Prevalence and determinants of Chlamydia trachomatis infections in women from Bogota, Colombia

Determinants of Chlamydia, Gonorrhea, and Coinfection in Heterosexual Adolescents Attending the National Public Sexually Transmitted Infection Clinic in Singapore

BACKGROUND

Amidst recent trends in rising rates of chlamydia and gonorrhea among Singaporean adolescents, there are limited data on risk factors associated with these infections that may inform prevention strategies in this population.

METHODS

A cross-sectional study of chlamydia and gonorrhea positivity was conducted among 1458 sexually active heterosexual adolescents between 14 and 19 years old attending the national public sexually transmitted infection clinic from 2006 to 2013. The association with demographic and behavioral characteristics was assessed by crude prevalence ratio, and negative binomial regression modeling was used to obtain adjusted prevalence ratios (aPRs).

RESULTS

Chlamydia positivity was found in 23.6% of males and 36.6% of females, gonorrhea positivity in 33.1% of males and 15.9% of adolescent girl, and coinfection positivity in 10.2% of males and 10.1% of females. In multivariable analysis, chlamydia was positively associated with being Malay (aPR, 1.6; 95% confidence interval [CI], 1.1-2.1) and inconsistent condom use for vaginal sex (aPR, 6.5; 95% CI = 2.4-17.4) in males and with being Malay (aPR, 1.9; 95% CI = 1.5-2.4), inconsistent condom use for vaginal sex (aPR, 2.0; 95% CI = 1.1-3.9), and number of lifetime partners in females (aPR, 1.1; 95% CI = 1.0-1.1). Gonorrhea was positively associated with being Malay (aPR, 3.2; 95% CI = 2.4-4.4), inconsistent condom use for vaginal sex (aPR, 5.4; 95% CI = 2.1-14.4), and number of lifetime partners (aPR, 1.1; 95% CI = 1.0-1.1) in males and with being Malay (aPR, 3.7; 95% CI = 2.4-5.7) in females. Malays had a higher proportion of sexual risk behaviors compared with the non-Malays.

CONCLUSIONS

Ethnicity and high-risk sexual behaviors are important determinants of chlamydia, gonorrhea, and coinfection for adolescents attending this clinic. Targeted interventions are needed to lower the prevalence of high-risk sexual behaviors for the Malay adolescents in this clinic.

Chlamydia trachomatis Frequency in a Cohort of HPV-Infected Colombian Women

Background

Chlamydia trachomatis (C. trachomatis), an obligate intracellular bacterium, is the commonest infectious bacterial agent of sexual transmission throughout the world. It has been shown that the presence of this bacteria in the cervix represents a risk regarding HPV persistence and, thereafter, in developing cervical cancer (CC). Prevalence rates may vary from 2% to 17% in asymptomatic females, depending on the population being analysed. This study reports the identification of C. trachomatis in a cohort of 219 HPV-infected Colombian females.

Methods

C. trachomatis infection frequency was determined during each of the study’s follow-up visits; it was detected by amplifying the cryptic plasmid sequence by polymerase chain reaction (PCR) using two sets of primers: KL5/KL6 and KL1/KL2.

Infection was defined as a positive PCR result using either set of primers at any time during the study. Cox proportional risk models were used for evaluating the association between the appearance of infection and a group of independent variables.

Results

Base line C. trachomatis infection frequency was 28% (n = 61). Most females infected by C. trachomatis were infected by multiple types of HPV (77.42%), greater prevalence occurring in females infected with HPV-16 (19.18%), followed by HPV-58 (17.81%). It was observed that females having had the most sexual partners (HR = 6.44: 1.59–26.05 95%CI) or infection with multiple types of HPV (HR = 2.85: 1.22–6.63 95%CI) had the greatest risk of developing C. trachomatis.

Conclusions

The study provides data regarding the epidemiology of C. trachomatis /HPV coinfection in different population groups of Colombian females and contributes towards understanding the natural history of C. trachomatis infection.

Chlamydia trachomatis infection: implications for HPV status and cervical cancer

Genital Chlamydia trachomatis (CT) infections have been identified as a major health problem concern. CT is associated with adverse effect on women reproduction and also associated with cervical hypertrophy and induction of squamous metaplasia, providing a possible relationship with human papillomavirus (HPV) infection. Infection by high-risk HPV types is crucial to the pathogenesis of invasive cervical cancer (ICC), but other co-variants/cofactors must be present for the development of malignancy. CT biological effect may damage the mucosal barrier, improving HPV infection, or may interfere in immune response and viral clearance supporting the persistence of HPV infection. Moreover, CT-related chronic cervical inflammation, decrease of lower genital tract antigen-presenting cells, inhibition of cell-mediated immunity, and anti-apoptotic capacity may influence the natural history of HPV infection, namely persistence progression or resolution. Although several epidemiological studies have stated a positive association involving CT and HPV-related cervical neoplastic lesions and/or cervical cancer (CC), the specific role of this bacterium in the pathogenesis of cervical neoplasia has not been completely clarified. The present review summarizes several studies on CT role in cervical cancer and suggests future research directions on HPV and CT interaction.

Prevalence of genital Chlamydia infection in urban women of reproductive age, Nairobi, Kenya

BACKGROUND

Chlamydia trachomatis is one of the major causes of sexually transmitted infections throughout the world. Most infections are asymptomatic and remain undetected. Burden of disease in the Kenyan population is not well characterised. This study was done to define the prevalence of genital Chlamydia infection in a representative female population.

FINDINGS

A cross-sectional study design was employed. All women attending out-patient clinics (antenatal, gynaecology, family planning) and accident and emergency departments at two study sites over a five month period were invited to consent to completion of a questionnaire and vaginal swab collection. A rapid point-of-care immunoassay based test was performed on the swabs. Women who tested positive for Chlamydia were offered treatment, together with their partner(s), and advised to come for a follow-up test.A total of 300 women were tested. The prevalence of genital Chlamydia trachomatis was found to be 6% (95% CI 3.31% - 8.69%). The prevalence was higher in women who represented a higher socioeconomic level, but this difference was not significant (p=0.061). Use of vaginal swabs was observed to be a more acceptable form of sample collection.

CONCLUSION

The prevalence of genital Chlamydia is significant in our female population. There is a justifiable need to institute opportunistic screening programs to reduce the burden of this disease. Rapid and low cost point-of-care testing as a potential component of sexually transmitted infection (STI) screening can be utilised.

Comparison of three genotyping methods to identify Chlamydia trachomatis genotypes in positive men and women

Chlamydia trachomatis (Ct) comprises 3 serogroups and 19 serovars. Different genotyping methods are available to differentiate between the serovars. The aim of this study was to evaluate the sensitivity and discriminatory power of three genotyping methods, respectively Omp1 sequencing, the Ct Detection and genoTyping (DT) assay and the pmpH real-time PCR discriminating an LGV infection from a non-LGV infection. In total, 50 Aptima Combo 2 (AC2) Ct positive samples were selected and tested with the 3 genotyping methods. The Ct-DT assay detected 3 double Ct infections that caused a non interpretable result by Omp1 sequencing, while Omp1 sequencing has a higher discriminatory power that gave additional information about Ct genovariants. All three methods detected the 6 LGV samples. Although the pmpH real-time PCR detected all LGV infections, a substantial amount (24%) of non-LGV infections were missed. The sensitivity compared to AC2 Ct detection was 80% (95% CI 67-89%) for the Ct-DT assay, 72% (95% CI 58-83%) for Omp1 sequencing and 64% (95% CI 50-76%) for the pmpH real-time PCR. In conclusion, the Ct-DT assay is appropriate for serovar distribution studies, epidemiological studies and differentiation between an LGV and non-LGV Ct infection, while Omp1 sequencing is more appropriate for phylogenetic studies. The pmpH real-time PCR is suitable as second assay to differentiate between an LGV and non-LGV infection, but not as primary detection assay, due to its low sensitivity for non-LGV strains.

Predictors of human papillomavirus persistence among women with equivocal or mildly abnormal cytology

We investigated short-term persistence of human papillomavirus (HPV) infection among 2,408 women with low-grade or equivocal cytological abnormalities followed for 24 months. Odds ratios (ORs) for persistence to the next 6-month visit were estimated by a discrete time survival model. Prevalent HPV infections persisted longer in older women, but no association with age was found for incident HPV infections. Increased likelihood of persistence was found among current smokers of >20 cigarettes per day compared with smokers of <or=10 cigarettes per day (OR=1.43; 95% confidence interval [CI]: 1.02-2.01) and among current injectable contraceptive users (OR=1.15; 95% CI: 1.01-1.32). Persistence was more likely among infections with higher viral load (OR=2.05; 95% CI: 1.65-2.53) or with concurrent cytological abnormalities (OR=1.19; 95% CI: 1.03-1.39 and 1.29; 95% CI: 0.99-1.70 for ASCUS/LSIL and ASC-H/HSIL, respectively). We conclude that new HPV infections in older women are not riskier by the metric of viral persistence than those in younger women. Other risk factors such as oral contraceptive use and multiparity that have been associated with cervical cancer or cervical intraepithelial neoplasia grade 3 were not associated with short-term HPV persistence.

Chlamydia trachomatis infection and associated risk factors in a low-income marginalized urban population in coastal Peru

OBJECTIVES

To estimate Chlamydia trachomatis (CT) infection prevalence and associated risk factors among a low-income marginalized urban population in Peru.

METHODS

Between April 2003 and April 2005, men and women at high-risk for sexually transmitted infections (STIs) were recruited from low-income urban areas in three coastal cities in Peru (Chiclayo, Lima, and Trujillo). Consenting participants were studied using a sero-epidemiologic survey. Urine and vaginal swabs collected from men and women were evaluated using polymerase chain reaction (PCR) (COBAS AMPLICOR (CT/NG) Test, Roche Molecular Diagnostics, Branchburg, NJ, USA) for CT.

RESULTS

Among the 2 440 participants recruited for the study (2 145 men and 295 women), overall prevalence of CT infection was 6.6% (95% CI, 5.6-7.6%): 5.5% (95% CI, 4.5-6.5%) in men and 14.9% (95% CI, 11.7-27.1%) in women. Chlamydial infection was inversely associated with age and positively associated with HIV infection and dysuria in men. Among women, chlamydial infection was inversely associated with age and positively associated with number of sex partners.

CONCLUSIONS

CT infection was common among high-risk men and women in urban coastal Peru. Because chlamydial infection is associated with complications related to female reproduction, including infertility and ectopic pregnancy, interventions to prevent and treat infection and studies to determine the feasibility of population-based screening for CT should be conducted among the high-risk female population.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Type I interferon signaling exacerbates Chlamydia muridarum genital infection in a murine model

Type I interferons (IFNs) induced during in vitro chlamydial infection exert bactericidal and immunomodulatory functions. To determine the precise role of type I IFNs during in vivo chlamydial genital infection, we examined the course and outcome of Chlamydia muridarum genital infection in mice genetically deficient in the receptor for type I IFNs (IFNAR(-/-) mice). A significant reduction in chlamydial shedding and duration of lower genital tract infection was observed in IFNAR(-/-) mice in comparison to the level of chlamydial shedding and duration of infection in wild-type (WT) mice. Furthermore, IFNAR(-/-) mice developed less chronic oviduct pathology in comparison to that in WT mice. Compared to the WT, IFNAR(-/-) mice had a greater number of chlamydial-specific T cells in their iliac lymph nodes 21 days postinfection. IFNAR(-/-) mice also exhibited earlier and enhanced CD4 T-cell recruitment to the cervical tissues, which was associated with increased expression of CXCL9 in the genital secretions of IFNAR(-/-) mice, but not with expression of CXCL10, which was reduced in the genital secretions of IFNAR(-/-) mice. These data suggest that type I IFNs exacerbate C. muridarum genital infection through an inhibition of the chlamydial-specific CD4 T-cell response.

A highly sensitive, multiplex broad-spectrum PCR-DNA-enzyme immunoassay and reverse hybridization assay for rapid detection and identification of Chlamydia trachomatis serovars

Chlamydia trachomatis (Ct) comprises distinct serogroups and serovars. The present study evaluates a novel Ct amplification, detection, and genotyping method (Ct-DT assay). The Ct-DT amplification step is a multiplex broad-spectrum PCR for the cryptic plasmid and the VD2-region of ompl. The Ct-DT detection step involves a DNA enzyme immunoassay (DEIA) using probes for serogroups (group B, C, and intermediate) and the cryptic plasmid, permitting sensitive detection of 19 Ct serovars (A, B/Ba, C, D/Da, E, F, G/Ga, H, I/Ia, J, K, L1, L2/L2a, and L3) without any cross-reactivity with other Chlamydia species and pathogenic bacteria or commensal organisms of the genital tract. Ct-positive samples are analyzed by a nitrocellulose-based reverse hybridization assay (RHA) containing probes for the 19 different serovars and for the cryptic plasmid. The sensitivity of the PCR-DEIA on clinical specimen is equivalent to that of the Cobas TaqMan assay [kappa = 0.95 (95% confidence interval = 0.92 to 0.99)]. Using the RHA, 98% of the Ct-DT detection step-positive samples could be typed. Analysis of cervical swabs from Uganda and The Netherlands revealed that the most common serovars in Uganda are G/Ga (45%), E (21%), K (13%), and F (8%), and in The Netherlands serovars E (38%), F (23%), G/Ga (11%), and D/Da (7%) were most common. Thus, multiplex broad-spectrum PCR in combination with DEIA and RHA permits highly sensitive and specific detection and identification of Ct serovars.

Frequency of Chlamydia trachomatis in women with cervicitis in Tehran, Iran

Chlamydia trachomatis (CT) is the most common cause of bacterial sexually transmitted infection (STI) worldwide, but current data concerning the prevalence of CT among women in Iran is scarce. Data regarding the frequency of CT infection among Iranian women can help to justify the implementation of a national CT screening program that can reduce the high morbidity associated with sequelae of CT infections by treating infected women. Endocervical secretions from 123 married women (20–55 years) with cervicitis were tested by a PCR-EIA method using primers to amplify a CT-specific plasmid. The digoxigenin-labeled amplicon was measured by hybridization to a biotin-labeled probe and a strepavidin-coated plate, followed by an enzyme-linked colorimetric analysis. Overall frequency of CT infection among women was 17% (21/123). The range of CT frequency among various age groups was 12–25%. The 31–40-year-age group comprised the majority (49%) of CT positive samples, followed by 20–30 year group (33%). Although the 20-to-30-year-old women reported the highest frequency of STI history, they had the lowest relative frequency of CT infection (12%). There is a high frequency of CT infection among women with cervicitis in Tehran, Iran, thus indicating a necessity to implement a routine CT screening program in the major cities of Iran and possibly nationwide. Identification of CT-infected women may prevent its spread, and thereby reduce the high morbidity associated with CT infections among women in Iran.

Molecular detection ofChlamydia trachomatis and HPV infections in cervical samples with normal and abnormal cytopathological findings

It has been suggested that Chlamydia trachomatis (CT) and human papillomaviruses (HPV) co-infection could contribute to development of intraepithelial lesions. In this study, HPV and CT-DNA were investigated in 250 cervicovaginal samples of patients from Minas Gerais, Brazil. The cytological analysis revealed that 70% of samples (175) were negative, 5.2% (13) presented atypical squamous or glandular cells of undetermined significance (ASCUS/AGUS), 12.4% (31) presented low-grade squamous intraepithelial lesion (LSIL), 10.8% (27) high-grade squamous intraepithelial lesion (HSIL), and 1.6% (4) invasive carcinoma. HPV-DNA and HPV/CT co-infection was observed in 40% (100/250) and in 5.2% (13/250) of samples, respectively. Among the positive cytological samples, HPV-DNA was detected in 73.3% and CT-DNA in 9.33% and in 13%, if only the HPV positive samples were considered. The highest co-infection rate (15.4%) was observed among ASCUS/AGUS samples. Although a significant association was found for HPV infection and the precursor lesions of cervical cancer, it was not possible to establish a significant association between these lesions and CT or HPV/CT co-infection.

Is there a correlation between vaginal chlamydia infection and cervical smear abnormalities? A community-based study in the Al-Ain district, United Arab Emirates

AIM

The purpose of this study was to determine the correlation between vaginal chlamydia infection and cervical abnormalities. The data on the prevalence of chlamydia infection and cervical abnormalities have been presented elsewhere and in this article we provide the results of a correlation analysis.

METHODS

In this cross-sectional, community-based survey, women attending primary and secondary care in the Al-Ain medical district, United Arab Emirates, were offered cervical screening using the Papanicolaou smear, and chlamydia testing. A total of 793 women underwent cervical screening and 728 were tested for chlamydia. A commercially available kit was used to determine the prevalence of chlamydia. The correlation between cervical abnormalities and chlamydia infection was tested using the chi-squared test or Fisher's exact test, as appropriate.

RESULTS

The prevalence of abnormal smears was 1.51% (95% confidence interval [CI], 0.66-2.4). Twelve subjects had abnormal smears, including smears showing atypical squamous cells of undetermined significance. The prevalence of chlamydia infection in this population was 2.5% (95% CI, 1.2-3.3). Statistical analysis showed no association (chi2 0.6, P = 0.4) between the prevalence of chlamydia infection and cervical abnormalities.

CONCLUSION

Although there have been earlier reports of an association between vaginal chlamydia and cervical abnormalities, our study does not provide evidence to support this association.

Developing a realistic sexual network model of chlamydia transmission in Britain

BACKGROUND

A national chlamydia screening programme is currently being rolled out in the UK and other countries. However, much of the epidemiology remains poorly understood. In this paper we present a stochastic, individual based, dynamic sexual network model of chlamydia transmission and its parameterisation. Mathematical models provide a theoretical framework for understanding the key epidemiological features of chlamydia: sexual behaviour, health care seeking and transmission dynamics.

RESULTS

The model parameters were estimated either directly or by systematic fitting to a variety of appropriate data sources. The fitted model was representative of sexual behaviour, chlamydia epidemiology and health care use in England. We were able to recapture the observed age distribution of chlamydia prevalence.

CONCLUSION

Estimating parameters for models of sexual behaviour and transmission of chlamydia is complex. Most of the parameter values are highly correlated, highly variable and there is little empirical evidence to inform estimates. We used a novel approach to estimate the rate of active treatment seeking, by combining data sources, which improved the credibility of the model results. The model structure is flexible and is broadly applicable to other developed world settings and provides a practical tool for public health decision makers.

Chlamydia trachomatis and Human papillomavirus infections in cervical disease in Argentine women

OBJECTIVES

To examine the prevalence of Human papillomavirus and Chlamydia trachomatis DNA in cervical samples among women with normal and abnormal cervical cytology from La Plata, Argentina.

METHODS

Two hundred and seventy-nine women (200 with cervical neoplasia or ICC and 79 women with normal cytology) provided cervical samples for the detection of HPV and C. trachomatis DNA by PCR-based assays.

RESULTS

HPV DNA increased with the cervical lesion severity, ranging from 30% among women with normal cytology to 99-100% among women with HSIL or ICC. C. trachomatis DNA prevalence increased from low levels in women with normal cytology (11%) to 47% in those with HSIL, but was uncommon among ICC patients (20%). Among women with normal cytology, C. trachomatis prevalence was higher in HPV DNA positive (12.5%) than HPV DNA negative women (10.9%), but this difference was not significant.

CONCLUSIONS

HPV prevalence in the general population is slightly higher than those reported for other developing countries. C. trachomatis DNA positivity was associated with a higher risk of both LSIL and HSIL lesions, but not with ICC.

The IARC commitment to cancer prevention: the example of papillomavirus and cervical cancer

Every year approximately half a million women worldwide develop cervical cancer (CC) of whom 80% live in poor countries where population-based screening programmes are virtually non-existent. The role of sexually transmitted agents in the aetiology of cervical cancer has been suspected for more than a century, but knowledge in this field has rapidly expanded only in the last 20 years, after major improvements were made in detection methods for human papillomavirus (HPV). A dozen types of HPV have been identified in 99% of biopsy specimens from CC worldwide and the relative risk estimates for HPV in case-control studies of CC are in the 50 to 100 range. A meta-analysis done at the International Agency for Research on Cancer (IARC) included a total of 10,058 CC cases from 85 published studies. The most common HPV types identified in CC were, in order of decreasing prevalence, HPV 16, 18, 45, 31, 33, 58, 52, 35, 59, 56, 6, 51, 68, 39, 82, 73, 66 and 70. Over two-thirds of CC cases were associated with an infection of either HPV 16 (51.0%) or HPV 18 (16.2%). Despite the overwhelming importance of HPV, other factors contribute to the rare occurrence of CC after HPV infection. Nine case-control studies from the IARC have confirmed the adverse effect of long-term use of oral contraceptives, high parity, smoking and sexually transmitted infections (i.e. Chlamydia trachomatis and herpes simplex virus-2) after adjustment for, or stratification by, HPV infection. Ten surveys of HPV infection in population-based samples of approximately 15,000 women in four continents have shown that: (1) the prevalence of HPV infection varies greatly (between 2% and nearly 30%); and (2) the age distribution also varies widely, pointing to cohort effects. There is no effective medical treatment for HPV, but a prophylactic vaccine, based on late (L) 1 HPV 16 proteins, has been shown to be safe, highly immunogenic and efficacious in preventing persistent HPV infections. A multivalent vaccine against the most common oncogenic HPV types may thus ultimately represent the most effective way to prevent CC worldwide either alone, or in combination with screening. It may, however, take several years before this approach becomes a reality. Thus, early detection of CC precursor lesions by screening, and their treatment, will remain the most important measures for the control of CC for the foreseeable future.