Susan Whittier - Academia.edu (original) (raw)

Papers by Susan Whittier

John Wiley & Sons, Inc. eBooks, Apr 1, 2016

Clinical and diagnostic laboratory immunology, Sep 1, 1997

A synthetic-peptide-based enzyme-linked immunosorbent assay (EIA) capable of screening for antibo... more A synthetic-peptide-based enzyme-linked immunosorbent assay (EIA) capable of screening for antibodies to both human immunodeficiency virus type 1 (HIV-1) and HIV-2 has been developed for use in blood banks and diagnostic laboratories. Microtiter wells are coated with two synthetic peptides, one corresponding to the highly conserved envelope region of HIV-1 and another corresponding to the conserved envelope region of HIV-2. Overall, sensitivity was 100% in 303 individuals diagnosed with AIDS and 96 individuals diagnosed with AIDSrelated complex, 14.8% in a study of 500 high-risk group members, 99.9% in 600 EIA repeatedly reactive (RR)-HIV-1 Western blot (WB)-positive repository specimens, and 100% for 222 geographically diverse HIV-1 specimens and 216 confirmed HIV-2-positive specimens evaluated. The specificity was determined to be 99.72% for a total of 13,004 serum and plasma samples from random volunteer donors evaluated across five blood banks. Forty donors who were found to be EIA RR-WB indeterminate but nonreactive on the United Biomedical, Inc., test (UBI HIV 1/2 EIA) were prospectively followed as an additional measure of specificity. None of the 40 low-risk cases evolved into a positive WB pattern at follow-up. The sensitivity and specificity of this new assay are comparable to those of other Food and Drug Administration-licensed HIV-1 and HIV-1-HIV-2 assays that are currently available in the United States. The UBI HIV 1/2 EIA affords laboratories another choice in the detection of antibodies for HIV-1 and HIV-2 with a test based on an alternative antigen format.

Carolina Digital Repository (University of North Carolina at Chapel Hill), 1993

Pulmonary colonization and infection of patients with cystic fibrosis by Mycobacterium spp. has r... more Pulmonary colonization and infection of patients with cystic fibrosis by Mycobacterium spp. has recently been recognized as a potentially important clinical problem. However, frequent contamination of mycobacterial cultures by pseudomonads has hampered efforts to define the extent of this problem. This study was done to evaluate current techniques and to establish a more efficient method of recovering mycobacteria from respiratory secretions of patients with cystic fibrosis. Decontamination of respiratory specimens (n = 121) with 0.25% N-acetyl-L-cysteine and 1% sodium hydroxide (NALC-NaOH) was associated with a high rate of pseudomonas overgrowth for both Lowenstein-Jensen slants (74%) and BacTec vials supplemented with PANTA (polymyxin B [50 U/mll, amphotericin B [5 ,ug/ml], nalidixic acid [20 ig/mll, trimethoprim [5 jig/mll, azlocillin [10 ,ug/ml]) (36%). This overgrowth limited recovery of mycobacteria to only 64% (9 of 14) of specimens positive by smear for acid-fast bacilli (AFB). Decontamination of specimens (n = 441) with NALC-NaOH, followed by 5% oxalic acid treatment, resulted in contamination of only 5% of Lowenstein-Jensen slants and 3% of BacTec vials. AFB were recovered from all 90 AFB smear-positive specimens following the use of this decontamination technique. We recommend that respiratory secretions be decontaminated with NALC-NaOH and oxalic acid to decrease the incidence of Pseudomonas aeruginosa overgrowth.

Influenza and Other Respiratory Viruses, Mar 27, 2016

Traditional surveillance for respiratory viruses relies on symptom detection and laboratory detec... more Traditional surveillance for respiratory viruses relies on symptom detection and laboratory detection during medically attended encounters for acute respiratory infection/influenza-like illness (ARI/ILI). Ecological momentary reporting using text messages is a novel method for surveillance. This study compares respiratory viral activity detected through longitudinal community-based surveillance using text message responses for sample acquisition and testing to respiratory viral activity obtained from hospital laboratory data from the same community. We demonstrate a significant correlation between community-and hospital laboratory-based surveillance for most respiratory viruses, although the relative proportions of viruses detected in the community and hospital differed significantly.

Antimicrobial Agents and Chemotherapy, Jun 1, 2019

mcr-1, a plasmid-associated gene for colistin resistance, was first described in China in 2015, b... more mcr-1, a plasmid-associated gene for colistin resistance, was first described in China in 2015, but its spread in the United States is unknown. We report detection of mcr-1-carrying Escherichia coli ST117 in a cluster of three liver transplant recipients.

Frontiers in Neurology, Mar 26, 2019

Objective: To assess the clinical utilization and performance of the FilmArray ® Meningitis/Encep... more Objective: To assess the clinical utilization and performance of the FilmArray ® Meningitis/Encephalitis (ME) multiplex polymerase chain reaction (PCR) panel in a hospital setting. Background: Rapid diagnosis and treatment of central nervous system (CNS) infections are critical to reduce morbidity and mortality. The ME panel is a Food and Drug Administration (FDA) approved rapid multiplex PCR assay that targets 14 bacteria, viruses, and fungi. Previous studies show an overall agreement of 93-99% between the ME panel and conventional diagnostic testing. However, few studies have evaluated the clinical implementation of the ME assay, which is available for routine use at our institution. Methods: We performed a single center retrospective chart review of inpatients who underwent ME panel testing from August 2016 to May 2017. Clinical, radiologic, and laboratory data were reviewed to determine the clinical significance of results. Indication for lumbar puncture (LP), time to results of the ME panel, and duration of antimicrobial therapy were evaluated. Results: Seven hundred and five inpatients underwent ME testing, of whom 480 (68.1%) had clinical suspicion for CNS infection with 416 (59.0%) receiving empiric antimicrobial treatment for CNS infection. The median time-to-result of the ME panel was 1.5 h (IQR, 1.4-1.7). Overall agreement between the ME panel results and clinico-laboratory assessment was 98.2%. Forty-five patients tested positive by ME, of which 12 (26.6%) were determined likely to be clinically insignificant. Radmard et al. Clinical Utilization of ME Assay results were deemed clinically insignificant, though the impact of these positive results requires additional evaluation. Twenty-four and forty-eight hours after the ME panel resulted, 68 and 25% of patients started on empiric therapy remained on antibiotics, respectively. The median time from diagnosis to discontinuation and/or narrowing of antibiotic coverage was 25.6 h (IQR, 3.6-42.5). Further consideration of the appropriate indications for use of the ME panel in clinical settings is required.

Journal of Investigative Dermatology, May 1, 2017

Open Forum Infectious Diseases, 2014

PubMed, Jun 1, 2002

Pseudomonas aeruginosa is a rare cause of community-acquired infection. The source of this organi... more Pseudomonas aeruginosa is a rare cause of community-acquired infection. The source of this organism has usually been inapparent or environmental (ie, contaminated humidifiers). We documented transmission of P aeruginosa leading to cavitary pneumonia and lung abscess from daughter to mother and confirmed the clonal identity of our two patients' isolates using pulsed-field electrophoresis.

PubMed, Oct 1, 1999

Tinea nigra, a superficial fungal infection caused by Phaeoannellomyces werneckii, presents as a ... more Tinea nigra, a superficial fungal infection caused by Phaeoannellomyces werneckii, presents as a hyperpigmented, nonscaling macule of variable size and shape. Typically lacking induration, erythema, or pruritus, these "ink spot" lesions may resemble junctional nevi or malignant melanoma. Rapid, noninvasive diagnosis can be provided by potassium hydroxide examination, demonstrating numerous large, dematiaceous hyphae.

ASM Press eBooks, 2003

Ghent University Ghent University Academic Bibliography. ...

Journal of Clinical Microbiology, Nov 1, 2014

The high sensitivity of PCR assays for diagnosing Clostridium difficile infection (CDI) has great... more The high sensitivity of PCR assays for diagnosing Clostridium difficile infection (CDI) has greatly reduced the need for repeat testing after a negative result. Nevertheless, a small subset of patients do test positive within 7 days of a negative test. The aim of this study was to evaluate the clinical characteristics of these patients to determine when repeat testing may be appropriate. The results of all Xpert C. difficile PCR (Cepheid, Sunnyvale CA) tests performed in the clinical microbiology laboratory at New York-Presbyterian Hospital, Columbia University Medical Center (NYPH/CUMC) from 1 May 2011 through 6 September 2013, were reviewed. A retrospective case-control study was performed, comparing patients who tested positive within 7 days of a negative test result to a random selection of 50 controls who tested negative within 7 days of a negative test result. During the study period, a total of 14,875 tests were performed, of which 1,066 were repeat tests (7.2%). Eleven of these repeat tests results were positive (1.0%). The only risk factor independently associated with repeat testing positive was history of a prior CDI (odds ratio [OR], 19.6 [95% confidence interval {CI}, 4.0 to 19.5], P < 0.001). We found that patients who test positive for C. difficile by PCR within 7 days of a negative test are more likely to have a history of CDI than are patients who test negative with repeat PCR. This finding may be due to the high rate of disease relapse or the increased likelihood of empirical therapy leading to false-negative results in these patients.

Pediatric Infectious Disease Journal, Apr 1, 1998

Outbreaks of nosocomial staphylococcal scalded skin syndrome (SSSS) in infants have been well-des... more Outbreaks of nosocomial staphylococcal scalded skin syndrome (SSSS) in infants have been well-described associated with the well baby nursery or delivery room. We describe two cases of SSSS in very low birth weight infants in a neonatal intensive care unit (NICU) and the success of infection control strategies used to prevent an outbreak. Staphylococcal scalded skin syndrome was diagnosed in two infants in the NICU: Case I (a 47-day-old, formerly 530-g female); and Case II diagnosed 48 h later (a 41-day old, formerly 706-g female). Multiple infection control measures were implemented: (1) isolation and intravenous antibiotic treatment of cases; (2) placement of exposed infants into a cohort; (3) prophylactic mupirocin treatment of the anterior nares of all infants in the NICU and staff colonized with Staphylococcus aureus; and (4) personnel hand washing with hexachlorophene. Detection of exfoliative toxin A and studies to determine the genetic relatedness of S. aureus strains isolated from patients and staff were performed. In addition to the two SSSS cases, S. aureus was isolated from 2 of 12 (17%) exposed asymptomatic infants, 2 of 20 (10%) ancillary staff, 8 of 30 (27%) nurses and 6 of 24 (25%) physicians. Exfoliative toxin A-producing strains were isolated from both cases and one asymptomatic infant. No toxin was expressed by strains isolated from staff. Pulse field gel electrophoresis demonstrated genetically identical strains of S. aureus from the two SSSS cases and the asymptomatic infant, whereas three staff members harbored strains genetically related to the case strain. Unexpectedly two additional unique clusters of genetically related S. aureus strains were identified from the surveillance cultures. This report documents the rare occurrence of nosocomial SSSS attributed to transmission in the NICU among extremely low birth weight infants. Multiple infection control strategies were effective in limiting the outbreak. Molecular epidemiology investigation supported a unique S. aureus strain responsible for this event and the presence of bidirectional spread between staff and patients of non-toxin-producing strains.

American Journal of Clinical Pathology, Sep 1, 1998

The rapid detection of Mycobacterium tuberculosis from respiratory specimens is critical for opti... more The rapid detection of Mycobacterium tuberculosis from respiratory specimens is critical for optimal treatment of patients. Several nucleic acid amplification-based systems designed to detect Mycobacterium tuberculosis complex directly from specimens have been developed, and 2 are commercially available. We studied the performance characteristics of these 2 systems (Gen-Probe Amplified Mycobacterium Tuberculosis Direct (MTD), Gen-Probe, San Diego, Calif; AMPLICOR, Roche Molecular Systems, Branchburg, NJ). Each uses a different amplification strategy, detection modality, and approach to inhibition of amplicon contamination. When compared with culture, the respective sensitivities and specificities were as follows: 92.2% and98.7% (study 1) and88.7% and95.3% (study 2); AMPLICOR, 87.5%> and 99.7%. Resolution of discordant results was accomplished by incorporating clinical data and multiple specimen analysis. An increased rate of false-positive results was encountered during 1 phase of the study. The conditions under which the test was performed were modified and the "contamination " issue was resolved. This report discusses the benefits and limitations of each assay, proposes cost-effective algorithms for their incorporation into routine laboratory workflow, and discusses the clinical usefulness of these molecular technologies.

Heart & Lung, Jul 1, 2000

Background: Changes in skin flora have been reported among hospitalized and critically ill patien... more Background: Changes in skin flora have been reported among hospitalized and critically ill patients, but little is known about whether these changes are associated with hospitalization or with chronic, serious illness. The purpose of this survey was to compare skin flora of ...

Clinical Infectious Diseases, Apr 9, 2018

Pediatric Infectious Disease Journal, Feb 1, 1999

Correctly diagnosing tuberculosis (TB) in children is critical to provide appropriate treatment a... more Correctly diagnosing tuberculosis (TB) in children is critical to provide appropriate treatment and to detect undiagnosed source cases. However, diagnosing TB in children may be difficult. We sought to determine whether Amplicor, a Food and Drug Administration-approved polymerase chain reaction (PCR) assay used to detect Mycobacterium tuberculosis in sputum and computerized tomography (CT) would facilitate the diagnosis of TB in children. We also examined the applicability of the Centers for Disease Control and Prevention clinical case definition for TB. A university-affiliated pediatric hospital in New York City. From March, 1995, to November, 1997, 27 children < 15 years of age (mean age, 3.9 years) were evaluated for suspected TB. M. tuberculosis was cultured from 5 of 76 (6.6%) gastric aspirate specimens, and PCR detected M. tuberculosis DNA in 3 (4.1%) of these specimens. There was poor correlation between culture and PCR because 6 specimens were discordant. CT scans were diagnostic of mediastinal or hilar adenopathy in 6 children with equivocal or negative chest radiographs and confirmed adenopathy in 8 others. Six children received alternative diagnoses. We conclude that the commercially available PCR technology had very limited utility in detecting M. tuberculosis from gastric aspirates, but CT scans were useful in assessing pediatric patients with suspected TB.

The New England Journal of Medicine, Sep 7, 2000

Background Nosocomial infections due to Pseudomonas aeruginosa have been well described, but the ... more Background Nosocomial infections due to Pseudomonas aeruginosa have been well described, but the environmental reservoir of the organism varies. We conducted an epidemiologic and molecular investigation of endemic P. aeruginosa infection among infants in a neonatal intensive care unit that was associated with carriage of the organisms on the hands of health care workers. Methods In August 1998, colonization or infection with P. aeruginosa was identified in six infants. Surveillance cultures for P. aeruginosa were obtained from the other 27 infants in the unit, and possible environmental reservoirs were also assessed. The hands of health care workers were inspected and cultured, and risk factors for P. aeruginosa colonization were evaluated. Isolates were analyzed for clonality by pulsed-field gel electrophoresis. Results Surveillance cultures showed that three additional infants were colonized with P. aeruginosa. Cultures of environmental specimens were negative, but cultures of the hands of 10 of 165 health care workers (6 percent) were positive for P. aeruginosa. Increasing age (P=0.05) and a history of the use of artificial fingernails or nail wraps (P=0.03) were both risk factors for colonization of the hands. From January 1997 to August 1998, 49 infants were infected or colonized with P. aeruginosa. Pulsed-field gel electrophoresis demonstrated that 17 of these infants and 1 health care worker who had onychomycosis had the same clone. Infants who were exposed to this health care worker in August 1998 were at greater risk of having this clone than infants who were not exposed to this health care worker (odds ratio, 41.2; 95 percent confidence interval, 1.8 to 940.0; P=0.006). Conclusions An increased rate of infection and colonization with P. aeruginosa among infants in neonatal intensive care units should be investigated by assessing potential reservoirs, including environmental sources as well as patients and health care workers.

Open Forum Infectious Diseases, Oct 1, 2019

International Journal of Antimicrobial Agents, Mar 1, 2007