Morbidity after termination of pregnancy in first trimester

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.

The role of epidemiology and surveillance systems in the control of sexually transmitted diseases

Surveillance and epidemiological studies are essential components of effective control programmes for sexually transmitted diseases. While other forms of basic biomedical research may add to our understanding of why an exposure or behaviour causes or prevents disease, only epidemiology allows the quantification of the magnitude of the exposure-disease relationship in humans. It is this measure of the association between risk and disease that is needed to inform rational policy on altering risk through intervention. Surveillance data are used both to determine the need for public health action and to assess the effectiveness of programmes: they are required for the setting of priorities, for planning and resource allocation, for the definition of population subgroups and risky behaviours for targeted interventions, for the development of disease prevention programmes, and for the evaluation of interventions. Data from surveillance systems and epidemiological studies can also inform diagnostic and therapeutic practice, and indicate areas for further research. Over the last 20 years chlamydia infections and viral agents have emerged as the major cause of STD in developed countries, and with this change in the aetiological mix of STD cases the focus of prevention and control of STDs has shifted from treatment and partner notification towards health education. In developing countries there is an urgent need for appropriate surveillance infrastructures, particularly now that there is evidence that STD control programmes, informed by surveillance data, can reduce HIV transmission at the population level. The importance of surveillance and epidemiology in the control of STDs is set to increase in the face of the changing pattern of sexually transmitted pathogens. The challenge to clinicians and epidemiologists is to work together in developing systems that will inform new approaches to control and prevention.

A study of the incidence of urogenital Chlamydia trachomatis in patients attending specialized departments of Rome, Milan and Turin, Italy

A study of Chlamydia trachomatis was conducted in 5270 subjects seen at clinics of the Faculty of Medicine and Surgery at La Sapienza University in Rome, the S. Anna Hospital in Turin, and the Provincial Maternity Hospital Institute in Milan. In these areas, C. trachomatis was present in 5.8% of the cases examined; in addition it was present with statistically significant frequencies in cases of salpingitis (49.1) and epididymitis (21.7). It may also be found in cases of extrauterine pregnancy, sterility and abortion. Those most affected were women who had begun their sexual activity at an early age, were under 25, had several sexual partners and who used the coil and/or spermicides. A routine check for C. trachomatis should be considered for those women with those risk factors.