Background. The role of suppressive HSV therapy in women coinfected with HSV-2 and HIV-1 taking highly active antiretroviral therapy (HAART) is unclear. Methods. 60 women with HIV-1/HSV-2 coinfection on HAART with plasma HIV-1 viral load (PVL) ≤75 copies/mL were randomized to receive acyclovir (N = 30) or no acyclovir (N = 30). PVL, genital tract (GT) HIV-1, and GT HSV were measured every 4 weeks for one year. Results. Detection of GT HIV-1 was not significantly different in the two arms (OR 1.23, P = 0.67), although this pilot study was underpowered to detect this difference. When PVL was undetectable, the odds of detecting GT HIV were 0.4 times smaller in the acyclovir arm than in the control arm, though this was not statistically significant (P = 0.07). The odds of detecting GT HSV DNA in women receiving acyclovir were significantly lower than in women in the control group, OR 0.38, P < 0.05. Conclusions. Chronic suppressive therapy with acyclovir in HIV-1/HSV-2-positive women on HAART significantly reduces asymptomatic GT HSV shedding, though not GT HIV shedding or PVL. PVL was strongly associated with GT HIV shedding, reinforcing the importance of HAART in decreasing HIV sexual transmission.
Quantitative real-time PCR (QRT-PCR) has been widely implemented for clinical viral load testing, but a lack of standardization and relatively poor precision have hindered its usefulness. Digital PCR offers highly precise, direct quantification without requiring a calibration curve. Performance characteristics of real-time PCR were compared to those of droplet digital PCR (ddPCR) for cytomegalovirus (CMV) load testing. Tenfold serial dilutions of the World Health Organization (WHO) and the National Institute of Standards and Technology (NIST) CMV quantitative standards were tested, together with the AcroMetrix CMV tc panel (Life Technologies, Carlsbad, CA) and 50 human plasma specimens. Each method was evaluated using all three standards for quantitative linearity, lower limit of detection (LOD), and accuracy. Quantitative correlation, mean viral load, and variability were compared. Real-time PCR showed somewhat higher sensitivity than ddPCR (LODs, 3 log10 versus 4 log10 copies/ ml and IU/ml for NIST andWHOstandards, respectively). Both methods showed a high degree of linearity and quantitative correlation for standards (R2>0.98 in each of 6 regression models) and clinical samples (R2=0.93) across their detectable ranges. For higher concentrations, ddPCR showed less variability than QRT-PCR for theWHOstandards and AcroMetrix standards (P<0.05). QRT-PCR showed less variability and greater sensitivity than did ddPCR in clinical samples. Both digital and real-time PCR provide accurate CMV load data over a wide linear dynamic range. Digital PCR may provide an opportunity to reduce the quantitative variability currently seen using real-time PCR, but methods need to be further optimized to match the sensitivity of real-time PCR.
Objectives: Despite plasma virologic suppression with antiretroviral therapy (ART), HIV persists in gut tissue. The objectives of this study were to compare plasma and rectal tissue HIV RNA dynamics and to assess relationships with dolutegravir (DTG) plasma and tissue concentrations. Design: A longitudinal cohort study of HIV-infected treatment-naïve individuals initiating DTG-based ART was conducted over 12 weeks with plasma and rectal tissue sampling (Clinicaltrials.gov:NCT02924389).Methods: HIV RNA and DTG concentrations were quantified in plasma and rectal tissue samples collected pre-ART (baseline) and post-ART at weeks 2, 6, and 12 using Abbott Real-Time HIV-1 assays and high-performance liquid chromatography tandem mass spectroscopy, respectively. Relationships between rectal tissue RNA and DTG concentrations were modeled using binary logistic regression, controlling for repeated measures. Results: Twelve participants were enrolled: six (50.0%) women, nine (75.0%) black, median age 42.0 years (Q1 31.2, Q3 52.0). All attained plasma virologic suppression by week 6. 11 of 12 (91.7%) had detectable rectal tissue HIV RNA at baseline, and only three of 11 (27.3%) achieved rectal tissue virologic suppression at any time-point. Compared with rectal tissue nonsuppressors, three of three (100.0%) of rectal tissue suppressors were women, had higher BMI, 35.9 kg/m2 (range 24.9 - 38.5) versus 20.6 (17.7 - 29.9), P ¼ 0.05, and lower baseline log plasma HIV RNA: 3.7 copies/ml (range 3.6 - 4.4) versus 4.7 (3.8 - 5.4), P ¼ 0.02. No significant relationships between rectal tissue RNA suppression and DTG concentrations were seen. Conclusion: Rectal tissue HIV RNA persisted in most participants and was not predicted by DTG concentrations. Impact of host factors, particularly sex, on tissue HIV viral dynamics warrants further exploration.
Viral load testing for hepatitis C virus (HCV) RNA has become a key parameter in the diagnosis of infection and treatment monitoring. This study evaluated the performance characteristics of the MultiCode-RTx HCV assay (MultiCode; EraGen Biosciences, Inc., Madison, WI), a real-time PCR test targeting the 3′ untranslated region (UTR) of the HCV genome, compared to the TaqMan HCV load ASR assay (TaqMan; Roche Diagnostics, Indianapolis, IN) that targets the 5′ UTR. For plasma specimens, the MultiCode assay had a limit of detection of 2.3 log10 IU/ml and a linear range of at least 6.7 log10 IU/ml. Comparison of plasma viral loads obtained by the MultiCode and TaqMan tests showed that they were in very close agreement (mean difference, −0.1 log10 IU/ml). No genotype bias was observed for genotypes 1, 2, and 3. When the MultiCode assay was evaluated with the MagNA Pure and easyMAG extraction methods, the viral loads for the easyMAG extraction were consistently higher for all specimens tested (mean difference, 0.45 log10 IU/ml). Aside from the limit of detection, the performance characteristics of the MultiCode assay were similar to the TaqMan assay for the clinical application of HCV load testing.
Bioaerosol samples were collected in an airborne infection isolation room, bathroom, and anteroom of a ventilated patient with coronavirus disease 2019. Twenty-eight samples were negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid, possibly due to the patient being on a closed-circuit ventilator or the efficiency of the air exchanges in the room.
OBJECTIVE:
To compare a real-time polymerase chain reaction (PCR) assay with broth culture for the detection of Trichomonas vaginalis using self-collected vaginal swabs.
METHODS:
Self-collected vaginal swabs were obtained from adolescent and young adult African-American women participating in HIV-1 prevention programs. T. vaginalis culture was performed using the InPouch TV System. Samples for the real-time PCR assay were collected using the BDProbeTec ET Culturette Direct Dry Swab system and tested in a laboratory-developed assay which targeted a repeated sequence of the genome. Discrepant samples that were culture negative and positive in the real-time PCR assay were tested in a confirmatory PCR which targeted a different region of the T. vaginalis genome, the18S ribosomal DNA gene.
RESULTS:
Of the 524 specimens tested by both culture and real-time PCR, 36 were culture positive and 54 were positive in the real-time PCR assay; 16 of the 18 discrepant specimens were also positive in the confirmatory PCR assay. Using a modified gold standard of positive by culture or positive in both PCR assays, the sensitivity of the real-time PCR assay was 100% and the specificity was 99.6%, whereas culture had a sensitivity of 69.2% and a specificity of 100%.
CONCLUSIONS:
The real-time PCR assay was sensitive and specific for the detection of T. vaginalis DNA from self-collected vaginal swab specimens. The ability to use the BDProbeTec dry swab system for the real-time PCR testing allowed for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and T. vaginalis from a single specimen.
by
Rebecca Rossetti;
Tara Smith;
Wei Luo;
Jennifer Taussig;
Mariah Valentine-Graves;
Patrick Sullivan;
Jessica Ingersoll;
Colleen Kraft;
Steve Ethridge;
Laura Wesolowski;
Kevin P Delaney;
Michele S Owen;
Jeffrey A Johnson;
Silvina Masciotra
Background: Currently, FDA-approved HIV-1 viral load (VL) assays use venipuncture-derived plasma. The Hologic Panther system uses 0.7 mL total volume for the Aptima HIV-1 Quant Assay standard (APT-Quant-std) and dilution (APT-Quant-dil) protocols. However, smaller plasma volumes from fingerstick whole blood (FSB) collected in EDTA-microtainer tubes (MCT) could provide an easier sample collection method for HIV-1 VL testing. Objectives: To evaluate the performance of the APT-Quant-std compared to the Roche CAP/CTM and Abbott m2000RT VL assays and an alternative APTQuant 1:7 dilution protocol, the latter using 100 μL of MCT-derived plasma from FSB. Study design: Linearity was determined using commercial HIV-1 RNA plasma controls. Dilutions ranging 1.56–2.95 log10 copies/mL were prepared to determine the APT-Quant-dil Limit of Quantitation (LOQ) using Probit analysis. Specificity of APT-Quant-std was calculated using 326 HIVnegative samples. To evaluate agreement, 329 plasma specimens were tested with APT-Quant-std, CAP/CTM, and m2000RT. Forty-seven matched venipuncture and MCT-derived plasma specimens were tested with APT-Quant-std and APT-Quant-dil. Results: Among the RNA controls, specificity was 99.69 % for APT-Quant-std. The R2 values were 0.988 (APT-Quant-std/CAP/CTM), 0.980 (APT-Quant-std/ m2000RT), and 0.997 (APT-Quant-std/APT-Quant-dil). The APT-Quant-dil LOQ was estimated at 2.7 log10 copies/mL (500 copies/mL) (95 %CI 2.62–2.87). At 2.3 log10 copies/mL (200 copies/mL), the overall agreement was 91.0 % for APT-Quant-std/CAP/CTM, 85.7 % for APT-Quant-std/m2000RT, and 82.9 % for APT-Quant-std/APT-Quant-dil. Quantified APT-Quant-std results were on average 0.2 log10 copies/mL higher than CAP/CTM and m2000RT and 0.14 log10 copies/mL higher than APT-Quant-dil. Conclusion: APT-Quant showed similar performance compared to the CAP/CTM and m2000RT assays and remains sensitive and accurate using the dilution protocol.
INTRODUCTION: Mounting evidence demonstrates potential for fecal-oral transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The US Food and Drug Administration now requires SARS-CoV-2 testing of potential feces donors before the use of stool manufactured for fecal microbiota transplantation. We sought to develop and validate a high-sensitivity SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) procedure for testing stool specimens. METHODS: A modified extraction method was used with an RT-PCR assay adapted from the Centers for Disease Control and Prevention PCR protocol for respiratory specimens. Contrived specimens were created using pre-COVID-19 banked stool specimens and spiking in known concentrations of SARS-CoV-2-specific nucleic acid. The highest transcript concentration at which 2/2 or 1/2 SARS-CoV-2 targets were detected in 9/10 replicates was defined as the dual-target limit and single-target limit of detection, respectively. The clinical performance of the assay was evaluated with stool samples collected from 17 nasopharyngeal swab RT-PCR-positive patients and 14 nasopharyngeal RT-PCR-negative patients. RESULTS: The dual-target and single-target limit of detection were 56 copies/μL and 3 copies/μL, respectively. SARS-CoV-2 was detected at concentrations as low as 0.6 copies/μL. Clinical stool samples from known COVID-19-positive patients demonstrated the detection of SARS-CoV-2 in stool up to 29 days from symptom onset with a high agreement with nasopharyngeal swab tests (kappa statistic of 0.95, P value < 0.001). DISCUSSION: The described RT-PCR test is a sensitive and flexible approach for the detection of SARS-CoV-2 in stool specimens. We propose an integrated screening approach that incorporates this stool test to support continuation of fecal microbiota transplantation programs.
Evidence varies as to how far aerosols spread from individuals infected with SARS-CoV-2 in hospital rooms. We investigated the presence of aerosols containing SARS-CoV-2 inside of dedicated COVID-19 patient rooms. Three National Institute for Occupational Safety and Health BC 251 two-stage cyclone samplers were set up in each patient room for a six-hour sampling period. Samplers were place on tripods, which each held two samplers at various heights above the floor. Extracted samples underwent reverse transcription polymerase chain reaction for selected gene regions of the SARS-CoV-2 virus nucleocapsid. Patient medical data were compared between participants in rooms where virus-containing aerosols were detected and those where they were not. Of 576 aerosols samples collected from 19 different rooms across 32 participants, 3% (19) were positive for SARS-CoV-2, the majority from near the head and foot of the bed. Seven of the positive samples were collected inside a single patient room. No significant differences in participant clinical characteristics were found between patients in rooms with positive and negative aerosol samples. SARS-CoV-2 viral aerosols were detected from the patient rooms of nine participants (28%). These findings provide reassurance that personal protective equipment that was recommended for this virus is appropriate given its spread in hospital rooms.
by
Jordan A Johnson;
Timothy Read;
Robert A, III Petit;
Vincent Marconi;
Kathryn L Meagley;
Maria C Rodriguez-Barradas;
David O Beenhouwer;
Sheldon T Brown;
Mark Holodniy;
Cynthia A Lucero-Obusan;
Patricia Schirmer;
Jessica Ingersoll;
Colleen Kraft;
Frederick H Neill;
Robert L Atmar;
Anita K Kambhampati;
Jordan E Cates;
Sara A Mirza;
Aron J Hall;
Cristina Cardemil;
Benjamin Lopman
Norovirus infection causing acute gastroenteritis could lead to adverse effects on the gut microbiome. We assessed the association of microbiome diversity with norovirus infection and secretor status in patients from Veterans Affairs medical centers. Alpha diversity metrics were lower among patients with acute gastroenteritis but were similar for other comparisons.