Epidemiology of genital Chlamydia trachomatis in England and Wales

Pelvic inflammatory disease

INTRODUCTION

Pelvic inflammatory disease is caused by infection of the upper female genital tract and is often asymptomatic. Pelvic inflammatory disease is the most common gynaecological reason for admission to hospital in the US, and is diagnosed in approximately 1% of women aged 16 to 45 years consulting their GP in England and Wales.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: How do different antimicrobial regimens compare when treating women with confirmed pelvic inflammatory disease? What are the effects of routine antibiotic prophylaxis to prevent pelvic inflammatory disease before intrauterine contraceptive device (IUD) insertion? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up to date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 13 RCTs or systematic reviews of RCTs that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review, we present information relating to the effectiveness and safety of the following interventions: antibiotics (oral, parenteral, different durations, different regimens) and routine antibiotic prophylaxis (before intrauterine device insertion in women at high risk or low risk).

Pelvic inflammatory disease

INTRODUCTION

Pelvic inflammatory disease is caused by infection of the upper female genital tract and is often asymptomatic. Pelvic inflammatory disease is the most common gynaecological reason for admission to hospital in the USA and is diagnosed in almost 2% of women aged 16-45 years consulting their GP in England and Wales.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of empirical treatment compared with treatment delayed until the results of microbiological investigations are known? How do different antimicrobial regimens compare? What are the effects of routine antibiotic prophylaxis to prevent pelvic inflammatory disease before intrauterine contraceptive device (IUD)8 insertion? We searched: Medline, Embase, The Cochrane Library and other important databases up to May 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 9 systematic reviews, RCTs or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics (oral, parenteral, empirical treatment, treatment guided by test results, different durations, outpatient, inpatient), and routine antibiotic prophylaxis (before intrauterine device insertion in women at high risk or low risk).

Chlamydia trachomatis in the United Kingdom: a systematic review and analysis of prevalence studies

OBJECTIVES

To undertake a systematic review to obtain estimates of genital Chlamydia trachomatis prevalence in various populations in the United Kingdom and Ireland; to determine which populations have the highest rates of infection; and to explore the most important determinants of infection.

METHODS

Electronic databases were searched using the keywords "chlamydia" and "England," "Wales," "UK," "Scotland," "Ireland," or "Britain." Additional unpublished data and references were solicited from experts. Studies were included in the analysis if C trachomatis prevalence was reported, and if they met inclusion criteria. Nine variables identified as potentially important descriptors of chlamydia prevalence were extracted from each study and analysed using various logistic regression models. Only studies reporting prevalence in female populations were included in the models, because there were few data from males.

RESULTS

357 studies were identified using the search methods, 90 of which met inclusion criteria, and 19 of which contributed to the final model. The most influential variables on prevalence were age and setting of the population tested. In general practice surgeries, the under 20 year old age group had an estimated prevalence of 8.1% (95% CI 6.5 to 9.9), 20-24 year olds 5.2% (95% CI 4.3 to 6.3), 25-29 year olds 2.6% (95% CI 2.0 to 3.3), decreasing to 1.4% (95% CI 1.0 to 1.9) in those aged over 30 years. Overall, healthcare settings had higher prevalence estimates than population based studies. For example, among under 20 year olds, estimates were 17.3% (95% CI 13.6 to 21.8) in genitourinary medicine clinics, 12.6% (95% CI 6.4 to 23.2) in antenatal clinics, 12.3% (95% CI 9.8 to 15.3) in termination of pregnancy clinics, 10.7% (95% CI 8.3 to 13.8) in youth clinics, 10.0% (95% CI 8.7 to 11.5) in family planning clinics, and 8.1% (95% CI 6.5 to 9.9) in general practice, compared to 5.0% (95% CI 3.2 to 7.6) in population based studies. The type of test, specimen used, date, and location of test were not strongly associated with chlamydia prevalence.

CONCLUSION

The chlamydia prevalence estimates by age and setting from the model may be used to inform chlamydia screening strategies. The systematic review revealed much heterogeneity in the studies identified, but with clear patterns of prevalence. It also indicated gaps in the knowledge about chlamydia prevalence in certain subgroups such as men and the general population.

Provision of chlamydia testing in a nationwide service offering termination of pregnancy: with data capture to monitor prevalence of infection

OBJECTIVES

To establish a methodology by which all women attending for termination of pregnancy (TOP) at British Pregnancy Advisory Service (BPAS) branches may be approached to participate in Chlamydia trachomatis screening. To examine the feasibility of monitoring C trachomatis prevalence and the impact of charging for screening on the uptake rate in this population.

METHODS

Patients attending for TOP at participating BPAS branches were offered a test for chlamydia infection and asked to complete a questionnaire. Urine samples from participants were tested using a nucleic acid amplification test (NAAT).

RESULTS

1001 women provided a urine sample, a 77% response rate among those participating in the study. Factors significantly associated with taking up chlamydia screening included symptoms, previous TOP, parity, and no previous chlamydial test. Overall prevalence of genital chlamydial infection was 7.5%, with highest age specific prevalences occurring among attendees aged 20-24 years (11.5%) and under 20 years (10.8%). In univariate analysis, chlamydia positivity was significantly associated with respondent age and previous diagnosis with chlamydia. Only 35% of women who had the screening test would have done so had they been asked to pay the pound 20 clinical, administrative, and laboratory costs of the examination.

CONCLUSIONS

We have demonstrated the feasibility of routine chlamydia screening and the potential for prospective prevalence monitoring across the nationwide BPAS service. In most cases the chlamydia result was available within the clinical contact period for the TOP. Charging patients directly for the test could reduce uptake of chlamydia screening to levels unsatisfactory for both the public health and prevalence monitoring purposes.

Choosing and using services for sexual health: a qualitative study of women's views

OBJECTIVE

To explore women's accounts of choosing and using specialist services for sexual health.

METHODS

A qualitative study involving semistructured interviews with 37 women screened for Chlamydia trachomatis attending genitourinary medicine and family planning clinics in an East Midlands health authority.

RESULTS

In making the decision to seek help, women act on a range of specific prompts, including lay ideas about the significance of symptoms; their own behaviour; their partner's symptoms or behaviour; contact tracing; and health promotion. Some women do not seek help specifically in relation to sexual health but are identified as being at risk of sexually transmitted infections (STIs) during routine consultations. Important influences on women's choice of services include the lay referral system, "insider" knowledge of health services, referral by health professionals, and need to have alternatives to general practice care. Women's willingness to access services is mediated by psychosocial factors such as embarrassment. They may use smear tests as a legitimate opportunity to raise questions about sexual health. Women's priorities for services are that their feelings of stigma and embarrassment are managed appropriately; that staff communicate well and are sensitive to their emotions and comfort during tests and procedures; that they are "in control" when obtaining test results; and that confidentiality is preserved.

CONCLUSIONS

A detailed understanding of both lay people's response to symptoms or behaviour that indicates risk of an STI and their needs when using services should inform interventions aimed at encouraging secondary prevention of STIs.

Demographic and behavioural profile of adults infected with chlamydia: a case-control study

OBJECTIVES

To determine which demographic and behavioural parameters are independently associated with chlamydial infection in adults.

METHODS

Subjects were recruited prospectively from male and female attendees at a large clinic for sexually transmitted infections (STI). All subjects were tested for chlamydia and gonorrhoea and asked to complete a questionnaire addressing demography, sexual and non-sexual (including drug taking) behaviour, and history of STI. Cases were those attending with a new clinical episode and found to be infected with chlamydia, but who did not have gonorrhoea. A control group was selected randomly from those found to be negative on screening for both infections.

RESULTS

986 cases and 1212 controls were recruited over one calendar year. The following were found to be independent risk factors for chlamydial infection on multivariate analysis (odds ratios with 95% confidence intervals in parentheses): being unmarried (1.8; 1.1-3.1); black Caribbean ethnicity (2; 1.5-2.7). Increasing age, fewer partners, and higher reported use of condoms were associated with a lower risk of infection.

CONCLUSION

Black Caribbeans are at increased risk from chlamydia after controlling for sexual behaviour and socioeconomic status. Future research should seek an explanation elsewhere-for example, in terms of differences in sexual mixing or effectiveness of healthcare interventions.

Multicenter evaluation of the BDProbeTec ET System for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens, female endocervical swabs, and male urethral swabs

The performance of the Becton Dickinson BDProbe Tec ET System Chlamydia trachomatis and Neisseria gonorrhoeae Amplified DNA Assays (BD Biosciences, Sparks, Md.) was evaluated in a multicenter study. Specimens were collected from 2,109 men and women, with or without symptoms, attending sexually transmitted disease, family planning, and obstetrics and gynecology clinics. Both swab and urine samples were collected, and the results obtained from 4,131 specimens were compared to those from culture and the LCx nucleic acid amplification test (Abbott Industries, Abbott Park, Ill.). PCR and cytospin of the culture transport medium with chlamydia direct fluorescent antibody staining were used to adjudicate chlamydia culture-negative results. Sensitivity and specificity were calculated both with and without use of the amplification control (AC), with little apparent difference in the results. Without the AC result, sensitivity for C. trachomatis and N. gonorrhoeae were 92.8 and 96.6%, respectively, for cervical swabs and 80.5 and 84.9% for urine from women. C. trachomatis and N. gonorrhoeae sensitivities were 92.5 and 98.5%, respectively, for male urethral swabs and 93.1 and 97.9% for urine from men. This amplified DNA system for simultaneous detection of chlamydial and gonococcal infections demonstrated superior sensitivity compared to chlamydia culture and has performance characteristics comparable to those of other commercially available nucleic acid-based assays for these organisms.

Sociodemography of genital Chlamydia trachomatis in Coventry, UK, 1992-6

OBJECTIVE

To describe the sociodemographic and geographic risk factors for incident Chlamydia trachomatis genital infection.

DESIGN

Cross sectional retrospective study of cases diagnosed in local genitourinary clinics.

SETTING

Coventry, West Midlands, from 1992 to 1996.

SUBJECTS

582 female and 620 male Coventry residents aged 15-64 years diagnosed with one or more episodes of genital Chlamydia trachomatis infection by enzyme immunoassay. Subjects were assigned a Townsend deprivation score based on residence. The denominator population aged 15-64 years was derived from 1991 census data.

RESULTS

The mean annual incidence of genital chlamydia was 151 episodes (95% CI 140-163) per 100,000 population in men and 138 episodes (95% CI 128-149) per 100,000 population in women. Highest subgroup incidence was observed in 15-19 year old black women (2367 (95% CI 1370-4560) per 100,000), and 20-24 year old black men (1951 (95% CI 1158-3220) per 100,000). In univariate analyses, the most important risk factor for chlamydia infection in males was being black (incidence 1377 (95% CI 1137-1652) per 100,000 for black v 133 (95% CI 122-145) per 100,000 for white; RR 10.4, p < 0.0001) and for women was young age (incidence 475 (95% CI 415-540) per 100,000 for age group 15-19 years v 52 (95% CI 45-60) per 100,000 for age group 25-64 years; RR 9.1, p < 0.0001). In Poisson regression models of first episodes of genital chlamydia, for both males and females the effect of ethnic group could not be fully explained by socioeconomic confounding. There were significant interactions between age and ethnic group for both sexes and between age and level of deprivation for men. Geographical analysis revealed a high incidence of genital chlamydia in estates on the edge of the city as well as the urban core.

CONCLUSIONS

There is a complex interaction between geographical location, age, ethnic group, and social deprivation on the risk of acquiring genital Chlamydia trachomatis in Coventry. Better population based data are needed.

A collaborative approach to management of chlamydial infection among teenagers seeking contraceptive care in a community setting

OBJECTIVES

To develop and assess a coordinated model of care for effective management of genital chlamydial infection in young women, identified through a selective screening programme in a community based teenage health clinic.

METHODS

Selective screening for genital Chlamydia trachomatis was undertaken among young women aged 13-19 years who were having a routine cervical smear test, being referred for termination of pregnancy, or who reported behavioural risk factors, for, and/or symptoms of, genital infection. Collaboration among family planning, genitourinary medicine (GUM), and public health staff was used to enhance management of infected individuals, with particular focus on partner notification.

RESULTS

94 young women had confirmed genital chlamydial infection, representing 11% of those tested. All index patients received appropriate antibiotic therapy and follow up; 93 (99%) of these were counselled by a health adviser, of whom 62 (66%) were able to provide sufficient details for partner notification, resulting in treatment of male partners associated with 51 (82%) of these young women. Younger age (< or = 16 years) was significantly associated with delay in attending for treatment.

CONCLUSIONS

Effective management of genital chlamydial infection is achievable in settings outside GUM clinics using a collaborative approach which incorporates cross referencing between community based services and GUM clinics.

Knowledge of Chlamydia trachomatis infection in genitourinary medicine clinic attenders

OBJECTIVES

To determine the level of awareness of genital chlamydial infection, and level of knowledge related to this infection, in genitourinary medicine (GUM) clinic attenders.

METHODS

500 consecutive patients attending a GUM clinic for the first time during a 3 month study period were invited to complete an anonymous self administered questionnaire on aspects of chlamydial infection.

RESULTS

482 (96.4%) questionnaires were available for analysis (57% female). 289 (60%) respondents had heard of Chlamydia trachomatis compared with 472 (98%) for thrush, 467 (97%) for HIV/AIDS, and 434 (90%) for gonorrhoea. Subjective knowledge of chlamydia, relative to the other infections, was poor. Overall, the mean chlamydial knowledge score was 0.38 (range 0.0-1.0). Females scored significantly higher than males (0.45 v 0.26; p < 0.00001) and younger females scored significantly higher than older females (p = 0.001). More females had experienced genital chlamydial infection than males (22.4% v 12.1%, p = 0.004). Those with prior exposure to C trachomatis had higher mean knowledge scores than those without (males 0.55 v 0.25, p < 0.00001; females 0.68 v 0.37, p < 0.00001).

CONCLUSION

Even for a population considered as "high risk" by their attendance at a GUM clinic, there was poor awareness of genital chlamydial infection, and mean knowledge scores were low. Whether increased knowledge was due to successful health education at the time of diagnosis in those with previous infection remains to be determined. In the future, one would hope for increased knowledge scores in those at risk before the acquisition of infection, which may be achieved by national health education programmes for C trachomatis.

Oral sex and transmission of non-viral STIs

OBJECTIVES

To review the literature on the role of oral sex in the transmission of non-viral sexually transmitted infections (STIs).

METHOD

A Medline search was performed using the keywords oro-genital sex, and those specific to each infection. Further references were then taken from each article read.

CONCLUSIONS

Oral sex is a common sexual practice between both heterosexual and homosexual couples. Oro-genital sex is implicated as a route of transmission for gonorrhoea, syphilis, Chlamydia trachomatis, chancroid, and Neisseria meningitidis. Other respiratory organisms such as streptococci, Haemophilus influenzae, and Mycoplasma pneumoniae could also be transmitted by this route. Fellatio confers risk for acquisition of infection by the oral partner. Cunnilingus appears to predispose to recurrent vaginal candidiasis although the mechanism for this is unclear, while a link between oro-genital sex and bacterial vaginosis is currently being studied. Oro-anal sex is implicated in the transmission of various enteric infections. In view of the increased practice of oral sex this has become a more important potential route of transmission for oral, respiratory, and genital pathogens.