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Background: WHO estimates that 131 million new cases of urogenital Chlamydia trachomatis (CT) infections occur globally every year. Most infections are asymptomatic. Untreated infection in women can lead to severe complications. Screening and treatment of at-risk populations is a priority for prevention and control., Objectives: To summarise systematic reviews of the performance characteristics of commercially available point-of-care tests (POCT) for screening and diagnosis of urogenital CT infection., Methods: Two separate systematic reviews covering the periods 2004-2013 and 2010-2015 were conducted on rapid CT POCTs. Studies were included if tests were evaluated against a valid reference standard., Results: In the first review, 635 articles were identified, of which 11 were included. Nine studies evaluated the performance of eight antigen detection rapid POCTs on 10 280 patients and two studies evaluated a near-patient nucleic acid amplification test (NAAT) on 3518 patients. Pooled sensitivity of antigen detection tests was 53%, 37% and 63% for cervical swabs, vaginal swabs and male urine, and specificity was 99%, 97% and 98%, respectively. The pooled sensitivity and specificity of the near-patient NAAT for all specimen types were >98% and 99.4%, respectively. The second review identified two additional studies on four antigen detection POCTs with sensitivities and specificities of 22.7%-37.7% and 99.4%-100%, respectively. A new two-step 15 min rapid POCT using fluorescent nanoparticles showed performance comparable to that of near-patient NAATs., Conclusions: The systematic reviews showed that antigen detection POCTs for CT, although easy to use, lacked sufficient sensitivity to be recommended as a screening test. A near-patient NAAT shows acceptable performance as a screening or diagnostic test but requires electricity, takes 90 min and is costly. More affordable POCTs are in development., Competing Interests: Competing interests: None declared.

Chlamydia trachomatis is responsible for both trachoma and sexually transmitted infections, causing substantial morbidity and economic cost globally. Despite this, our knowledge of its population and evolutionary genetics is limited. Here we present a detailed phylogeny based on whole-genome sequencing of representative strains of C. trachomatis from both trachoma and lymphogranuloma venereum (LGV) biovars from temporally and geographically diverse sources. Our analysis shows that predicting phylogenetic structure using ompA, which is traditionally used to classify Chlamydia, is misleading because extensive recombination in this region masks any true relationships present. We show that in many instances, ompA is a chimera that can be exchanged in part or as a whole both within and between biovars. We also provide evidence for exchange of, and recombination within, the cryptic plasmid, which is another key diagnostic target. We used our phylogenetic framework to show how genetic exchange has manifested itself in ocular, urogenital and LGV C. trachomatis strains, including the epidemic LGV serotype L2b.

If the cellular immune response to Chlamydia trachomatis is subject to genetic influences, the degree and mechanisms of such genetic control may have important implications for vaccine development. We estimated the relative contribution of host genetics to the total variation in lymphoproliferative responses to C. trachomatis antigen by analyzing these responses in 64 Gambian twin pairs from trachoma endemic areas. Zygosity was determined by restriction fragment length polymorphism analysis of minisatellite probes and microsatellite typing. Proliferative responses to serovar A elementary body antigen were estimated in monozygotic (MZ) and dizygotic (DZ) twin pairs. We found a stronger correlation and lower within-pair variability in these responses in MZ than in DZ twin pairs. The heritability estimate was 0.39 (P = 0.07) suggesting that host genetic factors contributed 39% of the variation. A better understanding of these genetic influences will contribute to the elucidation of preventive therapies for ocular C. trachomatis infection and may identify important mechanisms in protection for rational vaccine construction., (Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.)

This was one of the first epidemiological studies in China focused on genital Chlamydia trachomatis serotype distribution in high-risk female populations using omp1 gene-based restriction fragment length polymorphism analysis. One thousand seven hundred seventy cervical swab samples from women attending sexually transmitted disease clinics and female sex workers in six cities in China (Shenzhen and Guangzhou in southern China, Nanjing and Shanghai in eastern China, and Nanning and Chengdu in southwestern China) were subjected to serovar genotyping. The proportion of omp1 genes successfully amplified in 240 C. trachomatis plasmid-positive samples was 94.2% (226/240). Serotypes E (n = 63; 27.9%), F (n = 53; 23.5%), G (n = 28; 12.4%), and D (n = 25; 11.1%) were most prevalent. Though there was no significant difference in the geographic distribution of C. trachomatis, serotype E was predominant in the South (32.1%) and East (27.1%), while serotype F was predominant in the Southwest (28.3%). Serotype F infection was associated with young age and single status. Serovar G was associated with lower abdominal pain; 47.5% of asymptomatic patients were infected with serovar E. These results provide information on distribution of genital C. trachomatis serotypes among high-risk women in China and indicate that high-risk women, including those who are asymptomatic, can be infected with multiple serovars of C. trachomatis, revealing exposure to multiple sources of infection. Although the scope for generalizations is limited by our small sample size, our results showing clinical correlations with genotypes are informative.

Objectives: To determine the performance of a rapid Chlamydia trachomatis (CT) test (Clearview Chlamydia MF) compared to the current "gold standard" (Roche Amplicor CT assay) test, and to assess acceptability of the tests to patients., Methods: A total of 1497 women at sexually transmitted diseases (STD) clinics or re-education centres in six urban cities (Shanghai, Nanjing, Shenzhen, Guangzhou, Chengdu and Fuzhou) in China participated in the study. Three vaginal and three cervical swabs were collected from each participant. Rapid CT tests were performed locally on the first vaginal and cervical swabs and the results were read independently by two staff members. The second and third swabs were randomised for performing the Roche CT assay at the National STD Reference Laboratory. Acceptability of the rapid tests to patients was determined by asking patients in clinics about their willingness to wait for the results., Results: The prevalence of CT was 13.2% (197/1497), as determined by the Roche assay with cervical specimens. CT was detected in 78 vaginal and 127 cervical specimens by the rapid test and the positive rates determined with cervical specimens were significantly higher than those with vaginal specimens (p<0.001). There was good agreement between the results read by two independent staff for either vaginal or cervical specimens (both kappa = 0.98, p<0.001). Sensitivities for vaginal and cervical specimens were 32.8% and 49.7%, respectively, and specificities were 99.2% and 97.9%, respectively. The positive predictive value was 85.7% for vaginal and 78.4% for cervical specimens. The vast majority of the patients (99.1%) were willing to wait up to two hours for the results., Conclusion: Clearview Chlamydia MF, while yielding a rapid result and requiring minimal laboratory facilities, had unacceptably low sensitivity compared to a nucleic acid amplification test. Rapid tests yielding results within one hour are generally accepted by the clients.

Male circumcision has been shown to reduce the risk of acquiring and transmitting a number of venereal infections. However, little is known about the association between male circumcision and the risk of Chlamydia trachomatis infection in the female partner. The authors pooled data on 305 adult couples enrolled as controls in one of five case-control studies of invasive cervical cancer conducted in Thailand, the Philippines, Brazil, Colombia, and Spain between 1985 and 1997. Women provided blood samples for C. trachomatis and Chlamydia pneumoniae antibody detection; a type-specific microfluorescence assay was used. Multivariate odds ratios were computed for the association between male circumcision status and chlamydial seropositivity in women. Compared with women with uncircumcised partners, those with circumcised partners had a 5.6-fold reduced risk of testing seropositive for C. trachomatis (82% reduction; odds ratio = 0.18, 95% confidence interval: 0.05, 0.58). The inverse association was also observed after restricting the analysis to monogamous women and their only male partners (odds ratio = 0.21, 95% confidence interval: 0.06, 0.72). In contrast, seropositivity to C. pneumoniae, a non-sexually-transmitted infection, was not significantly related to circumcision status of the male partner. These findings suggest that male circumcision could reduce the risk of C. trachomatis infection in female sexual partners.

In a community of Tanzania where trachoma is endemic, we cultured conjunctival swabs from all residents who had active trachoma and were PCR positive for ocular Chlamydia trachomatis, both before (43 isolates) and 2 months after (9 isolates) mass antibiotic treatment. No clinically or programmatically significant increase in azithromycin or tetracycline resistance was observed.

Each year, Chlamydia trachomatis causes ~3 million new infections and results in more than 1 billion dollars in medical costs in the United States. Repeat or persistent infection occurs in 10%-15% of women who are treated for C. trachomatis infection. However, the role played by antimicrobial resistance in C. trachomatis treatment failures or persistent infection is unclear. With researchers in the field, we reviewed current knowledge and available approaches for evaluating antimicrobial resistance and potential clinical treatment failures for C. trachomatis. We identified key research questions that require further investigation. To date, there have been no reports of clinical C. trachomatis isolates displaying in vitro homotypic resistance to antimicrobials, but in vitro heterotypic resistance in C. trachomatis has been described. Correlation between the results of existing in vitro antimicrobial susceptibility tests and clinical outcome after treatment for C. trachomatis infection is unknown. Animal models may provide insight into chlamydial persistence, since homotypic resistance against tetracycline has been described for Chlamydia suis in pigs. Evaluating C. trachomatis clinical treatment failures, interpreting laboratory findings, and correlating the 2 clearly remain extremely challenging undertakings.

Trachoma is caused by Chlamydia trachomatis. Clinical grading with the WHO simplified system can be highly repeatable provided graders are adequately trained and standardized. At the community level, rapid assessments are useful for confirming the absence of trachoma but do not determine the magnitude of the problem in communities where trachoma is present. New rapid assessment protocols incorporating techniques for obtaining representative population samples (without census preparation) may give better estimates of the prevalence of clinical trachoma. Clinical findings do not necessarily indicate the presence or absence of C. trachomatis infection, particularly as disease prevalence falls. The prevalence of ocular C. trachomatis infection (at the community level) is important because it is infection that is targeted when antibiotics are distributed in trachoma control campaigns. Methods to estimate infection prevalence are required. While culture is a sensitive test for the presence of viable organisms and nucleic acid amplification tests are sensitive and specific tools for the presence of chlamydial nucleic acids, the commercial assays presently available are all too expensive, too complex, or too unreliable for use in national programs. There is an urgent need for a rapid, reliable test for C. trachomatis to assist in measuring progress towards the elimination of trachoma.

To determine whether Chlamydia trachomatis infection is consistently associated with an increased risk of invasive cervical carcinoma (ICC) after accounting for the strong effect of human papillomavirus (HPV) infection, a case-control study of 1,238 cases of ICC and 1,100 control women from 7 countries was carried out (hospital-based studies in Thailand, the Philippines, Morocco, Peru, Brazil and population-based studies in Colombia and Spain, all coordinated by the International Agency for Research on Cancer, Lyon, France). C. trachomatis serum antibody detection was made by means of a microfluorescence assay. Among HPV DNA-positive cases and controls, the risk of squamous cell ICC was elevated in C. trachomatis seropositive women (OR = 1.8; 95% CI = 1.2-2.7) after adjustment for age, center, oral contraceptive use, history of Pap smears, number of full-term pregnancies and herpes simplex virus 2 seropositivity. The effect of C. trachomatis seropositivity on squamous cell ICC risk increased with increasing C. trachomatis antibody titers and was higher in women under 55 years of age. C. trachomatis antibodies were not associated with adeno- or adenosquamous cell carcinoma (OR = 1.0; 95% CI = 0.53-1.9) in HPV DNA-positive women. An association of C. trachomatis with squamous cell ICC was found among all cases and control women with or without adjustment for HPV., (Copyright 2004 Wiley-Liss, Inc.)

Background: Antibiotics are an important part of WHO's strategy to eliminate trachoma as a blinding disease by 2020. At present, who needs to be treated is unclear. We aimed to establish the burden of ocular Chlamydia trachomatis in three trachoma-endemic communities in Tanzania and The Gambia with real-time quantitative PCR., Methods: Conjunctival swabs were obtained at examination from 3146 individuals. Swabs were first tested by the qualitative Amplicor PCR, which is known to be highly sensitive. In positive samples, the number of copies of omp1 (a single-copy C trachomatis gene) was measured by quantitative PCR., Findings: Children had the highest ocular loads of C trachomatis, although the amount of pooling in young age groups was less striking at the site with the lowest trachoma frequency. Individuals with intense inflammatory trachoma had higher loads than did those with other conjunctival signs. At the site with the highest prevalence of trachoma, 48 of 93 (52%) individuals with conjunctival scarring but no sign of active disease were positive for ocular chlamydiae., Interpretation: Children younger than 10 years old, and those with intense inflammatory trachoma, probably represent the major source of ocular C trachomatis infection in endemic communities. Success of antibiotic distribution programmes could depend on these groups receiving effective treatment.

The social context and epidemiology of STIs in remote communities in Northern Canada was examined. These communities have a persistently high reported incidence of gonorrhoea and chlamydial infection. They remain in the hyperendemic phase of the N. gonorrhoeae and C. trachomatis epidemics. They are ethnically and culturally homogeneous and contain no readily identifiable core groups, making it impossible to distinguish between spread and maintenance networks. Mass screening of the adult population can reduce the reservoir of C. trachomatis infection under these circumstances. It is particularly important to target men in settings such as this where women are routinely screened in antenatal and family planning clinics.

Chlamydia trachomatis infection was examined as a cause of invasive cervical cancer (ICC) among women with human papillomavirus (HPV) infection. In total, 499 women with incident ICC (ICC patients) and 539 control patients from São Paulo, Brazil, and Manila, the Philippines, were included. C. trachomatis antibodies were detected by microimmunofluorescence assay. Presence of HPV DNA in cervical specimens was determined by a polymerase chain reaction-based assay. C. trachomatis seropositivity was associated with sexual behavior but not with HPV infection. C. trachomatis increased the risk of squamous cervical cancer among HPV-positive women (odds ratio, 2.1; 95% confidence interval, 1.1-4.0). Results were similar in both countries. There was a suggestion of increasing squamous cancer risk with increasing C. trachomatis antibody titers. This large study examined C. trachomatis and cervical cancer, taking into account the central role of HPV infection. C. trachomatis infection was found to be a possible cofactor of HPV in the etiology of squamous cervical cancer, and its effect may be mediated by chronic inflammation.

A primate model of chlamydial pelvic inflammatory disease was used to characterize serum antibody responses to the 60 kDa chlamydial heat shock protein (CHSP60). Forty monkeys were infected in the fallopian tubes with Chlamydia trachomatis and then were treated. Twenty-three (58%) monkeys developed antibodies against CHSP60, of whom 6 (15%) had CHSP60 responses that persisted throughout the study and 17 (42.5%) had a transient response. A persistent CHSP60 antibody response was correlated with being culture- or ligase chain reaction-positive in the fallopian tubes (P=.004), but not in the cervix pretreatment, and with being tubal-positive posttreatment (P=. 02). Compared with tubal-negative monkeys, tubal-positive monkeys had more intense CHSP60 responses (P=.006) that lasted longer (P=. 002). Among CHSP60 responders, an OD>0.5 was correlated with more severe salpingeal pathology before treatment (P=.04). CHSP60 antibody response may be useful as a marker of persistent chlamydial infection in the fallopian tubes.

A total of 113 female commercial sex workers had individual alleles for HLA class II genes determined by using labeled sequence-specific oligonucleotide probes to hybridize to polymerase chain reaction products of amplified DNA. Women also had microimmunofluorescent (MIF) antibody titers to Chlamydia trachomatis elementary bodies and ELISA antibody to recombinant chlamydial heat-shock protein 60 (Chsp60) determined. Women were prospectively followed at monthly intervals over 2 years for incident C. trachomatis infection and acute pelvic inflammatory disease (PID). HLA DQA1*0401 and DQB1*0402 alleles were statistically associated with increased prevalence and amount of antibody to Chsp60 but not MIF antibody. However, these alleles did not alter the risk for chlamydial PID. The potential role that HLA DQ may play in chlamydial disease pathogenesis requires further study.

The anamnestic antibody response to the Chlamydia trachomatis major outer membrane protein (MOMP) was evaluated in mice after priming with serovar C and boosting either with the homologous serovar or with heterologous serovars (A, H, K, and B). Microimmunofluorescence antibody responses demonstrated that boosting with heterologous serovars strongly recalled antibody to serovar C, typical of an original antigenic sin (OAS) response. Boosting with serovars antigenically related to serovar C (A, H, and K) recalled antibody to the variable domain 1 (VD1) peptide of the MOMP of serovar C as determined by a pin-peptide ELISA. Complete amino acid substitution analysis of the VD1 peptide epitope of the MOMP showed that the original antigenic sin response to each boosting serovar contained antibodies with unique patterns of VD1 peptide recognition. The data suggest that antigenically related C. trachomatis serovars differentially recruit B cell lineages from a heterogeneous memory B cell pool that had been induced by priming with the original serovar and thus account for the OAS antibody response.

Objectives: To evaluate pooling of first catch urine (FCU) specimens as a cost effective strategy for chlamydia testing., Methods: Mock specimens were pooled with and without dilution to determine optimal pool size and ease of work flow. The performance of the Amplicor Chlamydia trachomatis PCR assay on pooled specimens was compared with individual testing using 370 FCU specimens from asymptomatic men presenting to an STD clinic. Cost savings associated with pooling were estimated., Results: Using mock specimens, the sensitivity and specificity of the Amplicor PCR assay were not affected by pool sizes of two and five, but at a pool size of 10 decreased sensitivity due to inhibition was observed in one of five mock pools when the pooling method which involved no dilution was used. Archived FCU specimens from a study of 370 asymptomatic men were combined consecutively into 74 pools of five and tested by PCR. Of the 18 pools that contained positive specimens, 17 were PCR positive. Compared with testing FCU specimens individually, pooling resulted in a sensitivity of 95%, specificity of 100%, and a cost savings of 57% based on reduced number of tests required., Conclusion: Depending on the prevalence of infection, pooling of FCU specimens for PCR testing may result in cost savings compared with testing specimens individually. Further evaluations to validate this strategy using fresh FCU specimens are needed.

To determine if serum antibody response to the 60-kDa chlamydial heat-shock protein (Chsp60) was associated with scarring trachoma, responses to Chlamydia trachomatis and to Chsp60 from 148 Gambian subjects with trachomatous scarring and from 148 controls without clinical evidence of disease from trachoma-endemic communities were characterized. Chsp60 response was found in 32% of cases and 16% of controls (P < .001). Although C. trachomatis titer was also higher in cases than controls, the prevalence of Chsp60 response between the 2 groups remained significantly different after stratifying for C. trachomatis titer (weighted odds ratio [OR] = 2.1, P = .02). Chsp60 response and C. trachomatis serovar A titer of > or =128 were independently associated with scarring trachoma. The presence of HLA class II allele DRB1*0701 was positively correlated with Chsp60 response (OR = 2.6, P = .02), and DQB1*0301 and DQB1*0501 were negatively associated (OR = 0.42, P < .001; OR = 0.55, P = .46, respectively).

A cross-sectional study of 306 women was done to correlate antibody to the chlamydial hsp60 (Chsp60) with epidemiologic, serologic, and laparoscopic findings of women with and without pelvic inflammatory disease (PID). Of the 306 women, 150 had confirmed PID by laparoscopic (n = 69) or histologic (n = 81) criteria, and 156 sexually transmitted disease clinic attendees without clinical PID did (n = 94) or did not (n = 62) have chlamydia. In multivariate analyses, Chsp60 antibody was independently associated with confirmed PID, age > 20 years, nonwhite race, > 10 lifetime sex partners, current oral contraceptive use, and IgG antibody titers; it was not associated with a positive Chlamydia trachomatis culture. Among the 69 women with laparoscopic evidence of PID, the highest level of Chsp60 antibody (optical density > 1.0) was found in 8 (80%) of 10 women with occluded tubes, compared with 11 (19%) of 58 with patent tubes (P < .001). We conclude that antibody to Chsp60 was significantly correlated with risk factors for PID, confirmed PID, and occluded fallopian tubes but not with acute C. trachomatis infection without PID.

To determine whether serum antibody to Chlamydia trachomatis antigens alters the risk of C. trachomatis pelvic inflammatory disease (PID), 280 female sex workers were prospectively evaluated over a 33-month period for incident C. trachomatis and Neisseria gonorrhoeae cervical infection and for clinical PID. At enrollment, women were tested for antibody to C. trachomatis elementary bodies by an indirect microimmunofluorescence assay and to recombinant chlamydial hsp60 (Chsp60) by an ELISA format. At each follow-up visit, women were tested for cervical chlamydial and gonococcal infection and were identified as having clinical PID if they complained of lower abdominal pain and were found to have uterine and adnexal tenderness on pelvic examination. The data demonstrate that antibody to Chsp60 predicts a 2- to 3-fold increased risk for C. trachomatis PID.

Objective: Our purpose was to examine clinical, microbiologic, serologic, and laparoscopic findings associated with perihepatitis., Study Design: In a prospective study of 157 women with a clinical diagnosis of pelvic inflammatory disease, 27 women with laparoscopically confirmed perihepatitis and salpingitis were compared with 46 patients with salpingitis alone., Results: Both current use or a history of ever using oral contraceptives was negatively associated with perihepatitis (p = 0.05 and p = 0.008, respectively). Moderate-to-severe pelvic adhesions were present at laparoscopy significantly more often in the perihepatitis-salpingitis group (70%) than in the salpingitis alone group (35%, p = 0.003). Antibody to the chlamydial 60 kd heat-shock protein at > or =0.5 optical density was detected in 67% of the perihepatitis-salpingitis group and in 28% of the salpingitis alone group (p = 0.005), and the median titer was significantly higher in the former group (p = 0.02)., Conclusion: Compared with women with salpingitis alone, patients with perihepatitis-salpingitis do not have distinctive clinical or microbiologic findings but do manifest a higher prevalence of moderate-to-severe pelvic adhesions and both a higher prevalence and higher titers of antibody to the chlamydial heat-shock protein-60.

Objective: To study the utility of testing for heat shock protein 60 (CHSP60) antibodies in the diagnosis of tubal factor infertility., Design: Prospective case control., Setting: Canadian university hospital infertility clinic., Patient(s): Women presenting for infertility investigation., Intervention(s): Sera were collected from 77 patients., Main Outcome Measure(s): The relationship between tubal factor infertility and the presence of antibodies to Chlamydia trachomatis and CHSP60 was assessed., Result(s): There were no significant differences between antibodies to C. trachomatis in women with tubal factor infertility (63%) and other causes of infertility (46%). However, more women with tubal factor infertility (44%) had anti-CHSP60 antibodies compared with other causes of infertility (8%). Antibody testing for C. trachomatis has only a 63% sensitivity and a 54% specificity for detecting tubal factor infertility. In contrast, the CHSP60 antibody test has a 44% sensitivity and a 92% specificity for detecting tubal factor infertility. There is a good positive likelihood ratio of 5.5 for CHSP60 antibody testing detecting the presence of tubal factor infertility. Combining CHSP60 antibody with antibody testing for C. trachomatis has an excellent positive likelihood ratio of 10 for the detection of C. trachomatis-associated tubal factor infertility., Conclusion(s): CHSP60 antibody testing is a more accurate test than antibody testing for C. trachomatis for predicting chlamydia-associated tubal factor infertility. These tests, when used in combination at initial infertility evaluation, would provide a rapid noninterventive means of diagnosing tubal factor infertility.

The recognition of genital chlamydial infection as an important public health problem was made first by the recognition of its role in acute clinical syndromes, as well as in serious reproductive and ocular complications, and secondly by our awareness of its prevalence when diagnostic tests became widely accessible. The recent availability of effective single dose oral antimicrobial therapy and sensitive molecular amplification tests that allow the use of noninvasive specimens for diagnosis and screening is expected to have a major impact in reducing the prevalence of disease in the next decade. Clinical manifestations associated with Chlamydia pneumoniae infection continue to emerge beyond respiratory illness. In particular, its association with atherosclerosis deserves further investigation. Chlamydia pecorum, a pathogen of ruminants, was recently recognized as a new species. The continued application of molecular techniques will likely elucidate an expanding role for chlamydiae in human and animal diseases, delineate the phylogenetic relationships among chlamydial species and within the eubacteria domain, and provide tools for detection and control of chlamydial infections.

Objective: To assess the suitability of vaginal washes as specimens for sexually transmitted disease diagnosis and determine the usefulness of PCR technology for Chlamydia trachomatis diagnosis in prepubertal girls., Study Design: Paired sets of vaginal secretions were collected with swabs and by vaginal wash from 138 prepubertal girls for evaluation because of alleged sexual abuse. Detection by culture of Neisseria gonorrhoeae and C. trachomatis was compared between the two sampling techniques. PCR techniques were also used to test 29 vaginal wash specimens for C. trachomatis., Results: In the prepubertal girls N. gonorrhoeae was detected in two wash specimens but in only one swab specimen; C. trachomatis was detected by culture in both paired specimens from two children and by PCR in vaginal washes from both of the two children positive by culture; PCR identified two other infected children., Conclusions: A vaginal wash technique coupled with newer molecular amplification technology may be useful in the assessment of sexually abused children.

Among 302 female sex workers in Nairobi, Kenya, who were followed for 17.6 +/- 11.1 months, 146 had one or more infections with Chlamydia trachomatis; 102 had uncomplicated cervical infection only, 23 had C. trachomatis pelvic inflammatory disease (PID), and 21 had combined C. trachomatis and Neisseria gonorrhoeae PID. As determined by multivariate logistic regression analysis, risk factors for C. trachomatis PID included repeated C. trachomatis infection (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.4; P = .0004), antibody to C. trachomatis heat-shock protein 60 (OR, 3.9; CI, 1.04-14.5; P = .04), oral contraceptive use (OR, 0.28; 95% CI, 0.08-0.99; P = .048), and number of episodes of nongonococcal nonchlamydial PID (OR, 1.7; 95% CI, 1.1-2.7; P = .02). Among human immunodeficiency virus (HIV)-seropositive women, a CD4 lymphocyte count of <400/mm3 was an additional independent risk factor for C. trachomatis PID (OR, 21.7; 95% CI, 1.2-383; P = .036); among HLA-typed women, HLA-A31 was independently associated with C. trachomatis PID (OR, 5.6; 95% CI, 1.1-29.4; P = .043). The results suggest an immune-mediated pathogenesis for C. trachomatis PID.

A PCR assay was evaluated for its ability to detect genital chlamydial infection in asymptomatic men and women. Urethral swab specimens were collected from 472 men for culture and PCR assay, and first-void urine (FVU) specimens were collected from 379 of these men for enzyme immunoassay (EIA) and PCR assay. Cervical swab specimens were collected from 242 women for culture, EIA, and PCR assay. Patients were considered infected if they were culture positive or positive by PCR with both plasmid- and major outer membrane protein-based primers. By using this extended "gold standard," the prevalence of infection in this population was 7.6% for men and 7.9% for women. For men, the sensitivities of urethral swab specimen culture and PCR and FVU specimen EIA and PCR were 61, 72, 55, and 91%, respectively. All assays had specificities of > or = 99.8%. The positive and negative predictive values for PCR testing of FVU specimens were 100 and 99.4%, respectively, compared with values of 96.3 and 97.8%, respectively, for PCR of urethral swab specimens. The sensitivities of cervical swab specimen culture and PCR testing were 42 and 90%, respectively, with corresponding specificities of 100 and 99.3%. All cervical swabs were negative by EIA. Molecular techniques such as PCR assays are valuable tools for the detection of symptomatic genital chlamydial infection. In particular, PCR assays of FVU specimens from men offer a highly sensitive, noninvasive screening tool that will likely improve patient compliance for diagnostic testing.

Objective: To examine IVF-ET outcome in patients with and without serologic evidence of Chlamydia trachomatis infection and chlamydia heat shock protein 60 (CHSP 60) antibodies., Design: Retrospective case control., Setting: University-affiliated IVF-ET program., Main Outcome Measures: A total of 195 IVF-ET patients with tubal factor infertility underwent oocyte pick-up, 166 of these women had ET resulting in a total of 37 pregnancies. Serum antibody testing for evidence of remote C. trachomatis and CHSP 60, as well as pregnancy outcome, were determined for all patients., Results: There were no differences in pregnancy rates or outcomes between C. trachomatis seropositive versus seronegative groups: 27/118 (23%) C. trachomatis seropositive versus 10/77 (13%) C. trachomatis seronegative patients achieved pregnancy per oocyte pick-up. Pregnancy rates per ET were 27/105 (26%) in C. trachomatis seropositive versus 10/61 (16%) C. trachomatis seronegative patients. In the C. trachomatis positive subgroup, significantly higher pregnancy rates were found in the CHSP 60 antibody positive patients: 24/67 (36%) CHSP 60 positive versus 3/51 (6.0%) CHSP 60 negative patients were pregnant after oocyte pick-up (OR = 8.9, 95% CI = 2.3 to 27.5). Pregnancy rates per ET were 24/57 (42%) in CHSP 60 positive versus 3/48 (7%) CHSP 60 negative patients (OR = 10.9, 95% CI = 2.8 to 33.6). There were no significant differences in any group when examining the following pregnancy outcomes: spontaneous abortion, ectopic pregnancy, preterm and multiple pregnancy rates., Conclusions: [1] There are no differences in pregnancy rates or outcomes in patients with and without serologic evidence of previous C. trachomatis infections. [2] In women seropositive for C. trachomatis, significantly higher pregnancy rates are found in women who are CHSP 60 antibody positive versus negative. [3] Pregnancy outcomes do not appear to be different between these groups.

Objective: To determine whether serologic evidence of Chlamydia trachomatis during pregnancy is a risk factor for preterm delivery (before 37 weeks' gestation)., Design: Chart review., Setting: Antenatal clinics associated with a teaching hospital., Patients: A group of 103 unselected consecutive patients presenting for routine prenatal care., Outcome Measures: Pregnancy outcome and C. trachomatis serologic status., Results: A total of 21 women (20%) were found to be seropositive for IgG antibodies to C. trachomatis. They were similar to the seronegative women with respect to maternal age, parity, history of preterm birth, obstetric or medical problems, smoking status, history of drug abuse, educational status and psychosocial stressors. The seropositive women were significantly more likely than the seronegative women to have a preterm birth (24% [5/21] v. 7% [6/82]i p = 0.029, odds ratio 3.96, 95% confidence interval 1.08 to 14.57), an infant with a lower mean gestational age at birth (262 [standard deviation (SD) 19] days v. 273 [SD 15] days; p = 0.0052) and an infant with a lower mean birth weight (3125 [SD 692] g v. 3473 [SD 696] g; p = 0.0434). The positive predictive value of a seropositive result for preterm birth was 31% (5/16); the negative predictive value of a seronegative result for preterm birth was 8% (6/76)., Conclusion: Women with serologic evidence of C. trachomatis may be at risk for preterm birth. Further study is required to determine whether serologic testing for C. trachomatis should be a routine part of prenatal care.

As an intracellular bacteria, Chlamydia trachomatis is an extraordinarily successful pathogen. Chlamydial infections are among the most common of all human infections. Chlamydial disease is less common than infection and is attributed to immune responses to specific antigens of the organism. A major variant surface protein, major outer membrane protein (MOMP), is the principal target of neutralizing antibodies and may be the target of protective immunity. The detailed genetic and immunochemical knowledge of MOMP has stimulated multiple attempts to design an oligopeptide vaccine. Success has been limited in part because of the antigenic variation that the protein exhibits and in part because of the absence of knowledge regarding the three-dimensional structure of the protein. Individuals with severe forms of chlamydial disease often display immune responses to a common chlamydial heat shock protein 60 (hsp60) antigen. Because the protein shares nearly 50% sequence identity with the human homolog, it is speculated that molecular mimacy may result in autoimmune inflammatory damage that in turn causes chlamydial disease sequelae. Because hsp60 immune responses are genetically determined, susceptibility genes for chlamydial disease may also exist. A detailed understanding of the immunobiology of C. trachomatis infection may result from molecular study of chlamydial antigens and the precise nature of immune responses they elicit. Nevertheless, even with the rapid progress that has been made in uncovering the major chlamydial antigens, more remains hidden than revealed. As demonstrated by their successful ecology, chlamydiae remain several stops ahead of even their most ardent pursuers.

Chlamydia trachomatis detection has been substantially advanced by molecular amplification methods. As diagnostic or screening tests, the methods have shown performance characteristics equivalent to culture, but are more rapid and have no special requirements for specimen transport. The challenge for this generation of diagnostic tests is to prevent laboratory and specimen cross contamination.

We have developed a novel enzyme immunoassay (EIA) for the specific detection of Chlamydia trachomatis utilizing a monoclonal anti-idiotypic antibody to an antibody directed against a chlamydia specific epitope on 60 kDa heat-shock protein (HSP60). The basis of the assay is the inhibition of the binding of idiotype to anti-idiotype by antigen present in test samples. Two configurations of the assay were developed: a blocking EIA and a competition EIA. Greater sensitivity was observed using the competition EIA, with the assay detecting purified recombinant HSP60 and purified chlamydia in a concentration-dependent manner from 0.01 to 10 micrograms protein and from 0.5 to 12 micrograms total protein, respectively. The assay is highly specific and offers several potential advantages over currently available EIAs for the detection of this pathogen.

Monoclonal antibodies to the major outer membrane protein of Chlamydia trachomatis were used to neutralize C. trachomatis infectivity in HeLa 229 cells and to determine the kinetics and stoichiometry of the reaction. In vitro neutralization of C. trachomatis infectivity proceeded as a first-order reaction and required an activation energy of approximately 20 kcal/mol (ca. 84 kJ/mol). The rate of neutralization was linear with respect to antibody concentration and reaction temperature. The efficiency of neutralization decreased exponentially as the ratio of noninfective to infective chlamydiae increased in the antigen preparation. The neutralization assay was also significantly affected by reaction parameters such as the reaction volume and the duration of incubation. Stoichiometric calculations showed that an average ratio of 10(3) and 10(4) immunoglobulin molecules per chlamydial particle was required to yield 50% neutralization by monoclonal antibodies specifying serovar-specific and species-specific epitopes, respectively. The implications of these findings for vaccine design and for the role of the major outer membrane protein in the pathogenesis of chlamydial infections are discussed.

Some of the newer fluoroquinolones may be suitable agents for the treatment of Chlamydia trachomatis infections and non-gonococcal urethritis. To date, small studies with both ofloxacin and fleroxacin appear to achieve cure rates of 85-100% for urethritis and cervicitis due to Chlamydia trachomatis. However, large well-designed clinical trials are required to determine the efficacy and acceptance of these and other fluoroquinolones in the treatment of patients with genital or respiratory syndromes due to chlamydiae or other bacterial pathogens causing infections with similar manifestations.

ATPase activity of elementary bodies (EBs) of Chlamydia trachomatis was investigated by using high-resolution 31P nuclear magnetic resonance spectroscopy. ATPase activity was detected in EBs of C. trachomatis serovars A, B, and L2 after treatment with the reducing agents 2-mercaptoethanol and glutathione. ATPase activity was oligomycin sensitive and magnesium ion dependent. EBs heated at 60 degrees C for 10 min or pretreated with Triton X-100 before exposure to 2-mercaptoethanol did not exhibit ATPase activity. Monoclonal antibody to the major outer membrane protein abrogated ATPase activity of EBs, whereas monoclonal antibody to chlamydial lipopolysaccharide only marginally reduced the level of ATPase activity. These findings suggest that EBs possess intrinsic ATPase activity and that cysteine-rich outer membrane proteins of EBs are important in the regulation of ATPase activity. The major outer membrane protein may be the major route through which ATP accesses ATPase.

We used monoclonal antibodies (MAbs) to examine the antigenic specificity and biologic function of several Chlamydia trachomatis antigens. Thirteen distinct MAbs to eight C. trachomatis antigens were produced. Six MAbs reacted with unique epitopes on the major outer membrane protein (MOMP) and two of these had neutralizing activity. MAbs were produced to each of the chlamydial antigens with molecular masses of 10, 29, 32, 57, 60, 70, and 75 kilodaltons (kDa). These MAbs showed species and genus specificity in an immunoblot assay. None of the MAbs had neutralizing activity. The epitopes recognized on MOMP, 29-, and 10-kDa (presumably lipopolysaccharide) antigens were surface exposed. MAbs to the 75-kDa, 57-kDa, and MOMP antigens were used for immunoaffinity purification of these antigens to produce monospecific antisera in mice. With polyclonal sera, we found that the 75-kDa antigen was also immunoaccessible and that antibody to MOMP and 75-kDa antigens neutralized C. trachomatis infectivity. We conclude that, in addition to MOMP and lipopolysaccharide, antigens with molecular masses of 75 and 29 kDa are surface exposed. Antibodies to MOMP and 75-kDa antigens can neutralize the organism in vitro.

We compared the prevalence of antibody to Chlamydia trachomatis among 88 women undergoing an evaluation for infertility and 49 women attending an antenatal clinic. Demographic data regarding sexual behavior were also collected. Eighteen women had tubal infertility and 70 had infertility due to a variety of other reasons. In comparison with women who had other causes for infertility, women with tubal infertility began coitus sooner (17.7 +/- 2.2 years vs. 19.5 +/- 3.4 years, P less than .05) and had more lifetime sex partners (4.5 vs. 1.33, P less than .001). Women with tubal infertility had a higher prevalence of antibody to C. trachomatis (13 of 18) than did women with nontubal causes for infertility (6 of 70, P less than .0001) or pregnant women (11 of 49, P = .0003). This high prevalence of antibody to C. trachomatis among women with tubal infertility was independent of sexual experience. By immunoblot analysis, an antigen of approximately 57,000 Da was immunodominant in 11 of 13 seropositive subjects with tubal infertility vs. 2 of 6 seropositive subjects with nontubal infertility (P = .046) and 1 of 11 seropositive pregnant women (P = .0003). Thus, women with tubal infertility frequently have serological evidence of prior infection with C. trachomatis and have a distinctive antigen-specific humoral immune response. These results further support the etiologic role of infection with C. trachomatis in tubal infertility.