Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chlamydia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

Mass media as a population-level intervention tool for Chlamydia trachomatis screening: report of a pilot study.

PURPOSE: To determine the feasibility and affect of mass media use in a population-level intervention for chlamydia screening promotion. METHODS: A population-level chlamydia intervention protocol was field tested. The intervention, targeting 15-25-year-old individuals, was designed to: (a) increase awareness of personal risk for chlamydial infection; (b) facilitate dissemination of chlamydia knowledge by use of a telephone hot line; and (c) promote care-seeking behavior (report for a chlamydia screening program). The intervention activities included: (a) mail outreach, (b) a television and radio campaign, (c) a prerecorded Check-It-Out chlamydia hot line, (d) a staffed chlamydia Options information line, and (e) a free confidential urine ligase chain reaction (LCR) test for chlamydia. Mass mailings were scheduled at intervals, starting two-weeks before the beginning of the television advertisement. The 30-second television advertisement was aired on local television stations 130 times in a 6-week period. The outcome measures were quantity and characteristics of incoming calls to the automated hot line and staffed chlamydia information phone line in response to the chlamydia campaign, and response to the urine screening program. Descriptive and bivariate analyses were used to evaluate the outcomes. RESULTS: The hot line was called 642 times during the monitoring period (November 1, 1999 to March 8, 2000), the majority (92%) during the 6 weeks of television advertisement, with an average of 99 calls per week, compared with an average of 9 calls per week after the commercial ended. Each bulk mailing was accompanied by a boost in the incoming hot line calls. The research staff triaged 133 calls to the "Options" phone line, 81% in the 6 weeks of the TV ad. The mean age of the 133 callers was 23.9 +/- 7.7 years (range 14-49 years). A majority called for screening information; 67% of callers were females and 84% of female callers were under age 26 years. Five percent of callers identified themselves as a parent of a teenager. The majority credited the TV ad as their source of the hot line number. Thirty-one individuals reported for a confidential chlamydia screening, 27 of 31 (87%) during the 6 weeks of TV advertising. No negative responses regarding the chlamydia campaign were encountered. CONCLUSION: This report describes strategies used to implement and measure the effectiveness of a mass media campaign and demonstrates evidence that mass media is effective in delivering STD intervention messages to young people.

Adolescent↗

Chlamydia trachomatis and Neisseria gonorrhoeae prevalence and coinfection in adolescents entering selected US juvenile detention centers, 1997-2002.

BACKGROUND: Juvenile detention centers offer public health practitioners an opportunity to gain access to large numbers of adolescents at risk for chlamydia and gonorrhea. GOAL: To describe the prevalence and coinfection of chlamydia and gonorrhea among adolescents in 14 US juvenile detention centers from 1997 to 2002. STUDY: We calculated the prevalence of chlamydia and gonorrhea in males and females, stratified by race/ethnicity, age group, and site. We also calculated the proportion of adolescents with chlamydia that were coinfected with gonorrhea and the proportion of those with gonorrhea that were coinfected with chlamydia. RESULTS: The prevalence of chlamydia was 15.6% in 33,619 females and 5.9% in 98,296 males; gonorrhea prevalence was 5.1% in females and 1.3% in males. Of females with gonorrhea, 54% were coinfected with chlamydia, and 51% of males with gonorrhea were coinfected with chlamydia. CONCLUSIONS: Chlamydia and gonorrhea prevalence was very high in females in all project sites. In males, chlamydia prevalence was high in some areas; however, gonorrhea prevalence was substantially lower. These prevalence data justify screening for chlamydia and gonorrhea among female adolescents in juvenile detention centers nationally.

Adolescent↗

[Study on the relationship between Chlamydia infection and otitis media with effusion].

OBJECTIVE: To evaluate the relationship between Chlamydia infection and otitis media with effusion and to establish a method for detection of Chlamydia antibodies in local fluids. METHODS: Sera and tympanocentesis aspirates from 44 patients with otitis media with effusion were collected. The specimens were used to detect the Chlamydia specific IgG, IgM antibodies using micro-immune fluorescent assay; to detect Chlamydia trachomatis plasmid DNA and Chlamydia pneumoniae genome DNA with polymerase chain reaction (PCR); and to separate Chlamydia pneumoniae in tympanocentesis aspirates with Hep-2 cell culture. RESULTS: One Chlamydia pneumoniae positive culture was found in tympanocentesis aspirate culture from one of the 44 patients, with positive Chlamydiae pneumoniae specific IgG antibody and DNA. Chlamydia trachomatis specific IgG antibody was increased in 14 cases sera and local secretion accordingly, with Chlamydia trachomatis plasmid DNA positive by PCR. CONCLUSION: Chlamydia is a common pathogen in otitis media with effusion.

Adolescent↗

[Chlamydia infections and sexual behavior among young women].

BACKGROUND: We wanted to determine the prevalence of Chlamydia trachomatis in a sample of young women and to assess risk factors related to sexual behaviour that are predictive of such infection. MATERIAL AND METHODS: 898 healthy, non-pregnant women aged 16 to 24 years attending primary care centres over a two-year period (September 1998 to December 2000) were recruited for the study. Uterine cervix samples were tested for Chlamydia trachomatis and participants were interviewed about their sexual behaviour. Chlamydia test results from 881 samples were valid. RESULTS: The prevalence of genital Chlamydia trachomatis infection was 2.4% (21/881). In univariable analyses, a high number of lifetime partners (four or more), smoking, previous pregnancy and a previous positive chlamydia test were factors predictive of a positive Chlamydia test. In multivariable analyses, previous pregnancy and a previous positive Chlamydia test were the only significant factors. The number of lifetime partners was higher among women who had been pregnant or previously had tested positively for Chlamydia. INTERPRETATION: The prevalence of Chlamydia was low in this population. Risk behaviour (frequent change of partners) can be expressed by teenage pregnancy and positive Chlamydia test results and these factors can be used for identification of women who should be tested more frequently than others for Chlamydia infection in a low-prevalence population.

Adolescent↗

[Testing pattern and prevalence of Chlamydia infection among women].

BACKGROUND: Chlamydia notification rates have increased in Norway over the recent years. The increase in notification cannot be interpreted as an increase in chlamydia prevalence since knowledge of testing patterns and prevalence of chlamydia by sex and age is virtually absent. MATERIAL AND METHODS: A data set, applying the woman as unit for analyses, comprising all test activity in one Norwegian county, was created for the period 1990-2003 (women 15-59 years old, resident in Sør-Trøndelag County, n = 56,220). Tests registered within 60 days from the previous test were excluded. Outcome measures are age-specific testing rates (first test), cumulative incidence of first test and incidence of repeated testing, proportion of positive first tests and cumulative incidence of being diagnosed with chlamydia before the age of 25, and 12-month incidence of chlamydia. RESULTS: Testing rates were high among young women throughout the study period. By the age of 25, almost all women had been tested at least once for chlamydia (85-90%). By the end of the year following the first test, one in five women with a negative first test and one in three women with a positive first test had been tested for chlamydia at least once more. The proportion of positive tests was highest among the youngest women (9-11% for women 15-24 years from 2000). Cumulative incidence of diagnosed chlamydia by the age of 25 years was 15% for women born 1976-79. Incidence of chlamydia during the first year after the first test was 2-3%. The relative risk for being diagnosed with chlamydia after the first test was highest for women who initially tested positive, and for teenagers. INTERPRETATION: The prevalence of chlamydia is high among young women. However, many women are not tested within a reasonable time after their first intercourse. Increased testing rates among teenagers can be achieved by focusing on easily available tests implying self-sampling methods.

Adolescent↗

[Basic evaluation of Chlamydia antigen detection by EIA using a dual amplification enhanced immunoassay method].

Chlamydia trachomatis is one of the important pathogens of STD in our country. Therefore, rapid accurate, reliable and convenient tests for its detection are required. So far, IDEIA Chlamydia has been employed as a useful diagnostic kit. Now, IDEIA PCE Chlamydia, applied as a dual amplification EIA method, has been developed. In our present studies, the sensitivity, reproducibility, cross reactivity, and reliability of IDEIA PCE Chlamydia were investigated and compared with those of IDEIA Chlamydia and LCR Chlamydia. The sensitivity of IDEIA PCE Chlamydia showed 2.4 x 10(2) IFU/ml for C. trachomatis D, 1.2 x 10(2) IFU/ml for C. trachomatis E, 3.8 x 10 IFU/ml for C. trachomatis F, and 1.25 x 10(2) IFU/ml for C. trachomatis L2. With regard to reproducibility, more than 2.4 x 10(2) IFU/ml of all strains of C. trachomatis and negative samples gave highly reproducible values. Though no cross reactivity was recognized among three strains of Staphylococcus aureus with concentrations of more than 10(9) IFU/ml, non-heated samples of over 10(6) CFU/ml showed cross reactivity. In our observations, phosphate, Mg2+, Ca2+, and Fe3+ inhibited the efficacy of both IDEIA and IDEIA PCE Chlamydia. Ca2+ per se could be an inhibitor in the case of urine samples analyzed by IDEIA and IDEIA PCE Chlamydia. These results indicate that IDEIA PCE Chlamydia kit for detection of C. trachomatis may be clinically useful because of its improved sensitivity over IDEIA Chlamydia and its invariable specificity and reliability.

Antigens, Bacterial↗

[Prevalence of Chlamydia pneumoniae in respiratory infections in children: an ambulatory diagnostic problem].

It has been recently suggested that Chlamydia Pneumoniae infection is a common finding among children with acute respiratory diseases. Chlamydia cell culture is difficult and time-consuming to perform. Polymerase chain reaction (PCR) is a more rapid but also more expensive technique used to identify Chlamydia in pharyngeal swab, but it can be performed only in few specialized laboratories. We tested a rapid enzyme immuno-assay to detect Chlamydia in 20 children with respiratory infections (mean age 3.29 years; male:female ratio = 12:8) and in 21 healthy children (mean age 4.70 years male:female ratio = 15:6). Prevalence of Chlamydia isolation from pharyngeal swab was very high in both patients and healthy children without a significative difference in the two considered groups (45% vs 42%, p = 0.8). Specific Chlamydia IgG antibodies were undetectable in all patients and healthy children. Nine out of 20 patients affected by acute respiratory disease were Chlamydia-positive and 11 out 20 were Chlamydia-negative: these two groups didn't differ in regard to clinical and laboratory features, whereas duration of symptoms was significantly longer in Chlamydia-positive patients (9.3 vs 5.5 days, p = 0.014). Our study suggests a high prevalence of Chlamydia pharyngeal swab positivity in both healthy and sick children. Diagnosis of Chlamydia infection was not feasible on the basis of the considered clinical and laboratory findings.

Acute Disease↗

[Morphological and morphogenetic characteristics of Chlamydia infection in sick animals].

Studies were carried out on the morphology and the morphogenesis of the Chlamydia organisms in animals with various Chlamydia infections. A total of 255 samples of placentae and parenchymal organs were investigated via the electron microscope, using the ultrathin section method and the negative contrasting method. A characteristic was made of Chlamydia infections in sheep, goats, cows, wild murine rodents, and birds. It was found that the morphologic and morphogenetic aspects of Chlamydia reproduction in diseased animals were the same as those described previously in the yolk sacs of chick embryos. The morphology of Chlamydia organisms in the viscera of animals with Chlamydia infections, and particularly in placentae of sheep that miscarried was characterized by the accumulation of elementary and initial bodies--condense, reticular, and intermediary. It was concluded that the morphogenesis of Chlamydia in animals with infections caused by Chlamydia represented a many sided morphologic process characterized by the following more important aspects: chlamydial matrix, initial chlamydial vacuoles, autonomic synthesis of chlamydial bodies in the initial vacuoles and the chlamydial matrix, high production of Chlamydia membranes, and accumulation of polymorphous Chlamydia bodies. Essential in the reproduction of Chlamydia was their massing into and around the capillaries.

Abortion, Veterinary↗

Chlamydiae in the ejaculate: their influence on the quality and morphology of sperm.

BACKGROUND: Given the lack of information concerning the role of Chlamydia trachomatis in male fertility, the aim of this study was to ascertain and analyze the quality of Chlamydiae-positive and -negative semen. MATERIAL AND METHODS: Sperm count was performed according to the 1999 World Health Organization (WHO) laboratory manual for examination of human semen and sperm-cervical mucus interaction, and sperm survival was assessed by a 120-min test. The evaluation of the morphological examination of ejaculates was carried out using the sasmo (strict morphological analysis of ejaculates) computer program. Chlamydiae were detected by immunofluorescent reaction using the Progen Biotechnik GmbH diagnostic set. Fisher's exact test and the chi-quadrate test were used for statistical analysis. RESULTS: Of the total of 627 sperm samples examined, Chlamydiae were detected in 136 cases (21.7%). Sperm analysis showed significant differences between Chlamydiae-positive and -negative samples. The Chlamydiae-contaminated group showed normal sperm morphology 14.4% lower, volume 6.4% lower, concentration 8.3% lower, motility 7.8% and velocity 9.3% lower than in Chlamydiae-negative samples. The average values for normal spermatozoa and motility in the Chlamydiae-positive group were also significantly reduced. CONCLUSION: Chlamydia trachomatis was found to be a possible factor in sperm pathology. These results could help to elucidate the role of Chlamydia trachomatis in male infertility.

Chlamydia Infections↗

Etiology of nongonococcal urethritis. Evidence for Chlamydia trachomatis and Ureaplasma urealyticum.

Chlamydia trachomatis, Ureaplasma urealyticum (T-mycoplasma), and Hemophilus vaginalis have previously been considered possible etiological agents in nongonococcal urethritis (NGU). In this study, current C. trachomatis infection was confirmed by culture and (or) micro-immunofluorescence serology in 26 of 69 men experiencing afirst episode of NGU, and 1 of 39 with no urethritis. Serum IgM immunofluorescent antibody to chlamydia was demonstrated in 16 of 20 men with chlamydia culture positive NGU, and 3 of 39 with chlamydia culture negative NG, and none of 34 with no urethritis. 9 of 10 culture positive men with less than or equal to 10 days symptoms developed immunofluorescent antibody seroconversion in paired sera. U. realyticum was isolated significantly more often and in significantly higher concentration from first voided urine from chlamydia-negative cases of NGU than from chlamydia-positive NGU. Ureaplasmacidal antibody titers increased fourfold in six men, four of whom had negative cultures for for unreaplasma. H. vaginalis was isolated from c9 of 33 men with no urethritis and 2 of 69 with NGU. C. trachomatis is susceptible, and U. urealyticum is resistant to sulfonamides. A 10-day course of sulfisoxazole therapy produced improvement in 13 of 13 chlamydia-positive, unreaplasma-negative, and only 14 of 29 chlamydia-negative, unreaplasma-positive NGU cases (P less than 0.002). Thus, culture, serology, and response to therapy support the etiologic role of chlamydia in NGU. Quantitative culture and response to therapy suggest U. unrealyticum may cause many cases of chlamydia-netative NGU.

Adult↗

A school-based Chlamydia control program using DNA amplification technology.

OBJECTIVES: Chlamydia trachomatis is the most prevalent bacterial sexually transmitted disease (STD) in the United States, with the highest rates reported among adolescents. Chlamydia has severe consequences including pelvic inflammatory disease and infertility, and is believed to be a cofactor in human immunodeficiency virus transmission. Given that chlamydia is predominantly asymptomatic, most cases are identified through routine screening in health care settings. Over time, screening and treatment appear to be associated with a decrease in the prevalence of disease in areas with consistent chlamydia control programs. The new availability of sensitive and specific urine tests for chlamydia (polymerase chain reaction [PCR] and ligase chain reaction [LCR]) provides the opportunity to screen large numbers of at-risk youth in a noninvasive manner. We used PCR/LCR testing to investigate the feasibility of a school-based chlamydia control program and to determine the prevalence of chlamydia infection among junior and senior high school students. DESIGN: At three junior/senior high schools, all students, regardless of symptoms or sexual history, were given the opportunity to be tested for chlamydia using urine-based PCR or LCR testing. Only students with parental consent were eligible. Parents could not obtain test results, except if their children told them. During the five 3-week testing periods, throughout the day, classes were escorted to the testing area and each student was individually counseled regarding the opportunity to participate in the testing. SETTING: Three urban public schools in Louisiana. PARTICIPANTS: A total of 1933 students in grades 7 through 12, including 861 girls and 1072 boys. INTERVENTION: All students were informed about the test and taught about chlamydia during the homeroom period. Students were asked to provide a first-void urine specimen of not more than 30 mL. Specimens were refrigerated and delivered to the laboratory on the same day. Infected students were counseled and offered treatment with azithromycin, 1 g orally. They were also referred for or offered additional STD and human immunodeficiency virus testing. Infected students were asked to refer their sex partners to the city STD clinic for treatment. MAIN OUTCOME MEASURE: Prevalence of C trachomatis infection by grade and gender. RESULTS: Parental consent was obtained for 2849 (86.9%) of the 3278 matriculated students in grades 7 through 12. Fifty-one parents (1.6%) returned consent forms refusing permission for their child to participate in this screening and treatment program. The remaining 378 (11.5%) could not be reached by mail or telephone. Among all students with consent, 1933 (67.8% of those consented and 59.0% of those matriculated) were tested. Girls were less likely to be tested than boys (861/1363 [63. 2%] vs 1072/1465 [73.2%]). The overall prevalence of C trachomatis was 6.5%, with rates among girls more than twice that of boys (9.7% vs 4.0%). Generally, rates of infection increased with age. The prevalence rates among boys were for 7th grade, 2/208 (1%); 8th grade, 2/196 (2%); 9th grade, 10/236 (4.2%); 10th grade, 12/185 (6. 5%); 11th grade, 8/146 (5.5%); and 12th grade, 9/101 (8.9%). For boys 15 to 19 year old, the prevalence of chlamydia was 5.7%. Among girls, the prevalence rates were 7th grade, 0/105 (0%); 8th grade, 11/166 (6.6%); 9th grade, 23/218 (10.6%); 10th grade 23/146 (15.8%); 11th grade, 13/118 (11%); and 12th grade, 13/107 (12.1%). Among girls 15 to 19 years old, 12.7% were infected. Of 126 infected students, treatment was provided to 111 (88%). For this project, the laboratory cost of LCR testing was $17.76 per test. Without considering clinical staff time to collect the specimens, the average laboratory cost per infected student identified was $272. For students 15 to 19 years of age, of whom 104 (8.9%) of 1170 were infected, the laboratory cost was $200 per case identified. CONCLUSION: (ABSTRACT TRUNCATED)

Adolescent↗

Chlamydia trachomatis among patients infected with and treated for Neisseria gonorrhoeae in sexually transmitted disease clinics in the United States.

BACKGROUND: For two decades, treatment guidelines for sexually transmitted diseases (STDs) have recommended empirical co-treatment for chlamydia when patients are treated for gonorrhea. Because the epidemiology of and diagnostic testing for STDs have changed over time, co-treatment may no longer be needed as a clinical or public health strategy. OBJECTIVE: To assess the prevalence of chlamydia among patients at STD clinics who are infected with and treated for Neisseria gonorrhoeae and to determine whether co-treatment recommendations are still justified. DESIGN: Cross-sectional analysis of data from a multisite study. SETTING: Five public STD clinics (Baltimore, Maryland; Denver, Colorado; Long Beach, California; Newark, New Jersey; and San Francisco, California), July 1993 through October 1995. PATIENTS: 3885 heterosexual patients (2184 men and 1701 women) who agreed to participate in a trial of counseling interventions and had conclusive results from diagnostic tests for gonorrhea and chlamydia performed routinely as part of the trial. MEASUREMENTS: Infection with Chlamydia trachomatis as determined by polymerase chain reaction. RESULTS: Chlamydia trachomatis was detected in 20% (95% CI, 16% to 24%) of 411 men and 42% (CI, 35% to 50%) of 151 women with laboratory-confirmed N. gonorrhoeae. Chlamydia trachomatis was detected in 19% (CI, 15% to 22%) of 410 men and 35% (CI, 28% to 43%) of 154 women with treatment indications for gonorrhea who would not otherwise have been treated for chlamydia: chlamydia prevalence among these patients was significantly higher than among patients without treatment indications for either gonorrhea or chlamydia: 7% in men and 9% in women (relative risk, 2.58 [CI, 1.92 to 3.47] and 4.12 [CI, 3.05 to 5.57], respectively). CONCLUSION: The frequent presence of chlamydia among patients at STD clinics who received treatment for gonorrhea, including sex partners of gonorrhea-infected patients, supports continuing current recommendations for co-treatment.

Adult↗

Chlamydia as a cause of late neonatal pneumonia at Kenyatta National Hospital, Nairobi.

BACKGROUND: Neonatal pneumonia is a common cause of morbidity and mortality all over the world. The problem is known to be higher in resource poor third world countries. Organisms (such as chlamydia) not covered by routine laboratory tests and regular antibiotic regimes may frequently contribute towards the causation of late neonatal pneumonia. It is therefore useful to gather epidemiological evidence to guide in the routine diagnosis and treatment of such infections. OBJECTIVE: To determine the prevalence of chlamydia associated pneumonia among infants developing the disease between the 7th and 30th days of life (late neonatal pneumonia). DESIGN: Cross sectional survey. SETTING: Newborn Unit, Kenyatta National Hospital. SUBJECTS: Fifty two newborns clinically diagnosed as having late neonatal pneumonia. They were all subjected to chest X-rays to confirm the clinical diagnosis. Nasopharyngeal aspirates for chlamydia antigen detection tests were then performed on all patients. The study was undertaken during the months of September through to November 2000. MAIN OUTCOME MEASURES: The proportion of newborns with late neonatal pneumonia that have chlamydia trachomantis as the sole or contributory causative agent. RESULTS: Fifty two newborns of postnatal age between seven and 30 days were recruited. Their sex distribution was about 1:1. Thirty three (63.5%) of these infants were found with chlamydia in their upper airways. Thirty out of 47 available chest X-rays, representing 63.8% had evidence of interstitial pneumonitis. Chlamydia associated pneumonia indicated by the presence of both interstitial pneumonia and colonization of the upper air ways was present in 24 out of 47 patients, 51% of the total cases of late neonatal pneumonia. When X-rays alone were compared with our gold standard for the diagnosis of chlamydia pneumonia (radiology and colonization), we computed a sensitivity of 100%, specificity 73%, negative predictive value 100% and positive predictive value of 80%. Mode of delivery, birth weight and gestation had no association with nasopharyngeal colonization by chlamydia or actual diagnosis of chlamydia pneumonia. CONCLUSION: The prevalence of chlamydia associated infection among newborns with late neonatal pneumonia at Kenyatta National Hospital is 51%, eight times more than that reported elsewhere. Chest X-rays appear to be a reliable diagnostic tool in this group. The use of antichlamydial drugs in addition to the regular antibiotics whenever a diagnosis of late neonatal pneumonia is made is justifiable.

Anti-Bacterial Agents↗

[Presence of genital Chlamydia trachomatis in abortion seekers--correlates with young age and nulliparity but not with previous genital infection].

Out of 432 women applying for termination of pregnancy, 7.9% (34/428) had cervical Chlamydia trachomatis and 0.7% (3/431) genital Neisseria gonorrhoeae. The prevalence of Chlamydia was 19.2% among the women applying for termination who were under 20 years and 12.8% among those aged 21-25 years. The finding of Chlamydia among nulliparae was 14.5%. Only 2.8% of the women with Chlamydia had previously had pelvic infections. Women with Chlamydia did not have significantly greater frequency of previous venereal diseases. It is concluded that women under the age of 25 years and nulliparae who apply for termination of pregnancy should be examined for Chlamydia and should be treated in connection with the intervention. Previous pelvic infections are observed significantly more rarely in women with Chlamydia applying for termination and thus do not constitute an indication for examination for Chlamydia. It is not yet elucidated whether women with previous venereal diseases should be examined for Chlamydia. On account of the low prevalence, there are no indications for performing routine smears in women applying for termination of pregnancy for gonococci but, on the other hand it appears relevant to examine women with Chlamydia for gonococci as double infections are frequently present.

Abortion Applicants↗

Incident Chlamydia trachomatis infections among inner-city adolescent females.

CONTEXT: Adolescents are at highest risk for infection with Chlamydia trachomatis, an important preventable cause of pelvic inflammatory disease and subsequent tubal factor infertility in US women. Current guidelines for delivery of adolescent primary care services recommend yearly chlamydia screening for those adolescent females considered to be at risk. OBJECTIVES: To describe the epidemiology of prevalent and incident chlamydia infection among adolescent females to assess the appropriate interval for chlamydia screening and to define risk factors that would identify adolescent females to target for screening. DESIGN: Prospective longitudinal study. PATIENTS: A consecutive sample of 3202 sexually active females 12 through 19 years old making 5360 patient visits over a 33-month period, January 1994 through September 1996. SETTING: Baltimore, Md, family planning, sexually transmitted disease, and school-based clinics. INTERVENTION: Testing for C trachomatis by polymerase chain reaction. MAIN OUTCOME MEASURES: Prevalence and incidence of C trachomatis infections; predictors of positive test result for C trachomatis. RESULTS: Chlamydia infection was found in 771 first visits (24.1%) and 299 repeat visits (13.9%); 933 adolescent females (29.1%) had at least 1 positive test result. Females who were 14 years old had the highest age-specific chlamydia prevalence rate (63 [27.5%] of 229 cases; P=.01). The chlamydia incidence rate was 28.0 cases per 1000 person-months (95% confidence interval, 24.9-31.5 cases). The median time was 7.2 months to a first positive chlamydia test result and 6.3 months to a repeat positive test result among those with repeat visits. Independent predictors of chlamydia infection--reason for clinic visit, clinic type, prior sexually transmitted diseases, multiple or new partners, or inconsistent condom use-failed to identify a subset of adolescent females with the majority of infections. CONCLUSIONS: A high prevalence and incidence of C trachomatis infection were found among adolescent females. We, therefore, recommend screening all sexually active adolescent females for chlamydia infection every 6 months, regardless of symptoms, prior infections, condom use, or multiple partner risks.

Adolescent↗

Detection of Chlamydia pneumoniae DNA in buffy-coat samples of patients with abdominal aortic aneurysm.

Recent studies have suggested that Chlamydia pneumoniae infection is a risk factor for abdominal aortic aneurysm. This study explores the presence of Chlamydia pneumoniae DNA in buffy-coat samples of control subjects and of patients with abdominal aortic aneurysm. The seroepidemiological association between abdominal aortic aneurysm and Chlamydia pneumoniae was also investigated. Buffy-coat samples and serum specimens were obtained from 88 patients and 88 control subjects. Detection of Chlamydia pneumoniae DNA in buffy-coat samples and measurement of IgG antibodies to Chlamydia pneumoniae in serum specimens were performed by polymerase chain reaction and microimmunofluorescence, respectively. Chlamydia pneumoniae DNA was detected in buffy-coat samples of 18 (20%) patients and 8 (9%) control subjects (adjusted odds ratio 2.9, 95% confidence interval 1-8.5). IgG antibodies to Chlamydia pneumoniae were detected in 85 (97%) patients and 71 (81%) control subjects (adjusted odds ratio 7.2, 95% confidence interval 1.7-31). The results show an association between abdominal aortic aneurysm and either the presence of Chlamydia pneumoniae DNA in buffy-coat samples or IgG antibodies to Chlamydia pneumoniae. These findings support the hypothesis that previous infection with Chlamydia pneumoniae might be a risk factor for abdominal aortic aneurysm.

Adult↗

Chlamydia trachomatis in subfertile women undergoing uterine instrumentation. Screen or treat?

Women who undergo uterine instrumentation are considered at risk for pelvic infections by Chlamydia trachomatis, which may derive either from ascending endocervical infections or from reactivation of micro-organisms persisting in the genital tract after previous chlamydia infections. Women presenting at fertility clinics frequently undergo uterine instrumentation (e.g. hysterosalpingography and laparoscopy with hydrotubation). Studies in subfertile women using DNA amplification techniques have shown that the prevalence of endocervical chlamydia infections is low (1.8%). In contrast, in 30-60% of subfertile women chlamydia IgG antibodies can be found in serum, indicating previous chlamydia infections. It has been demonstrated that, several years after chlamydia infections, viable micro-organisms may still be present in the upper genital tract. Therefore, subfertile women with chlamydia antibodies should be considered at risk for reactivation of persistent chlamydia infections after uterine instrumentation, even after exclusion of endocervical chlamydia infections. Moreover, in subfertile women without chlamydia antibodies, the presence of viable micro-organisms in the genital tract cannot be excluded. As a consequence, prophylactic antibiotics before uterine instrumentation should be considered in all subfertile women, instead of endocervical screening for C. trachomatis and treatment of positive cases only.

Antibiotic Prophylaxis↗

Chlamydia infection of epithelial cells expressing dynamin and Eps15 mutants: clathrin-independent entry into cells and dynamin-dependent productive growth.

Chlamydiae enter epithelial cells via a mechanism that still remains to be fully elucidated. In this study we investigated the pathway of entry of C. psittaci GPIC and C. trachomatis LGV/L2 into HeLa cells and demonstrated that it does not depend on clathrin coated vesicle formation. We used mutant cell lines defective in clathrin-mediated endocytosis due to overexpression of dominant negative mutants of either dynamin I or Eps15 proteins. When clathrin-dependent endocytosis was inhibited by overexpression of the dynK44A mutant of dynamin I (defective in GTPase activity), Chlamydia entry was not affected. However, in these cells there was a dramatic inhibition in the proliferation of Chlamydia and the growth of the chlamydia vacuole (inclusion). When clathrin-dependent endocytosis was inhibited by overexpression of an Eps15 dominant negative mutant, the entry and growth of Chlamydia was unaltered. These results indicate that the effect on the growth of Chlamydia in the dynK44A cells was not simply due to a deprivation of nutrients taken up by endocytosis. Instead, the dominant-negative mutant of dynamin most likely affects the vesicular traffic between the Chlamydia inclusion and intracellular membrane compartments. In addition, cytochalasin D inhibited Chlamydia entry by more than 90%, indicating that chlamydiae enter epithelial cells by an actin-dependent mechanism resembling phagocytosis. Finally, dynamin is apparently not involved in the formation of phagocytic vesicles containing Chlamydia.

Actins↗