Prevalence of antichlamydial antibody in London blood donors

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.

Seroepidemiology of chlamydia in Costa Rica

A population-based study of the sero-epidemiology of chlamydia was performed among a nationally representative sample of 760 Costa Rican women aged 25 to 59 years. Interviews and sera collection were completed between September 1984 and February 1985. The overall seroprevalence of chlamydial antibodies among these women was 56.1%. Women 25 to 39 years of age had a seroprevalence of 51.1%, while women 40 to 59 years of age had a seroprevalence of 64.2%. Women who reported no prior sexual activity had a seroprevalence rate of 48.6%, compared with a seroprevalence rate of 80.7% among women who reported three or more lifetime sexual partners. The geometric mean titre (GMT) of seropositive women ranged from 34.4 among the women who reported no prior sexual activity to 155.0 among the women with three or more lifetime sexual partners. Sero-positivity was more consistently associated with sexual activity than with age. Women with serological evidence of past Herpes simplex virus type 2 (HSV-2) or syphilis infection were more likely to be seropositive than were women without evidence of exposure to these sexually transmitted diseases, even when controlled for age and the number of lifetime sexual partners. The seropositivity among never sexually active women indicates the probable presence of Chlamydia pneumoniae infections, while the high seroprevalence of chlamydial antibodies among the sexually active women suggests that sexually transmitted Chlamydia trachomatis infections represent a public health problem not previously quantified in Costa Rica. Further seroepidemiological and/or culture studies are warranted to determine the incidence and prevalence of sexually transmitted chlamydial infection among men and younger women.

Prevalence of chlamydial antibody in Malaysians

A single antigen indirect immunofluorescence test was used to screen for chlamydial antibody among Malaysian infants, children, sexually active adults and prostitutes. Of 794 serum samples tested, 361 (45.5%) were positive. Seropositivity increased with age and sexual activity and ranged from 10 to 16% among children under 10 years old to 94.4% among prostitutes. Pregnant women and female adolescents showed a higher antibody prevalence than nonpregnant and older women. Six (13%) infants under 6 months of age were positive for chlamydial IgM.

Laboratory diagnosis of human chlamydial infections

Chlamydia trachomatis is a human pathogen that causes ocular disease (trachoma and inclusion conjunctivitis), genital disease (cervicitis, urethritis, salpingitis, and lymphogranuloma venereum), and respiratory disease (infant pneumonitis). Respiratory chlamydioses also occur with infection by avian strains of C. psittaci or infection by the newly described TWAR agent. Diagnosis of most acute C. trachomatis infections relies on detection of the infecting agent by cell culture, fluorescent antibody, immunoassay, cytopathologic, or nucleic acid hybridization methods. Individual non-culture tests for C. trachomatis are less sensitive and specific than the best chlamydial cell culture system but offer the advantages of reduced technology and simple transport of clinical specimens. Currently available nonculture tests for C. trachomatis perform adequately as screening tests in populations in which the prevalence of infection is greater than 10%. A negative culture or nonculture test for C. trachomatis does not, however, exclude infection. The predictive value of a positive nonculture test may be unsatisfactory when populations of low infection prevalence are tested. Tests that detect antibody responses to chlamydial infection have limited utility in diagnosis of acute chlamydial infection because of the high prevalence of persistent antibody in healthy adults and the cross-reactivity due to infection by the highly prevalent C. trachomatis and TWAR agents. Assays for changes in antibody titer to the chlamydial genus antigen are used for the diagnosis of respiratory chlamydioses. A single serum sample that is negative for chlamydial antibody excludes the diagnosis of lymphogranuloma venereum.

Acute conjunctivitis caused by an atypical chlamydial strain: Chlamydia IOL 207

A case of acute conjunctivitis in man caused by Chlamydia IOL 207 is described. Chlamydiae were isolated from the eye, and rising titres of type-specific antibodies to C. IOL 207, in serum and tears demonstrated an aetiological role for this agent. C. IOL 207 is an atypical chlamydial strain which serological studies suggest is widespread in some communities.

Chlamydial genital infection in Ibadan, Nigeria. A seroepidemiological survey

Sera from patients attending a sexually transmitted diseases (STD) clinic, a family planning clinic, and an antenatal clinic in Ibadan, Nigeria, as well as from male blood donors from the same area were tested for the presence of type specific antichlamydial antibodies using a modified micro-immunofluorescence test. Among men and women attending the STD clinic the exposure rates to Chlamydia trachomatis serotypes D to K (genital pathogens) were 18.7% and 26.7% respectively. Antibody titres suggesting active disease in these men and women were found in 11.8% and 22.7% respectively. The highest rate of exposure (35%) was among women attending the family planning clinic; of these women 25% had antibody suggesting active disease. Titres of IgG antibody in this study were similar to those found among men and women with chlamydial genital infections in the United Kingdom. Antibodies to serotypes D to K were also detected in 10.3% of women attending an antenatal clinic and in 9.9% of male blood donors. The prevalence of antibodies to C trachomatis serotypes A to C and lymphogranuloma venereum serotypes was low. These results suggest that the prevalence of chlamydial genital infections in Ibadan, both among STD patients and especially among those individuals not seeking treatment (family planning and antenatal clinic patients), is high. Since serious sequelae can follow chlamydial genital infections it is imperative to carry out further investigations in this area.

Chlamydial genital infection in Addis Ababa, Ethiopia. A seroepidemiological survey

A seroepidemiological survey was undertaken in Addis Ababa to assess the prevalence of chlamydial genital infections among patients attending a sexually transmitted diseases (STD) clinic and patients with no overt genital symptoms. In the STD clinic patients antibodies to Chlamydia trachomatis serotypes D to K (genital types) were detected in 68 of 210 (32.4%) men and in 72 of 159 (45.3%) women, a rate of exposure as high or higher than that found in Europe. Serological evidence of active chlamydial infection was present in 26.7% of men and 28.9% of women. Women were at risk of contracting STD, including chlamydial infections, at the age of 14 years or earlier. The titres of antichlamydial IgG were extremely high in some patients attending the STD clinic, with titres of between 1/512 and 1/8192 in 9.5% of men and 13.2% of women. This suggests that some patients had severe or disseminated chlamydial disease. The prevalence of exposure to chlamydial genital infections among 148 patients with no overt genital disease was 14.2%, which is significantly higher than that found in the United Kingdom. Among the total of 517 patients tested the prevalence of exposure to trachoma, lymphogranuloma venereum, and Chlamydia psittaci agents was very low.

Chlamydial immunofluorescence serology in anterior uveitis

Chlamydial immunofluorescence (IF) serology was determined in 118 patients with acute anterior uveitis (AAU), half of whom had anti-chlamydia antibodies. Men and women were equally affected. The chlamydial IF antibody titre was generally 1/16-64, but a few higher values were also measured. The age distribution, ocular pathology, and duration of AAU were identical in the chlamydial seropositive and seronegative patient groups. In the seropositive group there were 3 men with Reiter's syndrome. The prevalence of anti-chlamydia antibodies (50%) was higher than in other patients studied in the same laboratory. Further population studies are in progress to see whether our AAU patients represent an accumulation of chlamydial-positive persons.