Laura H. Bachmann

Nucleic Acid Amplification Tests for Diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis Rectal Infections

ABSTRACT It is uncertain which methods for the diagnosis of rectal gonococcal and chlamydial infection are optimal. This study evaluated the performance of culture and nucleic acid amplification tests (NAATs) for rectal chlamydial and gonococcal diagnosis. From July 2003 until February 2007, 441 rectal test sets were collected from individuals attending a sexually transmitted disease clinic and three HIV clinics who gave a history of anal intercourse or were women at high risk for Neisseria gonorrhoeae or Chlamydia trachomatis infections. Rectal swab specimens were tested using culture and commercial NAATs employing transcription-mediated amplification (TMA), strand displacement amplification (SDA), and PCR amplification. Test performance was evaluated using a rotating standard by which patients were classified as infected if either two or three comparator tests were positive. Test sensitivities for the detection of N. gonorrhoeae ranged from 66.7% to 71.9% for culture to 100% for TMA. Specificities were 99.7% to 100% for culture and greater than 95.5% for all three NAATs. Test sensitivities for C. trachomatis ranged from 36.1% to 45.7% for culture and among NAATS from 91.4% to 95.8% for PCR to 100% for TMA. Specificities of the NAATs ranged from 95.6% to 98.5% (two-of-three standard) and from 88.8% to 91.8% (three-of-three standard). Over 60% and 80% of gonococcal and chlamydial infections, respectively, among men who have sex with men and over 20% of chlamydial infections in women would have been missed if the rectal site had not been tested. Currently available NAATs are more sensitive for the detection of chlamydial and gonococcal infection at the rectal site than is culture.

Nucleic Acid Amplification Tests for Diagnosis of Neisseria gonorrhoeae Oropharyngeal Infections

ABSTRACT The optimal methods for the diagnosis of pharyngeal Neisseria gonorrhoeae infection are uncertain. The objective of this study was to define the performance of culture and nucleic acid amplification tests (NAATs) for the diagnosis of pharyngeal N. gonorrhoeae. In this cross-sectional study, males and females >15 years old who acknowledged performing fellatio or cunnilingus (in the previous 2 months) were recruited from three clinics (two human immunodeficiency virus clinics and one sexually transmitted diseases clinic) located in Birmingham, AL. The test performance of culture for N. gonorrhoeae, the Gen-Probe Aptima Combo 2 transcription-mediated amplification assay (TMA), the BD ProbeTec ET amplified DNA strand displacement assay (SDA), and the Roche Cobas Amplicor PCR was defined by using a rotating “gold standard” of any positive results by two or three of the three tests that excluded the test being evaluated. A total of 961 evaluable test sets were collected. On the basis of a rotating gold standard of positive results by two of three comparator tests, the sensitivity and the specificity were as follows: culture for N. gonorrhoeae, 50.0% and 99.4%, respectively; PCR, 80.3% and 73.0%, respectively; TMA, 83.6% and 98.6%, respectively; and SDA, 93.2% and 96.3%, respectively. On the basis of a rotating gold standard of positive results by three of three comparator tests, the sensitivity and specificity were as follows: culture for N. gonorrhoeae, 65.4% and 99.0%, respectively; PCR, 91.9% and 71.8%, respectively; TMA, 100% and 96.2%, respectively; and SDA, 97.1% and 94.2%, respectively. In conclusion, currently available NAATs are more sensitive than culture for the detection of pharyngeal gonorrhea in at-risk patients. PCR is substantially less specific than culture, TMA, or SDA and should not be used for the detection of pharyngeal gonorrhea.

A CBPR Partnership Increases HIV Testing Among Men Who Have Sex With Men (MSM): Outcome Findings From a Pilot Test of the CyBER/testing Internet Intervention

The Internet has emerged as an important tool for the delivery of health promotion and disease prevention interventions. Our community-based participatory research (CBPR) partnership developed and piloted CyBER/testing, a culturally congruent intervention designed to promote HIV testing among men who have sex with men (MSM) within existing Internet chat rooms. Using a quasi-experimental, single-group study design, cross-sectional data were collected from chat room participants, known as “chatters,” at pretest (n = 346) and posttest (n = 315). Extant profile data also were collected to describe the demographics of the online population. The intervention significantly increased self-reported HIV testing among chatters overall, increasing rates from 44.5% at pretest to nearly 60% at posttest (p < .001). Furthermore, chatters who reported having both male and female sexual partners had nearly 6 times the odds of reporting HIV testing at posttest. Findings suggest that chat room—based HIV testing intervention may increase testing among MSM who may be difficult to reach in traditional physical spaces.

Measured versus self-reported compliance with doxycycline therapy for chlamydia-associated syndromes: High therapeutic success rates despite poor compliance

OBJECTIVE To compare self-reported doxycycline compliance in men and women attending an STD clinic with indications for Chlamydia trachomatis treatment to compliance measured using microprocessor-containing medication vials to count each time and date medication vials were opened. A secondary objective was to correlate outcomes of therapy, as measured by symptom resolution and persistence of chlamydial nucleic acids, with measured doxycycline compliance. METHODS Between September 1995 and July 1997, Medication Event Monitoring System (MEMS) caps were used to measure compliance with recommended doxycycline therapy (14 doses over 7 days) in patients treated for presumed C. trachomatis infections. Polymerase chain reaction (PCR) assays for C. trachomatis were performed on urine specimens collected at the time of follow-up evaluation. RESULTS Of 221 evaluable participants, although 90% reported taking their medication as directed, only 33 (16%) managed this level of compliance according to data obtained from the MEMS cap. Although 144 (65%) patients took more than 11 of 14 doses over 8 days, 147 (67%) participants had at least one interval of 24 hours or longer between doses in an 8-day period. Of 81 participants with positive C. trachomatis cultures at enrollment, follow-up urine PCR for C. trachomatis was positive in 5 (6%). Medication Event Monitoring System data for four of the five patients with positive PCR tests as follow-up showed each had two or more 24-hour intervals when their medication vials were not opened and three of four had opened their vials less than 11 times. CONCLUSIONS This study suggests that few patients take medications as prescribed and that self-report substantially underestimates medication noncompliance. Despite poor compliance, there were few treatment failures.

Trichomonas vaginalis Genital Infections: Progress and Challenges

Trichomonas vaginalis (TV) infection is the most prevalent curable sexually transmitted infection in the United States and worldwide. Most TV infections are asymptomatic, and the accurate diagnosis of this infection has been limited by lack of sufficiently sensitive and specific diagnostic tests, particularly for men. To provide updates for the 2010 Centers for Disease Control and Preventions Sexually Transmitted Diseases Treatment Guidelines, a PubMed search was conducted of all TV literature published from 9 January 2004 through 24 September 2008. Approximately 175 pertinent abstracts and articles were reviewed and discussed with national experts. This article describes advances in TV diagnostics which have led to an improved understanding of the epidemiology of this pathogen, as well as potential biologic and epidemiological interactions between TV and human immunodeficiency virus (HIV). New data on treatment outcomes, metronidazole-resistant TV, management of nitroimidazole-allergic patients, frequency of recurrent TV infection following treatment, and screening considerations for TV in certain populations are also presented.

Patterns of Chlamydia trachomatis testing and follow-up at a University Hospital Medical Center.

OBJECTIVE Although testing for Chlamydia trachomatis is encouraged and increasingly practiced at sexually transmitted disease (STD) and family planning clinics, patterns of testing and follow-up in other settings are not well described. To begin to address these issues, we performed a chart review of patients with a positive laboratory test for C. trachomatis at a major university medical center. METHODS Chart review of medical records for all patients with positive laboratory tests for C. trachomatis during calendar year 1996. RESULTS Of 326 patients with positive tests, 95% were female and 5% were male. Median age was 22 for females and 25 for males. Most positive C. trachomatis test results were from the emergency room (ER)/walk-in clinic (55%) or patients receiving obstetric/gynecologic (OB/GYN) care (31%). While most C. trachomatis tests performed were on patients who had symptoms, patterns of treatment varied between sites. Fifty-seven percent of ER/walk-in patients received empiric antibiotics at the initial visit versus 36% of patients under OB/GYN care. Among patients with positive screening tests seen in the ER/walk-in clinic, 32% of patients had no treatment documented versus 14% of OB/GYN patients. Four percent of women with positive tests who did not receive therapy at the time of their initial evaluation developed pelvic inflammatory disease in the interval between testing and return to the medical center. CONCLUSIONS Of the patients with positive chlamydial screening tests, the proportion not treated was similar to that found in studies performed in STD clinics.

Risk and Prevalence of Treatable Sexually Transmitted Diseases at a Birmingham Substance Abuse Treatment Facility

OBJECTIVES We evaluated the prevalence of gonorrhea, chlamydia, trichomoniasis, and syphilis in patients entering residential drug treatment. METHODS Data on sexual and substance abuse histories were collected. Participants provided specimens for chlamydia and gonorrhea ligase chain reaction testing. Trichomonas vaginalis culture, and syphilis serologic testing. RESULTS Of 311 patients, crack cocaine use was reported by 67% and multisubstance use was reported by 71%. Sexually transmitted disease (STD) risk behaviors were common. The prevalence of infection was as follows: Chlamydia trachomatis, 2.3%; Neisseria gonorrhoeae, 1.6%; trichomoniasis, 43%; and syphilis, 6%. CONCLUSIONS STD counseling and screening may be a useful adjunct to inpatient drug treatment.

Compliance with doxycycline therapy in sexually transmitted diseases clinics.

Objective: To determine rates of compliance with doxycycline therapy for patients attending two inner city sexually transmitted diseases (STD) clinics using the MEMS (Medication Event Monitoring System) technology (Aprex Corporation, Fremont, CA). Design: An observational study. Setting: Two STD clinics in Brooklyn, New York and Birmingham, Alabama. Patients: Patients warranting doxycycline as antichlamydial therapy by usual clinical criteria (e.g., documented chlamydial infections, gonococcal urethritis, mucopurulent cervicitis) were enrolled consecutively from both clinics into four separate categories according to gender and the presence or absence of symptoms: symptomatic men (77), asymptomatic men (30), symptomatic women (83), asymptomatic women (33). Intervention: In the clinic area, patients were given their doxycycline in standard 30‐dram medication bottles fitted with the MEMS cap, which is capable of recording the date and time of each bottle opening and closing. This information was then retrieved using a software program developed by the manufacturer. Patients were instructed to return the bottle and cap at the completion of therapy. Efforts were made to contact those who did not return their bottles by both telephone and mail. Outcome Measures: Bottle openings as recorded by the MEMS were considered to represent use of medication. Patients were considered strictly compliant with prescription instructions if bottle openings and closings occurred at least twice daily for 6 consecutive days. Noncompliance was defined as initially opening the medication more than 48 hours after leaving the clinic or opening the bottle less than once daily for 5 consecutive days. Usage between these extremes was classified as intermediate. Results: Eighty percent of 223 patients enrolled completed the study by returning their bottles. The rate of strict compliance with prescription instruction was 25%. The rate of noncompliance was 24%. Fifty‐one percent used some intermediate amount of medication. There was no statistical difference in compliance by gender, presence or absence of symptoms, or site of enrollment. Conclusions: Few patients administered doxycycline in an STD clinic can be expected to take medication precisely as prescribed. Although most probably take enough to eradicate uncomplicated chlamydial infections, a sizable portion can be expected to use an inadequate amount of medication. This may contribute to persistence of genital chlamydia infections in the community.

Duration of Persistence of Gonococcal DNA Detected by Ligase Chain Reaction in Men and Women following Recommended Therapy for Uncomplicated Gonorrhea

ABSTRACT Neisseria gonorrhoeae infection remains relatively common in the United States, representing a public health challenge. Ligase chain reaction (LCR) is both highly sensitive and specific for the detection of N. gonorrhoeae in urine and patient-obtained vaginal swab specimens. Because of the LCR tests exquisite sensitivity, it may potentially detect DNA from nonviable organisms following effective therapy, leading to false-positive test results and unnecessary additional treatment. The purpose of the present study was to determine the duration that gonococcal DNA is detectable by LCR following therapy for uncomplicated gonococcal infection. One hundred thirty men and women between the ages of 16 and 50 years presenting to a sexually transmitted disease clinic with urogenital gonorrhea were enrolled. After the standard history was taken and a genital examination was done, the patients were asked to submit either a urine specimen (men) or a urine specimen plus a self-obtained vaginal swab specimen (women) for N. gonorrhoeae testing by LCR at the initial visit and each day during the study period. At enrollment, patients were treated with single doses of ofloxacin, cefixime, or ceftriaxone. The median time to a negative urine LCR test result was 1 day for the men (mean, 1.6 ± 0.14 days) and 2 days for the women (mean, 1.7 ± 0.19 days). Among the women the clearance time was significantly longer for vaginal specimens (mean, 2.8 ± 0.30 days) than for urine specimens (mean, 1.7 ± 0.11 days). Irrespective of patient gender and specimen type, gonococcal DNA can be expected to be absent from urogenital specimens within 2 weeks following successful therapy.

Concurrent Sexually Transmitted Infections (STIs) in Sex Partners of Patients with Selected STIs: Implications for Patient-Delivered Partner Therapy

BACKGROUND Patient-delivered partner therapy (PDPT) is the practice of providing disease-specific antimicrobial agents to patients for delivery to their sex partners. Some partners who receive PDPT may forgo clinical evaluation, resulting in missed opportunities for the diagnosis and treatment of comorbid conditions. METHODS We conducted a review of electronic charts for 8623 individuals attending 4 sexually transmitted disease clinics who were sex partners of patients with selected sexually transmitted infections (STIs). We evaluated the concordance between STIs diagnosed in partners and their reported exposures for which they might have received PDPT. RESULTS Among 3503 female and 4647 heterosexual male partners, 19 (0.4%) of 4716 individuals tested were newly diagnosed with human immunodeficiency virus (HIV) infection, and 61 individuals (0.7%) had syphilis. Pelvic inflammatory disease was diagnosed in 133 women (3.8%). Seventy-two (3.2%) of 2226 female and heterosexual male partners reporting exposure to patients with chlamydial infection had gonorrhea diagnosed. Chlamydial infection or gonorrhea was diagnosed in 81 heterosexual male partners (10.3%) who reported contact with women with trichomoniasis. Among 473 men who have sex with men (MSM; including bisexual men), 13 (6.3%) of 207 tested were newly diagnosed with HIV infection, and 8 (1.7%) had syphilis. Six (6.1%) of 98 MSM reporting exposure to patients with chlamydial infection had gonorrhea diagnosed. CONCLUSIONS Infrequent coinfections in female and heterosexual male partners exposed to patients with chlamydial infection or gonorrhea would not preclude use of PDPT. However, PDPT for male partners of women with trichomoniasis and for MSM requires further study.