Jaber Aslanzadeh

Prevalence of Trichomonas vaginalis and Coinfection with Chlamydia trachomatis and Neisseria gonorrhoeae in the United States as Determined by the APTIMA® Trichomonas vaginalis Nucleic Acid Amplification Assay

ABSTRACT Our aim was to determine Trichomonas vaginalis prevalence using the Aptima Trichomonas vaginalis assay (ATV; Gen-Probe) and the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae coinfections in U.S. women undergoing screening for C. trachomatis/N. gonorrhoeae. Discarded urogenital samples from 7,593 women (18 to 89 years old) undergoing C. trachomatis/N. gonorrhoeae screening using the Aptima Combo 2 assay (Gen-Probe) in various clinical settings were tested with ATV. Overall, T. vaginalis, C. trachomatis, and N. gonorrhoeae prevalences were 8.7%, 6.7%, and 1.7%, respectively. T. vaginalis was more prevalent than C. trachomatis or N. gonorrhoeae in all age groups except the 18- to 19-year-old group. The highest T. vaginalis prevalence was in women ≥40 years old (>11%), while the highest C. trachomatis prevalence (9.2%) and N. gonorrhoeae prevalence (2.2%) were in women <30 years old. Coinfection prevalences were 1.3% for C. trachomatis/T. vaginalis, 0.61% for C. trachomatis/N. gonorrhoeae and N. gonorrhoeae/T. vaginalis, and 0.24% for C. trachomatis/N. gonorrhoeae/T. vaginalis and highest in women <30 years old. T. vaginalis prevalence differed by race/ethnicity, with the highest prevalence in black women (20.2%). T. vaginalis prevalence ranged from 5.4% in family planning clinics to 22.3% in jails. Multivariate analysis determined that ages of ≥40 years, black race, and patient locations were significantly associated with T. vaginalis infection. T. vaginalis is the most common sexually transmitted infection (STI) in women of >40 years, while C. trachomatis and N. gonorrhoeae prevalence is lowest in that age group. Higher T. vaginalis prevalence in women of >40 years is probably attributed to the reason for testing, i.e., symptomatic status versus routine screening in younger women. Coinfections were relatively low. High T. vaginalis prevalence in all age groups suggests that women screened for C. trachomatis/N. gonorrhoeae, whether asymptomatic or symptomatic, should be screened for T. vaginalis.

Prospective Evaluation of Rapid Antigen Tests for Diagnosis of Respiratory Syncytial Virus and Human Metapneumovirus Infections

ABSTRACT Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are two important viral pathogens that cause respiratory tract infections in the pediatric population. The rapid detection of these agents allows the prompt isolation and treatment of infected patients. In the present prospective study, we evaluated the performances of four rapid antigen detection assays, including a rapid chromatographic immunoassay (CIA) for RSV (Directigen EZ RSV; Becton Dickinson, Sparks, MD), a direct fluorescent-antibody assay (DFA) for RSV (Bartels; Trinity Biotech, Carlsbad, CA), and two DFAs for hMPV manufactured by Diagnostic Hybrids Inc. (DHI; Athens, OH) and Imagen (Oxoid Ltd., Basingstoke, Hampshire, United Kingdom). The clinical specimens tested comprised 515 nasopharyngeal aspirates submitted to the Clinical Microbiology Laboratory at Hartford Hospital from 1 November 2006 to 21 April 2007. Compared to the results of real-time reverse transcription-PCR (RT-PCR), the CIA had a sensitivity of 79.8% and a specificity of 89.5%. The RSV DFA with Bartels reagents showed a sensitivity of 94.1% and a specificity of 96.8%. For hMPV, the sensitivity and specificity were 62.5% and 99.8%, respectively, for the DHI DFA and 63.2% and 100%, respectively, for the Imagen DFA. The hands-on and test turnaround times for CIA were 10 and 30 to 60 min, respectively, and the hands-on and test turnaround times for the RSV and hMPV DFAs were 30 and 105 min, respectively. We conclude that while the RSV CIA is user-friendly, it lacks sensitivity and specificity, especially during off-peak months. In contrast, the RSV DFA is more sensitive and specific, but interpretation of its results is subjective and it demands technical time and expertise. Similarly, both hMPV DFAs are highly specific in comparison to the results of RT-PCR, but their sensitivities await further improvements.

Early Antibiotic Discontinuation in Patients With Clinically Suspected Ventilator-Associated Pneumonia and Negative Quantitative Bronchoscopy Cultures*

Objectives:Preliminary data suggest that antibiotic discontinuation in patients with negative quantitative bronchoscopy and symptom resolution will not increase mortality. Because our hospital algorithm for antibiotic discontinuation rules out ventilator-associated pneumonia in the setting of negative quantitative bronchoscopy cultures, we compared antibiotic utilization and mortality in empirically treated, culture-negative ventilator-associated pneumonia patients whose antibiotic discontinuation was early versus late. Design:Retrospective, observational cohort study. Setting:Eight hundred sixty-seven bed, tertiary care, teaching hospital in Hartford, CT. Patients:Eighty-nine patients with clinically suspected ventilator-associated pneumonia and a negative (<104 colony forming units/mL) quantitative bronchoscopy culture between January 2009 and March 2012. Early discontinuation patients (n = 40) were defined as those who had all antibiotic therapy stopped within one day of final negative culture report, whereas late discontinuation patients (n = 49) had antibiotics stopped later than one day. Measurements:Univariate analyses assessed mortality, antibiotic duration, and frequency of superinfections. Multivariate logistic regression was performed to assess the effect of early discontinuation on hospital mortality. Results:Patients had a mean ± SD Acute Physiology and Chronic Health Evaluation II score of 26.0 ± 6.0. Mortality was not different between early discontinuation (25.0%) and late discontinuation (30.6%) patients (p = 0.642). Antibiotic duration (days) was also not different for patients who died vs. those who survived (Median [interquartile range]: 3 [1–7.5] vs. 3 [1.75–6.25], respectively, p = 0.87), and when controlling for baseline characteristics and symptom resolution, only Acute Physiology and Chronic Health Evaluation II score was associated with hospital mortality on multivariate analyses. There were fewer superinfections (22.5% vs. 42.9%, p = 0.008), respiratory superinfections (10.0% vs. 28.6%, p = 0.036), and multidrug resistant superinfections (7.5% vs. 35.7%, p = 0.003), in early discontinuation compared with late discontinuation patients. Conclusions:In this severely ill population with clinically suspected ventilator-associated pneumonia and negative quantitative bronchoalveolar lavage cultures, early discontinuation of antibiotics did not affect mortality and was associated with a lower frequency of MDR superinfections.

Correlation between vancomycin and daptomycin MIC values for methicillin-susceptible and methicillin-resistant Staphylococcus aureus by 3 testing methodologies

We examined the potential correlation between vancomycin and daptomycin MIC for 298 Staphylococcus aureus by broth microdilution (BMD), Etest, and MicroScan(®). Etest and BMD identified a significant, albeit poor, correlation between MICs (ρ = 0.29, P < .01, and ρ = 0.15, P = .01, respectively), but no correlation (ρ = 0.08, P = .18) was observed with MicroScan.

Biochemical Profile-Based Microbial Identification Systems

The first step in microbial identification is the phenotypic assessment of the growing colony. In many cases, colonial morphology such as color, shape, size, hemolytic reaction, and growth characteristics on various selective and differential media can place an organism in a single family, genus, or even species level. In fact, assessing the ability of an organism to grow on various laboratory media along with its oxygen requirements coupled with Gram stain morphology as well as a few rapid tests such as catalase, oxidase, coagulase, and indole often provides preliminary identification for many clinically significant isolates. For example, it is very likely that an organism that grows on MacConkey agar plate and ferments lactose is a member of the family Enterobacteriaceae or an oxidase-positive non-lactose fermenting Gram-negative rod that has distinct grape odor is likely to be Pseudomonas aeruginosa.

Antibiotic Utilization and Opportunities for Stewardship Among Hospitalized Patients With Influenza Respiratory Tract Infection

OBJECTIVE Hospitalized influenza patients are often treated with antibiotics empirically while awaiting final diagnosis. The goal of this study was to describe the inappropriate continuation of antibiotics for influenza respiratory tract infections (RTIs). DESIGN We retrospectively studied adults admitted to our institution over 2 respiratory flu seasons with positive influenza RTIs. Inappropriate antibiotic duration (IAD) was defined as antibiotic use for >24 hours after a positive influenza test in patients presenting with <72 hours of RTI symptoms and with no other indications of bacterial infection. RESULTS During the study period, 322 patients included in this study were admitted for influenza RTI. Respiratory cultures were ordered for 50 of these patients (15.5%) and 71 patients (22%) had a positive chest x-ray, but antibiotics were prescribed to 211 patients (65.5%) on admission. Antibiotics were inappropriately continued in 73 patients (34.5%). Patients receiving IAD had a longer length of stay (LOS) (median, 6 days; range, 4-9 days) compared with those whose antibiotics were discontinued appropriately (median, 5 days; range, 3-8 days) and those who were not treated with antibiotics (median, 4 days; range, 3-6 days; P<.001). However, mortality was similar among these 3 groups: 3 patients (4.1%) from the IAD cohort died; 6 patients (4.3%) from the group with an appropriate antibiotic duration died; and 2 patients [1.8%] from the group given no antibiotics died (P=.510). The 30-day readmission rates were similar as well: 9 patients (12.3%) from the IAD group were readmitted within 30 days; 21 patients (15.2%) from the group with appropriate antibiotic duration were readmitted; and 11 patients (9.9%) from the group given no antibiotics were readmitted (P=.455). Total hospital costs were greater in patients treated with IAD (

Effects of Clinically Meaningful Concentrations of Antipseudomonal β-Lactams on Time to Detection and Organism Growth in Blood Culture Bottles

10,645; range,

Response to “Implications of Trichomonas vaginalis Nucleic Acid Amplification Testing on Medical Training and Practice”

6,485-

Influence of automated screening and confirmation of extended-spectrum β-lactamase-producing members of the Enterobacteriaceae on prescribing of antibiotics

18,035) compared with the group treated with appropriate antibiotic duration (

Preventing PCR amplification carryover contamination in a clinical laboratory.

7,479; range,