Chlamydial infections

Chlamydia trachomatis infection causes mitotic spindle pole defects independently from its effects on centrosome amplification

Chlamydiae are Gram negative, obligate intracellular bacteria, and Chlamydia trachomatis is the etiologic agent of the most commonly reported sexually transmitted disease in the United States. Chlamydiae undergo a biphasic life cycle that takes place inside a parasitophorous vacuole termed an inclusion. Chlamydial infections have been epidemiologically linked to cervical cancer in patients previously infected by human papillomavirus (HPV). The inclusion associates very closely with host cell centrosomes, and this association is dependent upon the host motor protein dynein. We have previously reported that this interaction induces supernumerary centrosomes in infected cells, leading to multipolar mitotic spindles and inhibiting accurate chromosome segregation. Our findings demonstrate that chlamydial infection causes mitotic spindle defects independently of its effects on centrosome amplification. We show that chlamydial infection increases centrosome spread and inhibits the spindle assembly checkpoint delay to disrupt centrosome clustering. These data suggest that chlamydial infection exacerbates the consequences of centrosome amplification by inhibiting the cells' ability to suppress the effects of these defects on mitotic spindle organization. We hypothesize that these combined effects on mitotic spindle architecture identifies a possible mechanism for Chlamydia as a cofactor in cervical cancer formation.

Valuing experience factors in the provision of Chlamydia screening: an application to women attending the family planning clinic

OBJECTIVE

To examine women's preferences for characteristics of chlamydia screening. Chlamydia trachomatis is the most common curable sexually transmitted disease. To design effective screening programs, it is important to fully capture the benefits of screening to patients. Thus, the value of experience factors must be considered alongside health outcomes.

METHODS

A self-complete discrete choice experiment questionnaire was administered to women attending a family planning clinic. Chlamydia screening was described by five characteristics: location of screening; type of screening test; cost of screening test; risk of developing pelvic inflammatory disease if chlamydia is untreated; and support provided when receiving results.

RESULTS

One hundred twenty-six women completed the questionnaire. Respondents valued characteristics of the care experience. Screening was valued at 15 pound; less invasive screening tests increase willingness to pay by 7 pound, and more invasive tests reduce willingness to pay by 3.50 pound. The most preferred screening location was the family planning clinic, valued at 5 pound. The support of a trained health-care professional when receiving results was valued at 4 pound. Respondents under 25 years and those in a casual relationship were less likely to be screened.

CONCLUSIONS

Women valued experience factors in the provision of chlamydia screening. To correctly value these screening programs and to predict uptake, cost-effectiveness studies should take such values into account. Failure to do this may result in incorrect policy recommendations.

Are adolescent girls with Chlamydia infection notifying their partners?

OBJECTIVES

(1) To determine the proportion of inner-city adolescent girls diagnosed with chlamydial cervicitis who notify their sex partners; (2) to examine girls' attitudes and perceptions about partner notification and treatment; and (3) to assess whether or not girls knew if their partners were treated for chlamydia infection.

DESIGN/METHODS

Adolescent girls who had a positive DNA hybridization test for chlamydial cervicitis from March 2000 to May 2002 completed a 37-item self-administered survey assessing sexual behavior and partner notification, as well as the Rosenberg self esteem scale. Subjects completed the survey 1-3 months after the diagnosis of chlamydia infection.

RESULTS

Fifty-five adolescent girls (46% Hispanic, 36% African American) aged 13-21 years (mean 18.3 years) completed the survey. The median age at first intercourse was 14 (SD = 1.6); median number of lifetime sex partners was 4. Forty-one subjects (75%) notified their sex partners. The most common reasons for partner notification were"I did not want my sex partner to give the infection back to me"and"I wanted to let my sex partner know that he/she had given me the infection". There was a trend toward increased notification if the girls were 18 years of age or older (P = 0.07) or had only one lifetime sex partner (P = 0.08). Of the 41 subjects who notified their partners, 22 (54%) reported that the partners were treated; 16 did not know, and three knew that partners were not treated.

CONCLUSIONS

The majority of inner-city girls in this study notified their partners about chlamydia infection. Self-protection from re-infection was an important reason given for notification and suggests that girls in committed ongoing relationships might be more likely to notify partners.

A phase-II study of trovafloxacin for the treatment of Chlamydia trachomatis infections

BACKGROUND

Chlamydia trachomatis can cause an insidious, asymptomatic infection in both men and women. Trovafloxacin, a fluoronaphthyridone antibiotic related to the fluoroquinolones, has broad antibacterial activity that encompasses C. trachomatis.

GOAL OF STUDY

We designed a phase-II study to determine the efficacy and safety of trovafloxacin for chlamydial infections.

STUDY DESIGN

Four once-daily dosing regimens were used: 200 mg for 7 days, 200 mg for 5 days, 100 mg for 7 days, and 50 mg for 7 days.

RESULTS

Sixty-four men and 66 women were enrolled. Of the 73 bacteriologically evaluable patients, 20 received 200 mg for 7 days, 18 received 200 mg for 5 days, 14 received 100 mg for 7 days, and 21 received 50 mg for 7 days. Bacteriologic failure occurred in 1 patient (5%) in the 200-mg 7-day group, 2 patients (14%) in the 100-mg group, and 1 patient (5%) in the 50-mg group. No clinical failures were noted among the 30 C. trachomatis infected men with nongonococcal urethritis, although 1 patient had only improved at the final visit. Safety data were available from 119 patients. Of 86 patients receiving the three highest dosing regimens, 17 (20%) had at least one adverse event, judged treatment-related in only 9 (10 %). Of 33 patients receiving the lowest dose, 5 (15%) had an adverse event, three (9%) of which were considered treatment related. No adverse event was severe.

CONCLUSION

In doses ranging from 200 mg to 50 mg daily for a week and 200 mg daily for 5 days, trovafloxacin appears to be effective for chlamydial infections and is well tolerated.

Chlamydial infections and male infertility

Chlamydial infections may be difficult to diagnose due to the silent symptoms and difficulty in culturing. An infectious process may impair fertility by adversely affecting sperm functions, resulting in testicular damage or causing obstruction of the genital tract. In our study, we tried to find Chlamydial antigen by using EIA (Enzyme Immune Assay) and to compare the Ag(+) and Ag(-) groups according to semen parameters. Except for semen volume, we found significant differences in density, morphology, motility and viability (intervolume p > 0.05, interdensity p < 0.01, intermorphology p < 0.001, intermotility p < 0.001 and interviability p < 0.001).

Doxycycline and azithromycin for prevention of chlamydial persistence or recurrence one month after treatment in women. A use-effectiveness study in public health settings

BACKGROUND

To treat chlamydial infection, the Centers for Disease Control and Prevention recommends either a single dose of azithromycin or a 7-day course of doxycycline. Cost is a concern with the single-dose regimen; compliance is a concern with the multidose regimen.

GOAL

To compare the use-effectiveness of azithromycin and doxycycline for preventing persistence or recurrence of Chlamydia trachomatis infection in women and to evaluate associated risk behaviors.

STUDY DESIGN

One hundred and ninety-six chlamydia-infected women and their sex partners were recruited into a randomized controlled trial of single-dose versus multidose regimens in seven public health clinics, with no incentives for enrollment, compliance, or follow-up. The outcome, measure was a positive test for C. trachomatis by polymerase chain reaction testing at 1 month after treatment.

RESULTS

C. trachomatis positivity at 1 month was similar for women receiving single-dose (5.1%, 5/98) and multidose therapy (4.1%, 4/98). Reported compliance among 73 women taking multidose therapy was 94.5%. A twofold to threefold increased risk of chlamydial persistence or recurrence was observed among women who were < or = 24 and white or who reported: a recent new partner, multiple partners, or a partner who may have had multiple partners at the time of enrollment or that not all partners were treated during the 1-month follow-up period after initiation of treatment.

CONCLUSIONS

The use-effectiveness of single-dose and multidose therapy was comparably high. Observed rates of persistence or recurrence were consistent with reported rates of pharmacological treatment failure. However, all women with C. trachomatis detected at 1 month had behavioral risk factors that may have contributed to reinfection.

Current methods of laboratory diagnosis of Chlamydia trachomatis infections

Infections caused by Chlamydia trachomatis are probably the most common sexually transmitted diseases in the United States. Commonly unrecognized and often inadequately treated, chlamydial infections can ascend the reproductive tract and cause pelvic inflammatory disease, which often results in the devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. C. trachomatis infections are also known to increase the risk for human immunodeficiency virus infection. The obligate intracellular life cycle of C. trachomatis has traditionally required laboratory diagnostic tests that are technically demanding, labor-intensive, expensive, and difficult to access. In spite of these historical challenges, however, laboratory diagnosis of C. trachomatis has been a rapidly advancing area in which there is presently a wide array of commercial diagnostic technologies, costs, manufacturers. This review describes and compares the diagnostic methods for C. trachomatis infection that are currently approved for use in the United States, including the newest DNA amplification technologies which are yet to be licensed for commercial use. Issues to consider in selecting a test for purposes of screening versus diagnosis based on prevalence, performance, legal, social, and cost issues are also discussed.

Recurrent chlamydial infections increase the risks of hospitalization for ectopic pregnancy and pelvic inflammatory disease

OBJECTIVE

We examined whether the risks of hospitalization for ectopic pregnancy and pelvic inflammatory disease increase with increasing numbers of chlamydial infections.

STUDY DESIGN

A retrospective cohort design was used to evaluate the risks of hospitalization for ectopic pregnancy or pelvic inflammatory among 11,000 Wisconsin women who had one or more chlamydial infections between 1985 and 1992. Logistic regression was used to evaluate the strength of association between recurrent infection and sequelae.

RESULTS

After adjustment in multivariate analyses, we observed elevated risks of ectopic pregnancy among women who had two (odds ratio 2.1, 95% confidence interval 1.3 to 3.4) and three or more chlamydial infections (odds ratio 4.5, 95% confidence interval 1.8 to 5.3). These groups were also at increased risk for pelvic inflammatory (two infections: odds ratio 4.0, 95% confidence interval 1.6 to 9.9; three or more infections: odds ratio 6.4, 95% confidence interval 2.2 to 18.4).

CONCLUSIONS

A unique prevention opportunity occurs at the diagnosis of any chlamydial infection because women with subsequent recurrences are at increased risk for reproductive sequelae.

Macrolide antibiotics in paediatric infectious diseases

Erythromycin and other macrolides have enjoyed a renaissance in the 1970s, 1980s and 1990s secondary to the discovery of "new' pathogens such as Chlamydia, Legionella, Campylobacter and Mycoplasma spp. Erythromycin is an important therapeutic agent in the paediatric age group for several reasons: (a) it exhibits proven efficacy for a wide range of infections (upper and lower respiratory tract infections, skin/skin structure infections, prophylaxis of endocarditis/acute rheumatic fever/ophthalmia neonatorum and pre-colonic surgery, campylobacteriosis, chlamydial and ureaplasmal infections, diphtheria, whooping cough, streptococcal pharyngitis) and gastrointestinal (GI) dysmotility states; (b) intravenous formulations are widely available; and (c) it is available in a number of formulations as a generic product, which is likely to result in significant cost savings. Nevertheless, erythromycin and similar earlier macrolides are characterised by a number of drawbacks including a narrow spectrum of antimicrobial activity, unfavourable pharmacokinetic properties and poor GI tolerability. Newer macrolides such as clarithromycin and azithromycin are useful in serving the needs of paediatric patients who are erythromycin-intolerant or who have infections caused by organisms that are intrinsically erythromycin-resistant, or for which a high percentage of strains are resistant (e.g. Haemophilus influenzae, Helicobacter pylori, Mycobacterium avium complex). In addition, these newer macrolides may be considered as alternatives to oral amoxicillin-clavulanic acid, second or third generation cephalosporins, or erythromycin plus sulphonamide in this patient population. Selection between specific macrolides and between macrolides and other antibiotics in the paediatric population is likely to depend, at least for the immediate future, on separate comparisons of product availability, cost, effectiveness and tolerability profiles.

Risk for gonococcal and chlamydial cervicitis in adolescent females: incidence and recurrence in a prospective cohort study

PURPOSE

This study attempted to determine the incidence and risk for gonococcal and chlamydial cervicitis among sexually active urban adolescent females.

METHODS

The study design is a prospective cohort study. A cohort of 216 sexually active females were followed with repeat sexually transmitted diseases screening for 12-24 months. Subjects positive on any retest (FU) were compared with those who remained negative on all FU. Subjects were interviewed for history and screened for endocervical gonococcal and chlamydial infection.

RESULTS

The number of visits per patient ranged from 2 to 9 (median, 3). The initial Chlamydia trachomatis and Neisseria gonorrhoeae rates were 23.2 and 11.6%, respectively. The cumulative FU positive rates were 20.8% for C. trachomatis and 17.1% for N. gonorrhoeae. Although the initial gonococcal infection was a significant risk for a subsequent infection by C. trachomatis (p = .05) and N. gonorrhoeae (p = .001), the initial C. trachomatis status was not predictive of subsequent infections. The number of partners was not predictive of subsequent infections with either. In the entire study period, 86 patients had at least one episode of C. trachomatis and N. gonorrhoeae infection was confirmed in 52; 20 patients had recurrent cervicitis. During the study, 101 episodes of C. trachomatis and 68 episodes of N. gonorrhoeae infections were identified. Those with recurrent cervicitis (9.3%) were responsible for 33% of all cervicitis episodes identified during the study.

CONCLUSIONS

Adolescents in our study were at high risk for cervicitis, particularly as a result of C. trachomatis. Risk for subsequent C. trachomatis cervicitis was the same among initially positive and negative groups. Our data underscore the importance of repeat screening for sexually transmitted infections and treatment of contacts of adolescent females.

Use of the polymerase chain reaction for the detection of Chlamydia trachomatis in clinical specimens and its comparison to commercially available tests

A polymerase chain reaction (PCR) was developed to detect Chlamydia trachomatis in genital tract specimens. Two sets of primers for the PCR were used; one set amplifies a region of the plasmid present in all C trachomatis strains and the other amplifies a conserved region of the genome coding for the major outer membrane protein. The sensitivity of these PCRs were compared with each other, and with the sensitivities of antigen ELISA, Clearview and culture. Southern blotting and probing was used to increase sensitivity of detection.

Characteristics of murine model of genital infection with Chlamydia trachomatis and effects of therapy with tetracyclines, amoxicillin-clavulanic acid, or azithromycin

Following intravaginal inoculation of progesterone-treated outbred mice with Chlamydia trachomatis MoPn, 4 to 6 log10 inclusion-forming units were recovered in vaginal swabs for 21 days but all animals were culture negative after 28 days. Serum antibody titers were elevated and remained high for at least 70 days. Between 28 and 70 days, upper tract infection (inflammation and distension of the uterine horns, occlusion of oviducts with inflammatory exudate, pyosalpinx, and hydrosalpinx) was seen in > 80% of the animals. Mice were dosed orally, commencing at 7 days after infection, with minocycline, doxycycline, or amoxicillin-clavulanate. Further groups received azithromycin either as a single high dose or as lower once-daily doses. In addition, minocycline and amoxicillin-clavulanate were administered at 24 h after infection, and this early treatment prevented elevation of antibody titers whereas delayed therapy did not. Vaginal swabs from mice in all treatment regimens were culture negative except for 25% of mice receiving either early amoxicillin-clavulanate or low-dose azithromycin, which yielded low numbers (20 to 70 inclusion-forming units) of chlamydiae. Numbers of fertile mice in the early treatment regimens and their litter sizes were similar to those of noninfected controls, although 25% of amoxicillin-clavulanate-treated mice had unilateral hydrosalpinges. In comparison, 88% of untreated mice developed hydrosalpinges and only 25% conceived. Delayed dosing did not affect the outcome of amoxicillin-clavulanate therapy but did diminish the protective efficacy of minocycline such that 50% of treated mice had either unilateral hydrosalpinges or ovarian abscesses. Doxycycline and azithromycin were highly effective in restoring fertility. This model makes possible the study of both short- and long-term outcomes of chlamydial infection.

Risk factors for recurrent Chlamydia trachomatis infections in women

OBJECTIVE

We evaluated risk factors for recurrent Chlamydia trachomatis infections in women.

STUDY DESIGN

We used a retrospective cohort design to examine predictors of recurrent infection in the 38,866 female residents of Wisconsin whose first reported C. trachomatis infection occurred between 1985 and 1989.

RESULTS

Young age at first reported infection was the strongest predictor of recurrent C. trachomatis infection, after adjustment for covariates. Adolescents < 15 years old had an eightfold increased risk, those 15 to 19 years old had a fivefold increased risk, and women 20 to 29 years old had a twofold increased risk of recurrent C. trachomatis infection, compared with that among women 30 to 44 years old. In 54% of those aged < 15 at initial infection and 30% of those aged 15 to 19, recurrence developed. Other characteristics associated with recurrence included black race, residence in Milwaukee County, coinfection with gonorrhea, and past sexually transmitted diseases; receiving care in a family-planning clinic appeared protective.

CONCLUSIONS

Implementation of strategies to reduce the markedly elevated risk of recurrent chlamydia infections is urgently needed in female adolescents.

The effects of medium and rate of freezing on the survival of chlamydias after lyophilization

The effects of suspension media and rate of freezing on the survival of Chlamydia trachomatis LGV2 and Chlamydia pneumoniae after lyophilization were assessed. The highest loss in infectious elementary bodies (EBs) occurred during lyophilization. The survival was higher after freezing at a rate of 1 degree C min-1 and lyophilization than that after rapid freezing at -70 degrees C or -196 degrees C. The recovery (+/- 5%) was higher when fetal calf serum (FCS) containing glucose, saccharose or lactose were used as lyophilization media than that (0.5-3%) when yolk-sac, skimmed milk or phosphate buffer containing sucrose, glutamine and 10% FCS (SPG) were used. After lyophilization, the survival was not affected in the tested range from 10(4) to 5 x 10(6) inclusion-forming units (ifu) ml-1 prior to freezing. After storage for 4 months at 4 degrees C, the numbers of ifu of both Chlamydia serovars that were recovered were identical to the numbers of ifu immediately after lyophilization. It was concluded that chlamydias can be stored and transported in lyophilized form. However, a loss of 95% in infectious EBs should be taken into account.

Chlamydia trachomatis infections in female tertiary students

Chlamydial infection of the endocervix was identified in 19.8% of 258 University students undergoing pelvic examination in a Student Services Health Clinic. The majority of consultations were for routine Papanicolaou smear. Chlamydial infection was present in 50% (12 of 24) of the women who had clinical evidence of mucopurulent cervicitis.

Performance of the syva direct fluorescent antibody assay for Chlamydia in a low-prevalence population

Chlamydia trachomatis is the most common reportable sexually transmitted disease (STD) in the United States. In the 1980s, rapid diagnostic tests for chlamydia began to replace more cumbersome tissue culture methods. Current data on rapid antigen detection assays demonstrate acceptable sensitivity, specificity, and predictive values in populations with a high prevalence of chlamydia. Few studies report the performance of these assays in a low-prevalence obstetric and gynecologic (Ob/Gyn) population, This study compares the most commonly used direct fluorescent antibody (DFA) assay (Syva Microtrak) with tissue culture (TC) in a low-prevalence population. Endocervical specimens (775) were tested from women at risk for chlamydia infection, and the prevalence was found to be 7.7%. The DFA assay demonstrated a sensitivity of 80% and a specificity of 97% compared with TC. The positive and negative predictive values were 72% and 98%, respectively. The results of this study indicate that the Syva DFA assay lacks the sensitivity and positive predictive value for routine use in Ob/Gyn populations with a lowprevalence of C. trachomatis.

Chlamydial infection. Screening and management update, 1992

The need for a cost-effective, highly sensitive and specific test for Chlamydia trachomatis infection remains, although progress is being made. Clinicians can minimize the incidence of complications and erroneous test results by being alert to the possibility of this infection, screening appropriate patients, using careful collection techniques, following the most recent treatment recommendations, and knowing the limitations of available tests.

Fluoroquinolones for the treatment of nongonococcal urethritis/cervicitis

Approximately 50% of cases of nongonococcal urethritis reported among men are caused by Chlamydia trachomatis. Other pathogens implicated in the bacterial etiology of nongonococcal urethritis that occur independently or concurrently with gonorrhea include Ureaplasma urealyticum and species of Mycoplasma, including Mycoplasma hominis. The etiology of up to half of the cases, however, remains uncertain. Historically, C. trachomatis genital infections have been difficult to diagnose because of the need for expensive cell-culture methods that are technically difficult and produce delayed results. In addition, women with nongonococcal cervicitis/mucopurulent cervicitis are frequently asymptomatic except for vaginal discharge. Nongonococcal urethritis may also be asymptomatic in men. Increased morbidity is associated with unidentified and untreated C. trachomatis infections, especially in women and children. Currently, the Centers for Disease Control recommends that all patients diagnosed with nongonococcal urethritis, nongonococcal cervicitis, or gonorrhea--along with their sexual partners--receive adequate antimicrobial therapy that includes antimicrobial activity against chlamydiae. A tetracycline antibiotic is most commonly recommended. However, tetracyclines have variable in vitro activity against U. urealyticum and Mycoplasma species. New antibiotic therapy options with broader antimicrobial coverage are needed for the management of nongonococcal urethritis and cervicitis.