[Show abstract][Hide abstract] ABSTRACT: Invasive pulmonary aspergillosis (IPA) is an opportunistic fungal infection in patients undergoing chemotherapy for hematological malignancy, hematopoietic stem cell transplant, or other forms of immunosuppression. In this group, Aspergillus infections account for the majority of deaths due to mold pathogens. Although early detection is associated with improved outcomes, current diagnostic regimens lack sensitivity and specificity. Patients undergoing chemotherapy, stem cell transplantation and lung transplantation were enrolled in a multi-site prospective observational trial. Proven and probable IPA cases and matched controls were subjected to discovery proteomics analyses using a biofluid analysis platform, fractionating plasma into reproducible protein and peptide pools. From 556 spots identified by 2D gel electrophoresis, 66 differentially expressed post-translationally modified plasma proteins were identified in the leukemic subgroup only. This protein group was rich in complement components, acute-phase reactants and coagulation factors. Low molecular weight peptides corresponding to abundant plasma proteins were identified. A candidate marker panel of host response (9 plasma proteins, 4 peptides), fungal polysaccharides (galactomannan), and cell wall components (β-D glucan) were selected by statistical filtering for patients with leukemia as a primary underlying diagnosis. Quantitative measurements were developed to qualify the differential expression of the candidate host response proteins using selective reaction monitoring mass spectrometry assays, and then applied to a separate cohort of 57 patients with leukemia. In this verification cohort, a machine learning ensemble-based algorithm, generalized pathseeker (GPS) produced a greater case classification accuracy than galactomannan (GM) or host proteins alone. In conclusion, Integration of host response proteins with GM improves the diagnostic detection of probable IPA in patients undergoing treatment for hematologic malignancy. Upon further validation, early detection of probable IPA in leukemia treatment will provide opportunities for earlier interventions and interventional clinical trials.
PLoS ONE 11/2015; 10(11):e0143165. DOI:10.1371/journal.pone.0143165 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The recent development of the 1st WHO International Standard for human cytomegalovirus (CMV) and introduction of commercially produced secondary standards has raised hopes of improved agreement among laboratories performing quantitative CMV PCR. However, data are lacking to evaluate the trueness and uniformity of secondary standards and the consistency of results achieved when these materials are run on various assays. Three concentrations of each of three commercially prepared secondary CMV standards were tested in quadruplicate by three real-time and two digital PCR methods. Mean results were compared in a pairwise fashion with nominal values provided by each manufacturer. Agreement of results among all methods was also assessed for each sample and for like concentrations of each standard. The relationship between nominal values of standards and measured values varied depending upon assay used and manufacturer of standards, with the degree of bias ranging from +0.6 to -1.0 log10(IU/ml). The mean digital PCR result differed significantly among the secondary standards, as did the results of real-time PCR, particularly when plotted against nominal log10IU values. Commercially available quantitative secondary CMV standards produce variable results when tested by different real-time and digital PCR assays, with varying magnitudes of bias compared to nominal values. These findings suggest that the use of such materials may not achieve the intended uniformity among laboratories measuring CMV viral load, as envisioned by adaptation of the WHO standard.
Journal of Clinical Microbiology 02/2015; · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Introduction:
For developing countries, sexually transmitted infections (STIs) and their complications are ranked in the top 5 disease categories for which adults seek medical treatment. Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) are the three most common STIs worldwide, with TV accounting for over half of the cases. In developing countries, traditional methods for diagnosing STIs are laborious, often not very sensitive, and have a long turnaround time with most recent commercially available diagnostic tests targeting one or, at most, two of these STIs at a time. Here, we describe the development of a highly sensitive, rapid and affordable sample-to-answer multiplex PCR-based assay for the simultaneous detection of Trichomonas vaginalis, Neisseria gonorrhoeae, and Chlamydia trachomatis.
Materials and methods:
We designed a multiplex PCR assay for the detection of 4 targets (CT, TV, NG, and process/PCR control) using melt curve analysis. To establish the limit of detection (LOD) for each pathogen, we used previously extracted and quantified TV, NG, and CT genomic DNA (Vircell, Spain). For each target, the LOD was determined by lowering its copy number while increasing the other two STI loads in a stepwise fashion. The process/PCR control remained constant in the optimized assay and was spiked into each sample before extraction. For a concordance study, we tested urine, vaginal and rectal swab specimens from 26 patients positive for one or more of the tested STIs. In addition, 56 liquid cytology specimens (Thinprep) were used to assess specificity.
This assay has a turnaround time of less than 2h and has a limit of detection as low as 7-31 copies for each STI in the presence of the other 2 targets. Our assay also demonstrated 100% concordance with 26 known clinical samples from urine, vaginal and rectal swab specimens. TV, NG, CT, and our process/PCR control were consistently identified at 78°C, 82.3°C, 85.7°C, and ~92°C, respectively. When applied to DNA extracted from residual Thinprep specimens, the assay was negative in 54/56 samples. Two samples were found to be co-infected with CT.
Our multiplex assay combines a rapid and cost-effective approach to molecular diagnostics with the versatility required for use within a variety of laboratory settings. These performance characteristics make this multiplex STI assay highly suitable for use in a clinical laboratory.
[Show abstract][Hide abstract] ABSTRACT: Objective:To evaluate the efficacy of a brief, phone counseling Prevention Maintenance Intervention (PMI) to sustain STI/HIV-preventive behaviors and reduce incident STIs over a 36-month follow-up.
Design:A two-arm randomized controlled supplemental treatment trial
Setting:Three clinics in Atlanta, Georgia.
Participants:African-American adolescent females, 14-20 years, (N=701).
Intervention:Participants in the experimental condition received an adapted CDC-defined evidence-based STI/HIV intervention (HORIZONS) and a PMI consisting of brief, tailored phone counseling every 8 weeks over 36-months. Comparison condition participants received HORIZONS and a time- and dose-consistent PMI focused on general health.
Main Outcome Measure(s):Primary outcomes were proportion of participants with a laboratory-confirmed chlamydial or gonococcal infection. Behavioral outcomes include: (1) proportion of condom-protected sex acts (2) number of sexual episodes in which participants engaged in sexual intercourse while high on drugs/alcohol, and (3) number of vaginal sex partners.
Results: Over 36-months follow-up, fewer participants in the experimental condition had incident chlamydial (94 versus 104; RR = 0.47; 95%CI 0.25 to 0.89; p=.02) and gonococcal infections (48 versus 54; RR = 0.39; 95%CI 0.14 to 1.04; p=.060). A dose effect was observed; participants completing more phone contacts had a lower risk of chlamydial infection (RR= 0.94, 95%CI 0.89, 0.99; p=0.049). Participants in the experimental condition reported a higher proportion of condom-protected sex acts (mean difference6 months=.08; 95%CI 0.06, 0.10; p=0.036), and fewer episodes of sex while high on alcohol/drugs (mean difference=-0.61; 95%CI -0.98,-0.24; p=0.0001).
Conclusions and Relevance: Sustaining the long-term impact of HIV interventions is achievable with brief, tailored phone counseling.
142nd APHA Annual Meeting and Exposition 2014; 11/2014
[Show abstract][Hide abstract] ABSTRACT: Little is known about why some adolescents with internalizing symptoms engage in sexual behaviors that increase their risk for HIV. This study tested a mediation model of internalizing symptoms and safe sex intentions among adolescents receiving mental health treatment. Self-efficacy for HIV prevention, HIV knowledge, and worry about HIV were hypothesized to mediate associations between internalizing symptoms and safe sex intentions among sexually active and non-active adolescents receiving mental health treatment (N = 893, M age = 14.9). Significant indirect effects from internalizing symptoms to safe sex intentions varied according to sexual experience: for sexually non-active adolescents, HIV worry and knowledge mediated this link, whereas for sexually active adolescents, HIV self-efficacy was the significant mediator. Increasing both HIV knowledge and self-efficacy for HIV prevention are important targets for HIV prevention with adolescents with internalizing symptoms, and careful attention should be paid towards targeting these interventions to sexually experienced and inexperienced youth.
Children and Youth Services Review 11/2014; 46:177–185. DOI:10.1016/j.childyouth.2014.07.023 · 1.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Importance
Postnatal cytomegalovirus (CMV) infection can cause serious morbidity and mortality in very low-birth-weight (VLBW) infants. The primary sources of postnatal CMV infection in this population are breast milk and blood transfusion. The current risks attributable to these vectors, as well as the efficacy of approaches to prevent CMV transmission, are poorly characterized.Objective
To estimate the risk of postnatal CMV transmission from 2 sources: (1) transfusion of CMV-seronegative and leukoreduced blood and (2) maternal breast milk.Design, Setting, and Participants
A prospective, multicenter birth-cohort study was conducted from January 2010 to June 2013 at 3 neonatal intensive care units (2 academically affiliated and 1 private) in Atlanta, Georgia. Cytomegalovirus serologic testing of enrolled mothers was performed to determine their status. Cytomegalovirus nucleic acid testing (NAT) of transfused blood components and breast milk was performed to identify sources of CMV transmission. A total of 539 VLBW infants (birth weight, ≤1500 g) who had not received a blood transfusion were enrolled, with their mothers (n = 462), within 5 days of birth. The infants underwent serum and urine CMV NAT at birth to evaluate congenital infection and surveillance CMV NAT at 5 additional intervals between birth and 90 days, discharge, or death.Exposures
Blood transfusion and breast milk feeding.Main Outcomes and Measures
Cumulative incidence of postnatal CMV infection, detected by serum or urine NAT.Results
The seroprevalence of CMV among the 462 enrolled mothers was 76.2% (n = 352). Among the 539 VLBW infants, the cumulative incidence of postnatal CMV infection at 12 weeks was 6.9% (95% CI, 4.2%-9.2%); 5 of 29 infants (17.2%) with postnatal CMV infection developed symptomatic disease or died. A total of 2061 transfusions were administered among 57.5% (n = 310) of the infants; none of the CMV infections was linked to transfusion, resulting in a CMV infection incidence of 0.0% (95% CI, 0.0%-0.3%) per unit of CMV-seronegative and leukoreduced blood. Twenty-seven of 28 postnatal infections occurred among infants fed CMV-positive breast milk (12-week incidence, 15.3%; 95% CI, 9.3%-20.2%).Conclusions and Relevance
Transfusion of CMV-seronegative and leukoreduced blood products effectively prevents transmission of CMV to VLBW infants. Among infants whose care is managed with this transfusion approach, maternal breast milk is the primary source of postnatal CMV infection.Trial Registration
clinicaltrials.gov Identifier: NCT00907686
[Show abstract][Hide abstract] ABSTRACT: Importance
Behavioral change interventions have demonstrated short-term efficacy in reducing sexually transmitted infection (STI)/human immunodeficiency virus (HIV) risk behaviors; however, few have demonstrated long-term efficacy.Objective
To evaluate the efficacy of a telephone counseling prevention maintenance intervention (PMI) to sustain STI/HIV-preventive behaviors and reduce incident STIs during a 36-month follow-up.Design, Setting, and Participants
In a 2-arm randomized supplemental treatment trial at 3 clinics serving predominantly minority adolescents in Atlanta, Georgia, 701 African American adolescent girls aged 14 to 20 years received a primary treatment and subsequently received a different (supplemental) treatment (PMI) to enhance effects of the primary treatment.Interventions
Participants in the experimental condition (n = 342) received an adapted evidence-based STI/HIV intervention (HORIZONS) and a PMI consisting of brief telephone contacts every 8 weeks over 36 months to reinforce and complement prevention messages. Comparison-condition participants (n = 359) received HORIZONS and a time- and dose-consistent PMI focused on general health.Main Outcomes and Measures
The primary outcomes were percentage of participants with a laboratory-confirmed incident chlamydial infection and percentage of participants with a laboratory-confirmed gonococcal infection during the 36-month follow-up. Behavioral outcomes included the following: (1) proportion of condom-protected sexual acts in the 6 months and 90 days prior to assessments; (2) number of sexual episodes during the past 90 days in which participants engaged in sexual intercourse while high on drugs and/or alcohol; and (3) number of vaginal sex partners in the 6 months prior to assessments.Results
During the 36-month follow-up, fewer participants in the experimental condition than in the comparison condition had incident chlamydial infections (94 vs 104 participants, respectively; risk ratio = 0.50; 95% CI, 0.28 to 0.88; P = .02) and gonococcal infections (48 vs 54 participants, respectively; risk ratio = 0.40; 95% CI, 0.15 to 1.02; P = .06). Participants completing more telephone contacts had a lower risk of chlamydial infection (risk ratio = 0.95; 95% CI, 0.90 to 1.00; P = .05). Participants in the experimental condition reported a higher proportion of condom-protected sexual acts in the 90 days (mean difference = 0.08; 95% CI, 0.06 to 0.11; P = .02) and 6 months (mean difference = 0.08; 95% CI, 0.06 to 0.10; P = .04) prior to assessments and fewer episodes of sexual acts while high on drugs and/or alcohol (mean difference = −0.61; 95% CI, −0.98 to −0.24; P < .001).Conclusions and Relevance
Sustaining the long-term impact of an STI/HIV intervention is achievable with brief, tailored telephone counseling.Trial Registration
clinicaltrials.gov Identifier: NCT00279799
[Show abstract][Hide abstract] ABSTRACT: Invasive aspergillosis is a difficult-to-diagnose infection with a high mortality rate that affects high-risk groups such as patients with neutropenia and hematologic malignancies. We performed a bivariate meta-analysis of diagnostic data for an Aspergillus sp. PCR assay with blood specimens from high-risk hematology patients. We included all studies involving human subjects that assessed the performance of any PCR assay for invasive aspergillosis in whole blood or serum and that used the European Organization for the treatment of Cancer/Mycoses Study Group criteria as a reference standard. Three investigators independently searched the literature for eligible studies and extracted the data. Out of a total of 37 studies, 25 met strict quality criteria and were included in our evidence synthesis. Twenty-five studies with 2,595 patients were analyzed. The pooled diagnostic performance of whole-blood and serum PCR assays was moderate, with a sensitivity and specificity of 84% (95% confidence interval [CI], 75 to 91%) and 76% (95% CI, 65 to 84%), respectively, suggesting that a positive or negative result is unable, on its own, to confirm or exclude a suspected infection. The performance of a PCR assay of serum was not significantly different from that of whole blood. Notably, at least two positive PCR test results were found to have a specificity of 95% and a sensitivity of 64% for invasive infection, achieving a high positive likelihood ratio of 12.8. Importantly, the European Aspergillus PCR Initiative (EAPCRI) recommendations improved the performance of the PCR even further when at least two positive specimens were used to define PCR positivity. In conclusion, two positive PCR results should be considered highly indicative of an active Aspergillus sp. infection. Use of the EAPCRI recommendations by clinical laboratories can further enhance PCR performance.
[Show abstract][Hide abstract] ABSTRACT: Objectives:
To determine whether rhinovirus (RV) species is associated with more severe clinical illness in adults.
Seventy-two RV-positive viral respiratory samples from adult patients were sequenced and analyzed phylogenetically after reverse transcriptase polymerase chain reaction of the region spanning the VP4 gene and 5' terminus of the VP2 gene. The clinical features and severity of illness associated with the different RV species were compared.
Phylogenetic analysis identified three distinct clusters as RV-A (54%), B (11%), or C (35%) species. In an unadjusted model, patients with RV-B infection were significantly more likely to have the composite outcome variable of death or intensive care unit admission (P=.03), but this effect diminished when controlling for patient sex. A logistic model of the relationship between RV species and adverse outcomes produced nonsignificant odds ratios when controlling for patient sex.
Infection with RV-A or RV-B was associated with greater severity of illness in our adult population; however, the association disappeared after controlling for confounders.
American Journal of Clinical Pathology 08/2014; 142(2):165-72. DOI:10.1309/AJCPHIKRJC67AAZJ · 2.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.
[Show abstract][Hide abstract] ABSTRACT: Research to develop and validate novel methods for diagnosis of aspergillosis based on detection of galactomannan requires
the use of clinical specimens that have been stored frozen. Data indicating that galactomannan remains stable when frozen
are scant. The objective of this study was to determine the stability of galactomannan in clinical specimens stored at −20°C
that were positive in the Platelia Aspergillus enzyme immunoassay when initially tested. Prospective real-time testing of serum and bronchoalveolar lavage (BAL) fluid pools
from positive and negative patient specimens showed no decline in galactomannan index (GMI) over 11 months at −20°C and no
development of positive reactions in the negative-control pool. Retrospective testing of positive specimens that had been
stored at −20°C for 5 years showed that 28 of 30 serum (n = 15) or BAL (n = 15) specimens remained positive. These findings support the use of frozen serum or BAL specimens stored for at least 5
years in evaluation of diagnostic tests based on detection of galactomannan.
[Show abstract][Hide abstract] ABSTRACT: Piperacillin-tazobactam (PTZ) is known to cause false-positive results in the Platelia™ Aspergillus EIA, due to contamination with galactomannan (GM). We tested 32 lots of PTZ and 27 serum specimens from patients receiving PTZ. GM was not detected in lots; one serum (3.7%) was positive. PTZ formulations commonly used in the United States today appear to be a rare cause for false-positive GM results.