Increasing Chlamydia Positivity in Women Screened in Family Planning Clinics: Do We Know Why?

Center for Health Training, Seattle, Washington 98101-1313, USA.
Sex Transm Dis (Impact Factor: 2.84). 02/2008; 35(1):47-52. DOI: 10.1097/OLQ.0b013e31813e0c26
Source: PubMed


Following a 9-year 60% decline, chlamydia positivity increased 46% from 1997 through 2004 among young sexually active women screened in Region X family planning clinics. The objective of this analysis was to systematically examine the influences of risk factors, changing laboratory test methods, and interclinic variability on chlamydia positivity during this period.
We analyzed data from 520,512 chlamydia tests from women aged 15 to 24 years screened in 125 family planning clinics. Multivariate logistic regression modeling was used to adjust the annual risk of chlamydia for the demographic, clinical, and sexual risk behavior characteristics associated with infection and for the increasing use of more sensitive laboratory test methods. A generalized linear mixed model was used to adjust for interclinic variability.
We found a significant 5% annual increase in the risk of chlamydia even after adjusting for risk factors including laboratory test characteristics (odds ratio 1.05, 95% confidence interval: 1.04, 1.06). Variability among the clinics where screening occurred did not account for the increase.
Based on a review of all available data, we concluded that there was a true increase in chlamydia positivity over the 8-year period.

Full-text preview

Available from:
  • Source
    • "From 2006, the validity of earlier trials was more thoroughly and widely questioned in systematic reviews, prompting more empirical research outside England to underpin screening policy [26,27]. In addition, researchers have since given greater attention to the secular changes (eg lower rates of partner change as a result of HIV prevention messages in the 1990s) that may have explained the initial fall in chlamydia diagnoses following the introduction of screening programmes [28,29]. Evidence remained equivocal: for example, in 2010 a trial in England of chlamydia screening reported a non-significant benefit of screening for reducing pelvic inflammatory disease [30]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The rationale for the English National Chlamydia Screening Programme (NCSP) has been questioned. There has been little analysis, however, of what drove the NCSP's establishment and how it was implemented. Such analysis will help inform the future development of the NCSP. This study used a qualitative, theory-driven approach to evaluate the rationale for the NCSP's establishment and implementation. Semi-structured interviews with 14 experts in chlamydia screening were undertaken. The interview data were analysed with policy documents and commentaries from peer-reviewed journals (published 1996-2010) using the Framework approach. Two themes drove the NCSP's establishment and implementation. The first, chlamydia control, was prominently referenced in documents and interviews. The second theme concerned the potential for chlamydia screening to advance wider improvements in sexual health. In particular, screening was expected to promote sexual health services in primary care and encourage discussion of sexual health with young people. While this theme was only indirectly referenced in policy documents, it was cited by interviewees as a strong influence on implementation in the early years. However, by full rollout of the Programme, a focus on screening volume may have limited the NCSP's capacity to improve broader aspects of sexual health. A combination of explicit and implicit drivers underpinned the Programme's establishment. This combination may explain why there was widespread support for its introduction and why implementation of the NCSP was inconsistent. The potential to improve young people's sexual health more comprehensively should be made explicit in future planning of the NCSP.
    Full-text · Article · Apr 2012 · BMC Public Health
  • Source
    • "Applying these principles, one regional United States program reduced C. trachomatis prevalence 60% among young women during the first 9 years of its existence [9]. However, similar screening and treatment of young women in this region during the succeeding 7 years was associated with a 46% increase in chlamydial positivity [10]. This scenario was repeated in British Columbia—after introduction of a C. trachomatis infection control program case rates fell from 216 to 104 cases per 100 000 individuals but then steadily climbed to 193 cases per 100 000 individuals [11]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Chlamydia trachomatis control efforts that enhance detection and treatment of infected women may paradoxically increase susceptibility of the population to infection. Conversely, these surveillance programs lower incidences of adverse sequelae elicited by genital tract infection (e.g., pelvic inflammatory disease and ectopic pregnancy), suggesting enhanced identification and eradication of C. trachomatis simultaneously reduces pathogen-induced upper genital tract damage and abrogates formation of protective immune responses. In this paper, we detail findings from C. trachomatis infection control programs that increase our understanding of chlamydial immunoepidemiology and discuss their implications for prophylactic vaccine design.
    Full-text · Article · Nov 2011 · Infectious Diseases in Obstetrics and Gynecology
  • Source
    • "Some research suggests that the prevalence of genital C. trachomatis infections is increasing over time. However, increasing prevalence is difficult to establish definitively due to the need to control for testing effort and the effects of new testing methods in analysing rates of infection.23 "
    [Show abstract] [Hide abstract]
    ABSTRACT: Genital Chlamydia trachomatis is a sexually transmissible bacterial infection that is asymptomatic in the majority of infected individuals and is associated with significant short-term and long-term morbidity. The population prevalence of the infection appears to be increasing. C. trachomatis is of public health significance because of the impacts of untreated disease on reproductive outcomes, transmission of other sexually acquired infections, and the costs to health systems. At the individual level, C. trachomatis infection is readily treatable with antibiotics, although antibiotic resistance appears to be increasing. At the population level, public health control of spread of infection is more problematic. Approaches to control include primary preventive activities, increased access to testing and treatment for people with or at risk of infection, partner notification and treatment, and screening either opportunistically or as part of an organized population screening program. A combination of all of the above approaches is likely to be required to have a significant effect on the burden of disease associated with genital chlamdyia infection and to reduce population prevalence. The development of a vaccine for genital chlamydia infection could significantly reduce the public health burden associated with infection; however a vaccine is not expected to be available in the near future.
    Full-text · Article · May 2011 · Risk Management and Healthcare Policy
Show more