Urogenital Chlamydia trachomatis in Gabon: an unrecognised epidemic

Prevalence of Chlamydia trachomatis in women attending a family planning clinic in Papua New Guinea

OBJECTIVE

To determine the prevalence of Chlamydia trachomatis infection in women attending a family planning clinic in Papua New Guinea, in the period between April and June 1991.

SETTING

The outpatient department of Obstetrics and Gynaecology of Port Moresby General Hospital, Port Moresby, Papua New Guinea, the departments of Dermato-Venereology and Clinical Microbiology of the Erasmus University, Rotterdam, The Netherlands and the National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.

PATIENTS

A total of 254 consecutive women who attended the family planning clinic at Port Moresby General Hospital, Papua New Guinea were enrolled into this study.

METHODS

Cervical infections with C trachomatis were diagnosed using the direct immunofluorescent assay (DFA) and the polymerase chain reaction (PCR). Serum IgM and IgG antibodies directed against C trachomatis were detected using the enzyme-linked fluorescent assay (ELFA).

RESULTS

The prevalence of C trachomatis was 14.6% using the PCR, 9.1% using the DFA and 17.3% when the results of the PCR and the DFA were combined. An elevated IgM titre was observed in 14.2% of the women, whereas 44.1% had an elevated IgG titre. The titres of IgM or IgG were significantly higher in women who were positive using the PCR or the DFA than in those who were negative in both the PCR and the DFA (p = 0.032 and p = 0.0046, respectively).

CONCLUSION

Cervical infection by C trachomatis can be considered a major health problem in at least the studied population in Papua New Guinea. The prevalence of C trachomatis infection is at least comparable with that in groups with a high prevalence in industrialized countries. Effective screening and treatment programmes are imperative to combat this problem.

The value of urine specimens in screening for male urethritis and its microbial aetiologies in Tanzania

OBJECTIVE

To evaluate the first void urine (FVU) specimen in screening for urethritis and its microbial aetiologies in a male African population in which urinary schistosomiasis is also prevalent.

PATIENTS AND METHODS

Two hundred and forty eight males aged 15-54 years provided FVU specimens: 55 patients from a clinic for sexually transmitted diseases (STD), 151 patients from a medical outpatient clinic and 42 villagers from an area of high endemicity for S haematobium. Specimens were tested for leucocyte esterase (LE) using a dipstick (Nephur-Test+Leuco, Boehringer-Mannheim France SA). Ova of S haematobium were sought in terminal urine samples from all subjects. For all STD patients, and all medical outpatients with a positive LE test, urine and urethral swabs were tested for Chlamydia trachomatis antigen, and urethral swabs were tested for Neisseria gonorrhoeae by gram stain and isolation.

RESULTS

The prevalence of LE positivity was 38/41 in STD patients with urethral signs or symptoms (93%), 5/14 among other STD patients (36%), 21/151 among medical outpatients (15%) and 13/42 among villagers (31%). As a screening test for urethral infection (detection of gonorrhoea or chlamydia and/or > or = 5 polymorphs per high power field on gram stain) the LE test had a sensitivity of 94% and a specificity of 53% among STD patients. Of 24 STD patients with gonococcal or chlamydial infection, 23 had a positive LE test (96%). Among general medical outpatients, 12 of 22 with a positive LE test had either conventionally defined urethritis or gonococcal or chlamydial infection, giving a positive predictive value of 55% for the LE test in this group. Of 18 subjects in all groups with urinary schistosomiasis nine had a positive LE test (50%), although three of these also had gonorrhoea. Chlamydial antigen was detected in the FVU specimen of all six subjects in whom it was detected in a urethral swab, and in an additional three subjects in the outpatient group.

CONCLUSIONS

The FVU, which is an easily collected and non-invasive specimen, can provide valuable information on the prevalence of urethritis and on its microbial aetiology among the general male population in African countries.

Seroepidemiological and socioeconomic studies of genital chlamydial infection in Ethiopian women

OBJECTIVE

To measure the prevalence of chlamydial genital infection in Ethiopian women attending gynaecological, obstetric and family planning clinics; to identify the epidemiological, social and economic factors affecting the prevalence of infection in a country where routine laboratory culture and serological tests for chlamydial species are unavailable; to determine the risk factors for genital chlamydial infection in those with serological evidence of other sexually transmitted diseases.

SUBJECTS

1846 Ethiopian women, outpatient attenders at two teaching hospitals and a mother and child health centre in Addis Ababa, Ethiopia.

SETTING

Gynaecological outpatient department, antenatal, postnatal and family planning clinics.

METHODS

Sera were tested for type-specific anti-chlamydial antibodies using purified chlamydial antigens (C. trachomatis A-C (CTA-C), C. trachomatis D-K (CTD-K), Lymphogranuloma venereum (LGV1-3), and C. pneumoniae (CPn)), in a micro-immunofluorescence test. The genital chlamydia seropositivity was analysed against patient's age, clinic attended, ethnic group, religion, origin of residence, age at first marriage and first coitus, income, number of sexual partners, duration of sexual activity, marital status/profession, obstetric and contraceptive history, and seropositivity for other sexually transmitted diseases.

RESULTS

Overall exposure to chlamydia species was found in 84%, genital chlamydial infection in 62%, and titres suggestive of recent or present genital infection in 42% of those studied. Genital chlamydial infection was highest (64%) in family planning and lowest (54%) in antenatal clinic attenders. Exposure to genital chlamydia species was influenced by ethnic group and religion. Those married and sexually active under 13 years of age had greater exposure (69%) to genital chlamydial infection than those first sexually active aged over 18 (46%). Prevalence of infection was highest in those with more than five sexual partners (78%) and in bargirls (84%). The lowest income groups had a higher prevalence (65%) of genital chlamydial infection than the wealthiest (48%). Multivariate analysis showed the most important factors to be age at first coitus, religion, prostitution and present age of the woman in that order. Risk for genital chlamydial infection was increased in those with seropositivity for syphilis, gonorrhoea, HSV-2 but not HBV infection. CONCLUSION/APPLICATION: Chlamydial genital infections are highly prevalent in both symptomatic and asymptomatic Ethiopian women. The high prevalence of infection reported reflects a complexity of socioeconomic factors: very early age at first marriage and first coitus, instability of first marriage, subsequent divorce and remarriage or drift into prostitution, all of which are influenced by ethnic group, religion and poverty--together with transmission from an infected group of prostitutes by promiscuous males to their wives, lack of diagnostic facilities and inadequate treatment of both symptomatic and asymptomatic men and women. The problem of chlamydial disease in Ethiopia needs to be addressed urgently in the context of control of STD.

Chlamydia trachomatis and oral contraceptive use: a quantitative review

OBJECTIVES

Chlamydia trachomatis is now recognised as a major sexually transmitted disease; oral contraceptive use is rapidly increasing particularly in developing countries. There are thus important public health implications of the many reports that isolation of C trachomatis is more frequent among users of oral contraceptives. The aim of this analysis was to assess the strength and consistency of this association by summarising published studies between 1972 and 1990.

DESIGN

Studies identified were grouped according to whether they were prospective or case-control studies. Data were extracted and pooled estimates of the unadjusted odds ratios were made for all studies, as well as for sub-groups defined by an index of study quality, background prevalence of C trachomatis, and the contraceptive comparison being made.

LOCATION

Studies in the analysis were mainly conducted in Europe and North America; the meta-analysis was done at the Harvard School of Public Health, Boston, MA, USA.

RESULTS

The pooled estimated unadjusted odds ratio for 29 case-control studies examined was 1.93 (95% CI, 1.77-2.11), indicating an almost twofold increased risk of chlamydial infection for oral contraceptive users. Neither study quality nor prevalence of C trachomatis modified this risk. When compared to the use of barrier contraceptives, however, the risk of infection for women using oral contraceptives increased to 2.91 (95% CI, 1.86-4.55). The pooled estimated protective effect of barrier methods in these studies was 0.34 (95% CI, 0.22-0.54).

CONCLUSIONS

Cross-study comparisons of the relationship between oral contraceptive use and chlamydial infection are limited by the design and analysis of many component studies which did not control for confounding factors such as sexual behaviour and age. The almost twofold risk of increased chlamydial infection for oral contraceptive users, supported by the findings of two prospective studies, however, points to the importance of considering the risks and benefits of oral contraceptive use in women who are likely to be exposed to C trachomatis and other STDs. The protective effect of barrier methods emphasizes the continued need for promoting barrier methods of contraception.

Laboratory techniques for the diagnosis of chlamydial infections

Yolk-sac inoculation of embryonated eggs was superseded 25 years ago by the use of cell cultures (often McCoy) for the isolation of Chlamydia trachomatis. Centrifugation of specimens onto the cell monolayers was shown to increase sensitivity, but little of late has further improved sensitivity which is at least ten-fold greater than that of eggs. However, culture is slow and labour intensive so that non-cultural techniques without these drawbacks have come to dominate. Direct fluorescent antibody (DFA) tests are rapid and have sensitivities that range from 70% to 100% for men and 68% to 100% for women, and specificities that range from 87% to 99% for men and 82% to 100% for women; if the tests are read by competent observers the values are at the top end of the ranges. The detection rate may be enhanced even further by relatively low-speed centrifugation of specimens before staining. Skilled reading is not a feature of enzyme immunoassays (EIAs) which according to the literature have sensitivities that range from 62% to 97% for men and 64% to 100% for women, and specificities that range from 92% to 100% for men and 89% to 100% for women. However, comparison against poor reference tests is responsible for most of the higher values and the clinician should not be misled into believing that EIAs have excellent sensitivity; the lower values in the ranges are closer to reality. Furthermore, EIAs that are being designed for use by general practitioners should be regarded with the greatest caution since lack of sensitivity means that chlamydia-positive patients will go undetected. The polymerase chain reaction (PCR) is not bedevilled by insensitivity but it is no more sensitive than the most sensitive cell culture or DFA tests. PCR is unsuitable for routine diagnosis but has a place as a research tool. For men, examination of "first-catch" urine samples by the best of the non-cultural procedures provides an acceptable non-invasive approach to diagnosis; for women, the value of examining urine may be less, but needs to be thoroughly tested. However, there is little doubt that a Cytobrush used to obtain cervical specimens holds no practical advantage over a swab. Serological tests are reliant on the provision of paired sera for making a diagnosis; high antibody titres in single sera may be suggestive of an aetiological association in deep-seated chlamydial infections (epididymitis, arthritis, salpingitis, etc), but unequivocal interpretation is unusual, particularly in an individual case, since the distinction between a current and past infection is problematical.

Epidemiology of sexually transmitted diseases: the global picture

Sexually transmitted diseases (STD) are now the commonest group of notifiable infectious diseases in most countries, particularly in the age group of 15 to 50 years and in infants. Their control is important considering the high incidence of acute infections, complications and sequelae, their socioeconomic impact, and their role in increasing transmission of the human immunodeficiency virus (HIV). The worldwide incidence of major bacterial and viral STD is estimated at over 125 million cases yearly. STD are hyperendemic in many developing countries. In industrialized countries, the bacterial STD (syphilis, gonorrhoea, chancroid) declined from the peak during the Second World War till up to the late fifties, then increased during the sixties and early seventies, and they have been decreasing again from the late seventies till the present. In the industrialized world, diseases due to Chlamydia trachomatis, genital herpes virus, human papillomaviruses and human immunodeficiency virus are now more important than the classical bacterial ones; both groups remain major health problems in most developing countries. Infection rates are similar in both women and men, but women and infants bear the major burden of complications and serious sequelae. Infertility and ectopic pregnancies are often a consequence of pelvic inflammatory disease, and are preventable. Sexually transmitted diseases in pregnant women can result in prematurity, stillbirth and neonatal infections. In many areas 1-5% of newborns are at risk of gonococcal ophthalmia neonatorum, a blinding disease; congenital syphilis causes up to 25% of perinatal mortality. Genital and anal cancers (especially cervical cancer) are associated with viral sexually transmitted diseases (genital human papillomavirus and herpes virus infections). Urethral stricture and infertility are frequent sequelae in men.