bluuebunny/crossref_metadata_2025_split huggingface dataset:
389. Risk Factors and Outcomes of Patients with Infectious Complications After Surgical Treatment of Blount Disease
Authors: Polistico Jordan , Polistico Sarah , Dhar Sorabh , Bhargava Ashish 
Published: October 2019

Abstract

Background
Blount disease (idiopathic tibia vara) is an uncommon pediatric growth disorder characterized by unequal endochondral ossification of the medial aspect of the proximal tibial growth plate. Management of Blount’s disease involves performing osteotomy for improved outcomes. The objective of the study was to assess risk factors for infection, microbiology, and outcomes in patients following surgical correction.

Methods
This study is a retrospective case–control study of patients who underwent surgery for Blount disease at Children’s Hospital of Michigan, Detroit from January 1, 2000 to January 31, 2019. Charts from 44 patients who underwent surgical correction were reviewed (22 cases and 22 control patients) and analyzed for basic demographics, surgical risk factors, microbiology, treatment durations, and outcomes.

Results
A total of 44 patients (22 cases and 22 controls) were included. Baseline characteristics, risk factors, and outcomes are shown in Table 1. Significant risk factors for infection included increased obesity and BMI (P < 0.05). The median time to infection from index surgery was 12.5 days, with 11 (52.4%) of the infections categorized as superficial and 10 (46.6) as deep or organ space. 7 (31.8%) infections were polymicrobial and the common pathogen was Staphylococcus aureus (n = 7, 31.8%) (Table 2). Infected patients had an average of 3.25 incision and drainage procedures, and the average duration of antibiotic therapy was 23 days.

Conclusion
Obesity with an increased BMI was associated with increased risk of infectious complication following the surgical treatment of Blount’s Disease with Staphylococcus aureus, is the most common pathogen.

Disclosures
All authors: No reported disclosures.
391. Septic Arthritis and Acute Hematogenous Osteomyelitis in Children: Disease-Specific Antibiogram and Implications for Treatment
Authors: Mobayed Nisreen O , Schlidt Kevin , Roadman Daniel , Hahn Danita , Huppler Anna R 
Published: October 2019

Abstract

Background
Osteomyelitis and septic arthritis are common pediatric musculoskeletal infections with potential to cause significant morbidity. Empiric antibiotic selection is made prior to the availability of microbiologic data. The aim of this study was to compare the epidemiology of osteoarticular infections (OAI) to antibiotic regimens and local antibiograms.

Methods
A retrospective study was performed on patients aged 6 months to 18 years with a diagnosis of septic arthritis or acute hematogenous osteomyelitis in a large, free-standing children’s hospital between July 2012 and July 2017. Exclusion criteria were chronic osteomyelitis, prior trauma or surgery at the site, noninfectious arthritis, and Lyme arthritis. Data collected from the electronic medical record included demographics, initial and discharge antibiotic therapy, and microbiologic results. Data were compared with the local antibiogram during the same time period.

Results
A total of 207 patients were included: 66 patients <4 years (< 4Y) and 141 patients ≥4 years (≥4Y). Causative pathogens were identified in 70% of patients. Staphylococcus aureus comprised 55% of positive results in children < 4Y and 73% in children ≥4Y. Among S. aureus cultures, 70–76% were methicillin sensitive (MSSA). Overall clindamycin susceptibility was 97%, with all resistant strains detected in children ≥4Y with MSSA. This is strikingly different than the institutional antibiogram showing 79% overall clindamycin sensitivity in S. aureus [82% in MSSA, 72% in methicillin resistant (MRSA)]. Kingella kingae was exclusively identified in children <4Y (21% of positives), which was also the group with the highest rate of culture-negative infection (41%). Intravenous clindamycin alone was the most frequent initial antibiotic regimen, prescribed for 41% of all patients. Initial antibiotic regimens matched organism susceptibilities in 90% of MRSA and 100% of MSSA infections.

Conclusion
Our study revealed high rates of clindamycin-susceptible S. aureus in older children and K. kingae and culture-negative infection in children < 4 years with OAI. Antibiotic susceptibilities differing from our institutional antibiogram suggest that disease-specific antibiograms will aid with empiric treatment decisions.

Disclosures
All authors: No reported disclosures.
396. Aminoglycoside Acute Kidney Injury (AKI) Following the Implantation of Tobramycin Loaded Polymethylmethacrylate (PMMA) Cement and Calcium Sulfate (CaSO4) Beads for the Treatment of Periprosthetic Joint Infection (PJI)
Authors: Vasina Logan , Chinn Raymond , Minuto Joshua 
Published: October 2019

Abstract

Background
Antibiotic loaded bone cement (ALBC) in PMMA, generally with tobramycin and vancomycin (TV) is commonly used for the treatment of PJI. CaSO4 beads, loaded with TV is biodegradable and can be used alone or in combination with PMMA. Identification of AKI following documentation of sustained supra-therapeutic tobramycin levels a patient with chronic PJI treated with ALBC (both PMMA + CaSO4) prompted the development of guidelines to mitigate risk of AKI in patients treated with ALBC. Although AKI may be enhanced with vancomycin, case reports with TV in PMMA implicate tobramycin. We provide data in a cohort of patients treated for PJI using PMMA or PMMA + CaSO4.

Methods
Data were obtained to describe clinical findings. As part of a quality improvement initiative, tobramycin and serum creatinine levels were obtained in eight subsequent patients who received PMMA or PMMA + CaSO4 and clinical guidelines were developed to standardize aminoglycoside dosing and monitoring. Vancomycin levels were not routinely monitored.

Results
Figure 1 describes the clinical course of the index patient. Table 1 lists doses, serum creatinine and tobramycin levels the cohort of PJI patients. All patients treated with PMMA + CaSO4 had tobramycin levels from 3.5 to 8.7 µg/mL on a postoperative day (POD) 1 compared with < 2 µg/mL in patients treated with PMMA alone. All patients’ levels peaked on POD 1.

Conclusion
Patients treated with CaSO4 had higher levels in the early postoperative period compared with patients treated with PMMA. In all patients, serum levels appeared similar after 48 to 72 hours. Our experience suggests the use of CaSO4 + PMMA may have important clinical consequences in patients with decreased clearance and/or those at risk for early postoperative renal impairment. Guidelines developed mitigated this potential complication since we have not identified AKI in subsequent patients undergoing treatment of PJI with ALBC. Features of guidelines included: (1) identification of high-risk patients; (2) a flowsheet to guide dosing recommendations based on low/high risk; (3) routine monitoring of levels on POD 1 with a goal of tobramycin < 2 as a surrogate for toxicity. Pharmacy approved dosing must be incorporated into guidelines of care for patients undergoing arthroplasty where ALBC is used.

Disclosures
All authors: No reported disclosures.
401. Predictors of Treatment Failure for Hip and Knee Prosthetic Joint Infections in the Setting of Prosthesis Removal: A Multi-Center Retrospective Cohort
Authors: Kandel Christopher , Jenkinson Richard , Daneman Nick , Backstein David , Muller Matthew P , Katz Kevin , Sajja Abhilash , Garcia Jeldes Felipe , McGeer Allison 
Published: October 2019

Abstract

Background
Prosthetic hip and knee joint infections (PJIs) are challenging to eradicate despite prosthesis removal and long courses of antibiotics. We aimed to describe the risk factors for PJI treatment failure in a multicenter retrospective cohort.

Methods
A retrospective cohort of individuals who underwent prosthetic joint removal for a PJI at one of five hospitals in Toronto, Ontario, Canada from 2010–2014. Individuals eligible for the cohort were obtained by searching operative listings and PJIs were defined according to the criteria of the Musculoskeletal Infection Society. Treatment failure was defined as recurrent PJI, amputation, death or chronic antibiotic suppression. Potential risk factors for treatment failure were abstracted by chart review and assessed using a Cox proportional hazards model.

Results
533 PJIs were analyzed over a median follow-up duration of 1102 days with 21 surgeons performing more than 5 revision arthroplasties for a PJI. Two-stage procedures were performed in 81% (430/533) and the most common organism was coagulase negative staphylococci (32%). Treatment failure occurred in 28% (150/533) over 1443 patient-years and was caused by a different bacterial species in 53% (56/105). On multivariate analysis the characteristics associated with PJI treatment failure included liver disease (adjusted hazard ratio (aHR) 3.12, 95% confidence interval (95% CI) 2.09–4.66), the presence of a sinus tract (aHR 1.53, 94% CI (1.12–2.10), preceding debridement with prosthesis retention (aHR 1.68, 95% CI 1.13–2.51), a one-stage procedure (aHR 1.72, 95% CI (1.28–2.32), and infection due to Gram-negative bacilli (aHR 1.35, 95% CI 1.04–1.76).

Conclusion
PJI treatment failure remains high despite prosthesis removal and the patient risk factors identified are non-modifiable. Novel treatment paradigms are urgently needed along with efforts to reduce orthopedic surgical site infections.

Disclosures
All authors: No reported disclosures.
403. Clinical Features and Treatment Outcome of Enterobacter Prostethic Joint Infections
Authors: Youssef Dima , Hooshmand Babak , Bhargava Ashish 
Published: October 2019

Abstract

Background
Enterobacter prosthetic joint infections (PJIs) are rare, occurring mainly in elderly people usually with complex medical and surgical history, and their treatment is usually challenging. Aim of this study is to assess the characteristics and outcomes of Enterobacter PJIs.

Methods
A retrospective multi-centric cohort was studied at three hospitals from January 2012 to December 2018. Patients with PJIs were identified using ICD codes. Enterobacter PJIs were then identified through reviewing patients’ electronic medical records.

Results
13 enterobacter PJIs were identified. 9 (69%) were polymicrobial. Mean age of the patients was 61.7 years, and mean BMI was 34.6 kg/m2. 8 patients (62%) were females, and 8 patients (62%) were Caucasians. Infected sites were: Hip in 5 patients (38%%), knee in 5 patients (38%) and ankle in 3 patients (23%) patients. 9 patients (69%) had osteoarthritis, 3 patients (23%) had diabetes mellitus, and 1 patient (8%) had connective tissue diseases requiring steroids. Most patients (11 out of 13) (85%) presented within 1 week of symptoms onset. Presenting clinical features were pain in 9 patients (69%), drainage in 10 patients (77%), purulence in 7 patients (54%), and fever in 5 patients (38%). 11 patients (85%) were managed with debridement, antibiotics and implant retention (DAIR), and 2 patients (15%) with antibiotics alone. Antibiotics used while managing were as follows: Cefepime n = 6, quinolones n = 2, carbapenems n = 4 and aminoglycosides n = 1. Outcome: 4 patients (31%) developed deep surgical site infections (and two of them required implant removal), 5 patients had no events in 12 months of follow-up, 3 patients (23%) had less than 6 months of follow-up, and one patient died in the hospital due to cardiac failure.

Conclusion
In our study, most cases of Enterobacter PJIs were polymicrobial. The success rate in monomicrobial infections was 75% while overall it was noted to be 38%. DAIR was associated with high readmission rates and deep surgical site infections (36%). 18% cases managed with DAIR required implant removal.

Disclosures
All authors: No reported disclosures.
413. Differences in Inflammatory Mechanisms in Pseudomonas aeruginosa and Staphyloccoccus auereus Infections in Cystic Fibrosis
Authors: Phuong Melissa S , Hernandez Rafael E , Sad Subash 
Published: October 2019

Abstract

Background
Chronic bacterial lung infections are the primary cause of morbidity and mortality in cystic fibrosis (CF). The most common CF pathogens, Pseudomonas aeruginosa (P. aeruginosa) or Staphylococcus aureus (S. aureus), are common commensal or environmental organisms that adapt to the CF lung. We sought to investigate whether adaptation from early lung colonizer to chronic pathogen alters the bacterial effects on host inflammation.

Methods
P. aeruginosa (n = 25) and S. aureus (n = 25) isolates from CF patients with early and chronic infections were acquired from Seattle Children’s CF. Environmental (n = 8) and clinical, non-CF P. aeruginosa (n = 8) isolates were obtained from the University of Ottawa. P. aeruginosa reference strain PA14 and PA14 transposon mutants for T3SS and flagellin were used to observe the relationship between cell death and cytokine production. We infected THP-1-derived macrophages (PMA differentiated) in vitro for 3 hours with various MOIs. We subsequently measured cell death of THP-1-derived macrophages using neutral red assay and cytokine production using ELISAs.

Results
Infections with PA14 mutants and non-CF P. aeruginosa isolates demonstrated that rapid cell death of THP-1-derived macrophages caused a reduction in cytokine production relative to strains that did not cause as much cell death. At 10 MOI, early P. aeruginosa isolates from CF patients induced more THP-1-derived macrophage cell death compared with chronic isolates (P < 0.0001). Chronic P. aeruginosa isolates induced greater production of TNF, IL-8, and IL-6 (P < 0.01, P < 0.0001, and P < 0.0001, respectively) compared with early strains. No difference in IL-1β production was observed. When controlling for cell death between the two groups by using heat-killed bacteria, the only difference maintained was in TNF production (P < 0.01). Between early and chronic S. aureus isolates, the one difference observed was greater IL-8 production among early isolates (P < 0.01).

Conclusion
Chronic P. aeruginosa isolates from CF patients induce less cell death but more TNF, IL-8, and IL-6 production compared with early isolates. This suggests that P. aeruginosa producing chronic infections induce inflammatory signals that may contribute to increased morbidity among CF patients.

Disclosures
All authors: No reported disclosures.
417. Cytomegalovirus (CMV) and Sexually Transmitted infections (STIs) During Pregnancy
Authors: Geetha Pinninti Swetha , Van Der Pol Barbara , Daniel Grace , Fowler Karen , Boppana Suresh 
Published: October 2019

Abstract

Background
Congenital cytomegalovirus infection (cCMV) is a leading cause of hearing loss and neurodevelopmental disabilities. Although higher rates of CMV acquisition and reinfections with new virus strains are seen in women with STIs, the significance of CMV-STI co-infections during pregnancy and whether co-infections increase intrauterine transmission of CMV remains unclear. Higher rates of CMV genital shedding were seen in mothers of infants with cCMV compared with those with uninfected infants. The objective of this study was to determine the association between CMV seroprevalence and STIs and whether STIs during pregnancy influences CMV genital shedding.

Methods
Vaginal swabs from a cohort of CMV seropositive women in labor from a multi-center study were analyzed. After DNA extraction from vaginal swabs, PCR was performed for detection of CMV, Neisseria gonorrhoeae (GC), Chlamydia trachomatis (CT), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG). The prevalence of STIs in CMV seropositive pregnant women was determined in this cohort and CMV genital shedding rates were compared between groups with and without STIs.

Results
In this cohort, CMV genital shedding in late pregnancy was detectable in 13% (21/160) of women while rates of detection for MG, GC, CT and TV were 3%, 0.6%, 1.2% and 8%, respectively. CMV-STI co-infections were noted in 2.5% (4/160) of women. CMV genital shedding was documented in only one woman with STIs, compared with 12.5% (20/160) without STIs. Among women shedding CMV in the genital tract, CMV viral load levels ranged from 1.1 × 102 IU/mL to 2.2 × 104 IU/mL.

Conclusion
In a cohort of CMV seropositive women, the presence of STIs in late pregnancy did not increase CMV genital shedding. Our preliminary findings suggest CMV shedding is not associated with STIs detected late in pregnancy.

Disclosures
All authors: No reported disclosures.
422. Pooling Strategy for Chlamydia trachomatis and Neisseria gonorrhoeae Reduces Cost of GeneXpert Molecular STI Screening in Two Limited-Resource Clinics in Zambia
Authors: Connolly Sarah , Kilembe William , Inambao Mubiana , Visoiu Ana-Maria , Sharkey Tyronza , Parker Rachel , Hunter Eric , Allen Susan 
Published: October 2019

Abstract

Background
Risk of heterosexual HIV-1 transmission is elevated in the presence of sexually transmitted infections (STIs) such as chlamydia (CT) and gonorrhea (NG). Syndromic management is a common, low-resource, approach to detecting STIs. However, CT and/or NG infections in women are often asymptomatic and therefore missed by syndromic management. Molecular testing for STIs is highly sensitive, but time and cost restraints preclude implementation of these technologies in resource-limited settings. Pooling samples for testing together in GeneXpert cartridges is one strategy for reducing the cost per individual tested.

Methods
This project describes the development of a pooling strategy based on social and demographic factors associated with CT/NG prevalence rates in a cohort of high-risk women in Zambia. Logistic regression modeling was used to predict the probability of a positive CT/NG test result in the presence of various factors. Data from a 2016 cross-sectional sub-study on intra-vaginal practices in 509 women was examined and an easy-to-use diagnostic screening checklist was created to categorize women by probability of testing positive on the GeneXpert. An algorithm considering cost of each test and prevalence of disease in each group determined the optimal pool size for each risk category.

Results
Logistic regression identified CT/NG to be associated with: city, age, education, long-acting reversible contraception usage, and laboratory results for bacterial vaginosis, Trichomonas vaginalis, and incident syphilis on the day of CT/NG testing. Signs and symptoms were not found to be associated. The overall prevalence of either CT and/or NG infection in this population was 17%. Low, middle, and high-risk groups could be separated based on checklist score with 7.52%, 18.30%, and 46.51% CT/NG prevalence, respectively.

Conclusion
Pooling women with similar CT/NG predictive factors together, or testing those at highest risk individually, reduces the cost per test. Further implementation of this tool to guide presumptive treatment, in lieu of molecular testing, increases the cost-saving potential. The strategies described in this study are applicable to other low-resource clinical settings seeking to provide the accuracy of molecular testing with a reduced financial burden.

Disclosures
All authors: No reported disclosures.
425. Longitudinal Trends in Risk Behaviors and Sexually Transmitted Diseases among Adolescents and Young Adults at a Sexually Transmitted Diseases Clinic, 2013–2017
Authors: Rusley Jack , Tao Jun , Koinis-Mitchell Daphne , Rosenthal Alex , Montgomery Madeline , Nunez Hector R , Chan Philip , Chan Philip 
Published: October 2019

Abstract

Background
Sexually transmitted disease (STD) rates continue to rise in the United States (US). Over half of all new STDs occur in adolescents and young adults (AYA). Few studies have evaluated how sexual behaviors such as number of partners or condom use may contribute to this increase. We aimed to determine the association of sexual behaviors and condom use with STD incidence over time among AYA.

Methods
We reviewed all AYA ages 13–26 years attending a public STD clinic in Rhode Island from 2013–2017. We reviewed demographic and behavioral data including age, gender identity, risk group, race, ethnicity, insurance status, sexual behaviors, substance use, self-reported STD/HIV diagnosis (lifetime, past year), condom use, and HIV/STD testing results. We report proportions in 2013 and 2017, and performed trend analyses (Cocharn-Armitage test for categorical variables and Kruskal–Wallis trend test for continuous variables) to determine trends over time.

Results
A total of 3,822 AYA visited the clinic during the study time period. An increasing trend was observed for: multiple (≥5) partners (29% of AYA in 2013 vs. 38% in 2017, P < 0.001), self-reported past year and lifetime STD diagnosis (12 vs. 21%, P < 0.001 and 19 vs. 33%, P < 0.001, respectively), and lab-documented diagnosis of any STD (15 vs. 25%, P < 0.001), syphilis (2 vs. 5%, P = 0.006), any chlamydia (11 vs. 20%, P = 0.001), and any gonorrhea (3 vs. 8%, P = 0.008). A decreasing trend was observed for: white race (66% in 2013 vs. 43% in 2017, P < 0.001), uninsured (73 vs. 53%, P < 0.001), condomless sex during oral as well as vaginal/anal sex (22 vs. 10%, P = 0.001 and 16 vs. 8%, P = 0.001, respectively), and self-reported HIV diagnosis (2.5% to 0.9%, P = 0.016).

Conclusion
Among AYA, risk behaviors such as condomless sex and multiple partners increased significantly from 2013–2017, which may be contributing to an increase in STDs. Increased public health efforts are needed to promote education and other interventions to address behaviors associated with STD transmission.

Disclosures
All authors: No reported disclosures.
435. Iliopsoas Abscess in Egyptian Patients Presenting to Cairo University Hospitals
Authors: Elanany Mervat , Abdel Mageed Reham , Hasaballah Maha 
Published: October 2019

Abstract

Background
The incidence of iliopsoas abscess (IPA) is rare but the frequency of this diagnosis has increased with the use of ultrasonography and computed tomography (CT). The vague presentation leads to delays in diagnosis and increases morbidity. Managing iliopsoas abscess is still forming a therapeutic challenge. The aim of this research was to study the features of iliopsoas abscess cases including the etiology and clinical presentation.

Methods
Patients and Methods. all patients presented to the orthopedic outpatient clinic (Cairo university hospitals) by back pain were screened by plain X-ray and IPA was by ultrasonography (US). The confirmed patients were diagnosed as having psoas or iliopsoas collection and subjected to: full history taking, full laboratory workup, screening for tuberculosis, radiological studies and ultrasound-guided needle aspiration of the abscess. The aspirate samples were microbiologically tested by culture (aerobic, anaerobic and MGIT) and PCR technique. Follow-up US was done within 7 days from the first aspiration.

Results
The outpatient clinic received 40 thousand back pain cases during a one-year study. Only 14 patients were diagnosed as IPA. The age ranged 19–65years (mean 37years) and 57% were male. 44.4% patients had primary IPA while 55.5% patients had secondary IPA. All patients had limping and flank pain, backache or both. Fever was common 90% of patients. Leukocytosis was found in 55.5% of patients, ESR was elevated and CRP was positive in all patients. Z.N stain for AFB was negative in all patients. Culture of aspirated fluid revealed S.aureus as the commonest organism (44% of cultures), then E.coli in (22% of cultures), Mycobacterial tuberculosis in 7% by MGIT culture and PCR. Other cultures were negative. All patients were treated by drainage and appropriate antibiotics. surgical intervention was needed in 22% patients. Recurrence occurred in only 1 patient with tuberculous iliopsoas abscess.

Conclusion
Although IPA is rare, the appropriate diagnosis by US is needed. S.aureus is the commonest pathogen but Mycobacterial tuberculosis could be a cause for recurrence.

Disclosures
All authors: No reported disclosures.