Biomedical subjects

Judy A Daly

Publications and source records attributed to Judy A Daly.

9 recordsLinked to original sources

PubMed2005

A comparison of Thermo Electron RSV OIA to viral culture and direct fluorescent assay testing for respiratory syncytial virus.

BACKGROUND: Rapid diagnostic methods for respiratory syncytial virus are useful tools available for the clinician. OBJECTIVES: The Thermo Electron RSV OIA (optical immunoassay kit) was prospectively compared with direct immunofluorescent assay and viral culture at Primary Children's Medical Center, Salt Lake City, Utah. STUDY DESIGN: Specimens from three hundred and thirty patients exhibiting respiratory symptoms were collected for testing by the three methods above. Several specimens were positive by both OIA and DFA with a negative culture result. These culture results were verified by RT-PCR analysis. RESULTS: Overall, 107 specimens were positive for RSV by the reference tests (culture or RT-PCR). DFA analysis identified an additional 40 patient specimens positive for other respiratory viruses. Compared to the reference tests the sensitivity, specificity, positive, and negative predictive values of the OIA for detection of RSV were 87.9%, 99.6%, 98.9% and 94.5%, respectively. CONCLUSIONS: The rapid OIA assay format proved to be cost effective, and simple to use in comparison to DFA and viral culture. Negative rapid test results should still be confirmed with a secondary test.

Adolescent↗

PubMed2004

A comparison of Binax NOW to viral culture and direct fluorescent assay testing for respiratory syncytial virus.

The Binax NOW immunochromatographic assay for respiratory syncytial virus was prospectively compared with direct fluorescent assay and viral culture at Primary Children's Medical Center, Salt Lake City, Utah during February 2003. Three hundred ten patient specimens were collected for testing, of which 102 specimens were positive for respiratory syncytial virus by the reference tests, direct immunofluorescence assay (DFA), and culture or molecular analysis. DFA analysis identified an additional 40 patient specimens positive for other respiratory viruses. Compared to the reference tests, the sensitivity, specificity, and positive and negative predictive values of the rapid immunochromatographic assay for detection of respiratory syncytial virus were 89.2%, 100.0%, 100.0%, and 94.9%, respectively. This rapid assay format proved to be cost-effective and simple to use in comparison to DFA and viral culture. Negative rapid test results should still be confirmed with a secondary test.

Adolescent↗

PubMed2004

Molecular characterization of Streptococcus pyogenes isolates collected during periods of increased acute rheumatic fever activity in Utah.

BACKGROUND: Salt Lake City, Utah has seen a continuing resurgence of rheumatic fever (RF) since 1985. METHODS: emm genotyping and multilocus sequence typing of streptococcal isolates from periods of increased RF activity were performed. RESULTS: Multiple genotypes were present during 1985 and 1998, two peak years of RF activity, and in 1992, a year with reduced RF activity. emm3 and emm18.1 were present in 1985 and 1998, but not in 1992. Two other emm types, 12 and L28, were significantly elevated in 1998 (a peak RF year) over 1992 (a non-peak RF year). Allelic profiles for the emm3 and emm18.1 isolates exhibited clonality. CONCLUSIONS: During years of increased RF activity multiple emm types, including emm18.1 and emm3, were circulating in the community. During a year of decreased RF activity, emm3 and emm18.1 genotypes were absent. The clonality of the emm3 and emm18.1 types suggests that specific clones of both types are important in the resurgence of RF during these peak years. Two other genotypes, emm12 and emmL28, may also be associated with the persistence of RF in the Salt Lake City, UT area.

Bacterial Outer Membrane Proteins↗

PubMed2004

Temporal association of the appearance of mucoid strains of Streptococcus pyogenes with a continuing high incidence of rheumatic fever in Utah.

OBJECTIVE: Our objective was to confirm an observed temporal association of increased numbers of rheumatic fever cases concomitant with the appearance of an increased prevalence of mucoid strains of Streptococcus pyogenes. During the resurgence of rheumatic fever (RF) that has occurred in the Intermountain area surrounding Salt Lake City, Utah, since 1985, the largest number of cases occurred in 1985 and 1986 and 12 years later in 1997 and 1998. During the initial outbreak and the later exacerbation of the resurgence, an increased number of mucoid strains of S pyogenes were present in the community. METHODS: The referred cases of RF that fulfilled Jones criteria have been systematically reviewed by the medical staff at Primary Children's Medical Center yearly since 1985. Before the resurgence of RF, a program was initiated by the microbiology laboratory at Primary Children's Medical Center to store frozen isolates of S pyogenes. All frozen specimens were randomly selected and entered into a log; the coded entry allowed for comments regarding the origin of the isolate and whether the isolate had a mucoid appearance on the blood agar culture plate. This log was reviewed in October 2002 to determine whether the percentage of frozen mucoid isolates stored during the resurgence of RF would support the clinical and epidemiologic suspicion that mucoid isolates seemed to be present with a higher frequency during the 2 periods of high incidence of RF. The percentage of mucoid isolates was compared with the yearly number of cases of RF. A Pearson r correlation analysis was completed to determine whether there was a significant association between the percentage of mucoid isolates and the number of cases of RF. RESULTS: The highest number of cases of RF was temporally associated with the highest percentage of mucoid isolates. There was statistically significant correlation between percentage of mucoid strains and the number of RF cases. CONCLUSIONS: The Utah experience with the resurgence of RF in a civilian population during the last decade and a half of the 20th century confirmed the temporal association of mucoid strains of S pyogenes, primarily M-type 18, with a high incidence of RF.

Adolescent↗

PubMed2003

Description of a multiplex Bordetella pertussis and Bordetella parapertussis LightCycler PCR assay with inhibition control.

While culture for Bordetella species is highly specific, sensitivity is extremely variable due to patient age, immunization status, antibiotic treatment, and specimen transport conditions. We evaluated a real-time multiplex PCR assay as an alternative to culture for the detection and differentiation of Bordetella pertussis and Bordetella parapertussis. The PCR conditions allowed the simultaneous detection of one B. pertussis organism and five B. parapertussis organisms per reaction. An inhibition control was incorporated into the assay. Of 163 total samples evaluated, 37 of 38 samples positive by either culture or direct fluorescent antibody testing (DFA) were also positive by PCR (97% sensitivity). Of 125 culture- or DFA-negative samples, 101 were also negative by PCR (81% specificity). The described multiplex assay is a rapid, sensitive, contamination-limiting, real-time PCR assay that controls for inhibition. The assay performs well using liquid or swab samples and from dried material on slides.

Adult↗

PubMed2002

Genome sequence and comparative microarray analysis of serotype M18 group A Streptococcus strains associated with acute rheumatic fever outbreaks.

Acute rheumatic fever (ARF), a sequelae of group A Streptococcus (GAS) infection, is the most common cause of preventable childhood heart disease worldwide. The molecular basis of ARF and the subsequent rheumatic heart disease are poorly understood. Serotype M18 GAS strains have been associated for decades with ARF outbreaks in the U.S. As a first step toward gaining new insight into ARF pathogenesis, we sequenced the genome of strain MGAS8232, a serotype M18 organism isolated from a patient with ARF. The genome is a circular chromosome of 1,895,017 bp, and it shares 1.7 Mb of closely related genetic material with strain SF370 (a sequenced serotype M1 strain). Strain MGAS8232 has 178 ORFs absent in SF370. Phages, phage-like elements, and insertion sequences are the major sources of variation between the genomes. The genomes of strain MGAS8232 and SF370 encode many of the same proven or putative virulence factors. Importantly, strain MGAS8232 has genes encoding many additional secreted proteins involved in human-GAS interactions, including streptococcal pyrogenic exotoxin A (scarlet fever toxin) and two uncharacterized pyrogenic exotoxin homologues, all phage-associated. DNA microarray analysis of 36 serotype M18 strains from diverse localities showed that most regions of variation were phages or phage-like elements. Two epidemics of ARF occurring 12 years apart in Salt Lake City, UT, were caused by serotype M18 strains that were genetically identical, or nearly so. Our analysis provides a critical foundation for accelerated research into ARF pathogenesis and a molecular framework to study the plasticity of GAS genomes.

Acute Disease↗

PubMed2002

An epidemiological investigation of a sustained high rate of pediatric parapneumonic empyema: risk factors and microbiological associations.

We investigated the increasing incidence of pediatric empyema during the 1990s at Primary Children's Medical Center in Salt Lake City. Of 540 children hospitalized with community-acquired bacterial pneumonia (CAP) who were discharged from 1 July 1993 through 1 July 1999, 153 (28.3%) had empyema. The annual population incidence of empyema increased during the study period from 1 to 5 cases per 100,000 population aged <19 years. Streptococcus pneumoniae was identified as the most common cause of CAP with or without empyema; serotype 1 accounted for 50% of the cases of pneumococcal empyema. Patients with empyema were more likely to be >3 years old, to have > or =7 days of fever, to have varicella, and to have received antibiotics and ibuprofen before admission to the hospital, compared with patients without empyema (P<.0001 for each factor). The increasing incidence of empyema was associated with infection due to S. pneumoniae serotype 1, outpatient treatment with certain antibiotics, ibuprofen use, and varicella.

Child↗

PubMed2002

The effect of rapid respiratory viral diagnostic testing on antibiotic use in a children's hospital.

BACKGROUND: Acute viral respiratory disease is the most common reason for pediatric hospitalization in the United States. Viral illnesses may be mistaken for bacterial infection, and antibiotic therapy may be prescribed. Overprescribing of antimicrobials for viral illness is a factor contributing to increasing antimicrobial resistance among bacterial pathogens encountered in pediatrics. OBJECTIVE: To determine if the availability of a rapid diagnostic test for respiratory viruses would affect antibiotic use in a children's hospital. DESIGN: Retrospective medical record review. SETTING: A 232-bed urban children's hospital. PARTICIPANTS: All hospitalized infants and children who underwent rapid testing (SimulFluor Respiratory Screen; Chemicon International Inc, Temecula, Calif) for respiratory viruses by direct fluorescent assay (DFA) during 2 successive winter seasons. MAIN OUTCOME MEASURES: Rates of antibiotic prescribing in DFA-positive and DFA-negative patients during the 2 study periods. RESULTS: During the first winter season, DFA-positive patients had fewer days using intravenous antibiotics (2.4 vs 4, P =.04), fewer days using oral antibiotics (0.25 vs 2.5, P =.04), and fewer discharge prescriptions for oral antibiotics (37% vs 52%, P =.02) when compared with DFA-negative patients. Intravenous antibiotics were initiated less often for DFA-positive patients during the second winter season than during the first (26% vs 44%, P =.008). CONCLUSIONS: Direct fluorescent assay testing was associated with a decrease in inappropriate antibiotic use. The availability of rapid viral diagnostics is an important tool for decreasing antibiotic prescribing in pediatric patients.

Adolescent↗

PubMed2002

Molecular analysis of group A Streptococcus type emm18 isolates temporally associated with acute rheumatic fever outbreaks in Salt Lake City, Utah.

Acute rheumatic fever (ARF) and subsequent rheumatic heart disease are rare but serious sequelae of group A Streptococcus (GAS) infections in most western countries. Salt Lake City (SLC), Utah, and the surrounding intermountain region experienced a resurgence of ARF in 1985 which has persisted. The largest numbers of cases were encountered in 1985-1986 and in 1997-1998. Organisms with a mucoid colony phenotype when grown on blood agar plates were temporally associated with the higher incidence of ARF. To develop an understanding of the molecular population genetic structure of GAS strains associated with ARF in the SLC region, 964 mucoid and nonmucoid pharyngeal isolates recovered in SLC from 1984 to 1999 were studied by sequencing the emm gene. Isolates with an emm18 allele were further characterized by sequencing the spa, covR, and covS genes. Peak periods of ARF were associated with GAS isolates possessing an emm18 allele encoding the protein found in serotype M18 isolates. Among the serotype M18 isolates, the difference in the number of C repeats produced three size variants. Variation was limited in spa, a gene that encodes a streptococcal protective antigen, and covR and covS, genes that encode a two-component regulatory system that, when inactivated, results in a mucoid phenotype and enhanced virulence in mouse infection models. Pulsed-field gel electrophoresis showed a single restriction profile for serotype M18 organisms isolated during both peak periods of ARF. In SLC, the incidence of ARF coresurged with the occurrence of GAS serotype M18 isolates that have very restricted genetic variation.

Acute Disease↗