Chlamydia trachomatis infections in multi‐ethnic urban youth: a pilot combining STI health education and outreach testing in Rotterdam, Netherlands

Background/objectives     

Reinfections, persistent infections, and new infections after general population screening for Chlamydia trachomatis infection in the Netherlands

OBJECTIVES: The objectives of this study were to determine the rate of new infections and reinfections or persistent infections with Chlamydia trachomatis to define appropriate screening intervals and to identify risk factors for reinfection. DESIGN: This was a cross-sectional study among a subsample of participants in a population-based screening. SETTING: This study was conducted in urban and rural areas in The Netherlands. PARTICIPANTS: A total of 21,000 15- to 29-year-old women and men were invited for home-based urine testing. One year after the study, a subsample of 299 participants were offered retesting. MAIN OUTCOME MEASURES: The authors studied the rate of infection with C. trachomatis. Serovar determination was used to potentially discriminate between new infections and reinfections or persistent infections. RESULTS: Nine C. trachomatis infections were found among 187 responders (4.8% confidence interval, 1.7-7.9). The prevalence was 10.4% (5 of 48) in previous positives and 2.9% (4 of 139) in negatives. Three of 5 repeatedly positive participants were infected with a different C. trachomatis serovar. CONCLUSIONS: Our study indicates that infected persons found in a systematic, population-based screening should be re-screened within 1 year. Optimal screening intervals still need to be determined.     

Chlamydia trachomatis infections in eastern Europe: legal aspects,epidemiology, diagnosis,and treatment

OBJECTIVES: Knowledge concerning genital Chlamydia trachomatis infections in eastern Europe is scarce. Data on the legal aspects, epidemiology, diagnosis, and treatment of the infection have never been collected, summarised, and presented to the international scientific community. The aim of this study was to present the current situation on the main aspects of chlamydial infections in the countries of eastern Europe. METHODS: Written questionnaires concerning legal aspects, epidemiology, diagnosis, and treatment of the infection were distributed among national STI operating administrators as well as researchers who had presented papers at earlier meetings of European chlamydia or STI societies. RESULTS: Most of the countries have not legalised reporting of chlamydial infections and in those who have done so, the quality of the reporting system is poor. Contact tracing is mostly done on a voluntary basis. Reported chlamydia incidence varies from 21 to 276 per 100000 inhabitants. The most commonly used diagnostic test remains the direct immunofluorescence test; however, some tendencies towards nucleic acid amplification are in evidence. Diagnostic services are paid for by the patient himself, while treatment in many countries is partially or completely covered by public insurance. CONCLUSIONS: This is the first report summarising data concerning the situation on C trachomatis infections in eastern Europe. The reporting system and diagnosis of C trachomatis infections remain suboptimal, which allows neither control of the epidemiological situation nor optimal treatment of the patients. The most urgent work currently necessary is the education of professionals and the general population.     

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.     

Chlamydia trachomatis infections increase the risk for ectopic pregnancy: a population-based, nested case-control study

BACKGROUND: Chlamydia trachomatis (CT) as a risk factor for ectopic pregnancy (EP) has mainly been established through seroepidemiologic cross-sectional studies. GOAL: The goal of this study was to obtain EP risk estimates for women diagnosed with CT using women with negative tests as the reference group. METHODS: We linked prospectively collected CT laboratory data (1990-2003) to EP hospital data (discharge and outpatient registries) in a nested case-control study. Six hundred sixteen women with CT test(s) before first EP were eligible as cases. Three controls were matched to each case for year of birth, age at first test, and number of prior tests. RESULTS: Previous CT infection was associated with elevated EP risk (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.0-2.0). In stratified analysis, the association was only significant for the youngest women (born 1970-1984) who had a nearly complete CT testing history (OR, 2.1; 95% CI, 1.3-3.2). CONCLUSION: A history of diagnosed CT infection is associated with a 2-fold increased EP risk.     

High occurrence of a new variant of Chlamydia trachomatis escaping diagnostic tests among STI clinic patients in Stockholm, Sweden

BACKGROUND: In 2006, a genetic variant of Chlamydia trachomatis not detectable with the most commonly used diagnostic tests was identified. Initial reports suggested that as many as 10% to 13% of all chlamydia cases would have remained undiagnosed. The aim of the study was to find the occurrence and clinical findings of this genetic variant among a high-risk population in Stockholm, Sweden. METHODS: Samples were analyzed using the Cobas TaqMan CT test (Roche Diagnostics). To detect the new variant, an additional PCR-analysis, artus C. trachomatis LC MOMP PCR Kit (Qiagen) was performed on all negative samples. Positive results in the artus test were confirmed by a mutant specific PCR. Clinical data were retrospectively collected from medical records. RESULTS: Among 1009 samples analyzed, 115 were positive for C. trachomatis and among those, 27 were found to belong to the genetic altered strain. This variant constituted 23% of all chlamydia cases diagnosed, and 29% were found in the age group 20 to 29 years. Women with the new variant were younger and had more often performed another chlamydia test within the previous 6 months compared with those infected with the wild type. CONCLUSION: These results indicate that a large number of sexually active individuals might be infected despite a negative chlamydia test, thus facilitating a rapid transmission of the new variant. Accordingly, it is of great importance to be aware of limitations of the diagnostic methods used.     

STI prevention and the male sex industry in London: evaluating a pilot peer education programme

OBJECTIVE: To evaluate the effectiveness of a pilot peer education STI prevention programme with male sex workers. DESIGN: A process and outcome evaluation of the pilot programme undertaken in three London male escort agencies, using a quasi-experimental design. SUBJECTS: Workers in three London escort agencies, including 88 who completed a questionnaire, five peer educators, and a further 16 men (including management) working in two of these agencies. METHODS: A peer education STI prevention programme run by the Working Men Project (WMP), a specialist sexual health service for male sex workers, was piloted in two London escort agencies. Five male sex workers participated in a 2 day peer education training programme. They then returned to their respective agencies to disseminate information and condoms, in an attempt to influence norms of behaviour. An outcome evaluation aimed to assess changes in STI related knowledge, high risk sexual behaviour, and attendance at a sexual health service. A pre-intervention questionnaire assessing variables such as STI related knowledge, sexual behaviour, and demographic information was administered in both agency A and agency B and a third agency, C, which acted as a control. Ten weeks after the peer educators returned to their agencies, the same questionnaire was administered in the same agencies. Peer educator referrals to the WMP were also recorded over this time period. The process evaluation involved interviews and focus groups with peer educators, and the completion of diaries about their experiences in the role. A further 16 men working in the agencies (including managers and an owner) were interviewed about their experience of the programme. Participant observation was also undertaken through regular outreach work to the agencies. RESULTS: 57 men completed the questionnaire at time 1 and 44 at time 2. Unfortunately, only 13 of these were matched, precluding any meaningful analysis of change in STI related knowledge and sexual behaviour. The questionnaire provided a profile of the men working in the agencies. Of the 88 men who completed the questionnaire at least once, the majority were homosexual, and in their late teens/early 20s. Most were of a "white" ethnic group, though there was some range within these categories. Most preferred to speak English and education levels were high. Relative STI knowledge revealed a high understanding of HIV and hepatitis B, moderate understanding of gonorrhoea, syphilis, genital warts and herpes, and little knowledge of non-specific urethritis (NSU) or chlamydia. Sexual behaviour suggested a highly sexually active population with both male and female paying and non-paying partners. Condom use was highest for paying partners, particularly for anal sex. Condom use for oral sex with all partners was less consistent, and condom use for all types of sex with regular partners was lower than with other partners. The small number of men engaging in vaginal sex with paying and regular partners were less likely to use condoms. 26 new patients registered at the WMP as a result of peer educator referrals, representing 65% of all new contacts over the study period. The process evaluation revealed that while the training programme was considered adequate and while peer educators felt the programme and their roles to be a success, their experience of the role was difficult. The role of management support was crucial in supporting the programme. The assumption that "peers" are particularly effective educators was not borne out by the results. While peers were considered suitable to discuss some aspects of the industry, many preferred to consult "professionals" about health related matters. The concept of "peers" was problematic with most of the men drawing "peers" from subgroups within the agencies. Other constraints on behaviour such as a lack of power, particularly with regard to a lack of management support, or poverty, had a substantial impact on behaviour which were not influenced by the peer educators. CONCLUSIONS: The study illustrated the difficulties of utilising quasi-experimental evaluation methodology with this client group. It also demonstrated the limitations of peer education based on information provision health education models which focus on individual behaviour change. Suggestions are given for future interventions.     

Surveillance of Chlamydia trachomatis and Neisseria gonorrhoeae infections in women in detention in Baltimore,Maryland

BACKGROUND: In conjunction with a program to expand syphilis and HIV infection services, women were also offered screening for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) during intake at the Baltimore Women's Detention Center. GOAL: The goal was to assess the effectiveness of a routine screening program for CT and GC in women in a detention setting. The association among infection, race, and area of residence was also explored. STUDY DESIGN: CT and GC prevalences were determined and analyzed by demographic data, including zipcode, for 1,858 women enrolled over a 48-week period. Informed consent was obtained, and infections were detected with use of urine samples tested by ligase chain reaction. RESULTS: Overall, the population had prevalence rates of 5.9% (109/1,858) and 3.4% (63/1,858) for CT and GC respectively. Among whites, CT and GC prevalences were 9.0% (29/323) and 8.7% (28/323), respectively. Among African Americans the prevalence rates were 5.1% (77/1,510) and 2.3% (34/1,510) for CT and GC, respectively. White women <25 years of age were associated with the highest CT and GC prevalences, at 20.0% (13/65) and 13.9% (9/65), respectively. African American women <25 years of age also were associated with the highest CT and GC prevalences, at 13.9% (24/173) and 5.8% (10/173), respectively. Multivariate analysis of risk factors and demographic data indicated that ages <25 years and 25 to 34 years, white race, and certain zipcodes of residence were risk factors for infection. CONCLUSION: This study illustrated that urine-based screening for CT and GC is feasible in detention settings and can be productive in high-prevalence areas. Geographic analysis demonstrated no definitive relationship among race, infection, and area of residence, although it did demonstrate clustering of infected individuals and could be useful in future interventions. These findings demonstrated the need for implementing screening programs for sexually transmitted infections in detention centers.     

Chlamydia trachomatis infection in women attending urban midwestern family planning and community health clinics: risk factors, selective screening, and evaluation of non-culture techniques

To determine prevalence and risk factors for endocervical Chlamydia trachomatis infection in an urban midwestern population and to evaluate two non-culture direct tests for C. trachomatis, we studied 849 women attending two family planning clinics and a community health clinic in Milwaukee, Wisconsin. Adequate endocervical specimens were obtained from 751 women for chlamydial isolation in tissue culture and antigen tests using direct fluorescence (DFA) and enzyme immunoassay (EIA); 93 (12.4%) patients had cultures positive for C. trachomatis. Compared to culture, the DFA test had a 77.4% sensitivity, 96.8% specificity, and a predictive value positive (PVP) of 77%. For the EIA, these values were 83.9%, 97.0%, and 80%, respectively. No single historical, clinical, or laboratory variable, including the previously described cervicitis index and specific cytologic findings on Pap smear, had sufficient predictive value to be used as the only criterion for selective screening in this population. Criteria for selective screening were proposed that would result in screening 43% of patients and would identify 71% of infections. PVP of both non-culture tests was 89% in persons identified by these criteria to be at increased risk of C. trachomatis infection.     

Estimated incidence and prevalence of genital Chlamydia trachomatis infections in the United States, 1996.

BACKGROUND AND OBJECTIVE: Because genital Chlamydia trachomatis infections and their sequelae have a major impact on individuals and the health care system, it is important to periodically update estimates of chlamydia incidence and prevalence in the United States. STUDY DESIGN: Chlamydia incidence and prevalence were estimated using: (1) a method based on estimates of population-specific chlamydia prevalence, and (2) a method based on the chlamydia-to-gonorrhea case rate ratio. RESULTS: Using the prevalence-based method, point prevalence among persons 15 to 44 years of age was estimated to be 1.6 million chlamydial infections, and annual incidence, 2.4 million cases per year. Using a method based on the ratio of reported gonorrhea to chlamydia, incidence was estimated to be 2.8 million infections per year, and prevalence, 1.9 million. Adjustment for sensitivity of diagnostic tests yielded annual incidence estimates of 2.5 to 3.3 million infections. CONCLUSIONS: Using two methods, we estimated the annual incidence of chlamydial infections in the United States among persons 15 to 44 years of age to be approximately 3 million infections. Critical data needed for more precise estimates include: sensitivity of current diagnostics, better data on infections in males, the current extent of underdetection and underreporting, and better data on duration of infection in men and women.     

Simplifying chlamydia testing: an innovative Chlamydia trachomatis testing approach using the internet and a home sampling strategy: population based study

OBJECTIVES: To measure the coverage, gender distribution, and participants' prevalence of genital Chlamydia trachomatis infections using a new internet based self selective testing approach by means of home sampling in the general population in Sweden. To investigate factors associated with these measures. METHODS: Observational survey of people actively ordering coded testing packages, and checking their test results, from a known website. No personal invitations were sent out. All inhabitants (256 885 men and women) in a Swedish county were eligible to participate. A special interest was taken in coverage, gender distribution, participants' chlamydia prevalence, and determinants for infection. RESULTS: Testing was highest in the age group 20-24 years, where 298/9495 (3.1%) of all women and 171/9574 (1.8%) of all men in the population participated. The overall population participation (all ages) was 906/256 885 (0.4%). 40% (364/906) of the tests were from men and 60% (542/906) from women. The prevalence of Chlamydia trachomatis infection was 6.0% (95% CI: 3.6% to 8.4%) among male participants and 4.6% (95% CI: 2.8% to 6.4%) among female participants. Prevalence increased with decreasing age. Believing to be infected and having symptoms were the strongest determinants of infection. CONCLUSION: Simplifying and increasing the accessibility of chlamydia testing by means of internet and home sampling proved feasible. Self risk assessment improves the chance of finding people infected by Chlamydia trachomatis, especially among men, if an accessible testing method is offered. This new method can serve as a supplement to regular preventive methods and might encourage young people to be tested.     

Prevalence of Chlamydia trachomatis cervical infection in a college gynecology clinic: relationship to other infections and clinical features

A total of 479 sexually active college women presenting for routine gynecologic care were screened for gonorrheal and chlamydial infection of the cervix. Most of these women were asymptomatic; those with symptoms had minor complaints related to the lower genital tract. A direct fluorescent antibody test (DFA) showed the prevalence of chlamydial infection to be 8.1%, while culture for Neisseria gonorrhoeae indicated that the prevalence of gonorrhea was 1.5%. DFA-positive women had some minor alterations in the appearance of their cervix, but only 10% had overt mucopurulent cervicitis. The presence of purulent cervical discharge was four times more common in DFA-positive women, but only one-fourth of positive women had this finding. The use of an endocervical gram stain showing ten or more white cells per oil immersion field (x970) did not appear to be clinically useful in diagnosing suspected chlamydial infection because there was no significant difference in the number of white cells seen in specimens from DFA-positive (16 polymorphonuclear leukocytes) and DFA-negative women (ten polymorphonuclear leukocytes). Thus, use of the gram stain as an initial screening mechanism would not markedly reduce the number of women to be tested for Chlamydia trachomatis; half of all women met the gram-stain criterion, and nearly a quarter of the DFA-positive women would be overlooked.     

New methods in diagnostic and epidemiological research of Chlamydia trachomatis infections: the tide is turning molecular

Objective The aim of this review is to provide a primer on polymerase chain reaction (PCR) technology for the clinical diagnosis of Chlamydia trachomatis infections. Two main applications are reviewed: detection of Chlamydia trachomatis in clinical specimens For diagnosis, and genotyping of Chlamydia trachomatis for epidemiological purposes. Background Chlamydia trachomatis is one of the major causes of sexually transmitted diseases throughout the world. Laboratory techniques to establish a definitive diagnosis have been hampered by a lack of sensitivity. This review describes the state of the art of the application of polymerase chain reaction based assays to the diagnosis and epidemiology of Chlamydia trachomatis infections. Results The basic principles of PCR assays are described. General guide-lines for collecting specimens are reviewed. The application of home-made PCR-based assays and of the commercially available Amplieor assay in laboratory diagnosis is described. The first results of the application of LCR assays are mentioned. Comments arc made on the interpretation of the results and on the importance of quality assessment. Finally. PCR-based techniques for genotyping of clinical isolates in epidemiological studies are described. Conclusion The introduction of specific DNA amplification methods provides new ways to implement laboratory diagnosis and enhances our insights in the epidemiology of Chlamydia trachomatis infections. At this moment PCR-based assays are probably the most sensitive assays for detection of Chlamydia trachomatis available. Application of PCR-based assays might yield higher prevalences of Chlamydia trachomatis infections than currently recognized. Application of PCR-based genotyping methods will reveal more useful epidemiological data and will unravel more precisely existing sexual networks.