Journal of Infection (I992) aS, Supplement z, 39-45
REVIEW G e n i t a l Chlamydia trachomatis i n f e c t i o n s i n t h e f e m a l e Jorma Paavonen Department of Obstetrics and Gynecology, University Central Hospital, SF-oo290 Helsinki, Finland
Historical landmarks Chlamydia trachomatis was first isolated from the female genital tract in I959 and a tissue culture technique for the isolation of it was developed in I965. T h e microimmunofluorescence test for serotyping and seroepidemiological studies was developed in I97o. T h e clinical spectrum of genital chlamydial infections was largely known by the early I97Os (for review, see Mfirdh et al.1). Several landmark studies on the association of C. trachomatis with specific syndromes were reported from the Ophthalmology Clinic, L o n d o n Hospital. Chlamydial m u c o p u r u l e n t cervicitis and salpingitis were described in I976 at the Chlamydia meeting in Lake Placidfl Shortly thereafter, demographic, behavioural, microbiological and clinical characteristics of genital chlamydial infections were systematically analysed in case-control studies and randomised clinical trials were mainly reported from Scandinavian countries, a-9 By the late I97os the wide spectrum of clinical manifestations of genital chlamydial infections had largely been recognised. 1' 10 In the I98OS there has been a major progress in the molecular biology of C. trachomatis, and in the development and implementation of rapid diagnostic tests to replace cumbersome tissue cultures. 11-1~ Genital chlamydial infections have now been recognised as a major public health problem. In clinical studies the focus of the research has t u r n e d from acute infections to the immunobiology of C. trachomatis and chronic manifestations of C. trachomatis infection, such as chronic or subclinical pelvic inflammatory disease (PID), reactive arthritis, tubal pregnancy, tubal factor infertility, and adverse pregnancy outcome. In recent years, there has been a tremendous increase in our understanding of the genetics and molecular biology of C. trachomatis. 1' 11-13 Epidemiology Demographic factors associated with an increased risk for C. trachomatis infection include young age, single marital status, use of oral contraceptives, recent history of a new sex partner, i.e. factors associated with so-called risktaking behaviour. 14 M a n y studies have demonstrated a surprisingly high prevalence of asymptomatic C. trachomatis infections in adolescent populations, and in young people undergoing general health examinations (for instance college students, women seen in family planning clinics, and women undergoing cytologic screening). 1 Compared to older women, young women oi63-4453/92/Sioo39+o7 $03.00/0
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are more susceptible to C. trachomatis because of the presence of cervical ectopy which provides target cells for C. trachomatis. Detection of C. trachomatis might be more efficient in women with ectopy. In vitro studies have shown that contraceptive steroids stimulate the growth of C. trachomatis. T h e risk of C. trachomatis is increased several-fold (range from 2-I-2"5 in most studies) in users of oral contraceptives (OC). ' 5 0 C use may alter the susceptibility of mucosal cells to C. trachomatis, or modify the immune response to C. trachomatis.'6 However, although OC use increases the risk for chlamydial cervicitis, recent studies suggest that OC use decreases the risk for symptomatic P I D among women with C. trachomatis infection.'7 If the former effect was less than the latter, the net effect in the individual patient might be to increase the risk of chlamydial PID. However, if the risk of P I D is decreased about five-fold in women with chlamydial infection using OCs, it seems unlikely that the net effect of OC use would be to increase the risk of chlamydial P I D in the individual patient. Nevertheless, if the effect of OC use is to increase the efficacy of transmission of C. trachomatis, then the net effect of OC use could be to increase the overall risk of P I D in the community.
Clinical manifestations Mucopurulent cervicitis Chlamydia trachomatis is the major cause of mucopurulent cervicitis (MPC) and PID. M P C is the ignored counterpart in women of urethritis in men. '6 Simple objective criteria for the presumptive diagnosis of M P C include an increased number ( > / i o per high power field) of polymorphonuclear leucocytes in cervical smears, a positive swab test, and increased erythema, oedema, and induced mucosal bleeding (semiquantified as cervicitis severity score) in the area of ectopy and transformation zone.'8' 19 These clinical criteria seem to work better in populations with a high prevalence of cervicitis such as S T D clinics, but their performance seems to be less satisfactory in other clinical settingsfl ° Criteria for selective screening for C T infection in women attending family planning clinics have been developed for cost savings. 2'-23 Such historic and clinical criteria include for instance age