Chlamydial Serology Research Articles

Challenges in Chlamydial Serology: Insights from a Belgian and a Dutch Population Cohort.

Serology routinely serves as a diagnostic tool to confirm Chlamydia infections in humans. Particularly in delayed settings, such as post-outbreak scenarios where the acute phase of infection has subsided, serology is invaluable. Multiple studies, nonetheless, indicate deficiencies in specificity and sensitivity of current chlamydial antibody detection assays. Incorporation of multiple antigens per target is known to improve the accuracy of chlamydial serological assays. We, therefore, used the recomLine test (Mikrogen diagnostics) on serological samples of two cohorts, as it is the only commercially available test allowing detection of antibodies against three human pathogenic Chlamydia species (C. trachomatis, C. pneumoniae and C. psittaci) using multiple antigens per target. The first cohort (n = 156; samples collected between 2008 and 2022 during a C. trachomatis screening initiative) comprised women from the Netherlands (NL) with past exposure to C. trachomatis, while the second cohort (n = 44; samples collected in 2018 in a health examination survey) consisted of Belgian citizens (BE) with occupational or recreational exposure to chickens, representing a risk population for C. psittaci. The test indicated a statistically equivalent C. pneumoniae seroprevalence in both cohorts (39.10% in NL and 34.09% in BE; p = 0.337). As expected C. trachomatis seroprevalence was significantly higher (p < 0.001) in the Dutch cohort (48.72%), as compared to the Belgian cohort (4.55%). Lastly, C. psittaci seroprevalence did not significantly differ between the two groups (2.27% in BE and 1.92% in NL; p = 0.633), even though a higher prevalence was expected for the Belgian cohort. This prompts us to question whether the Belgian cohort truly constituted a C. psittaci risk population or whether the recomLine test is susceptible to cross-reaction of species-specific antibodies, thereby increasing C. psittaci prevalence in the Dutch cohort. We advocate for the development of affordable, highly sensitive antibody detection assays that can effectively distinguish between chlamydial species, addressing the increasing demand for enhanced serological testing methodologies.

Testing Technologies as Enhancers of Disease Intervention Specialist Activities: Applying Lessons From COVID-19.

Disease intervention specialists are often at the forefront of adoption of new technologies in support of sexually transmitted infection (STI) contact tracing efforts. Newer technology for detection of treatable STI includes point-of-care molecular tests for detection of chlamydia, gonorrhea, and trichomonas and syphilis serology point-of-care tests. Other additions to our case finding toolbox are the use of telemedicine and the proliferation of direct-to-consumer offerings, both of which rely on remote sample collection involving self-collection of specimens in nonclinical settings. Finally, on the near horizon are over-the-counter tests that will support self-testing without the involvement of a medical professional. Each of these new developments is discussed and contextualized in experiences resulting from the COVID-19 pandemic response. Many options are now available, or will be soon, for detection of STIs in nontraditional settings, and we need to consider the processes involved as we move toward adoption of these new tools.

A comparative study of prevalence of Chlamydia trachomatis infection among infertile and fertile women at a tertiary care center

Background and Aim: Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium causing sexually transmitted infection leading to urogenital infections which are asymptomatic. If untreated, leads to complications such as chronic pelvic pain, inflammation, and occlusion of the fallopian tubes, resulting in infertility and ectopic pregnancy. The association is found between C. trachomatis infection and female infertility with a prevalence rate of 15%–30%. The aim was to determine the prevalence of C. trachomatis infection in women with infertility. Materials and Methods: This was a hospital-based cross-sectional study of patients presenting with or without infertility. Group A (75 cases) cases with infertility with or without symptoms of pelvic inflammatory disease. Group B (75 cases) with no infertility matching age, symptoms with Group A. After history, physical examination cervical swab for chlamydial antigen and serology sample was taken and processed. Positive cases were followed by hysterosalpingography (HSG) and laparoscopy. Results: Out of 150 patients, 14 were positive for chlamydia in cases and 4 in the control group. Chlamydial prevalence was four times more in cases as compared to the control group, which is significant. The mean age was 27.97 + 4.520 years. Out of 14 positive cases, 8 (57.14%) had symptoms, whereas 6 (42.85%) were asymptomatic; in controls, 2 were symptomatic, whereas 2 were asymptomatic. HSG and laparoscopy were positive in chlamydia positive cases. Conclusion: It can be presumed that there is a significant role of C. trachomatis in infertility and also there is an association between chlamydia antigen detection and tubal factor infertility.

Clinico-Biological Profile of the Azoosperm Patient at the Urology and Andrology Department, Conakry University Hospital

Objective: Azoospermia is one of the most important causes of couple infertility. The objective of our study is to report the clinical-biological profile of the azoosperm patient to the Urology-Andrology Department of the Conakry University teaching Hospital. It aims to take stock of the diagnostic management of azoospermia at this time where the world scientific community seems to be turned towards the intracytoplasmic sperm injection in the treatment of men with severe spermiological dysfunction. Patients and Method: This was a descriptive retrospective study lasting 12 months from January 1 to December 31, 2015. It collected 151 patients out of a set of 544 follow-ups for desire to have children. Were included the patients whose files contained all the information of the clinical observation (general information, reason for consultation, evolution, history, data of the physical examination) and a paraclinical assessment consisting of the FSH level and two spermograms spaced three months, confirming the diagnosis of azoospermia. Results: The mean age was 36.4 years with extremes of 23 and 56 years old. Urogenital infections (36.4%) followed by a notion of inguinal surgery had been the main patients’ history. Primary infertility accounted for 76.8% of cases. The mean duration of infertility was 6.5 years with extremes of 2 and 19 years. Azoospermia affected 27.76% of patients who consulted for the desire to have a child. It was judged secretory in 59.6% of cases, excretory in 25.8% of cases, and undetermined in 14.6% of cases. Varicocele was the main associated abnormality (46.3%) followed by testicular hypotrophy (36.4%). Neisseria Gonorrhoeae was the most common germ in sperm culture (21.7%). Chlamydia serology was positive in 21.7% of patients. Conclusion: Azoospermia affects a non-negligible proportion of men admitted by consulting for desire to have a child in our context. Strengthening the diagnostic and therapeutic arsenal is necessary to improve the care of affected patients.

Role of Laparoscopic Surgery in the Management of Female Infertility at the Department of Gynecology of H&amp;#244;pital du Mali

Infertility is a socio-cultural drama in Africa, especially in Mali and remains difficult for couples to overcome. Laparoscopy, also called minimally invasive surgery or keyhole surgery, is an operative technique that permits to explore the pelvis and perform an appropriate therapeutic procedure. The objective of our work was to assess the role of laparoscopic surgery in the treatment of female infertility at Hopital du Mali. It was a retrospective descriptive study that was conducted over a period of 5 years (January 2013 to December 2018). Any patients followed for infertility and who underwent laparoscopic surgery in the gynecology department over a period of two (2) years were included. The outcome of laparoscopic surgery was evaluated in terms of conception of pregnancy. We had collected 103 infertile patients out of 2984, with a frequency of 3.45%. The mean age of our patients was 30.2 years. Housewives and out-of-school women accounted for 68.93% and 54.37% respectively. Nulligravida represented 41.75%. Regarding infertility, it was primary in 41.75% and secondary in 58.25%, with an average duration of 6.2 years. Systematic chlamydial serology was positive in 62.14% of our patients. Hysterosalpingography (HSG) revealed bilateral tubal obstruction in 53.33% of cases. Laparoscopy found tubal adhesions in 97.80% of cases. Adhesiolysis was the main procedure performed with 84.47% bilateral tubal patency achieved in the methylene blue test. Among our patients who had contracted a pregnancy (22.99%), 85% had carried their pregnancies to term. Tubal damage was the main cause of infertility. Adhesiolysis remains the main laparoscopic procedure for treatment.

Chlamydia trachomatis and Anti-MUC1 Serology and Subsequent Risk of High-Grade Serous Ovarian Cancer: A Population-Based Case–Control Study in Northern Sweden

BACKGROUND:Chlamydia trachomatis salpingitis causes inflammatory damage to the fallopian tube and could potentially cause initiation and progression of high-grade serous ovarian cancer (HGSC). Furthermore, C. trachomatis infection may stimulate mucin 1 (MUC1) protein production, possibly affecting anti-MUC1 antibody levels. The aim of this study was to examine if serology indicating past infection with C. trachomatis as well as anti-MUC1 production was associated with subsequent risk of HGSC. MATERIALS AND METHODS: In a prospective nested case–control study within the Northern Sweden Health and Disease Study and the Northern Sweden Maternity Cohort, the prevalence of chlamydial and anti-MUC1 antibodies was analyzed in blood samples drawn more than one year before diagnosis from 92 women with HGSC and 359 matched controls. Matching factors were age, date at blood draw, and sampling cohort. Plasma C. trachomatis IgG was analyzed using commercial micro-immunofluorescence test; chlamydial Heat Shock Protein 60 IgG (cHSP60) and anti-MUC1 IgG were analyzed with ELISA technique. RESULTS: The prevalence of C. trachomatis IgG and cHSP60 IgG antibodies, as well as the level of anti-MUC1 IgG was similar in women with HGSC and controls (16.3% vs. 17.0%, P = 0.87; 27.2% vs. 28.5%, P = 0.80; median 0.24 vs. 0.25, P = 0.70). Anti-MUC1 IgG and cHSP60 IgG levels were correlated (r = 0.169; P < 0.001). CONCLUSIONS: The findings of this prospective nested case–control study did not support an association between C. trachomatis infection, as measured by chlamydial serology, or anti-MUC1 IgG antibodies, and subsequent risk of HGSC.

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Role of Chlamydia trachomatis serology in conservative management of cervical intraepithelial neoplasia grade 2.

To evaluate the spontaneous progression of cervical intraepithelial neoplasia grade 2 (CIN2) in accordance with Chlamydia trachomatis (chlamydia) serology. A prospective observational study included women diagnosed with CIN2 by cervical biopsy and managed conservatively for 24months at Hospital del Mar, Barcelona, between December 2011 and October 2013. Serum anti-chlamydia immunoglobulin G (IgG), previous cytology, and high-risk human papillomavirus (HPV) genotyping were recorded at baseline. The outcome was regression, persistence, or progression of CIN2. Overall, 93 women aged 18-56years were enrolled. Spontaneous regression was observed for 61 (66%) women, and 21 (23%) progressed to CIN3. Eight (9%) women had chlamydia seropositivity at baseline. Multivariate analysis showed that anti-chlamydia IgG seropositivity (odds ratio [OR], 19.1; 95% confidence interval [CI], 1.9-189.7), previous high-grade squamous intraepithelial lesion cytology (OR, 5.0; 95% CI, 1.7-14.6), and HPV16 (OR, 4.8; 95% CI, 1.7-13.7) increased the risk of CIN2 persistence or progression. Women with CIN2 and chlamydia IgG seropositivity had increased risk of progression to CIN2+ and immediate treatment may be recommended for these women. Larger clinical studies are needed to confirm the results, but chlamydia serology might be introduced into CIN2 management to better individualize treatment.

Relation between Chlamydia trachomatis infection and pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility in a Dutch cohort of women previously tested for chlamydia in a chlamydia screening trial

ObjectivesA better understanding of Chlamydia trachomatis infection (chlamydia)–related sequelae can provide a framework for effective chlamydia control strategies. The objective of this study was to estimate risks and risk factors...

Community-level chlamydial serology for assessing trachoma elimination in trachoma-endemic Niger

BackgroundProgram decision-making for trachoma elimination currently relies on conjunctival clinical signs. Antibody tests may provide additional information on the epidemiology of trachoma, particularly in regions where it is disappearing or elimination targets have been met.MethodsA cluster-randomized trial of mass azithromycin distribution strategies for trachoma elimination was conducted over three years in a mesoendemic region of Niger. Dried blood spots were collected from a random sample of children aged 1–5 years in each of 24 study communities at 36 months after initiation of the intervention. A multiplex bead assay was used to test for antibodies to two Chlamydia trachomatis antigens, Pgp3 and CT694. We compared seropositivity to either antigen to clinical signs of active trachoma (trachomatous inflammation—follicular [TF] and trachomatous inflammation—intense [TI]) at the individual and cluster level, and to ocular chlamydia prevalence at the community level.ResultsOf 988 children with antibody data, TF prevalence was 7.8% (95% CI 6.1 to 9.5) and TI prevalence was 1.6% (95% CI 0.9 to 2.6). The overall prevalence of antibody positivity to Pgp3 was 27.2% (95% CI 24.5 to 30), and to CT694 was 23.7% (95% CI 21 to 26.2). Ocular chlamydia infection prevalence was 5.2% (95% CI 2.8 to 7.6). Seropositivity to Pgp3 and/or CT694 was significantly associated with TF at the individual and community level and with ocular chlamydia infection and TI at the community level. Older children were more likely to be seropositive than younger children.ConclusionSeropositivity to Pgp3 and CT694 correlates with clinical signs and ocular chlamydia infection in a mesoendemic region of Niger.Trial registrationClinicalTrials.gov NCT00792922.

The association between sperm quality and asymptomatic chlamydial infection in infertile men at a private fertility clinic in Nigeria

Background: Association between chlamydia trachomatis infection and male infertility is debated in literature. There is little or no information from Nigeria. The study aimed to determine the prevalence of chlamydial infection and its association with sperm quality parameters among asymptomatic men that present for infertility treatment in a Nigeria facility. Methods: A cross-sectional study conducted at a private assisted conception clinic in Lagos, Nigeria among 138 men seeking infertility care. Seminal fluid analysis and IgG Chlamydial serology were performed for each participant. Data obtained were analysed using SPSS; p was significant at <0.05. Results: Of the 138 men screened, 13.9% were Chlamydia-positive. Twenty-one per cent of clients who tested positive to Chlamydia had predominantly immotile sperm, compared with 10.2% without the infection; 26.3% with non-progressive motility had Chlamydia, compared with 2.8% men who were not infected. These differences were statistically significant (p = 0.001). More of those (57.9%) with Chlamydia (compared to 33.1% without) had significant leukocyte counts (p = 0.037). There were no statistically significant differences in sperm count and percent motility between serologically positive and negative men. Conclusion: Positive Chlamydia serology is associated with non-progressive motility and leukocytospermia in infertile Nigerian men. Keywords: Chlamydia, semen analysis, infertility

Bilateral but not unilateral tubal obstruction is associated with positive chlamydia serology.

Objective:To assess the association between positive Chlamydia trachomatis (C. trachomatis) serology and unilateral or bilateral tubal obstruction.Methods: This was a cross sectional study that evaluated the association of positive C. trachomatis serology (Immunofluorescence Indirect Serology, IIF or Enzyme Immune Essay, EIE), in two infertile groups: A. 243 patients (27 with unilateral obstruction and 216 without it). B. 247 patients (31 with bilateral obstruction and 216 without it). The exclusion criteria were tubal ligation (tubectomy) and tubal surgery. The statistical test (SPSS 17.0) was the Chi-Square with a p=5%. Tubal obstruction was diagnosed through hysterosalpingography (HSG).Results:The mean age of the patients without obstruction was 33.6 years, SD 4.9. The mean age of the patients with unilateral obstruction was 33.7 years SD 4.9. The mean age of the patients with bilateral obstruction was 33.6 years, SD 4.9. There was no statistically significant difference between the age groups. In group A (unilateral obstruction versus serology) the Chi-Square was 0.02 (p=n.s.) and the Attributable Risk (AR) = 0.7%. In Group B (bilateral obstruction versus serology) the Chi-Square test was 9.87 (p<0.005) and the AR = 14.8%.Conclusion:This study found a strong and statistically significant association between bilateral tubal obstruction and C. trachomatis positive serology. The power of the test was 86%. There was no association between unilateral obstruction and positive serology.

Discovery of Human-Specific Immunodominant Chlamydia trachomatis B Cell Epitopes.

Chlamydia species-specific serology is compromised by cross-reactivity of the gold standard microimmunofluorescence (MIF) or commercial enzyme-linked immunosorbent assays (ELISAs). This study was conducted to discover novel C.trachomatis-specific peptide antigens that were recognized only by the antibody response of the natural human host. We evaluated a library of 271 peptide antigens from immunodominant C.trachomatis proteins by reactivity with 125 C.trachomatis antibody-positive sera from women with PCR-confirmed C.trachomatis infection and 17 C.trachomatis antibody-negative sera from low-risk women never diagnosed with C.trachomatis infection. These C.trachomatis peptide antigens had been predicted in silico to contain B cell epitopes but had been nonreactive with mouse hyperimmune sera against C.trachomatis We discovered 38 novel human host-dependent antigens from 20 immunodominant C.trachomatis proteins (PmpD, IncE, IncG, CT529, CT618, CT442, TarP, CT143, CT813, CT795, CT223, PmpC, CT875, CT579, LcrE, IncA, CT226, CT694, Hsp60, and pGP3). Using these human sera, we also confirmed 10 C.trachomatis B cell epitopes from 6 immunodominant C.trachomatis proteins (OmpA, PmpD, IncE, IncG, CT529, and CT618) as host species-independent epitopes that had been previously identified by their reactivity with mouse hyperimmune sera against C.trachomatis ELISA reactivities against these peptides correlated strongly with the C.trachomatis microimmunofluorescence (MIF) text results (Pearson's correlation coefficient [R] = 0.80; P < 10-6). These C.trachomatis peptide antigens do not cross-react with antibodies against other Chlamydia species and are therefore suitable for species-specific detection of antibodies against C.trachomatis This study identified an extended set of peptide antigens for simple C.trachomatis-specific ELISA serology.IMPORTANCE Current serological assays for species-specific detection of anti-Chlamydia species antibodies suffer from well-known shortcomings in specificity and ease of use. Due to the high prevalences of both anti-C.trachomatis and anti-C.pneumoniae antibodies in human populations, species-specific serology is unreliable. Therefore, novel specific and simple assays for chlamydial serology are urgently needed. Conventional antigens are problematic due to extensive cross-reactivity within Chlamydia spp. Using accurate B cell epitope prediction and a robust peptide ELISA methodology developed in our laboratory, we identified immunodominant C.trachomatis B cell epitopes by screening performed with sera from C.trachomatis-infected women. We discovered 38 novel human host-dependent antigens from 20 immunodominant C.trachomatis proteins, in addition to confirming 10 host-independent mouse serum peptide antigens that had been identified previously. This extended set of highly specific C.trachomatis peptide antigens can be used in simple ELISA or multiplexed microarray formats and will provide high specificity and sensitivity to human C.trachomatis serodiagnosis.

Microbial etiology in hospitalized North Indian adults with community-acquired pneumonia.

Background:There is a paucity of literature regarding the microbial etiology of community-acquired pneumonia (CAP) in India. The current study was aimed to study the microbial etiology of hospitalized adults with CAP.Methods:The study was conducted in a 700-bedded North Indian hospital. Consecutive adults admitted with CAP over a period of 2 years from 2013 to 2015 were recruited for the study, and apart from clinical evaluation underwent various microbiological studies in the form of blood culture, sputum culture, urinary antigen for pneumococcus and Legionella, serology for Mycoplasma and Chlamydia and real-time reverse transcriptase polymerase chain reaction for influenza viruses. Radiographic studies were performed in all patients and repeated as required. The patients were treated with standard antibiotic/antiviral therapy and outcomes were recorded.Results:A total of 225 patients (median age: 59 years) were enrolled. Streptococcus pneumoniae was the most common organism found (30.5%), followed by Legionella pneumophila (17.5%), influenza viruses (15.4%), Mycoplasma pneumoniae (7.2%), Chlamydia pneumonia (5.5%), Mycobacterium tuberculosis (4.8%), Klebsiella pneumoniae (4.8%), methicillin-resistant Staphylococcus aureus (3.5%), Pseudomonas aeruginosa (3.1%), methicillin-sensitive S. aureus (1.7%), and Acinetobacter sp. (0.8%) with 4% of patients having multiple pathogens etiologies. High Pneumonia Severity Index score correlated with the severity and outcome of the CAP but was not predictive of any definite etiological pathogen. In-hospital mortality was 8%.Conclusion:Streptococcus pneumoniae, Legionella, and influenza constitute the most common etiological agents for north Indian adults with CAP requiring hospitalization. Appropriate antibiotic therapy and preventive strategies such as influenza and pneumococcal vaccination need to be considered in appropriate groups.

Association of Chlamydia serology with HIV in Nigerian women

This research was carried out to detect the presence of Chlamydia in pregnant women and gynaecologic patients in the North-central geopolitical zone of Nigeria. Blood samples were collected and analysed by ELISA techniques. The blood samples were also screened for HIV infection. A sero-prevalence of 59.0% was recorded for the study area. The sero-prevalence was higher among the gynaecologic patients (62.0%) than the pregnant women (57.5%). The difference was statistically significant (P = 0.0001). Of the four centers chosen for the study, the Federal Capital Territory (Abuja) had the highest prevalence (84.7%), while Niger State had the least (28.7%). The difference was also statistically significant (P&lt;0.0001). The prevalence rate of HIV among the participants in the study center was found to be 17.2%. Abuja had the highest prevalence rate of 24.6%, followed by Benue, 16.7%, then Kogi, 12.0% and finally, Niger, 4.7%. Chlamydia was found to be associated with HIV (p&lt;0.0001). The sero-prevalence of chlamydia in the North-Central zone of Nigeria was found to be high. Chlamydia was found to be correlated with HIV in the study area and may have contributed to the zone emerging with the highest HIV prevalence in the country. For an infection that is largely asymptomatic but has devastating effects on populations, only a preventive approach would have beneficial effects in controlling the disease and its effects on women’s health in the country.Keywords: Chlamydia trachomatis, HIV, pregnant women, gynaecologic patients, co-infection

Detection rate of Pneumococcal Pneumonia using the Urine Antigen Kit BinaxNow Streptococcus Pneumoniae Test: a Prospective Cohort Study in a Tertiary Hospital in Malaysia

Background: Pneumococcal pneumonia is the commonest type of bacterial pneumonia worldwide. In Malaysia, the reported incidence of pneumococcal pneumonia is low. This may be due to poor sensitivity of conventional methods. The use of BinaxNOW, a urinary antigen test for Streptococcus pneumoniae can aid in the diagnosis of pneumococcal pneumonia. Objective: To determine the detection rate of pneumococcal pneumonia using BinaxNOW kit and to compare this with the conventional culture method for blood and sputum. Methods: This was a prospective cohort study involving patients 18 year-old and above admitted for community-acquired pneumonia (CAP) or health-care associated pneumonia (HCAP) to UKMMC between December 2011 and June 2012. BinaxNOW test, serology for Mycoplasma, Legionella and Chlamydia and cultures from blood/sputum/other respiratory tract samples and other routine investigations were performed. Results: A total of 102 patients were recruited; 89 (87.3%) with CAP, 13 (12.7%) with HCAP. 57 (55.9%) had pneumonia of unknown aetiology, 11 patients (10.8%) had positive blood cultures, 8 patients (7.8%) had a positive urine BinaxNOW test and 6 patients (5.9%) had positive sputum cultures. Streptococcus pneumoniae was the commonest isolate accounting for 9 cases (8.8%) followed by Klebsiella pneumoniae in 7 cases (6.9%). 8 out of 9 patients with positive urine BinaxNOW test had negative cultures for Streptococcus pneumoniae. One patient grew Streptococcus pneumoniae from the tracheal aspirate however the urine BinaxNOW test was negative. Conclusion: The use of urine BinaxNOW kit in UKMMC increased the detection rate of pneumococcal pneumonia in hospitalized patients.

Evaluation of tubal and peritoneal factors in chlamydia positive infertile women by laparoscope

Background: Abnormalities or damage to the fallopian tube interferes with fertility and is responsible for abnormal implantation (eg, ectopic pregnancy). Obstruction of the distal end of the fallopian tubes results in accumulation of the normally secreted tubal fluid, creating distention of the tube with subsequent damage of the epithelial cilia (hydrosalpinx). Genital Chlamydia trachomatis infection has a worldwide distribution6 and is now recognized as the single most common cause of tubal peritoneal damage. The study explores the relationship between serum chlamydia antibody titres (CATs) and detection of tubal damage in infertile women.Objective: To Evaluation of tubal and peritonial factors in chlamydia positive infertile women by laparoscope.Methodology: The tubal status and pelvic findings in 138 women underwent laparoscopy for infertility were related to CAT, which was measured using the whole-cell inclusion immunofluorescence test. RESULTS: A total of 138 infertile women who underwent laparoscopic investigation for infertility were identified and they were divided in two groups, on the bsis of presence is absence Chlamydia positive (n=69) and Chlamydia Negative (n=69). Demographic status were almost similar between two groups, however service holder was found significantly higher in Chlamydia positive group (17 vs. 7). Tubal block was found in 44(63.7%) in Chlamydia positive and 37(53.6%) in Chlamydia negative. The difference was statistically significant (p&lt;0.01) between two groups. Site of block &amp; hydrosalpinges was almost similar between two groups. POD was completely obliterated in 10(14.5%) in Chlamydia positive and 3(4.3%) in Chlamydia negative. The difference was statistically significant (p&lt;0.05) between two groups.Conclusion: Chlamydia serology is useful mainly as a screening test for the likelihood of tubal damage in infertile women and may facilitate decisions on which women should proceed with further investigations without delay.J Shaheed Suhrawardy Med Coll, December 2015, Vol.7(2); 54-58

P11.11 High rates of co-occurring sexually transmissible infections among men who have sex with men attending high-caseload general practice and sexual health services in victoria

Introduction Sexually transmissible infection (STI) screening and treatment is a health priority for gay, bisexual and other men who have sex with men (GBM). Current Australian guidelines recommend frequent syphilis serology and screening for pharyngeal, anorectal and urogenital chlamydia and gonorrhoea infection, in addition to routine HIV testing. However, evidence from recent community surveys that many Australian GBM access only some of these tests suggests concurrent infections may remain undetected. Methods To better understand the epidemiology of co-occurring curative STIs, we calculated the proportion of positive tests for one or more STI among GBM attending two sexual health services and two gay-friendly high-caseload general practices in Victoria between 2007 and 2013. Among positive tests for chlamydia or gonorrhoea, we calculated the proportion positive at multiple anatomical sites. We examined demographic and risk behaviour associations with co-occurring STIs and positivity at multiple anatomical sites using adjusted logistic regression. Results There were 70977 test events between 2007 and 2013; 8316 (11.7%) were positive for at least one STI and of these, 792 (9.5%) were positive for more than one STI. Younger age (16–29 years) (aOR = 1.7, 95% CI = 1.1–2.7), being HIV-positive (aOR = 2.2, 95% CI = 1.5–3.1) and reporting inconsistent condom use (aOR = 1.3, 95% CI = 1.0–1.6) were associated with testing positive for co-occurring infections. Of 7584 test events positive for chlamydia or gonorrhoea, 1028 (13.6%) were positive for either infection at multiple sites. Being aged 16–29 (aOR = 2.9, 95% CI = 1.8–4.6) or 30–39 (aOR = 2.4, 95% CI = 1.5–3.9) was associated with testing positive for either infection at multiple sites. Conclusion The high prevalence of co-occurring STIs and infection at multiple anatomical sites supports national guidelines for frequent comprehensive testing for GBM. These results support the promotion of comprehensive STI testing for GBM, including in lower-caseload settings alongside taking appropriate sexual histories, and underline the importance of structural efforts to maximise access to comprehensive testing for GBM. Disclosure of interest statement All authors have no conflicts to declare. The authors gratefully acknowledge patients and participating clinics and laboratories for the ongoing data contribution. The authors acknowledge Drs Norm Roth and BK Tee for their ongoing support of surveillance work at the Burnet Institute. The Victorian Department of Health funds ongoing surveillance projects within the Burnet Institute. The authors would like to acknowledge the NHMRC who provide funding to Anna Wilkinson as a public health scholarship recipient. Mark Stoove is supported by an NHMRC Career Development Fellowship. The authors gratefully acknowledge the contribution to this work of Victorian Operational Infrastructure Support Program received by the Burnet Institute.

Defining species-specific immunodominant B cell epitopes for molecular serology of Chlamydia species.

Urgently needed species-specific enzyme-linked immunosorbent assays (ELISAs) for the detection of antibodies against Chlamydia spp. have been elusive due to high cross-reactivity of chlamydial antigens. To identify Chlamydia species-specific B cell epitopes for such assays, we ranked the potential epitopes of immunodominant chlamydial proteins that are polymorphic among all Chlamydia species. High-scoring peptides were synthesized with N-terminal biotin, followed by a serine-glycine-serine-glycine spacer, immobilized onto streptavidin-coated microtiter plates, and tested with mono-specific mouse hyperimmune sera against each Chlamydia species in chemiluminescent ELISAs. For each of nine Chlamydia species, three to nine dominant polymorphic B cell epitope regions were identified on OmpA, CT618, PmpD, IncA, CT529, CT442, IncG, Omp2, TarP, and IncE proteins. Peptides corresponding to 16- to 40-amino-acid species-specific sequences of these epitopes reacted highly and with absolute specificity with homologous, but not heterologous, Chlamydia monospecies-specific sera. Host-independent reactivity of such epitopes was confirmed by testing of six C. pecorum-specific peptides from five proteins with C. pecorum-reactive sera from cattle, the natural host of C. pecorum. The probability of cross-reactivity of peptide antigens from closely related chlamydial species or strains correlated with percent sequence identity and declined to zero at <50% sequence identity. Thus, phylograms of B cell epitope regions predict the specificity of peptide antigens for rational use in the genus-, species-, or serovar-specific molecular serology of Chlamydia spp. We anticipate that these peptide antigens will improve chlamydial serology by providing easily accessible assays to nonspecialist laboratories. Our approach also lends itself to the identification of relevant epitopes of other microbial pathogens.

PS-374a Predictors Of Bacterial Community Acquired Pneumonia In Children: Preliminary Results From Capes (community Acquired Pneumonia Aetiology Study)

Background The majority of childhood community acquired pneumonia (CAP) in developing countries is believed to be bacterial in origin. However, the predictors of bacterial versus non-bacterial (viral) pneumonia are not clearly defined. This is essential for judicious use of antibiotic therapy. Objective To determine the microbiologic aetiology of childhood CAP in India, and determine the predictors of bacterial pneumonia. Methods Children (1 month -1 2 years) fulfilling World Health Organisation criteria for pneumonia (cough or difficult breathing, and tachypnea; for 2 011-March2013) surveillance programme. Pneumonia severity was assessed using WHO criteria. Nasopharyngeal aspirate (NPA) culture, blood culture, IgM anti-Mycoplasma pneumoniae and IgM anti-Chlamydia pneumoniae were examined. Demographic characteristics, clinical profile, presence of ‘risk factors’, clinical examination findings, and radiographic features were evaluated as predictors of bacterial aetiology. Results 2333 children with CAP were enrolled. 61% were 5–12 years. Figure 1 presents the pneumonia severity. Bacterial pathogens were isolated in 12.7% NPA cultures with Pneumococcus (n = 223), Staphylococcus aureus (n = 27), and Haemo philus influenzae (n = 23) predominating. Blood culture yielded bacteria in only 3.3%. S. aureus (n = 25), Gram negative bacilli (n = 21), and Alpha-hemolytic Streptococcus (n = 15) predominated. Pneumococcus (n = 3) accounted for a minority. Serology for Mycoplasma and Chlamydia were positive in 4.4% and 1.6% samples respectively (Figure 2A,2B). Table 1 highlights the unadjusted odds ratio for various factors explored as predictors of bacterial aetiology. Exposure to over-crowding at home appeared to be associated with a lower risk of bacterial aetiology, whereas exposure to tobacco smoke was associated with higher risk. None of the other factors predicted bacterial aetiology. Conclusion The majority of childhood community acquired pneumonia appears to be non-bacterial in origin. Bacterial aetiology could not be predicted by demographic, clinical, or radiographic features, that are usually believed to be associated with bacterial aetiology.