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92 result(s) for "Peel, Sheila A"
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Risk of sexually transmitted infections among U.S. military service members in the setting of HIV pre-exposure prophylaxis use
The evidence for an increased incidence of sexually transmitted infections (STIs) among patients utilizing HIV pre-exposure prophylaxis (PrEP) has been inconsistent. We assessed the risk of incident STI while on PrEP compared to periods off PrEP among military service members starting PrEP. Incidence rates of chlamydia, gonorrhea, syphilis, hepatitis C virus, and HIV were determined among military service members without HIV prescribed daily oral tenofovir disoproxil fumarate and emtricitabine for HIV PrEP from February 1, 2014 through June 10, 2016. Hazard ratios for incident STIs were calculated using an Anderson-Gill recurrent event proportional hazard regression model. Among 755 male service members, 477 (63%) were diagnosed with incident STIs (overall incidence 21.4 per 100 person-years). Male service members had a significantly lower risk of any STIs (adjusted hazard ratio (aHR) 0.21, 95% CI 0.11-0.40) while using PrEP compared to periods off PrEP after adjustment for socio-demographic characteristics, reasons for initiating PrEP, surveillance period prior to PrEP initiation, and the effect of PrEP on site and type of infection in multivariate analysis. However, when stratifying for anatomical site and type of infection, the risk of extragenital gonorrhea infection (pharyngeal NG: aHR 1.84, 95% CI 0.82-4.13, p = 0.30; rectal NG: aHR 1.23, 95% CI 0.60-2.51, p = 1.00) and extragenital CT infection (pharyngeal CT: aHR 2.30, 95% CI 0.46-11.46, p = 0.81; rectal CT: aHR 1.36, 95% CI 0.81-2.31, p = 0.66) was greater on PrEP compared to off PrEP although these values did not reach statistical significance. The data suggest entry into PrEP care reduced the overall risk of STIs following adjustment for anatomical site of STI and treatment. Service members engaged in PrEP services also receive more STI prevention counseling, which might contribute to decreases in STI risk while on PrEP.
Recent symptoms and multiple partners associated with increased risk of recurrent chlamydia and gonorrhea infections in U.S. Army soldiers
Background Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are highly prevalent sexually transmitted infections (STIs) with significant negative impacts on military readiness. Reinfections are common, and identifying risk factors can inform risk-based screening strategies. This study investigated factors associated with chlamydia and gonorrhea reinfections within six months following an initial infection among United States Army soldiers at Fort Bragg. Methods Soldiers diagnosed with CT or NG were followed for six months with visits at 2, 3, 4, or 5 months and a final visit at 6 months. Reinfections were defined as positive CT or NG tests or self-reported diagnoses at study visits or through chart review. A recurrent events model was used to analyze associations between reinfections and sexual practices, travel, and self-reported symptoms. Results Among 275 (79%) of the 347 enrolled participants who completed at least one follow-up visit > 30 days post-treatment, 63 (23%) experienced at least one reinfection. Having symptoms since the last visit (adjusted hazard ratio [aHR], 95% confidence interval [CI]: 3.62, 2.12–6.18) and having two or more partners (aHR, 95% CI: 2.00, 1.13–3.52) since the last visit were significantly associated with a higher risk of reinfection compared to no symptoms and one partner, respectively. Conclusions This study identified experiencing symptoms and having multiple recent sexual partners as factors associated with chlamydia and gonorrhea reinfections. These findings can inform risk-based screening strategies to improve military health and readiness. Future research with longer follow-up is needed to further explore the association between reinfections and recent sexual practices and travel.
Performance evaluation of a laboratory developed PCR test for quantitation of HIV-2 viral RNA
Management of Human Immunodeficiency Virus Type 2 (HIV-2) infections present unique challenges due to low viral titers, slow disease progression, and poor response to standard antiviral therapies. The need for a nucleic acid assay to detect and quantify HIV-2 virus has led to the development of a number of molecular-based assays for detection and/or quantification of HIV-2 viral RNA in plasma in order to provide laboratory evidence of HIV-2 infection and viral loads for use in treatment decisions. As HIV-2 is less pathogenic and transmissible than HIV-1 and has resistance to several of the antiretroviral drugs, delay of treatment is common. Cross sero-reactivity between HIV-1 and HIV-2 makes it difficult to distinguish between the two viruses based upon serological tests. As such we developed a quantitative reverse transcription PCR (qRT-PCR) assay targeting the 5' long terminal repeat of HIV-2 for detection and quantification of HIV-2 viral RNA in plasma to identify HIV-2 infection and for use in viral load monitoring. Serial dilutions of cultured HIV-2 virus demonstrated a wide dynamic range (10 to 100,000 copies/ml) with excellent reproducibility (standard deviation from 0.12-0.19), linearity (R2 = 0.9994), and a lower limit of detection at 79 copies/ml (NIH-Z). The assay is highly specific for HIV-2 Groups A and B and exhibits no cross reactivity to HIV-1, HBV or HCV. Precision of the assay was demonstrated for the High (Mean = 6.41; SD = 0.12) and Medium (Mean = 4.46; SD = 0.13) HIV-2 positive controls. Replicate testing of clinical specimens showed good reproducibility above 1,000 copies/ml, with higher variability under 1,000 copies/ml. Analysis of 220 plasma samples from HIV-2 infected West African individuals demonstrated significantly lower viral loads than those observed in HIV-1 infections, consistent with results of previous studies. Slightly more than seven percent of clinical samples (7.3%) demonstrated viral loads above 100,000 copies/ml, while 37.3% of samples were undetectable. The high sensitivity, specificity, precision, and linearity of the WRAIR qRT-PCR assay makes it well suited for detection and monitoring of HIV-2 RNA levels in plasma of infected individuals.
Prospective screening for sexually transmitted infections among US service members with Chlamydia trachomatis or Neisseria gonorrhoeae infection
Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most common bacterial causes of sexually transmitted infection (STI) in the United States (US). The purpose of this study was to determine the frequency of reinfection during a six-month study period and to evaluate the retesting interval for those infected with CT or NG. We conducted a prospective, six-month follow-up study among US military personnel with new onset, laboratory-confirmed CT or NG, recruited from an STI clinic at a large military base from January 2018 to January 2020. Each participant was randomly assigned to one of four groups, which differed only by the timing of the first study-associated follow-up visit after CT or NG diagnosis. Of the 347 initially recruited into the study, 267 participants completed a follow-up visit prior to their scheduled, final visit 6 months after initial infection. The median age at enrollment was 22 years and 41.0% were female. There were 32 (12.0%) reinfections (30 CT and 2 NG) after treatment of an index diagnosis of CT or NG within the six-month study period. Six of the CT reinfections were only detected at the final visit. A review of medical records revealed additional CT and NG reinfections. The probability of detecting a reinfection did not vary significantly by timing of follow-up. The likelihood of detecting CT or NG reinfection did not differ according to time of follow up visit among study participants, thus supporting CDC guidance to retest three months post treatment. Efforts should continue to focus on STI prevention and risk reduction.
Analytical validation of quantitative SARS-CoV-2 subgenomic and viral load laboratory developed tests conducted on the Panther Fusion® (Hologic) with preliminary application to clinical samples
Validate the performance characteristics of two analyte specific, laboratory developed tests (LDTs) for the quantification of SARS-CoV-2 subgenomic RNA (sgRNA) and viral load on the Hologic Panther Fusion® using the Open Access functionality. Custom-designed primers/probe sets targeting the SARS-CoV-2 Envelope gene (E) and subgenomic E were optimized. A 20-day performance validation following laboratory developed test requirements was conducted to assess assay precision, accuracy, analytical sensitivity/specificity, lower limit of detection and reportable range. Quantitative SARS-CoV-2 sgRNA (LDT-Quant sgRNA) assay, which measures intermediates of replication, and viral load (LDT-Quant VLCoV) assay demonstrated acceptable performance. Both assays were linear with an R2 and slope equal to 0.99 and 1.00, respectively. Assay precision was evaluated between 4-6 Log10 with a maximum CV of 2.6% and 2.5% for LDT-Quant sgRNA and LDT-Quant VLCoV respectively. Using negative or positive SARS-CoV-2 human nasopharyngeal swab samples, both assays were accurate (kappa coefficient of 1.00 and 0.92). Common respiratory flora and other viral pathogens were not detected and did not interfere with the detection or quantification by either assay. Based on 95% detection, the assay LLODs were 729 and 1206 Copies/mL for the sgRNA and VL load LDTs, respectively. The LDT-Quant sgRNA and LDT-Quant VLCoV demonstrated good analytical performance. These assays could be further investigated as alternative monitoring assays for viral replication; and thus, medical management in clinical settings which could inform isolation/quarantine requirements.
Prioritizing interventions for preventing COVID-19 outbreaks in military basic training
Like other congregate living settings, military basic training has been subject to outbreaks of COVID-19. We sought to identify improved strategies for preventing outbreaks in this setting using an agent-based model of a hypothetical cohort of trainees on a U.S. Army post. Our analysis revealed unique aspects of basic training that require customized approaches to outbreak prevention, which draws attention to the possibility that customized approaches may be necessary in other settings, too. In particular, we showed that introductions by trainers and support staff may be a major vulnerability, given that those individuals remain at risk of community exposure throughout the training period. We also found that increased testing of trainees upon arrival could actually increase the risk of outbreaks, given the potential for false-positive test results to lead to susceptible individuals becoming infected in group isolation and seeding outbreaks in training units upon release. Until an effective transmission-blocking vaccine is adopted at high coverage by individuals involved with basic training, need will persist for non-pharmaceutical interventions to prevent outbreaks in military basic training. Ongoing uncertainties about virus variants and breakthrough infections necessitate continued vigilance in this setting, even as vaccination coverage increases.
Hepatitis B Virus Coinfection Negatively Impacts HIV Outcomes in HIV Seroconverters
Background. Understanding the impact of hepatitis B virus (HBV) in human immunodeficiency virus (HIV) coinfection has been limited by heterogeneity of HIV disease. We evaluated HBV coinfection and HIV-related disease progression in a cohort of HIV seroconverters. Methods. Participants with HIV diagnosis seroconversion window of ≤3 years and serologically confirmed HBV infection (HB) status were classified at baseline into 4 HB groups. The risk of clinical AIDS/death in HIV seroconverters was calculated by HB status. Results. Of 2352 HIV seroconverters, 474 (20%) had resolved HB, 82 (3%) had isolated total antibody to hepatitis B core antigen (HBcAb), and 64 (3%) had chronic HB. Unadjusted rates (95% confidence intervals [CIs] of clinical AIDS/ death for the HB-negative, resolved HB, isolated HBcAb, and chronic HB groups were 2.43 (2.15-2.71); 3.27 (2.71-3.84); 3.75 (2.25-5.25); and 5.41 (3.41-7.42), respectively. The multivariable risk of clinical AIDS/death was significantly higher in the chronic HB group compared to the HB-negative group (hazard ratio [HR], 1.80; 95% CI, 1.20-2.69); while the HRs were increased but nonsignificant for those with resolved HB (HR, 1.17; 95% CI, .94-1.46) and isolated HBcAb (HR, 1.14; 95% CI, .75-1.75). Conclusions. HBV coinfection has a significant impact on HIV outcomes. The hazard for an AIDS or death event is almost double for those with chronic HB compared, with HIV-monoinfected persons.
Validation of SARS-CoV-2 pooled testing for surveillance using the Panther Fusion® system: Impact of pool size, automation, and assay chemistry
Combining diagnostic specimens into pools has been considered as a strategy to augment throughput, decrease turnaround time, and leverage resources. This study utilized a multi-parametric approach to assess optimum pool size, impact of automation, and effect of nucleic acid amplification chemistries on the detection of SARS-CoV-2 RNA in pooled samples for surveillance testing on the Hologic Panther Fusion ® System. Dorfman pooled testing was conducted with previously tested SARS-CoV-2 nasopharyngeal samples using Hologic’s Aptima ® and Panther Fusion ® SARS-CoV-2 Emergency Use Authorization assays. A manual workflow was used to generate pool sizes of 5:1 (five samples: one positive, four negative) and 10:1. An automated workflow was used to generate pool sizes of 3:1, 4:1, 5:1, 8:1 and 10:1. The impact of pool size, pooling method, and assay chemistry on sensitivity, specificity, and lower limit of detection (LLOD) was evaluated. Both the Hologic Aptima ® and Panther Fusion ® SARS-CoV-2 assays demonstrated >85% positive percent agreement between neat testing and pool sizes ≤5:1, satisfying FDA recommendation. Discordant results between neat and pooled testing were more frequent for positive samples with C T >35. Fusion ® C T (cycle threshold) values for pooled samples increased as expected for pool sizes of 5:1 (C T increase of 1.92–2.41) and 10:1 (C T increase of 3.03–3.29). The Fusion ® assay demonstrated lower LLOD than the Aptima ® assay for pooled testing (956 vs 1503 cp/mL, pool size of 5:1). Lowering the cut-off threshold of the Aptima ® assay from 560 kRLU (manufacturer’s setting) to 350 kRLU improved the assay sensitivity to that of the Fusion ® assay for pooled testing. Both Hologic’s SARS-CoV-2 assays met the FDA recommended guidelines for percent positive agreement (>85%) for pool sizes ≤5:1. Automated pooling increased test throughput and enabled automated sample tracking while requiring less labor. The Fusion ® SARS-CoV-2 assay, which demonstrated a lower LLOD, may be more appropriate for surveillance testing.
Evaluation of Antibody-Dependent Fc-Mediated Viral Entry, as Compared With Neutralization, in SARS-CoV-2 Infection
Fc-mediated virus entry has been observed for many viruses, but the characterization of this activity in convalescent plasma against SARS-CoV-2 Variants of Concern (VOC) is undefined. In this study, we evaluated Fc-mediated viral entry (FVE) on FcγRIIa-expressing HEK293 cells in the presence of SARS-CoV-2 convalescent plasma and compared it with SARS-CoV-2 pseudovirus neutralization using ACE2-expressing HEK293 cells. The plasma were collected early in the pandemic from 39 individuals. We observed both neutralization and FVE against the infecting Washington SARS-CoV-2 strain for 31% of plasmas, neutralization, but not FVE for 61% of plasmas, and no neutralization or FVE for 8% of plasmas. Neutralization titer correlated significantly with the plasma dilution at which maximum FVE was observed, indicating Fc-mediated uptake peaked as neutralization potency waned. While total Spike-specific plasma IgG levels were similar between plasma that mediated FVE and those that did not, Spike-specific plasma IgM levels were significantly higher in plasma that did not mediate FVE. Plasma neutralization titers against the Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1) and Delta (B.1.617.2) VOC were significantly lower than titers against the Washington strain, while plasma FVE activity against the VOC was either higher or similar. This is the first report to demonstrate a functional shift in convalescent plasma antibodies from neutralizing and FVE-mediating against the earlier Washington strain, to an activity mediating only FVE and no neutralization activity against the emerging VOC, specifically the Beta (B.1.351) and Gamma (P.1) VOC. It will be important to determine the in vivo relevance of these findings.
DNA Vaccine Delivered by a Needle-Free Injection Device Improves Potency of Priming for Antibody and CD8+ T-Cell Responses after rAd5 Boost in a Randomized Clinical Trial
DNA vaccine immunogenicity has been limited by inefficient delivery. Needle-free delivery of DNA using a CO2-powered Biojector® device was compared to delivery by needle and syringe and evaluated for safety and immunogenicity. Forty adults, 18-50 years, were randomly assigned to intramuscular (IM) vaccinations with DNA vaccine, VRC-HIVDNA016-00-VP, (weeks 0, 4, 8) by Biojector® 2000™ or needle and syringe (N/S) and boosted IM at week 24 with VRC-HIVADV014-00-VP (rAd5) with N/S at 10(10) or 10(11) particle units (PU). Equal numbers per assigned schedule had low (≤500) or high (>500) reciprocal titers of preexisting Ad5 neutralizing antibody. 120 DNA and 39 rAd5 injections were given; 36 subjects completed follow-up research sample collections. IFN-γ ELISpot response rates were 17/19 (89%) for Biojector® and 13/17 (76%) for N/S delivery at Week 28 (4 weeks post rAd5 boost). The magnitude of ELISpot response was about 3-fold higher in Biojector® compared to N/S groups. Similar effects on response rates and magnitude were observed for CD8+, but not CD4+ T-cell responses by ICS. Env-specific antibody responses were about 10-fold higher in Biojector-primed subjects. DNA vaccination by Biojector® was well-tolerated and compared to needle injection, primed for greater IFN-γ ELISpot, CD8+ T-cell, and antibody responses after rAd5 boosting. ClinicalTrials.gov NCT00109629.