Performance of Chlamydia trachomatis OmcB Enzyme-Linked Immunosorbent Assay in Serodiagnosis of Chlamydia trachomatis Infection in Women.

Chlamydia trachomatis serological assays with improved sensitivity over commercially available assays are needed to evaluate the burden of C. trachomatis infection and the effectiveness of prevention efforts. We evaluated the performance of a C. trachomatis outer membrane complex protein B (OmcB) enzyme-linked immunosorbent assay (ELISA) in the detection of anti-C. trachomatis antibody responses in C. trachomatis-infected women. OmcB ELISA was less sensitive than our C. trachomatis elementary body (EB) ELISA, but it was highly specific. The magnitude of the antibody response was higher in African-Americans and those with prior C. trachomatis infection. Unlike EB ELISA, the IgG1 response to C. trachomatis OmcB was short-lived and was not maintained by repeat C. trachomatis infection.

Immunoglobulin-Based Investigation of Spontaneous Resolution of Chlamydia trachomatis Infection.

Chlamydia trachomatis elementary body enzyme-linked immunosorbent assay (ELISA) was used to investigate serum anti-CT immunoglobulin G1 (IgG1; long-lived response) and immunoglobulin G3 (IgG3; short-lived response indicating more recent infection) from treatment (enrollment) and 6-month follow-up visits in 77 women previously classified as having spontaneous resolution of chlamydia. Of these women, 71.4% were IgG1+IgG3+, consistent with more recent chlamydia resolution. 15.6% were IgG3- at both visits, suggesting absence of recent chlamydia. Using elementary body ELISA, we demonstrated approximately 1 in 6 women classified as having spontaneous resolution of chlamydia might have been exposed to C. trachomatis but not infected. Further, we classified their possible infection stage.

Population-attributable fraction of tubal factor infertility associated with chlamydia.

BACKGROUND: Chlamydia trachomatis infection is highly prevalent among young women in the United States. Prevention of long-term sequelae of infection, including tubal factor infertility, is a primary goal of chlamydia screening and treatment activities. However, the population-attributable fraction of tubal factor infertility associated with chlamydia is unclear, and optimal measures for assessing tubal factor infertility and prior chlamydia in epidemiological studies have not been established. Black women have increased rates of chlamydia and tubal factor infertility compared with White women but have been underrepresented in prior studies of the association of chlamydia and tubal factor infertility. OBJECTIVES: The objectives of the study were to estimate the population-attributable fraction of tubal factor infertility associated with Chlamydia trachomatis infection by race (Black, non-Black) and assess how different definitions of Chlamydia trachomatis seropositivity and tubal factor infertility affect population-attributable fraction estimates. STUDY DESIGN: We conducted a case-control study, enrolling infertile women attending infertility practices in Birmingham, AL, and Pittsburgh, PA, during October 2012 through June 2015. Tubal factor infertility case status was primarily defined by unilateral or bilateral fallopian tube occlusion (cases) or bilateral fallopian tube patency (controls) on hysterosalpingogram. Alternate tubal factor infertility definitions incorporated history suggestive of tubal damage or were based on laparoscopic evidence of tubal damage. We aimed to enroll all eligible women, with an expected ratio of 1 and 3 controls per case for Black and non-Black women, respectively. We assessed Chlamydia trachomatis seropositivity with a commercial assay and a more sensitive research assay; our primary measure of seropositivity was defined as positivity on either assay. We estimated Chlamydia trachomatis seropositivity and calculated Chlamydia trachomatis-tubal factor infertility odds ratios and population-attributable fraction, stratified by race. RESULTS: We enrolled 107 Black women (47 cases, 60 controls) and 620 non-Black women (140 cases, 480 controls). Chlamydia trachomatis seropositivity by either assay was 81% (95% confidence interval, 73-89%) among Black and 31% (95% confidence interval, 28-35%) among non-Black participants (P < .001). Using the primary Chlamydia trachomatis seropositivity and tubal factor infertility definitions, no significant association was detected between chlamydia and tubal factor infertility among Blacks (odds ratio, 1.22, 95% confidence interval, 0.45-3.28) or non-Blacks (odds ratio, 1.41, 95% confidence interval, 0.95-2.09), and the estimated population-attributable fraction was 15% (95% confidence interval, -97% to 68%) among Blacks and 11% (95% confidence interval, -3% to 23%) among non-Blacks. Use of alternate serological measures and tubal factor infertility definitions had an impact on the magnitude of the chlamydia-tubal factor infertility association and resulted in a significant association among non-Blacks. CONCLUSION: Low population-attributable fraction estimates suggest factors in addition to chlamydia contribute to tubal factor infertility in the study population. However, high background Chlamydia trachomatis seropositivity among controls, most striking among Black participants, could have obscured an association with tubal factor infertility and resulted in a population-attributable fraction that underestimates the true etiological role of chlamydia. Choice of chlamydia and tubal factor infertility definitions also has an impact on the odds ratio and population-attributable fraction estimates.

Staphylococcus aureus Colonization and Strain Type at Various Body Sites among Patients with a Closed Abscess and Uninfected Controls at U.S. Emergency Departments.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a prevalent cause of skin and soft tissue infections (SSTI), but the association between CA-MRSA colonization and infection remains uncertain. We studied the carriage frequency at several body sites and the diversity of S. aureus strains from patients with and without SSTI. Specimens from the nares, throat, rectum, and groin of case subjects with a closed skin abscess (i.e., without drainage) and matched control subjects without a skin infection (n = 147 each) presenting to 10 U.S. emergency departments were cultured using broth enrichment; wound specimens were cultured from abscess cases. Methicillin resistance testing and spa typing were performed for all S. aureus isolates. S. aureus was found in 85/147 (57.8%) of abscesses; 49 isolates were MRSA, and 36 were methicillin-susceptible S. aureus (MSSA). MRSA colonization was more common among cases (59/147; 40.1%) than among controls (27/147; 18.4%) overall (P < 0.001) and at each body site; no differences were observed for MSSA. S. aureus-infected subjects were usually (75/85) colonized with the infecting strain; among MRSA-infected subjects, this was most common in the groin. The CC8 lineage accounted for most of both infecting and colonizing isolates, although more than 16 distinct strains were identified. Nearly all MRSA infections were inferred to be USA300. There was more diversity among colonizing than infecting isolates and among those isolated from controls versus cases. CC8 S. aureus is a common colonizer of persons with and without skin infections. Detection of S. aureus colonization, and especially MRSA, may be enhanced by extranasal site culture.

Hygiene strategies to prevent methicillin-resistant Staphylococcus aureus skin and soft tissue infections: a cluster-randomized controlled trial among high-risk military trainees.

BACKGROUND: Effective measures are needed to prevent methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) in high-risk community settings. The study objective was to evaluate the effect of personal hygiene-based strategies on rates of overall SSTI and MRSA SSTI. METHODS: We conducted a prospective, field-based, cluster-randomized trial in US Army Infantry trainees from May 2010 through January 2012. There were 3 study groups with incrementally increased education and hygiene-based interventions: standard (S), enhanced standard (ES), and chlorhexidine (CHG). The primary endpoints were incidence of overall SSTI and MRSA SSTI. RESULTS: The study included 30 209 trainees constituting 540 platoons (168 S, 192 ES, and 180 CHG). A total of 1203 (4%) participants developed SSTI, 316 (26%) due to MRSA. The overall SSTI rate was 4.15 (95% confidence interval [CI], 3.77-4.58) per 100 person-cycles. SSTI rates by study group were 3.48 (95% CI, 2.87-4.22) for S, 4.18 (95% CI, 3.56-4.90) for ES, and 4.71 (95% CI, 4.03-5.50) for CHG. The MRSA SSTI rate per 100 person-cycles for all groups was 1.10 (95% CI, .91-1.32). MRSA SSTI rates by study group were 1.0 (95% CI, .70-1.42) for S, 1.29 (95% CI, .98-1.71) for ES, and 0.97 (95% CI, .70-1.36) for CHG. CONCLUSIONS: Personal hygiene and education measures, including once-weekly use of chlorhexidine body wash, did not prevent overall SSTI or MRSA SSTI in a high-risk population of military trainees. CLINICAL TRIALS REGISTRATION: NCT01105767.

Methicillin-resistant Staphylococcus aureus colonization of the groin and risk for clinical infection among HIV-infected adults.

Data on the interaction between methicillin-resistant Staphylococcus aureus (MRSA) colonization and clinical infection are limited. During 2007-2008, we enrolled HIV-infected adults in Atlanta, Georgia, USA, in a prospective cohort study. Nares and groin swab specimens were cultured for S. aureus at enrollment and after 6 and 12 months. MRSA colonization was detected in 13%-15% of HIV-infected participants (n=600, 98% male) at baseline, 6 months, and 12 months. MRSA colonization was detected in the nares only (41%), groin only (21%), and at both sites (38%). Over a median of 2.1 years of follow-up, 29 MRSA clinical infections occurred in 25 participants. In multivariate analysis, MRSA clinical infection was significantly associated with MRSA colonization of the groin (adjusted risk ratio 4.8) and a history of MRSA infection (adjusted risk ratio 3.1). MRSA prevention strategies that can effectively prevent or eliminate groin colonization are likely necessary to reduce clinical infections in this population.

Expedited partner therapy in federally qualified health centers--New York City, 2012.

BACKGROUND: Management of patients' sex partners is a critical element of sexually transmitted disease (STD) control. Expedited partner therapy (EPT), a practice in which patients deliver medication or a prescription directly to their partners, is one option for partner management. As of 2009, New York State law specifically allows EPT for chlamydial infection. Federally qualified health centers (FQHCs) in New York City (NYC) care for patients at risk for STDs. We describe the policies and practices surrounding EPT and other STD management in NYC FQHCs. METHODS: In 2012, we surveyed medical directors at all NYC FQHC parent entities and clinicians at a sample of their corresponding clinical sites about written policies and actual practices regarding EPT for chlamydial infection and other STD management. RESULTS: Twenty-two entities (22/29; 76%) and 51 sites (51/72; 70%) responded to the survey. More than half of entities have a written policy permitting EPT, and 80% of sites provide EPT. Most entity policies allow EPT for, and most sites provide EPT to, adolescents and adults with both opposite-sex and/or same-sex partners. Most sites use electronic health records and provide EPT by prescriptions, and one third of sites do not provide educational materials with EPT. CONCLUSIONS: Our results indicate widespread EPT provision by NYC FQHCs; however, areas for improvement exist, specifically in following guidelines that recommend providing educational materials with EPT and do not recommend EPT for men with male partners. The use of prescriptions for EPT and electronic health records were identified as potential barriers to EPT provision.

Prevalence of methicillin-resistant staphylococcus aureus as an etiology of community-acquired pneumonia.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin infections. Recent case series describe severe community-acquired pneumonia (CAP) caused by MRSA, but the prevalence and risk factors are unknown. METHODS: We prospectively enrolled adults hospitalized with CAP from 12 university-affiliated emergency departments during the winter-spring of 2006 and 2007. Clinical information and culture results were collected, and factors associated with MRSA were assessed. RESULTS: Of 627 patients, 595 (95%) had respiratory (50%) and/or blood cultures (92%) performed. A pathogen was identified in 102 (17%); MRSA was identified in 14 (2.4%; range by site, 0%-5%) patients and in 5% of patients admitted to the intensive care unit. Two (14%) MRSA pneumonia patients died. All 9 MRSA isolates tested were pulsed-field type USA300. Features significantly associated with isolation of MRSA (as compared with any other or no pathogen) included patient history of MRSA; nursing home admission in the previous year; close contact in the previous month with someone with a skin infection; multiple infiltrates or cavities on chest radiograph; and comatose state, intubation, receipt of pressors, or death in the emergency department. CONCLUSIONS: Methicillin-resistant Staphylococcus aureus remains an uncommon cause of CAP. Detection of MRSA was associated with more severe clinical presentation.

Impact of USA300 methicillin-resistant Staphylococcus aureus on clinical outcomes of patients with pneumonia or central line-associated bloodstream infections.

BACKGROUND: The USA300 methicillin-resistant Staphylococcus aureus (MRSA) strain, which initially emerged as a cause of community-associated infections, has recently become an important pathogen in healthcare-associated infections (HAIs). However, its impact on patient outcomes has not been well studied. We evaluated patients with invasive MRSA infections to assess differences in outcomes between infections caused by USA100 and those caused by USA300. METHODS: Population-based data for invasive MRSA infections were used to identify 2 cohorts: (1) nondialysis patients with central line-associated bloodstream infections (CLABSIs) and (2) patients with community-onset pneumonia (PNEUMO) during 2005-2007 from 6 US metropolitan areas. Medical records of patients with confirmed MRSA USA100 or USA300 infection were reviewed. Logistic regression and, when appropriate, survival analysis was performed to evaluate mortality, early and late complications, and length of stay. RESULTS: A total of 236 and 100 patients were included in the CLABSI and PNEUMO cohorts, respectively. USA300 was the only independent predictor of early complications for PNEUMO patients (odds ratio [OR], 2.6; P = .02). Independent predictors of CLABSI late complications included intensive care unit (ICU) admission before MRSA culture (adjusted OR [AOR], 2.1; P= .01) and Charlson comorbidity index (AOR, 2.6; P = .003), but not strain type. PNEUMO patients were significantly more likely to die if they were older (P = .02), black (P < .001), or infected with USA100 strain (P = .02), whereas those with CLABSI were more likely to die if they were older (P < .001), had comorbidities (P < .001), or had an ICU admission before MRSA culture (P = .001). CONCLUSIONS: USA300 was associated with early complications in PNEUMO patients. However, it was not associated with mortality for either PNEUMO or CLABSI patients. Concerns regarding higher mortality from HAIs caused by USA300 may not be warranted.

Comparison of Staphylococcus aureus from skin and soft-tissue infections in US emergency department patients, 2004 and 2008.

BACKGROUND: In the past decade, new methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as a predominant cause of community-associated skin and soft-tissue infections (SSTIs). Little information exists regarding trends in MRSA prevalence and molecular characteristics or regarding antimicrobial susceptibility profiles of S. aureus isolates. METHODS: We enrolled adults with acute, purulent SSTIs presenting to a US network of 12 emergency departments during August 2008. Cultures and clinical information were collected. S. aureus isolates were characterized by antimicrobial susceptibility testing, pulsed-field gel electrophoresis, and toxin genes detection. The prevalence of S. aureus and MRSA and isolate genetic characteristics and susceptibilities were compared with those from a similar study conducted in August 2004. RESULTS: The prevalence of MRSA was 59% among all SSTIs during both study periods; however, the prevalence by site varied less in 2008 (38%-84%), compared with 2004 (15%-74%). Pulsed-field type USA300 continued to account for almost all MRSA isolates (98%). Susceptibility to trimethoprim-sulfamethoxazole, clindamycin, and tetracycline among MRSA isolates remained greater than 90% in 2008. A higher proportion of MRSA infections were treated with an agent to which the infecting isolate was susceptible in vitro in 2008 (97%), compared with 2004 (57%). CONCLUSIONS: Similar to 2004, MRSA remained the most common identifiable cause of purulent SSTIs among patients presenting to a network of US emergency departments in 2008. The infecting MRSA isolates continued to be predominantly pulsed-field type USA300 and susceptible to recommended non-ß-lactam oral agents. Clinician prescribing practices have shifted from MRSA-inactive to MRSA-active empirical antimicrobial regimens.

Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children.

Evidence-based guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections were prepared by an Expert Panel of the Infectious Diseases Society of America (IDSA). The guidelines are intended for use by health care providers who care for adult and pediatric patients with MRSA infections. The guidelines discuss the management of a variety of clinical syndromes associated with MRSA disease, including skin and soft tissue infections (SSTI), bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system (CNS) infections. Recommendations are provided regarding vancomycin dosing and monitoring, management of infections due to MRSA strains with reduced susceptibility to vancomycin, and vancomycin treatment failures.

Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children: executive summary.

Evidence-based guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections were prepared by an Expert Panel of the Infectious Diseases Society of America (IDSA). The guidelines are intended for use by health care providers who care for adult and pediatric patients with MRSA infections. The guidelines discuss the management of a variety of clinical syndromes associated with MRSA disease, including skin and soft tissue infections (SSTI), bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system (CNS) infections. Recommendations are provided regarding vancomycin dosing and monitoring, management of infections due to MRSA strains with reduced susceptibility to vancomycin, and vancomycin treatment failures.

Mupirocin resistance.

With increasing pressure to prevent methicillin-resistant Staphylococcus aureus (MRSA) infection, it is possible that there will be increased use of mupirocin for nasal decolonization of MRSA. Understanding the mechanisms, clinical significance, and epidemiology of mupirocin resistance is important for predicting how changes in mupirocin use may affect bacterial populations and MRSA control. High-level mupirocin resistance in S. aureus is mediated by a plasmid-encoded mupA gene. This gene can be found on conjugative plasmids that carry multiple resistance determinants for other classes of antimicrobial agents. High-level resistance has been associated with decolonization failure, and increased resistance rates have been associated with increased mupirocin use. Low-level mupirocin resistance is mediated via mutation in the native ileS gene, and the clinical significance of this resistance is unclear. Laboratory tests to detect and distinguish between these types of resistance have been described but are not widely available in the United States. Institutions that are considering the implementation of widespread mupirocin use should consider these resistance issues and develop strategies to monitor the impact of mupirocin use.

Methicillin-resistant S. aureus infections among patients in the emergency department.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly recognized in infections among persons in the community without established risk factors for MRSA. METHODS: We enrolled adult patients with acute, purulent skin and soft-tissue infections presenting to 11 university-affiliated emergency departments during the month of August 2004. Cultures were obtained, and clinical information was collected. Available S. aureus isolates were characterized by antimicrobial-susceptibility testing, pulsed-field gel electrophoresis, and detection of toxin genes. On MRSA isolates, we performed typing of the staphylococcal cassette chromosome mec (SCCmec), the genetic element that carries the mecA gene encoding methicillin resistance. RESULTS: S. aureus was isolated from 320 of 422 patients with skin and soft-tissue infections (76 percent). The prevalence of MRSA was 59 percent overall and ranged from 15 to 74 percent. Pulsed-field type USA300 isolates accounted for 97 percent of MRSA isolates; 74 percent of these were a single strain (USA300-0114). SCCmec type IV and the Panton-Valentine leukocidin toxin gene were detected in 98 percent of MRSA isolates. Other toxin genes were detected rarely. Among the MRSA isolates, 95 percent were susceptible to clindamycin, 6 percent to erythromycin, 60 percent to fluoroquinolones, 100 percent to rifampin and trimethoprim-sulfamethoxazole, and 92 percent to tetracycline. Antibiotic therapy was not concordant with the results of susceptibility testing in 100 of 175 patients with MRSA infection who received antibiotics (57 percent). Among methicillin-susceptible S. aureus isolates, 31 percent were USA300 and 42 percent contained pvl genes. CONCLUSIONS: MRSA is the most common identifiable cause of skin and soft-tissue infections among patients presenting to emergency departments in 11 U.S. cities. When antimicrobial therapy is indicated for the treatment of skin and soft-tissue infections, clinicians should consider obtaining cultures and modifying empirical therapy to provide MRSA coverage.

A review of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections.

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a cause of infection among otherwise healthy children and adults in the community. Skin and soft tissue infections are most common, but invasive manifestations also occur. A limited number of strains that may possess unique virulence or transmissibility factors have accounted for the majority of these infections. These strains emerged in the community but now are being transmitted in both community and healthcare settings. Incision and drainage remains the primary treatment for skin abscesses. Strains of MRSA circulating in the community generally are susceptible to a number of nonbeta-lactam antimicrobial agents, although resistance patterns may vary temporally and geographically. Educating patients on strategies to prevent further transmission is a critical component of case management. More data are needed to determine optimal strategies for management and prevention of MRSA skin infections in the community.

Methicillin-resistant Staphylococcus aureus: a primer for dentists.

BACKGROUND AND OVERVIEW: In 2005 in the United States, an estimated 94,370 new, invasive infections and 18,650 deaths were associated with methicillin-resistant Staphylococcus aureus (MRSA); most of these infections were in people with exposures in health care settings. MRSA also has emerged as a community-based pathogen, causing primarily skin infections that are not life-threatening, but occasionally causing more severe and invasive infections. The authors describe the history of MRSA; identify populations at greatest risk of experiencing MRSA colonization and infection; compare characteristics of MRSA infections occurring in health care and community settings; and summarize strategies, based on U.S. Centers for Disease Control and Prevention recommendations and the literature, to prevent transmission of MRSA in dental offices. CONCLUSIONS AND CLINICAL IMPLICATIONS: Standard infection control precautions should be enforced strictly in all ambulatory care settings, including dental offices, to prevent facility-based transmission of MRSA and other infectious agents.

Advancing the public health applications of Chlamydia trachomatis serology.

Genital Chlamydia trachomatis infection is the most commonly diagnosed sexually transmitted infection. Trachoma is caused by ocular infection with C trachomatis and is the leading infectious cause of blindness worldwide. New serological assays for C trachomatis could facilitate improved understanding of C trachomatis epidemiology and prevention. C trachomatis serology offers a means of investigating the incidence of chlamydia infection and might be developed as a biomarker of scarring sequelae, such as pelvic inflammatory disease. Therefore, serological assays have potential as epidemiological tools to quantify unmet need, inform service planning, evaluate interventions including screening and treatment, and to assess new vaccine candidates. However, questions about the performance characteristics and interpretation of C trachomatis serological assays remain, which must be addressed to advance development within this field. In this Personal View, we explore the available information about C trachomatis serology and propose several priority actions. These actions involve development of target product profiles to guide assay selection and assessment across multiple applications and populations, establishment of a serum bank to facilitate assay development and evaluation, and development of technical and statistical methods for assay evaluation and analysis of serological findings. The field of C trachomatis serology will benefit from collaboration across the public health community to align technological developments with their potential applications.

Trends in invasive methicillin-resistant Staphylococcus aureus infections.

OBJECTIVE: To describe trends in the incidence of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections in children during 2005-2010. METHODS: We evaluated reports of invasive MRSA infections in pediatric patients identified from population-based surveillance during 2005-2010. Cases were defined as isolation of MRSA from a normally sterile site and classified on the basis of the setting of the positive culture and presence or absence of health care exposures. Estimated annual changes in incidence were determined by using regression models. National age- and race-specific incidences for 2010 were estimated by using US census data. RESULTS: A total of 876 pediatric cases were reported; 340 (39%) were among infants. Overall, 35% of cases were hospital-onset, 23% were health care-associated community-onset, and 42% were community-associated (CA). The incidence of invasive CA-MRSA infection per 100000 children increased from 1.1 in 2005 to 1.7 in 2010 (modeled yearly increase: 10.2%; 95% confidence interval: 2.7%-18.2%). No significant trends were observed for health care-associated community-onset and hospital-onset cases. Nationally, estimated invasive MRSA incidence in 2010 was higher among infants aged <90 days compared with older infants and children (43.9 vs 2.0 per 100000) and among black children compared with other races (6.7 vs 1.6 per 100000). CONCLUSIONS: Invasive MRSA infection in children disproportionately affects young infants and black children. In contrast to reports of declining incidence among adults, there were no significant reductions in health care-associated MRSA infections in children. Concurrently, the incidence of CA-MRSA infections has increased, underscoring the need for defining optimal strategies to prevent MRSA infections among children with and without health care exposures.