bluuebunny/crossref_metadata_2025 huggingface dataset:
Note: Measuring grating periods by diffraction method with a fore-end light path comprising fused fiber couplers and fiber port collimators
Authors: Sheng Bin , Chen Guohua , Huang Yuanshen , Luo Luwen
Published: October 2017

Based on the Littrow and Littman configurations for autocollimation, two methods are proposed herein with a fore-end light path comprising fused fiber couplers and fiber port collimators to measure the diffraction grating period. The experimental data from a uniform-line-spacing grating with a nominal value of 1200 lines/mm agreed well with theoretical values and with measurement errors of the Littrow and the Littman configurations of 1.05 × 10−4 and 4.99 × 10−5, respectively. Both methods were demonstrated to reduce the diameter of the laser spot and improve the alignment precision of the measurement system.
Solving the non-isentropic Navier-Stokes equations in odd space dimensions: The Green function method
Authors: Du Linglong , Wu Zhigang
Published: October 2017

In this paper, we investigate the wave structure of the solution for the compressible Navier-Stokes equations in both one space dimension and three space dimensions. First, we give the pointwise estimate on the Green function for the linearized system by dividing the physical domain into two parts, which are the finite Mach number region and outside finite Mach number region. We use long-wave short-wave decomposition and a weighted energy estimate method in each region separately. The Green function provides a complete picture of the wave pattern, with explicit leading terms. Then with the help of the Duhamel principle, we give the pointwise estimate of the solution for the nonlinear problems (1.1) and (1.2). Specially, we find that the decay rate in Lp(R3) (2<p≤∞) for the energy ω̃ is faster than those for the density ρ̃ and the momentum m̃.
Investigation of femtosecond laser-produced plasma from various metallic targets using the Langmuir probe characteristic
Authors: Nica P. , Gurlui S. , Osiac M. , Agop M. , Ziskind M. , Focsa C.
Published: October 2017

The Langmuir probe is used to characterize the plasma produced by fs-laser ablation from pure metallic targets. Time dependence of the probe current and the total collected charge is discussed in terms of a shifted Maxwell–Boltzmann distribution function, and from probe characteristics the plasma temperature and average charge state are calculated. Target materials of various physical properties (atomic mass, thermal constants) are used to find possible correlations with resulting plasma parameters. By positively biasing the probe, the collected charge –probe voltage characteristic is in general vertically shifted, and for low negative probe potentials an effect consisting in an abnormal decrease of the ion current is observed. Periodic falls of the total collected charge vs. probe voltage are experimentally recorded, the effect being more significant at high background pressure. They are tentatively attributed to secondary ionization.
Genome-wide identification and comparative analysis of NBS-LRR resistance genes in Brassica napus
Authors: Alamery Salman , Tirnaz Soodeh , Bayer Philipp , Tollenaere Reece , Chaloub Boulos , Edwards David , Batley Jacqueline
Published: October 2017

Plant disease-resistance genes play a critical role in providing resistance against pathogens. The largest family of resistance genes are the nucleotide-binding site (NBS) and leucine-rich repeat (LRR) genes. They are classified into two major subfamilies, toll/interleukin-1 receptor (TIR)-NBS-LRR (TNL) and coiled-coil (CC)-NBS-LRR (CNL) proteins. We have identified and characterised 641 NBS-LRR genes in Brassica napus, 249 in B. rapa and 443 in B. oleracea. A ratio of 1 : 2 of CNL : TNL genes was found in the three species. Domain structure analysis revealed that 57% of the NBS-LRR genes are typical resistance genes and contain all three domains (TIR/CC, NBS, LRR), whereas the remaining genes are partially deleted or truncated. Of the NBS-LRR genes, 59% were found to be physically clustered, and individual genes involved in clusters were more polymorphic than those not clustered. Of the NBS-LRR genes in B. napus, 50% were identified as duplicates, reflecting a high level of genomic duplication and rearrangement. Comparative analysis between B. napus and its progenitor species indicated that >60% of NBS-LRR genes are conserved in B. napus. This study provides a valuable resource for the identification and characterisation of candidate NBS-LRR genes.
The extension and convergence of mean curvature flow in higher codimension
Authors: Liu Kefeng , Xu Hongwei , Ye Fei , Zhao Entao
Published: October 2017

In this paper, we investigate the convergence of the mean curvature flow of closed submanifolds in

R

n
+
q

\mathbb {R}^{n+q}

. We show that if the initial submanifold satisfies some suitable integral curvature conditions, then along the mean curvature flow it will shrink to a round point in finite time.
Effects of indiscriminate fisheries on a group of small data-poor species in Thailand
Authors: Aylesworth Lindsay , Phoonsawat Ratanavaree , Vincent Amanda C J
Published: October 2017

As catches of economically valuable target fishes decline, indiscriminate fisheries are on the rise, where commercial and small-scale fishers retain and sell an increasing number of marine species. Some of these catches are destined for international markets and subject to international trade regulations. Many of these species are considered “data-poor” in that there are limited data on their biology, ecology, and exploitation, which poses a serious management challenge for sustainable fisheries and trade. Our research explores the relative pressure exerted by such indiscriminate fisheries on a data-poor marine fish genus—seahorses (Hippocampus spp.)—whose considerable international trade is regulated globally. Our focus is Thailand, a dominant fishing nation and the world‘s largest exporter of seahorses, where we gathered data by interviewing commercial and small-scale fishers and through port sampling of landed catch. We estimate that annual catches were more than threefold larger than previously documented, approximating 29 million individuals from all gears. Three fishing gears–two commercial (otter and pair trawl) and one small-scale (gillnet)–caught the most individuals. Results from port sampling and our vulnerability analysis confirmed that H. kelloggi, H. kuda, and H. trimaculatus were the three species (of seven found in Thai waters) most susceptible to fishing. Small-scale gillnets captured the majority of specimens under length at maturity, largely due to catches of juvenile H. kuda and H. trimaculatus. This research indicates a role for vulnerability analysis to initiate precautionary management plans while more extensive studies can be conducted.
Étale Fundamental Groups of Strongly $\boldsymbol{F}$-Regular Schemes
Authors: Bhatt Bhargav , Carvajal-Rojas Javier , Graf Patrick , Schwede Karl , Tucker Kevin
Published: October 2017

We prove that a strongly $F$-regular scheme $X$ admits a finite, generically Galois, and étale-in-codimension-one cover $\tilde X \to X$ such that the étale fundamental groups of $\tilde X$ and $\tilde X_{{\mathrm{reg}}}$ agree. Equivalently, every finite étale cover of $\tilde X_{{\mathrm{reg}}}$ extends to a finite étale cover of $\tilde X$. This is analogous to a result for complex klt varieties by Greb, Kebekus, and Peternell.
The Association of Molecular Characteristics, Vancomycin MIC and Clinical Outcomes in Methicillin-susceptible Staphylococcus aureus Osteoarticular Infections in Children
Authors: McNeil Jonathon , Vallejo Jesus G , Rosas Louie , Mason Edward O , Kaplan Sheldon L , Hulten Kristina G
Published: October 2017

Background

Methicillin-resistant Staphylococcus aureus, particularly those belonging to the USA300 pulsotype and bearing Panton–Valentine leucocidin (pvl), have been well described to cause severe osteoarticular infection (OAI). Vancomycin minimum inhibitory concentration (MIC) ≥ 1.5 µg/ml has been demonstrated to contribute to disease severity in MRSA bacteremia. Little data exist to describe the spectrum of outcomes in MSSA OAI in terms of molecular characteristics and vancomycin MIC.

Methods

OAI isolates were identified from 2011 to 2016 and subjected to vancomycin E-tests. MSSA isolates underwent PFGE, PCR for pvl, and a stepwise assay to determine accessory gene regulator (agr) group. A review of the medical record was performed. Orthopedic complications included chronic osteomyelitis, pathologic fracture, and growth arrest.

Results

During the study period, 167 cases of S. aureus OAI were identified; 115 were MSSA (68.9%). 29.1 and 26.1% of MSSA isolates were USA300 and pvl positive, respectively. USA300 isolates were more likely to be pvl-positive (66.7 vs. 13.6%, P < 0.001) and agr I (80% vs. 57.5%, P = 0.001). The presence of pvl was associated with agr I (P = 0.03), larger abscesses (6 vs. 2cm, P = 0.04), ICU admission (16.7 vs. 3.5%, P = 0.03) and a longer length of stay (11 vs. 6 days, P = 0.05). agr III and IV were associated with a higher rate of orthopedic complications (36.4 vs. 13.9%, P = 0.03) and surgical procedures (90.1 vs. 64.5%, P = 0.02) than other agr groups. An increase in the proportion of MSSA isolates with a vancomycin MIC ≥ 1.5 µg/ml occurred in the study period (P = 0.007, Figure 1). In MSSA, vancomycin MIC ≥ 2 µg/ml was associated with agr III (p = 0.07) and higher rates of orthopedic complications (P = 0.08) and venous thrombosis (P = 0.06, Figure 2).

Conclusion

MSSA accounts for 70% of S. aureus isolates causing OAI at TCH. While pvl-positive strains are associated with worse short-term outcomes, agr III and IV are associated with long-term morbidity. Vancomycin E-test MICs appear to be increasing among MSSA; vancomycin MIC ≥ 2 µg/ml are associated with agr-III and adverse clinical outcomes suggesting that this may be a surrogate for disease severity. Further work is needed to understand the contribution of these factors to invasive MSSA disease.

Disclosures

J. McNeil, NIAID, NIH: Grant Investigator, Grant recipient.  S. L. Kaplan, Pfizer: Grant Investigator and Speaker at PCV13 Launch Meeting in China, Research grant and Speaker honorarium
U.S. Combat-related Invasive Fungal Wound Infection (IFI) Epidemiology and Wound Microbiology: Afghanistan Theater 2009–2014
Authors: Ganesan Anuradha , Shaikh Faraz , Peterson Philip , Bradley William P , Blyth Dana M , Lu Dan Z , Bennett Denise , Schnaubelt Elizabeth , Johnson Brian , Merritt Teresa , Flores Nicole , Hawthorne Virginia , Wells Justin , Carson Leigh , Tribble David R
Published: October 2017

Background

Culturing combat-related wounds often yields both fungi and bacteria. It is difficult to differentiate fungal contamination from infection, and objective criteria that identify patients at risk for IFI are needed. This study was designed to characterize IFI among US combat casualties in the Afghanistan Theater.

Methods

This retrospective study includes subjects with any labortory evidence of fungi (either histopathology or cultures). Wounds with ongoing necrosis and labortory evidence of infection were classified as IFI). Wounds with labortory evidence of fungal infection, but without ongoing necrosis were classified as either highly suspicious wounds based on objective clinical criteria (i.e., presence of systemic and local signs of infection and use of antifungals for ≥10 days) or non-IFI wounds if they failed to meet clinical criteria.

Results

Of 1932 subjects, 246 (12.7%) had labortory evidence of fungal infection. There were a total of 143 IFI wounds (n = 94), 157 non-IFI wounds (n = 96), and 113 high suspicion wounds (n = 56). IFI subjects had significantly higher injury severity scores (ISS median: 39.5 vs. 33), Sequential Organ Failure Assessment (SOFA) scores (7 vs. 2) and were more likely to require mechanical ventilation (66 vs. 28%). IFI patients also had higher ISS (93 vs. 84% with ISS >25) and SOFA scores (7 vs. 4) compared with the subjects with high suspicion wounds. IFI wounds often grew molds belonging to the order Mucorales compared with high suspicion (19 vs. 10%, P = 0.04) and non-IFI wounds (19 vs. 7%, P = 0.02). About half of the IF wounds grew fungi of the order Mucorales either isolated alone or in conjunction with other fungi, in comparison, 25% of the high suspicion wounds and 11% of the non-IFI wounds grew fungi of the order Mucorales. Three groups of fungi belonging to the order Mucorales, genus Aspergillus and Fusarium accounted for 83% of the IFI wounds and 74% of the high suspicion wounds.

Conclusion

Labortory evidence of fungal infection is common among combat casualties. Clinical characteristics and wound microbiology allows us to group subjects into groups at low and high risk of IFI. Fungi of the order Mucorales, genus Aspergillus and Fusarium should not be considered contaminants. The presence of these fungi should obligate close clinical follow-up and debridement as needed.

Disclosures

All authors: No reported disclosures.
Current Epidemiology of Serogroup W Meningococcal Disease—United States, 2010–2015
Authors: Soeters Heidi , Blain Amy , Chang How-Yi , Whaley Melissa , Macneil Jessica
Published: October 2017

Background

Serogroup W (NmW) meningococcal disease is a rare but severe infection. Following an NmW outbreak after the Hajj in 2000, NmW disease, predominantly caused by sequence type (ST)-11 clonal complex (cc), rapidly increased in South Africa, South America, and the UK. We describe NmW meningococcal disease epidemiology in the USA during 2010–2015.

Methods

Data were collected from the National Notifiable Diseases Surveillance System, Active Bacterial Core surveillance, and state health departments. Isolates were serogrouped via slide agglutination and real-time polymerase chain reaction. For cases lacking a serogroup result at CDC, the state result was used. Case-fatality ratios (CFR) were calculated using the proportion of cases with known outcomes as the denominator. cc and ST were determined using multilocus sequence typing (MLST).

Results

From 2010 to 2015, 3,504 meningococcal disease cases were reported to CDC; 2,976 (85%) had a serogroup result, of which 290 (10%) were NmW. Although the number of NmW cases reported annually remained fairly stable (range: 40–57), the total number of reported meningococcal disease cases decreased by 60%, and the proportion of cases due to NmW increased from 6% (42/830) in 2010 to 12% (40/332) in 2015. The majority of NmW cases were reported from five states: Florida (n = 106), California (n = 31), New York (n = 25), Georgia (n = 19), and Oregon (n = 11). Half of people with NmW disease were male, 185 (64%) were white, and 84 (29%) were Hispanic. The median age was 51 years (interquartile range: 26–70). Overall, 20% (52/259) of NmW cases were fatal, compared with CFRs for serogroups B (15%), Y (18%), or C (24%). NmW CFR was highest among adults aged 50–59 years (38%). MLST results were available for 119 (41%) of NmW cases: 76 (64%) were cc11, 40 (34%) were cc22, and 1 each were cc23, cc32, and an unassigned cc. cc appeared to be geographically associated: cc11 was concentrated in Florida and Georgia, while cc22 predominated on the West coast. Within cc11, the majority of isolates (86%) were ST-11, and within cc22 the majority (73%) were ST-22.

Conclusion

A rapid increase in NmW disease has not been observed in the USA. Most NmW cases were reported in a limited number of states, with geographic differences in clonal complex.

Disclosures

All authors: No reported disclosures.
Detection of Respiratory Pathogens in Parapneumonic Effusions by Hypothesis-free, Next-Generation Sequencing (NGS)
Authors: Ampofo Krow , Pavia Andrew , Blaschke Anne J , Schlaberg Robert
Published: October 2017

Background

Species-specific polymerase chain reaction (PCR) testing of pleural fluid (PF) from children with parapneumonic effusion (PPE) has increased pathogen identification in pediatric PPE. However, a pathogen is not detected in 25–35% of cases. Hypothesis-free, next-generation sequencing (NGS) provides a more comprehensive alternative and has led to pathogen detection in PCR-negative samples. However, the utility of NGS in the evaluation of PF from children with PPE is unknown.

Methods

Archived PF (n = 20) from children younger than 18 years with PPE and hospitalized at Primary Children’s Hospital, Utah, in 2015 and previously tested by PCR were evaluated. Ten PCR-negative and 10 PCR-positive PF specimens were tested using RNA-seq at an average depth of 7.7×106 sequencing reads per sample. NGS data were analyzed with Taxonomer. We compared pathogens detected by blood and PF culture, PCR, and NGS.

Results

Overall, compared with blood/PF culture, PF PCR and PF NGS testing of PF increased bacterial identification from 15% to 50% (P < 0.05) and 65% (P = 0.003), respectively. Pathogen detection in PF by PCR and NGS were comparable (50 vs. 65%, p = NS) (Table). However, compared with PF PCR, NGS significantly increased detection of S. pyogenes (20% vs. 55%; P < 0.05), with 100% concordance when detected by PCR and culture. Detection of Fusobacterium spp. (10 vs. 10%) by PF NGS and PF PCR were comparable. In contrast, there was no detection of S. pneumoniae (15 vs. 0%) by PF NGS compared with PF PCR.

Conclusion

PF NGS testing significantly improves bacterial identification and comparable to PF PCR testing, which can help inform antimicrobial selection. However there were differences in detection of S. pneumoniae and S. pyogenes. Further studies of NGS testing of PF of children with PPE are needed to assess its potential in the evaluation of PPE in children.

Disclosures

A. J. Blaschke, BioFire Diagnostics LLC: Collaborator, Have intellectual property in BioFire Diagnostics through the University of Utah and Investigator, Licensing agreement or royalty and Research support; R. Schlaberg, IDbyDNA: Co-founder, Consultant and Shareholder, Stock
Trends and Associations with PrEP Prescription Among 602 New York City (NYC) Ambulatory Care Practices, 2014–2016
Authors: Salcuni Paul , Smolen Jenny , Jain Sachin , Myers Julie , Edelstein Zoe
Published: October 2017

Background

Concern over equitable access to HIV preexposure prophylaxis (PrEP) informs comprehensive scale-up efforts in New York City (NYC). We examined trends plus patient and practice factors associated with PrEP prescribing by NYC ambulatory care practices.

Methods

We queried electronic health records (EHR) from Q1 2014 to Q2 2016 using the NYC Health Department’s “Hub.” Data from 602 practices were aggregated quarterly by patient factors, including age (18–29, 30–100); sex (male, female); and race/ethnicity (Asian, Black, Hispanic, White, other, missing). Practice factors included location (Manhattan, other); type (community health center [CHC], hospital, independent); number of infectious disease (ID) specialists; and proportion of patients (ranked by quartile) from high poverty neighborhoods (ZIP codes in which ≥20% of residents live below the federal poverty level). PrEP prescription was defined as tenofovir/emtricitabine prescription without other antiretrovirals or diagnoses of HIV, HIV-related opportunistic infections or hepatitis B. Rates were calculated per 105 patients seen. We used generalized estimating equations clustered by practice to examine trends overall and by sex, as well as associations among males. Factors and time interactions that were significant (P < 0.05) in bivariate analysis were assessed for inclusion in the final model.

Results

Overall, PrEP prescription rose from 38.9 per 105 in Q1 2014 to 418.5 per 105 in Q2 2016, a 976% increase. Increases were significant for both sexes (P < .0001; Figure 1). In multivariate analysis (Table 1), PrEP prescription was associated with both patient (younger age, white race/ethnicity) and practice factors (Manhattan location, CHCs, and on-site ID specialists). While practices with a greater proportion of patients from high poverty neighborhoods were less likely to prescribe PrEP initially, this association weakened over time (Table 2).

Conclusion

PrEP prescription increased over 9-fold from 2014 to 2016 among NYC ambulatory care practices, but disparities persisted. While efforts to promote PrEP may have helped attenuate the disparity by neighborhood poverty of the patient population, continued work may be needed to facilitate PrEP access for women, persons of color and for those in care at non-CHCs or practices outside of Manhattan.

Disclosures

All authors: No reported disclosures.
Estimating Risk to Humans Exposed to Highly Pathogenic Avian Influenza Outbreaks in the United States, 2014–2017
Authors: Olsen Sonja , Havers Fiona , Rolfes Melissa , Blanton Lenee , Rooney Jane , Gomez Thomas , Nelson Deborah , Karli Steven , Trock Susan C , Fry Alicia M
Published: October 2017

Background

In the USA, poultry outbreaks of highly pathogenic avian influenza viruses (AI) caused by H5 and H7 viruses have raised concern about the risk of infections in humans. Based on data from Asian lineage H5 and H7 AI, which sporadically transmit from poultry to humans, CDC currently recommends active daily monitoring of persons exposed to H5 and H7 AI viruses, including those who wear personal protective equipment (PPE).

Methods

Persons exposed to HPAI-infected birds or contaminated environments in the USA were actively monitored during exposure and for 10 days post-exposure for illness, during 2014–2017. Some exposed persons were monitored on-site by USDA or contract safety officers, company staff, or state health officials. State health department staff monitored people during the 10-day post-exposure period. Persons reporting any respiratory illness or conjunctivitis were swabbed for molecular influenza testing. Preliminary results are presented.

Results

From 2014 to 2017, 270 detections in poultry/wild birds were reported and at least 606 persons were potentially exposed to AI virus by exposure to birds, carcasses, or environment. Most exposed persons wore PPE. No human infections with AI viruses were detected.

Conclusion

The risk of transmission of these H5 and H7 AI viruses to humans was low. These preliminary data offer evidence to change the recommendations for monitoring in persons exposed to these viruses. If final data support these findings, self-monitoring by workers with reporting to health departments if symptoms develop, rather than active monitoring by public health personnel, could be considered. However, it will be important to reconsider and update recommendations as the viruses evolve. Furthermore, risk of infection likely varies by exposure and those without PPE should be actively monitored.

Disclosures

All authors: No reported disclosures.
Interdisciplinary Public Health Intervention in a Multigenerational Tuberculosis (TB) Outbreak in Harris County, Texas: A Case Study with Implications for Disease Control Process Improvement and Transmission Cycle Interruption
Authors: Haynie Aisha , Plasencia Carlos , Fields Kimberly , Nesbitt Elna , Lovings-Clark Audrey , Scott Mary , Wiltz-Beckham Dana , Reed Brian , Shah Umair A
Published: October 2017

Background

Harris County Public Health (HCPH) is the health department for Harris County, Texas jurisdiction. Harris County as a whole is the nation’s third most populous county, with 4.3 million residents, and a TB case rate more than double that of the USA. (7.6 cases per 100,000 pop). A total, 327 individuals were diagnosed with TB in Harris County during 2015, over two-thirds occurring in foreign-born individuals. In 2016, HCPH treated an immigrant female with active TB. Initial contact investigation (CI) yielded five household contacts (HHC). Two tested positive, but refused subsequent clinical evaluation by HCPH. Two months later, HCPH was notified of a HHC hospitalized with TB. After hospital discharge, the sick HHC moved into a motel in attempts to self-isolate, but refused evaluation of additional HHC in the home, and banned home access, precluding adequate CI. After numerous phone calls, visits to motel and home, and multiple rescheduled appointments, legal action appeared inevitable. Days later, HCPH was notified of another HHC diagnosed with active TB.

Methods

With alarm regarding the family’s adherence to control orders, TB staff implemented an innovative multidisciplinary team-based intervention in hopes of avoiding legal action. A site visit was paid to the motel by a local health authority, two TB staff, a county public investigator, and a refugee clinic outreach worker fluent in the family’s language. Patients were presented with letters requesting immediate cooperation to avoid court filings. Questions were answered, misinformation corrected, and education provided.

Results

Intermediary on-site intervention using a compassionate, firm multidisciplinary team approach resulted in 16 additional family members tested, yielding an infant with active TB (Case 4) and 8 with TB Infection (TBI). Isolation breaches were also discovered. Most importantly, TB transmission cycle was interrupted. Cultural and economic barriers hindering successful interaction with family were addressed, TB misconceptions corrected, and trusting relationship developed.

Conclusion

This innovative multidisciplinary intervention avoided court proceedings and curtailed the TB transmission cycle. HCPH improved its non-adherence intervention process, and modified TB control orders for infectious patients residing in congregate settings.

Disclosures

All authors: No reported disclosures.
Getting it Right the First Time: Relating Pharmacokinetic-Pharmacodynamic Target Attainment and Patient Outcomes
Authors: Bulik Catharine C , Bader Justin C , Lakota Elizabeth A , Bhavnani Sujata M , Rubino Christopher M , Sweeney Kim L , Ambrose Paul G , Owens Robert C
Published: October 2017

Background

The importance of delivering appropriate therapy to patients at the onset of treatment is well established. However, this goal is easier said than done given the complexity and uniqueness of each patient case. Nonetheless, treatment decisions driven by pharmacokinetic-pharmacodynamic (PK-PD) can account for patient variability and assist in selecting patient-specific therapies. Using data obtained from electronic decision support software (EDSS), we evaluated the relationship between the probability of PK-PD target attainment (PTA) and patient outcomes.

Methods

Data obtained over a 20-month period from an EDSS were evaluated and included: (1) patient demographics; (2) infection type; (3) pathogen; (4) clinician-selected antimicrobials; (4) pathogen susceptibility; (5) clinician-provided early and late outcomes. Data calculated by the EDSS included the PTA for all evaluated antimicrobial regimens. Using logistic regression, relationships between the probability of PTA and clinical improvement and clinical success at 48 hours and Days 7–10, respectively, were assessed.

Results

Data for 121 patient cases with various infection types were available. The most common pathogens reported were MRSA (14.9%) and K. pneumoniae (14.9%). Overall, 76.3% of patients demonstrated clinical improvement at 48 hours while 70.3% of patients demonstrated clinical success at Days 7–10. Based on the relationship between the probability of PTA and clinical improvement at 48 hours (Figure 1), for every 10% increase in PTA, patients were 1.74 times more likely to demonstrate clinical improvement (OR [95% CI] 1.74 [1.28–2.37], P < 0.001). At Days 7–10 (Figure 2), patients were 1.82 times more likely to have a successful response (OR [95% CI] 1.82 [1.29–2.58], p < 0.001). Based on these relationships, the predicted percent probability of a positive outcome at 48 hours and Days 7–10 for an initial treatment regimen with PTA of 90% was 77.2% and 76.1%, respectively.

Conclusion

Statistically significant positive relationships between PTA and clinical outcomes at 48 hours and Days 7–10 were identified. These data demonstrate the value of PK-PD in dosing regimen selection and provide a path toward delivering appropriate initial therapy to optimize patient outcomes.

Disclosures

S. M. Bhavnani, ICPD Technologies: Shareholder, stock options; C. M. Rubino, ICPD Technologies: Shareholder, stock options; P. G. Ambrose, ICPD Technologies: Shareholder, stock options
A Novel Antimicrobial Stewardship Program-Guided Procalcitonin Initiative for Emergency Department Diagnosis of Bacterial Pneumonia in New York City
Authors: Rodriguez George D , Yashayev Roman , Yushuvayev Bella , Kula Anna , Warren Nathan , Dhillon Geeti , Tsapepas Demetra , Keane Caroline , Rodgers William H , Siegal Jonathan , Sharma Manish , Segal-Maurer Sorana
Published: October 2017

Background

An accurate diagnosis of bacterial pneumonia in the Emergency Department (ED) is challenging, resulting in inappropriate antibiotic use, adversely impacting patient care and safety. Procalcitonin (PCT), a serum biomarker, has good positive predictive value for bacterial lower respiratory tract infections. We sought to evaluate the impact of using PCT in an antimicrobial stewardship program (ASP)-driven algorithm to manage patients with presumed pneumonia in the ED.

Methods

We performed an IRB-approved quality initiative, 4-month retrospective evaluation of adult patients evaluated for pneumonia using PCT in a 515-bed university-affiliated hospital. Initial PCT use was restricted to ED for hemodynamically stable patients with presumed pneumonia. Subsequent PCT levels were ordered by ASP team members at 8- to 12-hours and days 3, 5, and 7 to guide the duration of antibiotic use and interpreted as per existing guidelines. Prior to start of initiative, aggressive education was provided by ASP to ED staff, followed by algorithm implementation. Outcomes included hospital admission, days of antibiotics, antibiotic use ≤48 hours, total PCT levels, length of stay, and 30-day pneumonia readmission.

Results

Baseline demographics of initial 182 patients differed between negative and positive PCT groups with age (78 vs. 84, P = 0.037) and sexfemale (88 vs. 15, P = 0.001). Negative PCT was associated with lower temperature (P = 0.0002), and white blood cell count (P = 0.0001) on admission (Figure 1). Patients with negative PCT had reduced antibiotic initiation (71% vs. 95%, P = 0.001) and were less likely to be admitted (89% vs. 98%, P = 0.078). A total of 460 PCT levels were collected [negative group: 303, median 2(2,2), positive group: 157, median 4(3,4)]. Patients with negative PCT had reduced antibiotic duration (P < 0.001) and length of stay (P = 0.004) (Figures 2 and 3). There were no reported adverse events or differences in 30-day pneumonia readmissions.

Conclusion

Implementation of a PCT algorithm through ASP is a novel and efficacious addition to improving diagnostic yield, targeting appropriate therapy, and reducing length of stay. The impact on antibiotic resistance remains to be determined.

Disclosures

All authors: No reported disclosures.
Clinical Impact of Two Different Multiplex Respiratory Panel Assays on Management of Hospitalized Children Aged ≤24 months
Authors: Hassan Ferdaus , Lee Brian , Goldman Jennifer , Jackson Mary Anne , Selvarangan Rangaraj
Published: October 2017

Background

Highly multiplexed molecular assays are popular in clinical laboratories due their high sensitivity, specificity and relatively rapid turn-around time (TAT) for results. Luminex™ respiratory viral panel (RVP) detects 12 respiratory viruses, while BioFire™ respiratory panel (RP) detects 20 respiratory pathogens (17 viruses, 3 bacteria). The aim of the current study was to compare the impact of RVP and RP assay on management of hospitalized children aged ≤24 months.

Methods

Retrospective data were collected to compare the clinical impact from two multiplex molecular assays (RVP, December 2008–May 2012; RP August 2012–June 2015) on management and outcomes of hospitalized patients. Patients aged ≤24 months and positive for at least one respiratory virus were included. Patients who were (1) receiving immune suppressive therapy, (2) neonates requiring intensive care, or (3) hospitalized for >7 days were excluded.

Results

A total of 810 patients in RVP and 2,095 patients in RP group were included. The median TAT for RVP and RP assay were 29 hours (IQR 26–58 hours) and 4 hours (IQR 2–8 hours), respectively (P < 0.001). Significantly higher number of children in RVP group (44%, 357/810) received empiric antibiotic therapy compared with RP group (28%, 595/2095) (P < 0.001). Following PCR test reporting, the rate of antibiotic discontinuation was higher in the RP group (23%, 135/595) vs. RVP group (16%, 56/357) (P < 0.001). Antibiotics were discontinued more often in older children aged 6–24 months (23%, 113/492) compared with children aged < 60 days (11%, 34/297) (P < 0.001). Following positive influenza test results, more children received timely oseltamivir in the RP group (85%, 48/56) compared with the RVP group (17%, 7/41) (P < 0.001). The median length of hospitalization (LOH) was shorter in the RP group (48 hours, IQR 32–76 hours) than in the RVP group (54 hours, IQR 39–89 hours) (P < 0.001).

Conclusion

Rapid availability of test results from RP assay was associated with reduced antibiotic use, timely antiviral therapy and decreased LOH. The implementation of a more comprehensive respiratory multiplex molecular assay with rapid reporting of test results has the potential to improve management of hospitalized children, decrease unnecessary antibiotic therapy and reduce overall costs.

Disclosures

R. Selvarangan, BioFire Diagnostics: Board Member and Investigator, Consulting fee and Research grant; Luminex Diagnostics: Investigator, Research grant
Clinical Yield of Routine Use of Molecular Testing for Adult Outpatients with Diarrhea
Authors: Clark Stephen , Sidlak Michael , Mathers Amy , Poulter Melinda , Platts-Mills James
Published: October 2017

Background

Molecular diagnostics for enteropathogens increase yield while reducing turnaround time. However, many pathogens do not require specific therapy, and the cost is substantial.

Methods

We reviewed the use of the FilmArray GI Panel (BioFire Diagnostics, Salt Lake City, Utah) in adult outpatients at the University of Virginia and identified clinical features that could limit testing without reducing yield. We defined yield as (a) detection of a pathogen, (b) detection of a pathogen for which antimicrobial therapy is indicated, or (c) detection of a pathogen that can change management, which additionally included viral pathogens in immunocompromised patients.

Results

Between March 23, 2015 and February 25, 2016, we reviewed 452 tests from adult outpatients with diarrhea. A pathogen was detected in 88/452 (19.5%). The most common pathogens were: enteropathogenic E. coli (36; 8.0%), norovirus (17; 3.8%), Campylobacter (7, 1.5%), enteroaggregative E. coli (6, 1.3%), Giardia (6; 1.3%), and sapovirus (5; 1.1%). Based on clinical guidelines, antimicrobial treatment was clearly indicated for 19/452 subjects (4.2%). Limiting testing to patients with an additional enteric symptom (abdominal pain, nausea, vomiting, fecal urgency, tenesmus, or flatulence), a travel history, or an immunocompromising condition would reduce testing by 25.9%, with a treatable pathogen identified in 18/331 (5.4%) (sensitivity 94.7%, specificity 27.7%). Further modifying testing criteria to exclude subjects with vomiting, 18/288 (6.3%) had a treatable pathogen (sensitivity 94.7%, specificity 37.3%), and a pathogen which could change management was detected in 28/288 (9.7%) (sensitivity 96.6%, specificity 38.5%). Excluding immunocompromised subjects or those with a travel history, American College of Gastroenterology guidelines for testing were met by 293/348 (84.2%) with a documented duration of diarrhea, and a treatable pathogen was detected in 8/293 (2.7%) vs. 3/55 (5.5%) who did not meet testing guidelines.

Conclusion

Testing could be reduced by 36.3% without decreasing clinical yield by limiting testing to patients with diarrhea with an additional enteric symptom and no history of vomiting, a travel history, or an immunocompromising condition. ACG guidelines did not improve testing efficiency.

Disclosures

All authors: No reported disclosures.
Bare Below the Elbows: A Randomized Trial to Determine Whether Wearing Short-Sleeved Coats Reduces the Risk for Pathogen Transmission
Authors: John Amrita , Alhmidi Heba , Gonzalez-Orta Melany , Cadnum Jennifer , Donskey Curtis J
Published: October 2017

Background

Physician’s white coats are frequently contaminated, but seldom cleaned. Therefore, in the UK, a “bare below the elbows” dress code policy includes a recommendation that personnel wear short sleeves. However, it has not been demonstrated that wearing short sleeves reduces the likelihood of pathogen transmission.

Methods

We conducted a randomized, cross-over trial involving simulated patient care interactions to test the hypothesis that transmission of pathogens occurs less frequently when personnel wear short- vs long-sleeved coats. Healthcare personnel were randomized to wear either long- or short-sleeved white coats while examining a mannequin contaminated with cauliflower mosaic virus DNA followed by examination of an uncontaminated mannequin. We compared the frequency of transfer of the DNA marker with the sleeves and/or wrists and with the uncontaminated mannequin. During work rounds, physicians were observed to determine how often the sleeves of white coats contacted patients or the environment.

Results

During work rounds and simulated examinations, the sleeve cuff of long-sleeved coats frequently contacted the patient/mannequin or environment. Contamination with the DNA marker was detected significantly more often on the sleeves and/or wrists when personnel wore long- vs short-sleeved coats (5 of 20, 25% vs 0 of 20, 0%; P = 0.02). In one of five (20%) instances of sleeve and/or wrist contamination, the DNA marker was transferred to the second mannequin. It was also observed that healthcare personnel were less likely to include their wrist in handwashing between simulations if they were wearing long-sleeved coats.

Conclusion

During simulations of patient care, the sleeve cuff of long-sleeved white coats frequently became contaminated with a viral DNA marker that could be transferred. These results provide support for the recommendation that healthcare personnel wear short sleeves to reduce the risk for pathogen transmission.

Disclosures

All authors: No reported disclosures.
Obesity Following Antiretroviral Therapy (ART) Initiation is Common and Influenced by Both Traditional and HIV-/ART-Specific Risk Factors
Authors: Bakal David , Coelho Lara , Luz Paula M , Clark Jesse L , De Boni Raquel , Cardoso Sandra Wagner , Veloso Valdilea , Lake Jordan , Grinsztejn Beatriz
Published: October 2017

Background

Weight gain commonly occurs among HIV-infected (HIV+) adults initiating modern ART regimens, and obesity is increasingly reported in this population. However, data regarding specific risk factors for obesity development after ART initiation are conflicting.

Methods

We retrospectively analyzed data from a cohort of HIV+ adults who initiated ART between January 1, 2000 and December 31, 2015 in Rio de Janeiro, Brazil. Body mass index (BMI) was assessed at ART initiation. Participants who were non-obese (BMI < 30kg/m2) at baseline and had ≥90 days of ART exposure were followed for development of obesity. Participants were censored at the time of obesity diagnosis or at end of follow-up (defined as death, loss to follow-up, end of study period or 2 years after their last weight measurement). Incidence rates were estimated using Poisson regression models and risk factor assessment was calculated using Cox regression models accounting for death and loss to follow-up as competing risks.

Results

Participants (n = 1,794) were 61.3% male, 48.3% white and had a median age of 36.3 years. At ART initiation, participants had a median BMI of 22.6kg/m2 and BMI category distribution was: underweight 14%, normal weight 56%, overweight 22% and obese 8%. Of the 1,567 non-obese participants followed after ART initiation, 76% gained weight, 44% increased their BMI category and 18% developed obesity. Median BMI at the end of follow-up was 24.7kg/m2 (0.4kg/m2 median annual change), the obesity incidence rate was 37.4 per 1000 person-years and the median time to obesity diagnosis was 1.9 years (vs. 4.7 years of follow-up for participants remaining non-obese). Factors associated with obesity after ART initiation included younger age at ART initiation, female sex, higher baseline BMI, lower baseline CD4+ T lymphocyte count, higher baseline HIV-1 RNA, having an integrase inhibitor as the most-used ART core drug and having diagnoses of hypertension and diabetes mellitus (Figure).

Conclusion

Obesity following ART initiation is frequent among HIV+ adults, with rates increasing in recent years. Both traditional (female sex) and HIV-specific (more advanced HIV disease, integrase inhibitor use) risk factors contribute importantly to obesity incidence following ART initiation.

Disclosures

All authors: No reported disclosures.
The Incidence of Hepatocellular Carcinoma Is not Increased in Individuals with Chronic Hepatitis C After Treatment with Interferon-free Regimens: an ERCHIVES Study
Authors: Li Darrick K , Ren Yanjie , Saikh Obaid , Fierer Daniel S , Re Vincent Lo , Abou-Samra Abdul-Badi , Chung Raymond T , Butt Adeel
Published: October 2017

Background

Sustained virologic response (SVR) after interferon-based treatment for chronic hepatitis C virus (HCV) infection has been strongly linked with decreased incidence of hepatocellular carcinoma (HCC). Surprisingly, several recent studies have reported higher rates of HCC in individuals treated with direct-acting antivirals (DAAs). However, making definitive conclusions has been challenging due to the heterogeneous populations and methodologies of these reports. As such, we sought to investigate whether DAA use is associated with increased rates of incident HCC.

Methods

Using the Electronically Retrieved Cohort of HCV Infected Veterans (ERCHIVES) database, we identified 17,836 patients without a prior diagnosis of HCC and divided them into 3 groups based on treatment: (a) pegylated interferon and ribavirin (IFN) (n = 3,534); (b) DAA-based therapy (n = 5,734); and (c) an untreated control group (n = 8,468). Predictors of HCC were identified using multivariate Cox proportional hazards analysis. HCC-free survival in cirrhotics was assessed by Kaplan–Meier analysis.

Results

SVR was achieved by 66.6% and 96.2% of the IFN and DAA groups, respectively. In our cohort, the incidence rate of HCC was not different between IFN and DAA groups (7.48/1000 vs. 7.92/1000 patient-years of follow-up; P = 0.72). Moreover, DAA treatment was not associated with an increased risk of HCC (HR 1.16; [95% CI: 0.79, 1.71]) compared to IFN treatment. Other risk factors for HCC included older age, alcohol abuse/dependance history, smoking history, HCV genotype 3 infection, proton-pump inhibitor use, AFP > 20, and cirrhosis. Notably, among cirrhotics who achieve SVR, HCC-free survival was not different between IFN and DAA treated groups, and both groups had significantly improved HCC-free survival compared with untreated patients.

Conclusion

Among cirrhotic patients with HCV, DAA treatment is associated with a comparable risk of HCC to IFN treatment. Furthermore, the rate of HCC after SVR by any treatment was significantly lower than for those untreated or who failed to achieve SVR. Previously reported increases in HCC associated with DAA treatment appear to be explained by the presence of pre-existing risk factors for HCC.

Disclosures

R. T. Chung, Gilead: Investigator, Research grant; Abbvie: Investigator, Research grant; Merck: Investigator, Research grant; Janssen: Investigator, Research grant; A. Butt, Merck: Investigator, Grant recipient
Antiviral Treatment among Hepatitis B Virus-Infected Pregnant Women—New York City and Michigan, 2013–2015
Authors: Link-Gelles Ruth , Koneru Alaya , Lazaroff Julie , Fineis Patrick , Nelson Noele , Schillie Sarah
Published: October 2017

Background

Individuals with chronic hepatitis B virus (HBV) infection are at increased risk for cirrhosis and hepatocellular carcinoma. Chronic HBV infection develops in 90% of persons infected at birth. Although postexposure prophylaxis (PEP), consisting of hepatitis B vaccine and immune globulin at birth, and completion of the three-dose vaccine series prevents up to 95% of perinatal HBV infections; however, breakthrough infections can occur, especially among infants born to women with high viral loads (VLs). Maternal antiviral treatment during pregnancy can reduce perinatal HBV transmission by 70% above the effect of infant PEP alone. We assessed factors associated with maternal antiviral treatment in a cohort of HBV-infected pregnant women with high VL.

Methods

During 2013–2015, the CDC-funded Supplemental Perinatal Hepatitis B Prevention Program collected information from interviews and medical charts of HBV-infected pregnant women in two sites. We assessed the association of demographic and clinical factors with maternal treatment in women with high VL (>200,000 IU/mL), considering statistical significance at P < 0.05.

Results

Among 1,521 women with maternal treatment and VL data, 151 (10%) had high VL. Among these 151 women, 66 (44%) received antiviral treatment (Table), all of whom were of Asian/Pacific Island race. None of the seven women of other races were treated (P = 0.02). Fifty-nine women (48%) receiving Medicaid were treated compared with six women (24%) who had private insurance (P = 0.04).

Conclusion

Mother’s race, country of birth, and insurance status were significantly associated with treatment in women with high VL. Because most women with high VL did not receive antiviral treatment during pregnancy, opportunities to reduce perinatal HBV transmission exist.

Disclosures

All authors: No reported disclosures.
Maternal Risk Factors Associated with Inadequate Testing and Loss to Follow-up in Infants with Perinatal Hepatitis C Virus Exposure
Authors: Bhardwaj Amrita , Mhanna Maroun , Abughali Nazha
Published: October 2017

Background

Lack of adequate testing and follow-up in infants born to hepatitis C virus (HCV) infected mothers continue to be a major challenge. There are multiple risk factors associated with this low rate of testing and follow-up including maternal, healthcare-related, and social factors. We sought to identify maternal risk factors that are associated with low HCV testing and follow-up in perinatally exposed infants.

Methods

In a retrospective cohort study, all HCV-infected pregnant women and their infants were reviewed. The study period expanded from June 1993 to May 2016. Medical records were reviewed for maternal characteristics and risk factors that could be associated with inadequate testing and loss to follow-up in infants with perinatal HCV exposure.

Results

During the study period, medical records of 407 mothers and their infants were reviewed. Only 26.5% (108/407) of all infants had adequate testing and follow-up for HCV. Among all infants, history of maternal intravenous drug use (IVDU) was significantly higher in infants with inadequate HCV testing than infants who were adequately tested [88% (193/218) vs. 76% (70/92) respectively; P = 0.005]. Infants who were adequately tested for HCV had a higher percentage of mothers on methadone maintenance therapy during pregnancy than infants who were not adequately tested [53% (35/66) vs. 34% (65/186) respectively; P = 0.010]. Also, infants with mothers who had HCV care were more likely to be adequately tested than infants whose mothers did not have HCV care [54% (56/102) vs. 41% (106/255), respectively; P = 0.022]. HCV transmission rate among infants with adequate testing was 11.1% (12/108).

Conclusion

Infants born to HCV infected mothers continue to have suboptimal testing. Maternal history of IVDU is associated with inadequate testing and loss to follow-up among infants exposed perinatally to HCV. Whereas, maternal methadone maintenance therapy during pregnancy, and maternal HCV medical care are associated with better follow-up. Screening pregnant women with HCV infection for history of IVDU and linking them to drug treatment centers as well as to HCV medical care may improve testing and follow-up in infants with perinatal HCV exposure.

Disclosures

All authors: No reported disclosures.