Reasons for Chlamydia trachomatis testing and the associated age-specific prevalences

Over-screening for chlamydia and gonorrhea among urban women age ≥25 years

OBJECTIVE

The purpose of this study was to determine the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in older women who are at increased risk of sexually transmitted infections (STIs) based on community STI prevalence. Additionally, we explored the associations between STI risk factors and CT/NG to determine the percentage of women who were over-screened.

STUDY DESIGN

We conducted a retrospective chart review of women ≥25 years old who were either tested or screened for CT/NG during a gynecology visit at an urban teaching institution. Pregnancy and HIV infection were exclusion criteria. Descriptive statistics, univariate analyses, and logistic regression were performed.

RESULTS

Of 658 eligible women, the median age of those positive for CT/NG was 30 years (range, 26-41 years). Chlamydia and gonorrhea prevalence was 1.7% (11/658 women) and 0.3% (2/658 women), respectively. All positive results were captured by testing women of any age who reported symptoms or an STI exposure and by screening women who were ≤40 years old. After adjustment of data for age, we found that symptomatic women were 3 times more likely to test positive for CT/NG (adjusted odds ratio, 3.4; 95% confidence interval, 1.1-10.3) and that STI-exposed women were 10 times more likely to test positive for CT/NG (adjusted odds ratio, 10; 95% confidence interval, 1.9-52.5). In asymptomatic non-STI-exposed women, nonmonogamous relationship (P = 1.0), abnormal examination results (P = 1.0), and previous STI (P = .35) were not associated with CT/NG. Over-screening occurred in 21% of women (141/658), all of whom were menopausal, had a hysterectomy, or were >40 years old.

CONCLUSION

CT/NG prevalence among older women was low, even in a community of high STI prevalence. More than 20% of women could have avoided CT/NG evaluation without impacting the detection of positive results in our clinic cohort. Over-screening occurred among asymptomatic, non-STI-exposed women who were menopausal, had a hysterectomy, and were >40 years old.

Social-, age- and gender differences in testing and positive rates for Chlamydia trachomatis urogenital infection - a register-based study

BACKGROUND

Chlamydia trachomatis is suspected of causing female infertility. It is the most widespread sexually transmitted infection with an estimated general prevalence of ~5-10% with a peak in younger individuals. C. trachomatis infection is more prevalent among lower social classes.

OBJECTIVE

In this study, the association between age, gender, social status and testing and positive rates is investigated in the age group 15-24 years.

DESIGN

Case-control study linked to data from Statistics Denmark.

METHODS

Data from the Department of Microbiology, Hvidovre University Hospital, Copenhagen were used and included 21887 people tested by general practitioners (GPs) and 3177 people tested at a venereological clinic. The age range was 15-24 years in 2011. These data were linked with the parental educational status delivered by Statistics Denmark, which also delivered a matched control group. The data were analysed using a case-control design.

RESULTS

Testing was more frequent in the following groups: age range 20-24 years, females and patients with higher parental educational status. About 87.3% of patient had been tested by GPs. Positive rates were highest among males at the general practice constituting 17.1% versus females 10.6%, younger individuals and patients with lower parental educational status.

CONCLUSIONS

The C. trachomatis testing pattern and positive rates highlight a need for a greater focus on males, younger patients and individuals with a lower social status.

Performance of a screening algorithm for chlamydial infection in 2 samples of patients in general practice

This paper evaluates the performance of an algorithm developed for opportunistic, selective screening of women for chlamydial infection in general practice in Antwerp, Belgium. Its performance was examined in 2 independent sets of patients: A) a cohort of 326 women participating in a pilot screening study, and B) a sample of 25 Chlamydia positive women, identified from the records of a laboratory of clinical microbiology. For group A, positive and negative predictive values were calculated and the accuracy of the algorithm was assessed. For group B, we examined the proportion of patients complying with the algorithm. In group A, the screening algorithm would have detected 73% of the cases in 35.6% of the population. The positive and negative predictive values were 7.7% and 98.4%, respectively. In group B, 84% of patients complied with the algorithm. The screening algorithm worked reasonably well in 2 datasets from a similar population studied 2 y later, but needs further validation.

Highly discriminative genotyping of Chlamydia trachomatis using omp1 and a set of variable number tandem repeats

This article reports the development of a method for genotyping Chlamydia trachomatis, using PCR and sequencing of omp1, supplemented with three new variable number tandem repeat (VNTR) loci of C. trachomatis. Typeability, reproducibility and discriminatory power were assessed using four groups of samples: two groups (I and II) of C. trachomatis-positive patients and their positive partner(s), one group (III) of patients with recurrent or persistent C. trachomatis infections, and one group (IV) comprising samples containing a newly discovered mutant strain with a 377-bp deletion in the cryptic plasmid, the new variant C. trachomatis (nvCT). The VNTR loci (designated CT1335, CT1299, and CT1291) were all single nucleotide repeats chosen for maximal mutability and variation. In the study material, nine variants of CT1335, eight variants of CT1299 and five variants of CT1291 were found. The discriminatory power (D) of omp1 in the present material was D(omp1) = 0.69. Ds for VNTRs CT1335, CT1299 and CT1291 were 0.53, 0.74 and 0.74, respectively. The resolution power of the omp1-VNTR assay was 0.94. Stability over time of the VNTRs was investigated and found to be adequate for epidemiological studies. Using this genotyping assay, it was confirmed that the nvCT strain was indeed a clone. These results indicate that, with this novel method, strains of C. trachomatis can be individually identified, and epidemiological associations established.

Norwegian men diagnosed with genital Chlamydia trachomatis infection notified two-thirds of their sexual partners

Chlamydia trachomatis (CT) is a widespread, sexually transmitted disease with potential long-term effects on female reproductive health. The objective of this study was to investigate compliance to treatment, partner notification, and attendance for test-of-cure among Norwegian men diagnosed with CT. We conducted a longitudinal case-series study among 81 CT positive men identified in a cross-sectional study (n = 1032, April-December 2005). Participants were interviewed on partner notification intentions at the treatment visit and on partner notification actions at the test-of-cure visit. Of the 81 patients, 8 (10%) did not meet for treatment, 2 were treated elsewhere, and 6 were treated but not interviewed. At the treatment visit, the 65 interviewed men reported that they intended to notify 100 out of 165 partners (61%). 40 of 71 treated patients attended for test-of-cure (56%). Four men (10%) needed repeated treatment. The 35 men interviewed at test-of-cure visit reported that 63 out of 95 partners (68%) had been notified. In conclusion, men diagnosed with CT infection are relatively open on notifying sexual partners but have low compliance to meeting for test-of-cure.

Chlamydia trachomatis among young Norwegian men: sexual behavior and genitourinary symptoms

OBJECTIVE

The study objective was to assess Chlamydia trachomatis (CT) prevalence, risk factors, and genitourinary symptoms among young men.

METHODS

Sexually active men 18 to 30 years old were recruited during April through October 2005 at the student health services and through field work at university campuses in 2 Norwegian cities. A total of 1,032 participants completed a questionnaire on sexual behavior and provided first-void urine for CT testing.

RESULTS

The overall CT prevalence was 7.8% (81 of 1,032). In multivariable analysis, >or=5 lifetime sexual partners (adjusted odds ratio [aOR]: 2.7, 95% confidence interval [CI]: 1.4-5.2), a burning sensation on urination (aOR: 5.7, 95% CI: 3.1-10.5), and penile discharge (aOR: 2.6, 95% CI: 1.1-6.3) were significant risk factors for a positive CT test, whereas condom use (last intercourse) was preventive (aOR: 0.4, 95% CI: 0.2-0.8).

CONCLUSIONS

A CT prevalence of 7.8% was found among male students. Promotion of increased testing among men is important to prevent CT transmission.

Selective testing of women based on age for genital Chlamydia trachomatis and Neisseria gonorrhoeae infection in a centralized regional microbiology laboratory

Calgary Laboratory Services, Alberta, Canada, provides microbiology services via a centralized laboratory to the Calgary Health Region. A selective genital Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (GC) testing policy for women >35 years was implemented. The changes in physician ordering practice, the rate of detection of infections, and the test turnaround times were monitored. The volume of tests, the cost/test, and the total service costs accrued in the year before and after this policy change were compared. An immediate impact was a 30% decrease in tests performed due to the laboratory rejecting samples from older women. Subsequently, physicians' practice changed so that tests were ordered when test criteria were met. Detection rates did not change in any age group. A 27.9% decrease in the total service costs resulted in a labor reduction of 0.2 FTE. Selective testing of women >35 years with a low prevalence of CT/GC infection is clinically relevant and cost-effective.

Prediction of costs, effectiveness, and disease control of a population-based program using home sampling for diagnosis of urogenital Chlamydia trachomatis Infections

OBJECTIVE

To estimate the incremental effects and costs of a home sampling screening approach for Chlamydia trachomatis over the current in-office screening practice in Denmark.

GOALS

To assess the effect of a new screening strategy.

STUDY DESIGN

A dynamic Monte Carlo model estimated prevalence and incidence over 10 years for a home sampling screening program and the current in-office screening. Subsequently, the incremental number of major outcomes averted (MOA) and the related direct and indirect costs were estimated.

RESULTS

Infection prevalence after 10 years was 1.0% with a home sampling program and 4.2% with the current in-office screening practice. The total costs per MOA reached 3186 US dollars during the first year of the home sampling strategy, but in year 4, the accumulated indirect costs offset the direct costs, and the program henceforth saved society costs.

CONCLUSIONS

Home sampling should be considered a relevant alternative to the current practice of in-office screening.

Chlamydia trachomatis Testing Patterns and Prevalence of Genital Chlamydial Infection Among Young Men and Women in Central Norway 1990–2003: A Population-Based Registry Study

OBJECTIVE

The study objective was to investigate Chlamydia trachomatis (CT) testing patterns, prevalence, and incidence among men and women in Sør-Trøndelag county, central Norway, 1990-2003.

GOAL

The goal of this study was to obtain data for recommendations regarding CT screening.

STUDY DESIGN

Laboratory data on CT tests for persons 15 to 24 years old were retrieved and analyzed.

RESULTS

Four percent of men and 44% of women had been CT tested at least once by the age of 20. By the age of 25, 44% of men and 84% of women had been tested. Prevalence at first test was at its peak in 2000-2002 (men: 15-19 years 18%, 20-24 years 23%; women: 15-19 years 11%, 20-24 years 9%). Incidence estimates were higher for persons with a positive first test than for persons with a negative first test.

CONCLUSIONS

More men and more female teenagers need to be tested. Repeat testing is particularly important among people who have been diagnosed with CT.

Ectopic Pregnancies and Reproductive Capacity After Chlamydia trachomatis Positive and Negative Test Results: A Historical Follow-Up Study

BACKGROUND

Recent studies have shown that women with Chlamydia trachomatis-positive test results worry about their future fertility.

GOAL

The goal of this study was to give women infected with C. trachomatis a fertility prognosis by analyzing ectopic pregnancies and birth rates

STUDY DESIGN

An historical follow-up study in a cohort of 22,264 women tested for the infection was conducted.

RESULTS

Cox regression analysis with time-dependent covariates showed that women with at least 1 C. trachomatis-positive test result had a lower incidence rate of ectopic pregnancy than women with negative test results only (adjusted hazard ratio, 0.55; 95% confidence interval [CI], 0.31-0.96). We found comparable birth rates in the 2 groups (adjusted hazard ratio, 0.92; 95% CI, 0.84-1.00).

CONCLUSIONS

Counseling of women with a C. trachomatis-positive test result should emphasize the benefit of detection and treatment of the infection in terms of future morbidity.

Surveillance systems for STIs in the European Union: facing a changing epidemiology

OBJECTIVES

To characterise the nature, content, and performance characteristics of existing national STI surveillance systems in the European Union (EU) and Norway, to facilitate collection of comparable surveillance data.

METHODS

Cross sectional survey using a structured questionnaire.

RESULTS

Case reporting from clinicians and/or laboratories is the mainstay of EU surveillance systems for bacterial STIs. Coverage of case reporting varies from less than 10% to over 75%, and lack of and/or heterogeneity in case definitions affect the relative specificity and sensitivity of reporting systems. Considerable variations also exist in STI care sites; the populations who use these services; and in partner notification practices, STI screening practices, and STI laboratory diagnostic tests employed, affecting the representativeness of reported data and the sensitivity of surveillance systems for detecting the true number of STI cases.

CONCLUSIONS

The heterogeneity of current surveillance systems complicates direct comparison of STI incidence rates across Europe. Introduction of standardised case definitions for reporting, and increased coverage of mandatory reporting systems where necessary, are needed. Definition of standardised minimum datasets and use of sentinel and enhanced surveillance systems to supplement universal case/laboratory notification data, could improve our understanding of the distribution and determinants of STIs across Europe, and aid in the design of effective public health responses. In the context of the changing epidemiology of STIs, systems for detection and monitoring of localised outbreaks of acute bacterial STIs (syphilis and antimicrobial resistant gonorrhoea), as well as prevalence monitoring systems for frequently asymptomatic STIs (chlamydial infection and viral STIs), are also necessary.