and immunoassays using different recombinant proteins as antigens

To improve the reliability of the serodiagnosis of Chlamydia trachomatis infections, an immunoblot analysis, a microimmunofluorescence titration, and different immunoassays using synthetic peptides derived from species-specific epitopes in variable domain IV of the major outer membrane protein or recombinant antigens (heat shock protein 70 [hsp70], hsp60, hsp10, polypeptide encoded by open reading frame 3 of the plasmid [pgp3], macrophage infectivity potentiator, and a fragment of the total lipopolysaccharide) were evaluated. Because cross-reactions between chlamydial species have been reported, the microimmunofluorescence tests were also performed with Chlamydia pneumoniae and Chlamydia psittaci used as antigens, and C. pneumoniae-specific antibodies were also determined by immunoassays. Since the presence of antimicrobial antibodies must be interpreted in light of their prevalence in the general population, responses obtained with serum samples from patients with well-defined infection (i.e., with positive urethral or endocervical C. trachomatis DNA amplification) were compared to those obtained with samples from healthy blood donors. The best sensitivity (86%) with a specificity of 81% was obtained for immunoblotting results, when the number of individuals with > or =10 immunoglobulin G (IgG) and/or > or =2 IgM responses to the different C. trachomatis antigens was considered. A 13-kDa antigen was recognized by most of the samples (86% for IgG) from patients with acute urogenital infection but rarely (3%) by those from healthy blood donors (P < 0.0001). The sensitivity and specificity results obtained for serum antibodies to peptides or recombinant antigens were slightly lower than those results obtained for the number of responses to whole C. trachomatis antigens, which were 76 and 77%, respectively, when IgG responses to both recombinant hsp60 and pgp3 were considered.

Participation in a school-based sexually transmitted disease screening program

BACKGROUND

A school-based chlamydia screening program was offered repeatedly in three Louisiana public high schools in an effort to expand sexually transmitted disease screening services for adolescents.

GOAL

To describe participation of a fixed cohort of students to elucidate the impact of screening on chlamydia prevalence.

STUDY DESIGN

Five opportunities for chlamydia testing were offered in 3 schools during 3 school years (1995-1996, 1996-1997, 1997-1998). Only students with parental consent could be tested. Students consistently enrolled during the 3 years (n = 1475) were included in this analysis.

RESULTS

During the 3 school years, parental consent was cumulatively obtained for 1443 students (97.8%), and 1305 students (88.5%) were tested at least once. Of those tested, 81.1% tested more than once. The prevalence of Chlamydia trachomatis infection at first test among students who tested more than once was 1.8% for males and 7.7% for females. Among students tested only once, 6.2% of males and 12.7% of females had chlamydial infection. Among students tested more than once, no significant difference in C. trachomatis prevalence was associated with repeat screenings. Incidence rates per 1000 person-months were 4.3 (2.2, males; 7.1, females; P < 0.0001). Reinfections explained only 5.6% of all incident cases.

CONCLUSION

The documented high response from both parents and students to this school-based chlamydia screening program offers great promise for sexually transmitted disease control among adolescents. Overall, C. trachomatis prevalence was two times higher among students testing only once than among those testing more than once. Routine and continued availability of school-based chlamydia screening programs can potentially reduce the burden of disease among adolescents.

Evaluation of the Gen-Probe PACE 2 assay for the detection of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees

BACKGROUND

The LET and Gen-Probe PACE 2 assay are used to screen male arrestees for evidence of infection with chlamydia and gonorrhea in the intake/booking area of the Jefferson Parish Correctional Center.

GOAL OF THIS STUDY

To determine the accuracy of the Gen-Probe PACE 2 assay for the detection of asymptomatic infection with Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees.

STUDY DESIGN

From December 1993 to March 1994, 196 arrestees younger than 22 years were screened with the Gen-Probe PACE 2 assay and McCoy shell vial culture for Chlamydia trachomatis. From April to October 1994, 444 arrestees of all ages were screened with the Gen-Probe PACE 2 assay and standard culture for Neisseria gonorrhoeae. The sensitivity, specificity, and predictive values of the Gen-Probe PACE 2 assay, compared with culture, were calculated with 95% confidence intervals.

RESULTS

The Gen-Probe PACE 2 assay compared with culture had a sensitivity, specificity, and positive predictive value for Chlamydia trachomatis of 84%, 99%, and 93% and for Neisseria gonorrhoeae of 54%, 99.5%, and 78%.

CONCLUSION

The Gen-Probe PACE 2 assay is useful for screening young males in this jail setting and is more accurate for detecting Chlamydia trachomatis compared with Neisseria gonorrhoeae.

Epidemiology of genital Chlamydia trachomatis in England and Wales

OBJECTIVE

To describe the recent epidemiology of genital Chlamydia trachomatis infection in England and Wales.

DESIGN

Retrospective study of routinely available surveillance datasets and ad hoc prevalence studies.

METHODS

Numbers of new cases of genital C trachomatis infection, obtained from the Department of Health and Welsh Office, were combined with the estimated mid-year resident population of England and Wales. Rates were analysed for trend over time using a log linear age period model in GLIM4. Ad hoc prevalence and case finding studies carried out over the past 20 years were critically assessed in terms of study design and testing methodologies.

RESULTS

Attendance rates at genitourinary medicine (GUM) clinics were higher for women than men over the period 1989 to 1994 as were the number of laboratory reports. The highest rate of attendance (GUM clinic data) was for women aged 16 to 19 years. There was an overall significant linear decrease in the attendance rates over time for both men (p = 0.0172) and women (p = 0.0000) between 1989 and 1994. There was considerable variation in the prevalence of genital C trachomatis infection detected within different clinical settings, together with a substantial level of asymptomatic infection.

CONCLUSIONS

Genital C trachomatis infection is broadly distributed throughout the sexually active population, with a substantial reservoir of asymptomatic infection among those generally perceived to be at low risk of a sexually transmitted infection. Young people, particularly women aged 16 to 19 years, are at highest risk of genital C trachomatis infection. This is of concern since younger women are more susceptible than older women to developing complications of chlamydial infection, such as pelvic inflammatory disease. The broad distribution of infection across all sexually active health service attenders and the high level of asymptomatic infection suggest that a new, screening based, approach to the control of genital C trachomatis infection is required. Recommendations are made as to the epidemiological research required to guide such work.

Epidemiology of gonococcal and chlamydial infections in Harrow and Brent

OBJECTIVE

To describe the epidemiology and associated clinical features of gonorrhoea and chlamydial infection and to develop a profile of sexually transmitted diseases (STDs) in an outer London health district.

DESIGN

Hospital-based retrospective study.

SETTING

Genitourinary medicine clinic, Northwick Park Hospital, Harrow and Brent Health Authority.

SUBJECTS

70 male and female individuals with gonorrhoea and 129 with chlamydial infection, diagnosed consecutively over 28 months in 1992-94.

RESULTS

More men than women had gonorrhoea (43 versus 27) but more women than men had chlamydial infection (84 versus 45), p < 0.001. There was a clear tendency for cases with either infection to locate along major road and rail transport routes. Foci of gonococcal infection were concentrated mainly in the densely populated areas, whereas chlamydial cases were more evenly spread. There was no significant effect of gender or type of STD on the odds ratio for residence in Harrow, single marital status or attendance for test of cure. However, the odds ratios for women having sexual intercourse with a regular partner only or previous STD were 5 (95% CI 2.4 to 10.2), p < 0.001 and 0.3 (95% CI 0.18 to 0.69), p = 0.002 times the odds for men, respectively. The odds ratios for patients with gonococcal infection being employed or having sex with a regular partner only were 0.5 (95% CI 0.27 to 0.98), p = 0.04 and 0.30 (95% CI 0.15 to 0.60), p < 0.001 times the odds for patients with chlamydial infection, respectively. Of the women with gonorrhoea and previous pregnancy, 68% gave a history of abortion compared with 44% of those with chlamydial infection (p = 0.03).

CONCLUSION

The identification of foci gonococcal and chlamydial infection and apparent location of these infections along the major transport routes in our health district require further study. That chlamydial infection, unlike gonorrhoea, is evenly distributed irrespective of population concentration and deprivation, suggests urgent need for a comprehensive local effort to control both STDs.

Gonococcal and chlamydial genitourinary infections in symptomatic and asymptomatic adolescent women

To determine the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae endocervical infections in a group of adolescent women, gynecologic histories and evaluations were done on symptomatic and asymptomatic adolescent women presenting for pelvic examinations in an urban, hospital-based, adolescent clinic. C. trachomatis and N. gonorrhoeae cultures and three nonculture diagnostic tests for chlamydia (two ELISA assays and one DNA-probe) were performed on each patient. Patients were 12 to 21 years of age (mean 17.0); 53% were African-American, and 47% were Caucasian. Two hundred twenty-eight women were asymptomatic and 249 women had symptoms. There were 64 cases of chlamydia and 19 cases of gonorrhea; an additional 11 patients had both chlamydia and gonorrhea. Approximately one third of patients with chlamydia, gonorrhea, or both had asymptomatic disease an important reservoir of infection.

Factors associated with genital chlamydial and gonococcal infection in males

BACKGROUND

Predictors of chlamydia and gonorrhoea can be used to increase the cost-effectiveness and acceptability of screening programmes, and allow targeting of control strategies.

METHOD

All men attending an STD clinic in 1988-1990 were offered screening for chlamydia and gonorrhoea, and the test results correlated with a wide range of potential predictors using multiple logistic regression.

RESULTS

Of 9622 attenders, 7992 (82.3%) were tested over a total of 10,110 episodes for chlamydia and 10,090 episodes for gonorrhoea, yielding 729 (7.2%) chlamydial and 123 (1.2%) gonococcal infections. Having urethral discharge and/or dysuria, being heterosexual, and STD contact, unmarried, uncircumcised, tattooed and not having had an STD previously were independently associated with chlamydial infection. Having urethral discharge and/or dysuria, being Aboriginal, an STD contact, homosexual, uncircumcised, tattooed and having sex outside the state in the past three months, no steady partner in the past three months and multiple partners in the past month were associated with urethral gonococcal infection. Selective screening criteria for gonorrhoea provided 90% of positives, eliminated the need for 58% of tests and resulted in an increased yield ratio of 2.2 whereas the corresponding outcomes for screening criteria for chlamydia were 93% 20% and 1.2 respectively.

CONCLUSIONS

The widespread influence of confounding on potential predictors for both gonorrhoea and chlamydia may provide misleading indicators of risk factors by univariate analysis. In the setting studied the benefits of selective screening for gonorrhoea in men would be substantial, whereas satisfactory criteria for selective screening for chlamydia could not be identified.

Evaluation of chlamydiazyme enzyme immunoassay for detection of Chlamydia trachomatis in urine specimens from men

Paired first-voided urine and urethral swab specimens were collected from 540 men attending sexually transmitted disease clinics in three geographic locations. Urine specimens were tested for the presence of Chlamydia trachomatis by commercial enzyme immunoassay (Chlamydiazyme), and the results were compared with those of urethral swab cultures. Overall prevalence of urethral C. trachomatis by culture was 14%, and the Chlamydiazyme assay had an overall sensitivity of 83%, a specificity of 96%, a positive predictive value of 76%, and a negative predictive value of 97%. Sensitivity was greater (94%) in those culture-positive samples with a high antigen load (> or = 20 inclusion-forming units per coverslip) than those with a lower antigen load (68%). Assay of urine specimens from men attending sexually transmitted disease clinics by Chlamydiazyme appears to be a reliable, noninvasive method of detection of C. trachomatis infection, and further evaluation of its performance in asymptomatic and low-prevalence populations is indicated.

Infection and pyospermia in male infertility

Infections of the male genitourinary tract may contribute to infertility by adversely affecting sperm function, causing anatomical obstruction or initiating a leukocyte response. The majority of infertile males are asymptomatic, and the significance and the criteria for the diagnosis of a genital tract infection are controversial. The evaluation for a genital tract infection focuses on urine and semen cultures as well as on the accurate quantitation of seminal leukocytes. An elevated seminal leukocyte count, pyospermia, can be associated with male infertility and may reflect an infectious or inflammatory disorder. In addition, the role of specific genital tract infections such as chlamydiosis, gonorrhea, ureaplasma and trichomoniasis and their possible association with male infertility is addressed.

A controlled trial of a single dose of azithromycin for the treatment of chlamydial urethritis and cervicitis. The Azithromycin for Chlamydial Infections Study Group

BACKGROUND

Currently, there is no single-dose therapy that is effective in the treatment of urethral or endocervical infections with Chlamydia trachomatis. Azithromycin is a new azalide antibiotic that has substantial activity against C. trachomatis, is concentrated intracellularly, and has a long half-life in serum and tissue.

METHODS

We conducted a trial in which 299 female patients and 158 male patients with uncomplicated genital infection and a positive C. trachomatis antigen test were randomly assigned to receive either azithromycin (1 g once orally) or doxycycline (100 mg orally twice daily for seven days). Only patients subsequently determined to have a culture positive for C. trachomatis at base line were included in the evaluation of efficacy.

RESULTS

Among the patients who could be evaluated, 5 of the 141 patients (4 percent) treated with azithromycin did not respond to treatment, as compared with 3 of the 125 patients (2 percent) treated with doxycycline (difference between groups, 2 percent; 95 percent confidence interval, 0 to 6 percent). Of the patients evaluated 21 to 35 days after treatment, none of 112 treated with azithromycin and 1 of 102 treated with doxycycline had a positive culture. The rates of bacteriologic cure were similar for the 98 female patients (97 percent) and the 43 male patients (95 percent) treated with azithromycin. Seventeen percent of the patients who received azithromycin and 20 percent of those treated with doxycycline had mild-to-moderate drug-related side effects, mainly gastrointestinal symptoms.

CONCLUSIONS

A single 1-g dose of azithromycin is as effective for the treatment of uncomplicated genital chlamydial infections as a standard seven-day course of doxycycline.

Isolation of Chlamydia trachomatis from prostatic tissue of patients undergoing transurethral prostatectomy

Chlamydia trachomatis was isolated from three of 100 prostatic tissue specimens obtained from patients undergoing transurethral resection of the prostate. All examined patients were free from symptoms of urethral or prostatic inflammation. Our findings are in accordance with the high incidence of asymptomatic chlamydial infection of the lower genital tract and the increasing evidence that C. trachomatis can cause infection of the prostate.

Chlamydial infections

Chlamydia trachomatis is a unique intracellular parasite that causes a number of common sexually transmitted disease syndromes, including nongonococcal urethritis in both men and women, epididymitis in men, and pelvic inflammatory disease in women. Infants exposed at delivery are at risk for the development of conjunctivitis and pneumonia. There is strong evidence that Chlamydia is a cause of obstructive infertility and ectopic pregnancy in women. It appears that these complications result from the chronic inflammatory response and secondary scarring that are elicited by long-term asymptomatic or nearly asymptomatic fallopian tube infections. Because treatment with tetracycline, doxycycline, or erythromycin is simple, effective, and inexpensive, major efforts should be put into identifying asymptomatic young women through screening of the subpopulations at highest risk. These include sexually active adolescent women and older women who are not monogamous. Blacks are at higher risk than other ethnic groups for infection. The cost of diagnosing chlamydial infection has decreased with the introduction of new nonculture diagnostic tests. This should increase the availability of testing for screening purposes. It is critical to remember that male sex partners of infected women must be treated; otherwise all efforts to prevent long-term complications by identifying and treating asymptomatic women are doomed to failure.